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Table of Contents
Title PageCopyright PagePart IAcknowledgementsAbout the AuthorsIntroduction
Introduction to Part I: - TheNavy SEAL Physical FitnessGuide
Chapter 1 - Overview of PhysicalFitness
Exercise PhysiologyMuscle Structure and FunctionPrinciples of Physical TrainingSpecificity of TrainingDetermining Your Training Heart
RateEnergy Systems Used by
Exercising MuscleMethods of Physical TrainingConditioning and DeconditioningActive Recovery
Chapter 2 - SEAL Mission-RelatedPhysical Activities
Mission-Specific ActivitiesSpecific Mission-Related
Physical TasksSummary
Chapter 3 - CardiorespiratoryConditioning
Basics Concepts of
Cardiorespiratory ExerciseHow to Estimate Your Maximal
Aerobic CapacityTypes of Aerobic Activities and
Basic WorkoutsOther Terms for Work RateSummary
Chapter 4 - Running for Fitness
Running Gear
Running SurfacesWarm-UpCool-Down and StretchingRunning Gait or FormBuilding Your MileageVarying Your WorkoutsCommon Running Injuries or
ProblemsResources
Chapter 5 - Swimming for Fitness
Open Water GearOpen Water TrainingSwimming Pool GearPool Training: Building Strength
and EnduranceDeveloping Stroke Skills
Common Problems
Chapter 6 - Strength Training
Weight Training Gear andEquipment
Strength Training Guidelines andTerms
Types of WorkoutsWarming UpCooling Down and StretchingCommon ProblemsConclusionsResourceAcknowledgment
Chapter 7 - Flexibility
Flexibility BenefitsDefinitionThe Stretch Reflex and
theLengthening ReactionFlexibility Training MethodsWarming-Up and StretchingActivity-Specific Warm-UpRecommended StretchesA Post-Exercise Total
BodyStretching ProgramResources
Chapter 8 - Calisthenics
The Muscle Strength-Endurance
ContinuumCalisthenics in Naval Special
Warfare
Balancing Abs and Hip Flexorsand Extensors
Recommendations forCalisthenics
Resources
Chapter 9 - Plyometrics
How Plyometrics WorkPreparation for Plyometric
TrainingPlyometric TrainingPlyometric ExercisesEccentric Downhill TrainingResources
Chapter 10 - Load-Bearing
Physiological and EnvironmentalFactors
Physical Training for Load-Bearing
Optimizing Load-BearingCommon Medical ConditionsConclusionAcknowledgments
Chapter 11 - Training for SpecificEnvironments
Training in Hot EnvironmentsTraining in Cold EnvironmentsTraining at AltitudeTraining in Confined SpacesDeconditioning
Chapter 12 - Training and SportsRelated Injuries
Treatments for TrainingRelated
InjuriesReconditioning for Return to Full
ActivityTypes of InjuriesCommon Mission and Trainin
Related InjuriesOvertraining SyndromeWhen to Seek Medical Care
Chapter 13 - Harmful Substances thatAffect Performance
Anabolic/Androgenic SteroidsOther Harmful Chemicals
SummaryResources
Chapter 14 - Other TrainingRelatedIssues
Winter Warfare TrainingThe High Mileage SEALNutritional Ergogenic AgentsResource
Chapter 15 - Physical Fitness andTraining Recommendations
The SEAL Physical Fitness
ProgramA Physical Fitness Program for
Confined Spaces
A Physical Fitness Program forComing Off Travel
Elimination of “Old” ExercisesA Short Flexibility ProgramThe Navy SEAL Physical
Readiness Test (PRT)Final Comments From: RADM
SmithSummary
Appendix A - Weight Lifting TechniquesAppendix B - Common AnatomicalTerms and DiagramsAppendix C - Foot Care for Load-Bearing
Part II - Nutrition
Preface to Part II: The NavySEAL Nutrition Guide
About the Authors - Part II: TheNavy SEAL Nutrition Guide
Chapter 1 - Energy Balance = EnergyExpenditure - Energy Intake
Units of EnergySensitivity of Energy BalanceComponents of Energy
ExpenditureTotal Energy ExpenditureBody Size and Body Mass IndexHow To Calculate Energy
Expenditure
Chapter 2 - Carbohydrate, Fat and
Protein: The Energy-ProvidingMacronutrients
CarbohydrateFatProtein
Chapter 3 - Micronutrients: Vitamins andMinerals
What are the Recommended
Dietary Allowances?What are Vitamins?What are MineralsWhat Substances May Interfere
With Micronutrients?Summary
Chapter 4 - Vitamin and MineralSupplements
Role of Vitamins and Minerals in
Physical ActivityBenefits of SupplementationSupplement Use and
PerformanceRisks of SupplementationWhat to Look for When Buying
SupplementsSummary
Chapter 5 - Fiber and Health
What is Dietary Fiber?Why Should I Eat More Fiber?How Can I Get More Fiber in
My Diet?When Should I Minimize My
Fiber Intake?
Chapter 6 - Fluid Replacement: Waterand Other Beverages
Distribution and Functions of
WaterHow to Maintain Water BalanceWhat Conditions Will Increase
Water Losses?How Can You Make Sure to Get
Enough Fluids?What You Should DrinkWhen and How Much to Drink?
Chapter 7 - Healthy Snacking
Tips for Healthy SnackingWhat Snacks are Best for
Different Occasions?
Chapter 8 - Restaurants, Fast Foods andEating Out
Fast Food RestaurantsRecommendations for Selecting
High CHO Foods at Restaurants
Chapter 9 - Nutritional ConsiderationsFor Endurance Activities
Glycogen Stores and Meeting
Your Energy NeedsCarbohydrates and Endurance
PerformanceCHO Loading/ Glycogen
SupercompensationProtein NeedsVitamin and Mineral NeedsFluid RequirementsNutritional Interventions During
Training SessionsSummary
Chapter 10 - Nutritional ConsiderationsFor Strength Training
Benefits of Strength TrainingFactors determining Muscle
MassProtein Requirements For
Strength Training
Other Nutritional RequirementsMulti-Ingredient Steroid
Alternatives - The Bottom LineSummary
Chapter 11 - Nutrition for OptimumMission Performance
Nutritional Readiness Before a
Specific MissionNutrition for Maintaining
Performance During Training andMissions
Dietary Considerations forSelected Training and MissionScenarios
Chapter 12 - Nutritional Interventions
for Mission Recovery
Glycogen RestorationRehydrationSodium/Electrolyte ReplacementSummary
Chapter 13 - Food for the Field:Military and Other Rations
The Meal, Ready-to-Eat,
Individual (MRE) MenusRation, Cold Weather (RCW)Ration Lightweight - 30 Days
(RLW-30)Food Packet, Long Range Patrol,
(Improved) (LRP[I])Commercial Freeze-Dried
ProductsWhat Do You Choose?Other Ration Information
Chapter 14 - Nutritional ConsiderationsFor Adverse Conditions
Heat ExposureCold ExposureSustained OperationsDiving and Immersion in WaterAltitudeSummary
Chapter 15 - Ergogenic Agents -Looking for “The Edge”
Nutritional Products Advertised
as Ergogenic AgentsProtein-Carbohydrate
Supplements
Chapter 16 - Ergolytic Agents - “GoingBackwards”
AlcoholSmokeless TobaccoAntihistamines
Appendix 1 - Carbohydrate Content ofSelected FoodsAppendix 2 - Fat Content of SelectedFoodsAppendix 3 - Protein Content ofSelected FoodsAppendix 4 - Energy Expenditure ForVarious Activities
Appendix 5 - Good Food Sources ofVitaminsAppendix 6 - Good Food Sources ofMineralsAppendix 7 - Sample High CarbohydrateMenusAppendix 8 - US Navy Special Warfare10 Commandments Of Nutrition
Copyright © 2007 by Skyhorse Publishing, Inc.
All Rights Reserved. No part of this book may bereproduced in any manner without the express written
consent of the publisher, except in the case of briefexcerpts in critical reviews or articles. All inquiriesshould be addressed to: Skyhorse Publishing, 555Eighth Avenue, Suite 903, New York, NY 10018.
www.skyhorsepublishing.com
10987654321
Library of Congress Cataloging-in-Publication Data
Deuster, Patricia A.
The Navy SEAL guide to fitness and nutrition PatriciaA. Deuster, Anitafont>
Singh, Pierre A. Pelletier.p. cm.
Originally published as 2 books: Navy SEAL fitnessguide. [Bethesda, Md] : Department of Military andEmergency Medicine, 1994 ; and The Navy SEAL
nutrition. [Bethesda, Md] : Department of Military andEmergency Medicine, 1994.
ISBN-13: 978-1-60239-030-0 (pbk. : alk. paper)ISBN-10: 1-60239-030-4 (pbk. : alk. paper)
1. United States. Navy. SEALs. 2. Physical fitness. 3.Exercise. 4.
Nutrition. I. Singh, Anita. II. Pelletier, Pierre A. III.Title.
GV481.D43 2007
613.7—dc222007005547
Printed in the United States of America
Part I
Physical Fitness
Edited by Patricia A. Deuster, Ph.D.,M.P.H.
Acknowledgments
The authors would like to recognizethe invaluable contributions to thedevelopment of this guide by thefollowing individuals. CAPT KennethLong participated in both panel reviewsand provided useful suggestions andcomments. His meticulous work wasgreatly appreciated by all. CAPT PeterToennies reviewed and providedsubstantive comments about the chapter“Swimming for Fitness”. Mr. JeremyLevine and Ms. Brandi Schoeberprovided information about strengthtraining.
Importantly, we were extremelyfortunate to receive valuable input fromseveral SEALs throughout thedevelopment of this guide. ENS FrancesFranky and BM1 George Verniaparticipated in the first panel review andtheir suggestions were incorporated inthe second draft of the manual. BM1Vernia helped organize and participatedin the second and final panel review.Other SEAL panel reviewers includedCW03 John Shellnut, Master Chief BobBender, LCDR Pat Butler, and BMCSDuane Noel. Each one of these SEALsprovided suggestions and practicalrecommendations which wereinstrumental in the finalization of the“The Navy SEAL Physical Fitness
Guide”.
About the Authors
Part I: The Navy SEALPhysical Fitness Guide
CAPT Frank K. Butler, Jr., M.D.,developed the chapter “SEAL Mission-Related Activities”. He is currently theBiomedical Research Director for theNaval Special Warfare Command,Chairman of the U.S. Special OperationsCommand Biomedical InitiativesSteering Committee, and a StaffOphthalmologist at the Naval Hospital,Pensacola, Florida. He obtained hisundergraduate degree from Georgia
Institute of Technology in 1971, withhigh honors. His medical degree is fromMedical College of Georgia, 1980. Dr.Butler’s Family Practice Internship wasat the Navy Regional Medical Center,Jacksonville, Florida (1980-1981) andhis Ophthalmology Residency was at theNational Naval Medical Center,Bethesda, MD. where he was ChiefResident (1988-1989). He completed hisUndersea Medical Officer Training fromthe Undersea Medical Institute, Groton,Ct., 1981. CAPT Butler has been aplatoon Commander for UnderwaterDemolition Team TWELVE and SEALTeam ONE, and a Diving MedicalResearch Officer at the NavyExperimental Diving Unit. He has
published extensively and been afrequent guest lecturer on the subject ofclosed-circuit diving and SpecialWarfare.
CAPT John S. Hughes, M.D.,
developed the chapter “Swimming forFitness” and contributed to “OtherTrainingRelated Issues”. He is a NavyReserve Undersea Medical Officer whoresides near Littleton, Colorado. Agraduate of the University of ColoradoSchool of Medicine, Dr. Hughes has aNaval Reserve assignment to NAVSEAin Crystal City, Virginia, where he isassigned to the Supervisor of Diving andSalvage. Dr. Hughes has been involvedwith Navy diving medicine since 1981.
He is Board Certified in OccupationalMedicine and his civilian medicalpractice in Colorado and Wyominginvolves operation of clinics and healthfacilities covering a wide range of highrisk industries including commercialdiving.
Special qualifications allow Dr.Hughes to participate in the developmentof the Navy SEAL Physical FitnessGuide. He swam freestyle in the NCAAChampionships and won the 1976 Big 8Conference Championship in the 1650yd freestyle for the University ofColorado and has remained active as acompetitive swimmer. As a mountaineerand cross country skier he has organizedand participated in numerous climbs,
including two on Denali and DenaliNorth Peak in Alaska. His instrumentalwork with the SEAL team in developinga winter warfare program during 1982led him to participate as a staff memberof the SEAL winter warfare Greenlandoperation in 1983. For this involvement,Dr. Hughes received a letter ofappreciation from the CO of SEAL TeamTWO, CDR Rick Woolard. With thetheme of Dr. Hughes’ career beingmedical support of high risk military andindustrial operations, he feels that workfor the SEALs is at the head of the list.
CDR Joseph Moore, M.D.,
developed the chapter “Training andSports-Related Injuries. He completed
his undergraduate degree in 1978, andmedical degree in 1982 from theUniversity of Virginia after which hewas commissioned as a Lieutenant in theNaval Medical Corps. CDR Moorecompleted his internship at NavalMedical Center, Oakland, California, inJune 1983, and received orders to the1st Marine Division, Camp Pendleton,California. He served as BattalionSurgeon, 2nd Battalion, 9th Marinesfrom July 1983 to October 1985,deploying to Okinawa, Korea andPanama. He also served as 5th MarinesRegimental Surgeon during this timeperiod. He completed a Family Practiceresidency at the Naval Hospital, CampPendleton in 1987, followed by a tour as
Senior Medical Officer on the island ofLa Maddalena, Italy. CDR Moore wasthe first Navy physician selected for aprimary care Sports Medicinefellowship, and trained at the San DiegoSports Medicine Center and San DiegoState University from December 1989through January 1991.
CDR Moore is currently the
Department Head and FellowshipDirector for the Navy’s Sports Medicineprogram at the Naval Hospital andMarine Corps Base, Camp Pendleton. Inaddition to his duties as SpecialtyLeader to the Surgeon General, Dr.Moore serves as chairman of the SportsMedicine Advisory Panel to the U.S.
Naval Special Warfare Command,Coronado, and advisor to Marine CorpsCombat Development Command,Quantico. His work with the civiliancommunity has earned him anappointment by the Governor ofCalifornia to the Governor’s Council onPhysical Fitness and Sports. He alsoholds an appointment to the UnitedStates Olympic Committee TeamPhysician Development Program,Colorado Springs, CO. He is co-chairman of the American Academy ofFamily Physicians’ Review Course forSports Medicine.
CDR Brad L. Bennett, Ph.D.,
developed the Chapter “Load Bearing”
and he has written a technical report“Load Carriage: Are You PreparingCorrectly? Naval Medical ResearchInstitute, Technical Memo 96-71, 1991”.He is a research physiologist currentlyassigned to theDepartment of Military and EmergencyMedicine, School of Medicine,Uniformed Services University of theHealth Sciences, Bethesda, MD. Heserves as an Assistant Professor andDirector of the Basic Sciences Division.He is a graduate of WildernessMedicine, and Tactical EmergencyMedical Technician courses, and is adepartment faculty member in theCounter Narcotics Tactical OperationsMedical Support (CONTOMS) course
as sponsored by the Department ofDefense. He earned a Bachelor andMaster Degrees in Exercise Sciencefrom San Diego State University and aPh.D. in Kinesiology from the Universityof Maryland.
He has completed the Navy’s diving
medicine course and became designatedas a Navy Medical Department DeepSea Diving Officer. He has conductedbiomedical research on the impact ofenvironmental stressors on humanperformance of Navy Special Warfare(SEAL) personnel, U.S. Marine Corpspersonnel, and Navy damage controlpersonnel. Dr. Bennett currently servesas the Special Advisor to Navy Surgeon
General for Physiology.
Dr. Bennett has enjoyed long distancerunning (10k, half marathons andmarathons) for over twenty years. Otherhobbies of interest are hiking, kayaking,camping, weight training, target andskeet shooting.
LCDR Lisa Thorson, M.D., wrote theChapters on Flexibility, Calisthenics andPlyometrics. She earned her B.S. inpsychology at the University ofOklahoma in Norman, Oklahoma, andher M.D. from the University ofOklahoma School of Medicine. She hascompleted the Undersea Medical Officercourse and had a tour of duty at the
Diver Second Class TrainingDepartment, Naval Amphibious School,Naval Amphibious Base, Coronado.LCDR Thorson been involved with theExercise-Related Injury Program, andall aspects of injury prevention for theSpecial Forces Community. Projectshave included the development of injurytracking software used by the SpecialForces community. She also organizedthe first Naval Special Warfare SpotsMedicine conference held May 1994.Recommendations from this conferenceare documented in Naval HealthResearch Center Technical DocumentNumber 95-4D, “Naval Special WarfareSports Medicine ConferenceProceedings,” and Number 95-5D,
“Expert Panel Review of the NavalSpecial Warfare Calisthenics SportsMedicine Conference Summary.”
Currently she is in Residency training
in Preventive Medicine at the UniformedServices University of the HealthSciences, Bethesda, Maryland, whereher work documenting injuries in theSpecial Forces community will continue.She has 13 years of ballet training, hastaught and competed in aerobic dancecompetitions, and spends her timeweight-training.
Patricia Deuster, Ph.D., M.P.H., the
editor of this guide, wrote“Cardiorespiratory Conditioning” and
“Strength Training” and contributed to“Other TrainingRelated Issues”. Shecompiled the group’s recommendationsand wrote the chapter “Physical Fitnessand TrainingRecommendations”. She is an AssociateProfessor and Director of the HumanPerformance Laboratory in theDepartment of Military and EmergencyMedicine at the Uniformed ServicesUniversity of the Health Sciences,School of Medicine in Bethesda,Maryland. She has an undergraduatedegree in Mathematics, and graduatedegrees in Physical Education (M.A.),Nutritional Sciences (Ph.D.), and PublicHealth (M.P.H.). Her credentials forediting this book are many. She has been
conducting research in the area of sportsnutrition and exercise physiology forover 14 years, has published numerouspapers on the nutritional needs of U.S.Navy SEALs, and has given many sportsnutrition seminars to high school,college, and professional athletes,recreational athletes, SWAT teams,dietitians, and other healthprofessionals. She is also an athleteherself. She was a tennis professionalfor five years and has competed inseveral triathlons and over 20marathons; her best marathon time was a2:48 in the Boston Marathon. Dr.Deuster was a nationally ranked runnerfor several years and a qualifier for theFirst Women’s Olympic Marathon
Trials. She is an avid sportswoman anda former skydiver who has logged inover 100 jumps.
Anita Singh, Ph.D., wrote “Overview
of Physical Fitness” and “Running forFitness” and assisted Dr. Deuster withthe editing of this guide. She is anAssistant Professor in the Department ofMilitary and Emergency Medicine at theUniformed Services University of theHealth Sciences, Bethesda, Maryland.Dr. Singh has a Ph.D. in Nutrition fromthe University of Maryland and she hasbeen working in the area of SportsNutrition and Exercise Physiology forover 10 years. In addition to looking atnutritional needs of U.S. Navy SEAL
trainees, she has studied marathoners,ultramarathoners, and recreationalathletes. She has presented her researchwork at various national andinternational meetings. Dr. Singh haspublished extensively in scientificjournals and she co-authored “The NavySEAL Nutrition Guide”. She runs andplays tennis.
LDCR Kevin C. Walters, M.D.,
developed the chapter “Training forSpecific Environments”. He is a DivingMedical Officer at the Naval SpecialWarfare Center in Coronado, CA. Dr.Walters enlisted in the Navy in 1974 andgraduated from BUD/S in 1976 (class87) and served five and a half years at
SEAL Team ONE. He left active duty in1983 to return to college and graduateschool. He received his M.D. degree in1993 from the Uniformed ServicesUniversity of the Health andsubsequently completed a TransitionalInternship at the Naval Medical Center,San Diego, CA.
CDR Steve Giebner, M.D.,
contributed to the chapter “HarmfulSubstances that Affect Performance”. Heis currently the Force Medical Officerfor Commander, Naval Special WarfareCommand. His association with theNaval Special Warfare community goesback to 1982 when he took his firstoperational assignment as the Diving
Medical Officer for the Naval SpecialWarfare Training Department of theNaval Amphibious School, Coronado.He is also plank owner at Naval SpecialWarfare Center as the first MedicalOfficer assigned to that command.
Dr. Giebner specialized in Sport and
Exercise Preventive Medicine andHealth Promotion, having earned theMaster of Public Health degree in thePreventive Medicine residency at theUniversity of California at San Diegoand San Diego State University. He haslong been an active proponent of SportsMedicine in the Navy, and especiallywithin Naval Special Warfare His longassociation with Navy SEALs and his
professional training uniquely qualifyhim to contribute to this manual.
In addition to recreational tennis, golf,
and in-line skating, Dr. Giebner hasconsistently participated in commandendorsed physical training programsthroughout his Naval career. This yearmarks his first entry in the San DiegoMarathon and a Superfrog Triathlonrelay team.
HMC Denise E. Becker, USNR,
developed “Appendix A - Weight LiftingTechniques” and assisted in the editingof this guide. She has a B.S. inOccupational Education and is pursuinga Masters degree in Exercise
Physiology. She has served as theTraining Chief and is currently assignedto Assault Craft Unit-4 Det 1 as DivisionOfficer and the Medical DepartmentRepresentative. An avid sportswoman,she has participated in several halfmarathons, 10 and 5K races, andtriathlons. She competed in theTidewater All-Navy Tennis Tournament.Chief Becker is married to a SEAL, AlBecker, LCDR, USN-RET and they havefive children. The whole family hasparticipated in the UDT/ SEAL ReunionFamily Fun Run the past 10 years.
An Introduction by RADMRaymond C. Smith
Membership in the Naval Special
Warfare (NSW) community requires anextraordinarily high level of total bodyphysical fitness. A combination ofmuscular strength. flexibility andcardiovascular fitness is essential tocarry out assigned missions.
To train most effectively for thesephysically demanding tasks. SEALs andothers within the NSW community needclear, concise. and authoritativeguidance on physical fitness trainingregimens. This manual. The Navy SEALPhysical Fitness Guide. has beenwritten to meet this need.
The authors of this comprehensiveguide. physicians and physiologists.were chosen because of their specialqualifications in the area of physical
fitness and their knowledge of the NSWand SEAL community. Their expertiseensured the guide would be written withthe unique requirements of the NSWcommunity in mind, and that our goal ofexpanding the individual Navy SEAL’sknowledge of attaining and retaining ahigh level of fitness would be achieved.
I commend The Navy SEAL Physical
Fitness Guide as a superb source ofinformation. Following the advice in thisguide will enable SEALs and othermembers of the NSW community toprepare for the physically demandingmissions to which they are assigned inthe future.
Introduction to Part I:
The Navy SEAL PhysicalFitness Guide
The Navy SEAL Physical FitnessGuide has been prepared for the SEALcommunity with several goals in mind.Our objective is to provide you, theoperator, with information to help:
♦ Enhance the physical abilitiesrequired to perform SpecialOperations mission-relatedphysical tasks;
♦ Promote long-termcardiovascular health andphysical fitness;
♦ Prevent injuries and acceleratereturn to duty;
♦ Maintain physical readinessunder deployed or embarkedenvironments.
If this guide is able to achieve thosegoals, it will be a major success. Beinga SEAL is a tough job and requiresenormous physical strength and stamina.Injuries, both chronic and acute areoccupational hazards, but there aretraining measures and precautions thatcan be used to decrease the incidence ofthese injuries. Understanding the basics
of physical fitness can go a long way toachieving these goals.
Physical fitness is typically
considered a set of characteristics thatpeople gain through various physicalefforts. In fact, physical fitness consistsof a variety of measurable components,some of which are skill-related andothers which are health-related. Thecomponents of physical fitness arepresented in Table I-1.
Table I-1. Skill-and Health-RelatedComponents of Physical Fitness
Definitions for each of thesecomponents/terms are provided inChapter 1: Overview of PhysicalFitness; all are extremely important inSEAL training. Because thesecomponents are measurable, it is clearthat there are levels of physical fitnesswhich can range from very low toexceptionally high. Moreover, a wide
range may exist across particularcomponents within an individual. Forexample, a person may have exceptionalcardiorespiratory endurance, but havevery poor flexibility. Thus, a high levelin one component does not translate intohigh physical fitness. A highly fit personshould achieve a high level in each ofthe health-related components forprotection of health. However, for SEALtraining, components of both skill andhealth-related groups are requisite. Thisguide should help you achieve a morefavorable balance among the variouscomponents, and serve as a resource foryou in the future.
Chapter 1
Overview of PhysicalFitness
This chapter will introduce termsand definitions commonly used tomeasure or define fitness levels, andother terms associated with athletictraining. Terms such as aerobic andanaerobic will be appearing throughoutthis fitness guide and various trainingtechniques to optimize fitness will bediscussed in greater detail in subsequentchapters. We suggest that you take some
time to familiarize yourself with theterms and concepts in this chapter as thiswill greatly enhance your ability toapply the information provided in theremaining chapters.
Exercise Physiology
Exercise physiology is a branch ofscience which studies how the bodyresponds and adapts physically toexercise training or to an acute bout ofphysical exertion. Such information isused for designing physical education,fitness and athletic programs. Physicalfitness includes cardiopulmonaryendurance, body composition, muscularstrength and endurance, and flexibility.
Definitions and Terminology
Following are some commonly usedexercise physiology terms and theirdefinitions. You will come across manyof these terms in subsequent chapters.
Aerobic: A process of producing energythat requires oxygen.
Aerobic Capacity: Total or maximalamount of aerobic work that can bedone.
Aerobic Metabolism: Most of theenergy needed to support exercise thatgoes beyond 3 minutes is provided by
aerobic or oxidative energy metabolism.In other words oxygen is required toproduce energy.
Agility: Ability to change physicalposition with speed and accuracy.
Anaerobic: A process of producingenergy that does not require the presenceof oxygen.
Anaerobic Capacity: Total or maximalamount of anaerobic work that can bedone.
Anaerobic Glycolysis: A process of
breaking down glycogen stores withoutoxygen; lactate (lactic acid) is the by-product of this process.
Anaerobic Metabolism: A type ofenergy metabolism that does not requireoxygen.
Anaerobic Threshold: Transition pointwhen aerobic metabolism can no longermeet the energetic demands, and energyfrom sources independent of oxygen arerequired. This is also the work rate atwhich blood lactate concentrations startto increase during graded exercise.
Adenosine Triphosphate (ATP): Energy
released from food is stored in themuscle in the form of ATP. When ATP isbroken down energy is released.
Balance: Ability to maintainequilibrium when stationary or whilemoving.
Cardiorespiratory Fitness: Ability ofthe heart, lung and blood vessels totransport oxygen and to remove wasteproducts from the exercising muscle.
Concentric Contraction: Shortening ofthe muscle as it develops tension. Thistype of exercise is sometimes alsoknown as “positive exercise”.
Coordination: Ability to use the senses,such as sight, along with the functioningof a set of muscle groups to complete anactivity accurately. For example: hand-eye coordination during rifle shooting.
Dynamic Exercise: Alternatecontraction and relaxation of a skeletalmuscle or muscles causing partial orcomplete range of movement through ajoint.
Eccentric Contraction: Involves thelengthening of a muscle as it developstension and is also known as “negativeexercise”. Eccentric contractions are
used when resisting gravity as is thecase in walking down hill or downstairs.
Electrocardiogram (ECG): A tracingthat shows the electrical activity of theheart.
Ergometer: Instrument used to measurework and power.
Ergometry: Measurement of work andpower during exercise.
Exercise: Planned, structured, andrepetitive movements performed to
improve or maintain components ofphysical fitness. The components includecardiorespiratory fitness, musclestrength and endurance, flexibility andbody composition (see Introduction).
Fartlek Training: An unstructured typeof interval training for speed-work.
Flexibility: Controlled range of motionof a specific joint. The range is afunction of elasticity of the tendons,ligaments, and surrounding soft tissue.Control is a function of strength at eachdegree of motion, especially at the endranges.
Glycogen: A form of carbohydrates thatis stored in the liver and in muscles forenergy.
Glycolysis: Breaking down of simplesugars into simpler compounds (chieflypyruvate and lactate) for energy. Thisprocess is anaerobic.
Glycolytic: Pertaining to or promotingglycolysis.
Heart Rate: Number of heart beats perminute.
Interval Training: Very intense exercise
bouts are alternated with rest or periodsof low intensity exercise. Exerciseduring intervals is typically anaerobic.
Isokinetic: Contraction of a muscle ormuscle group which results in jointmovement at a constant angular velocity.For example: the arm stroke during freestyle swimming.
Isometric (Static): Muscle contractswithout shortening or lengthening suchthat tension is developed but nomuscular work is performed; energy islost as heat. There is no joint movementduring this type of exercise.
Isotonic (Dynamic): Muscle contractsand maintains constant tension bylengthening or shortening.
Lactic Acid (lactate): A by-product ofanaerobic metabolism.
Ligament: A band of fibrous tissue thatconnects bone to bone or bone tocartilage so as to strengthen joints.
Maximal Oxygen Uptake (VO2max): Ameasure of aerobic fitness: the maximalrate of oxygen uptake, and thereforeaerobic energy utilization duringexercise. Typically expressed as litersper minute or milliliters per kilogram
(kg) body weight per minute(ml/min/kg).
MET (Metabolic Equivalent Unit): Aunit used to estimate the metabolic costof physical activity. One MET is theenergy used by an individual at rest.This is equivalent to 3.5 ml of oxygenconsumed per kg body weight perminute.
Metabolism: Physical and chemicalprocesses that maintain life.
Minute Ventilation: Volume of airbreathed per minute.
Muscular Endurance: Ability of amuscle or muscle group to contract at asubmaximal force, usually against 50 to60% of maximal resistance, over aperiod of time. Measured as the numberof repetitions completed.
Muscular Strength: Maximal force ortension generated by a muscle or musclegroup.
Myoglobin: An iron containing muscleprotein that is responsible for thereddish color of various muscle fibertypes.
Physical Activity: Movement byskeletal muscles that results in energyexpenditure.
Physical Fitness: Ability to performphysical activity.
Plyometrics: Also known as explosivejump training. Muscles are rapidlystretched prior to contraction. Examplesinclude standing jumps, multiple jumps,etc.
Power: Ability of a muscle to quicklygenerate force over a very short periodof time. Examples include sprint starts,vertical jumps, kicks and throwing a
punch.
Rating of Perceived Exertion (RPE):Measured using the Borg Category RPEScale. As exercise intensity increases,the RPE increases and in general it isclosely associated with physiologicalmeasures such as heart rate and oxygenconsumption.
Reaction Time: Time taken betweenreceiving a signal and reacting to it.
Respiratory Exchange Ratio: Ratio ofcarbon dioxide produced to oxygenconsumed. An indication of the primaryenergy source used during exercise.
Speed: Ability to perform a movementin a short period of time.Strength: Ability of a muscle tocontract against resistance and providecontrol throughout the full range ofmotion.
Stroke Volume: Volume of bloodpumped from the heart with each beat.Tendon: A fibrous cord in which thefibers of a muscle end and by which themuscle is attached to a bone or otherstructure.
Tidal Volume: Volume of air movedduring one breathing cycle while
inhaling or exhaling.
Muscle Structure andFunction
The three major types of muscle are:
♦ Cardiac muscle♦ Skeletal muscle♦ Smooth muscle
This discussion will be limited toskeletal muscles which, by convertingchemical energy to mechanical energy,produce movement. We will present adescription of the subtypes of skeletalmuscles, including their characteristicsand distribution. Although there may bemany new subtypes of skeletal musclefibers, generally skeletal muscle can be
characterized into three basic types:
♦ Slow Twitch Oxidative (Type I)♦ Fast Twitch Oxidative-Glycolytic
(Type IIa)♦ Fast Twitch Glycolytic (Type IIb)
Type I Muscle Fibers
Type I muscle fibers are involved inendurance activities. These fibers, alsocalled slow twitch fibers, are noted fortheir ability to produce energy in thepresence of oxygen. Thus, they areprimarily aerobic. The main fuel sourcefor this fiber is fats (fatty acids), whichallow the muscle to work at a steady ratewith noticeable resistance to fatigue.Their color is typically quite red, aresult of the high content of“myoglobin”, an iron-containing proteinthat stores and delivers oxygen. Slowtwitch fibers are not noted for theirspeed, their anaerobic capacity, or theirability to contract at a fast rate
repeatedly, but rather theirindefatigability and aerobic capacity.
Type II Muscle Fibers
Type II fibers can be categorized intoat least two types: Type IIa and Type IIb.These fibers are adapted for strength andpower activities. The Type IIa fiber is across between a slow twitch and a fasttwitch fiber in that it is both aerobic(oxidative) and anaerobic (glycolytic).Whereas, it is “faster” than the slowtwitch fiber, it is not as well suited forendurance activities. Its color is alsoreddish, a result of the myoglobincontent.
In contrast, the Type IIb fiber is truly
a fast twitch fiber, with very high
contraction speeds. These fibers arealmost exclusively anaerobic and haveminimal capacity for aerobic productionof energy. They rely primarily onglycogen within the muscle for energyand are therefore very susceptible tofatigue. Their color is pale, and someconsider it “white” because it lacksmyoglobin. Type IIb fibers tend toaccumulate lactate, which ultimatelyleads to rapid fatigue if the lactate is notremoved.
It should be noted that each of the
fiber types has different recruitmentpatterns, and typically the Type IIb fiberis only recruited for use during maximaleffort. The other fibers contract during
light as well as moderate activity.Moreover, physical training can leadto changes in the characteristics of thefibers. Thus, endurance training wouldlead to changes in the Type IIa fiber suchthat they take on more characteristics ofthe Type I, or slow twitch fiber. Table 1-1 presents the distinguishingcharacteristics of the various fiber types.
Table 1-1. DistinguishingCharacteristics of Major Muscle FiberTypes
Distribution of Fiber Types
The amount of Type I and Type IImuscle fibers in an individual isgenetically predetermined, and allnormal skeletal muscle contains all fibertypes. However, the proportion ordistribution of these fiber types withinand across individuals differs.Moreover, within an individual, thedistribution of fibers in various musclescan vary widely. Physical training maytransform muscle fiber type, and themetabolic capacity of both type I andtype II muscle fibers can be modifiedby endurance and power training. Itshould be noted that performance
depends not only on your fiber typecomposition, but also on the interplaybetween a variety of factors such astraining, and diet, etc. Figure 1-1represents the average percentage ofslow twitch (Type I) fibers found invarious subgroups of the population. Ascan be seen, persons whose activitiesare primarily endurance-related have ahigher proportion of Type I fibers ascompared to sprinters or wrestlers. Alsoin Figure 1-1 are the maximal aerobiccapacities of these groups: the greaterthe proportion of Type I fibers, thehigher the maximal aerobic capacity.Note the wide variability in the group of“recreational athletes”. Specific types oftraining can induce changes in muscle
fiber composition and characteristics.
Figure 1-1. Muscle Fiber Compositionand Maximal Oxygen Uptake Valuesfor Various Athletes by Sport
Principles of PhysicalTraining
The goal of any training program is toimprove performance. You are unique interms of your excellent physicalcondition and your dedication to furtherenhancing your fitness. The fourprinciples that apply to all physicaltraining programs are discussed below.
Overload
According to this principle, exercisemust be done at a higher level than usualto bring about various trainingadaptations. Once the body has adaptedto the higher level of exercise it willfunction more effectively and efficiently.The overload can be obtained bymanipulating various combinations ofexercise frequency, intensity, durationand type of exercise. Increasingintensity, duration and frequency can behelpful for running, cycling orswimming, and increasing resistance andrepetitions can improve strength training.
Specificity of Training
This principle refers to the training-induced adaptations in metabolic andphysiologic systems which are specificto the type of exercise. For example,running will increase physical fitness butit will not increase swimmingperformance and vice versa. Thus, it isimportant to train muscles involved in aspecific type of exercise to realizegreater performance benefits.
Individual Differences
Responses to a particular trainingprogram can vary from one individual toanother. According to this principle,exercise programs should beindividualized to meet the trainingrequirements and physical capacity ofeach person.
Detraining
Regular exercise is necessary tomaintain fitness. Beneficial effects ofexercise are gradually lost or reversedafter a few weeks off from training. Thisdeconditioning or detraining effect willbe discussed later in this chapter.
Because of the nature of your missions
it is imperative that you develop allaspects of physical fitness: strength,speed, flexibility, and endurance.Therefore, it is important for you toconsider your training in terms of theFITT principle.
FITT = Frequency, Intensity, Time&Type
All four aspects of the FITT principlemust be included to achieve the mostbenefit from your training program.Number and intensity of workouts isimportant as is the time spent exercisingand cross training (see Chapter 3).Information on how to determine yourtraining intensity is provided next.
Determining Your TrainingHeart Rate
When reading the training methodspresented in this chapter and throughoutthis guide, you will come acrossreferences to exercise intensity.Intensity is the rate at which exerciseis performed. If you work out in a gymyou may have used an exercise machinethat monitors exercise intensity. A quickand easy method for measuring theintensity of your workout is bymeasuring your heart rate and checkingto see if you are within your targettraining zone (see below).
Measure your heart rate by taking yourpulse at the carotid artery (neck) or theradial artery (wrist) for 15 seconds;multiply this value by four to get yourheart rate in beats per minute. Comparethis heart rate value to your targettraining intensity. If your heart rate is toolow, increase the intensity of yourworkout. If it is too high, reduce theintensity slightly.
Your target training heart rate can becalculated as follows:
To maintain aerobic conditioning,exercise should be performed at a heartrate between 70% and 90% of yourmaximal heart rate (Max HR).
Remember, this is only an estimate ofyour maximal heart rate.
Depending on your particular“physiology” and physical conditioning,your Max HR could be higher than whatyou derive from this equation. However,this is the way it is routinely estimated.
Max HR in beats per minute =220 - your age (years)
To calculate 70% and 90% of yourMax HR, multiply Max HR by 0.70 and0.90, respectively. This is your targettraining intensity zone or the rangewithin which your heart rate should bewhile working out. Figure 1-2 presents
an example of how to calculate yourdesired training heart rate by thismethod.
Figure 1-2. An Example forDetermining Your Target TrainingHeart Rate
Calculate your target training heartrate zone using the formula provided
above or use the chart shown in Figure1-3. It is important to note that maximalheart rates tend to be lower duringswimming and arm exercises. For theseactivities you should subtract 13 fromyour maximal heart rate to beforeobtaining your training heart rate. Anexample of this is shown in Figure 1-4.
Figure 1-3. Target Training HeartRate Zone
Figure 1-4. An Example forDetermining Your Target TrainingHeart Rate for Swimming
Energy Systems Used byExercising Muscle
Before describing the methods usedfor physical training, it is important tounderstand the three systems that provideenergy to the exercising muscle. Allthree systems are important. Dependingon the activity, there may be a greaterreliance on one system over the others.
ATP-CP System for Speed Work
Adenosine triphosphate (ATP) is theimmediate source of energy within allcells of our body for activities such assprinting. There are small stores of ATPwithin skeletal muscle, and these energystores provide immediate energy tosustain physical activities for a shorttime. Once the ATP is used, it breaksdown into adenosine diphosphate(ADP). For regeneration of ADP intoATP for more energy, creatine phosphate(CP) is needed. It is the CP thatregenerates the ATP. Without CP, ATPcould provide energy for only a fewseconds. With CP, the ATP-PC systemcan provide energy for about 30 seconds
before other energy systems must takeover. Thus, this ATP-CP system,sometimes referred to as the phosphatepool or reservoir, provides immediateanaerobic energy for muscle contraction.
Lactic Acid and ATP-CP System forAnaerobic Work
This is a transitional system. Whenall-out exercise continues beyond 30seconds, the only way to continueproviding ATP to the exercising muscleis by using sugar (glucose) in the muscle.Sugar in the muscle is obtained fromglycogen, and the process of breakingdown sugar for energy is calledglycolysis. However, in the process ofgenerating ATP from glucose, lactic acid(also known as lactate) is formed.Normally there is a only a small amountof lactate in blood and muscle. Whenlactate begins to accumulate in muscleand then blood, you will begin to
experience muscular fatigue, unless it iscleared by the body. Lactate is clearedfrom the muscle if the intensity of theexercise is moderate. This happensbecause after a few minutes the aerobicor oxygen system, which supplies energyfor sustained work, kicks in. If an all outeffort is sustained, fatigue is inevitablewithin three to five minutes.
Oxygen System for Aerobic Energy
The oxygen, or aerobic, systemprovides energy to support long-termsteady state exercise, such as longdistance running or swimming. Musclescan use both glucose and fatty acidsfor energy. These fuel sources can betaken from the circulating blood andfrom stores within the muscle. Glucoseis stored as glycogen and fatty acids arestored as “triglycerides” in the muscle.When long duration activities areperformed at a slow pace more “fat” inthe form of fatty acids is used for energythan muscle glycogen.
During many types of exercise, allthree energy transfer systems are used atvarious times. The amount that eachsystem contributes to energy metabolismis related to the duration, intensity andtype of activity. In general, high intensity,short duration exercises rely mainly onanaerobic energy. Other examplesspecific to various activities areprovided in Table 1-2.
Table 1-2. Percentage Contributed byEach Energy System to OverallEnergy Needs of Various Activities
Methods of PhysicalTraining
Most people think of exercise asbeing either aerobic or anaerobic.However, in most types of exercise, ablend of both aerobic and anaerobicexercise is involved. For example,during a 1500 m run, energy is providedby anaerobic metabolism at thebeginning and the end of the run whereasaerobic metabolism supports the middleor the steady state part of the run.Aerobic and anaerobic capacity can beimproved by using appropriate physicaltraining techniques. The contribution ofthe three energy systems to the various
training methods is shown in Table 1-3.The various physical training techniquesare presented below, and can be used forenhancing performance during variousphysical activities.
Table 1-3. Contribution of the VariousEnergy Systems According to TrainingMethods
Interval Training
Exercise bouts are alternated with restor relief periods. Relief periods usuallyinvolve mild to light exercise.Generally, in swimming no exercise isperformed during the relief periods. Theduration, intensity, and number(repetitions) of exercise bouts and thelength and type of relief intervals arechosen to suit specific exerciseperformance requirements. Intervaltraining allows you to exercise at ahigher intensity than you could if youwere exercising continuously. This typeof training helps to develop the muscleATP-PC energy system. Both aerobicand anaerobic metabolism can be
improved by interval training.
Sprint Training
Sprint training helps develop speedand increase muscle strength.Individuals are required to sprintrepeatedly at maximum speed whileallowing for complete recovery betweensprints. In general, 6 seconds are neededto go from a stationary position tomaximum speed. For a runner this wouldmean running 55 to 60 meters to reachthat maximum speed.
Interval Sprints
This method involves alternatelysprinting for 45 to 50 meters and joggingfor 55 to 60 meters while covering adistance of about 3 miles. Intervalsprinting helps to develop aerobiccapacity.
Acceleration Sprints
Acceleration sprint training developsspeed and strength. Running speed isgradually increased from jogging tostriding to sprinting, followed by arecovery walk. This sequence isrepeated. Intervals may range from 50 to100 meters each. For example: 50meters jogging, 50 meters striding, 50meters sprinting and 50 meters walking.
Fartlek or Speed Play
The work Fartlek means “speed play”in Swedish. It involves running at fastand slow speeds on both level and hillycourses. Unlike interval training, thefartlek form of training does not involvespecific exercise and rest periods; youdo it as desired. For example, you maysay to your buddy “I’ll race you to thenext stop sign”, and you would both runas fast as you can to that point. You mayrun at a slower pace for a few minutes,and then run fast again for as long as youwant. In other words, it is a speedworkout without structure. As such, it iswell suited to general conditioning andprovides variety to workouts.
Continuous Exercise Training
This type of training is needed tobuild endurance for activities such asdistance running and open oceanswimming. Exercise is performed withdistance in mind and may be done at aslow or a fast pace. The aerobic systemis the main energy source for this type ofactivity. Specific training requirementsfor endurance training in running andswimming will be discussed in Chapters4 and 5.
Repetition Running
This method is similar to intervaltraining, but unlike interval training, thelength of the intervals are longer andusually range from 0.5 to 2.0 miles.Recovery between intervals lasts untilthe heart rate is under 120 beats perminute, or within 60% of your estimatedMax HR.
Conditioning andDeconditioning
Conditioning and deconditioning, alsoknown as training and detraining, areresponsible for gains and losses,respectively, in fitness levels. Whereasconditioning is a gradual process andmay take six or more weeks to seespecific effects, deconditioning occursrelatively quickly. Some of the variousmetabolic and cardiorespiratory effectsof conditioning are presented in Table 1-4.
Table 1-4. Various Effects of PhysicalConditioning
Effects of deconditioning will benoticed within one to four weeks.Deconditioning reverses the positivemetabolic, cardiac, respiratory andmuscle enzyme effects that result fromconditioning. Some major effects ofdeconditioning include:
• Decrease in maximal aerobic
capacity - Heart rate for a givenexercise workload is higher andthe amount of blood pumped bythe heart with each beat isreduced.
• More rapid build up of lactic acidduring exercise which leads toearlier fatigue.
• Reduction in levels of key muscleenzymes which regulate themuscle’s ability to generateenergy from various sources.
• Reduced ability to store glycogenin muscle between workouts.
• Reduced breathing volume whichwill decrease the amount ofoxygen being taken to theexercising muscle
• Decreased endurance capacity -time to fatigue is shortened.
• Decreased ability to dissipatebody heat during exercise: theability to exercise in adverseenvironments, such as in the heat,is reduced due to all factorsmentioned above.
Retraining is necessary to reverse theperformance reducing effects ofdeconditioning. However,deconditioning can be prevented orminimized by maintaining usualexercise intensity during enduranceand strength workouts, when thenumber or length of work outs isdecreased. Aerobic capacity and
decreased lactic acid accumulationduring exercise can be maintained bytraining at least two to three times perweek at your usual training intensity.Strength gains can be maintained byincluding one to two strength trainingworkouts sessions per week. Specifictraining methods for maintaining fitnessunder deployed conditions and whileovercoming an injury will be discussedin other chapters (see Chapters 11 and12).
Active Recovery
This type of recovery means that youcontinue to exercise at a low tomoderate (30% to 50% of your maximalheart rate) intensity for several minutesafter your regular workout. For example,walk for 5 to 10 minutes aftercompleting a run. The benefits of activerecovery and additional informationabout this type of recovery are providedin Chapter 3: CardiorespiratoryConditioning.
Chapter 2
SEAL Mission-RelatedPhysical Activities
The primary goal of SEAL physicalfitness training is to maximize mission-related performance. SEALs need aphysical training program whichencompasses all of the various mission-related tasks that need to be performed.Thus, before deciding on a physicalfitness training regimen, the specifictypes of athletic activities involved inyour missions must be clearly defined. It
is important for you to establish specificgoals. An athlete training for a marathonwill want to train such that he will finishthe race in the shortest possible time.Everything else in your program will besecondary to the primary objective ofmaximizing lower extremity aerobicperformance. Likewise, a kayaker willmaximize his aerobic performance byfocusing on upper extremityconditioning. A competitive weightlifter, in contrast, will strive to maximizethe amount of weight that he can lift,with little or no emphasis on endurancetraining.
What are “mission-related tasks?”As an illustration, let’s consider
bicycling. Cycling is a superb way toobtain an intense aerobic (or anaerobic)workout and is very useful in promotinggeneral cardiovascular fitness, butSEALs do not cycle during missions. Nomission scenarios require you to hop onyour bikes and ride 25 miles. In contrast,a two mile swim in fins also provides anexcellent cardiovascular workout, andmore closely approximates activitiesrequired on Special Warfare missions.
Although a good cardiovascular
workout on a bike will confer a trainingbenefit for SEALs, cycling is not thepreferred substitute for mission-relatedtraining. Being in shape for one activitydoes not necessarily translate into being
in shape for another activity which usesentirely different muscle groups.Training by running or biking to performa long distance swim will result in ahigh incidence of muscle fatigue and legcramps on the mission. Some swimmingmust be incorporated into a trainingprogram. Moreover, swimming with finson a regular basis will ensure that theoperator is comfortable in his fins andwet suit booties, and prevent thedevelopment of painful blisters on themission. Thus, there are many reasonsfor specificity of training.
Swimming is not the only mission-
related task. The goal of this chapter isto present mission-specific activities
and determine the physical tasksassociated with these missions. Thedoctrine that you should train as youfight is also true for physical fitnesstraining.
Mission-Specific Activities
What sort of physical activities willSEALs be required to perform in thecourse of their missions? To answer thisquestion, the types of missions that youperform need to be examined. A partiallist of these missions is shown in Table2-1, and a brief description of thesemissions is provided below.
Table 2-1. A Summary of VariousSEAL MissionsTypes of SEAL MissionsSmall Unit Patrolling High Speed Boat
Operations Combat Swimmer Operations
SDV and Dry Deck ShelterOperations Urban Warfare Winter Warfare Operations
Small Unit Patrolling
One capability that will be needed inalmost all SEAL land warfareoperations is the ability to carry asubstantial amount of weight over longdistances. You will typically carry twoweapons and a supply of ammunition.There is no good way to know exactlyhow much ammunition you will berequired to carry for a particular missionand SEAL operators tend to pack heavyin this category. In addition, your loadswill often include explosives andspecialized items. Water needs to becarried in the loadout and, if the missionis a sustained one, rations must also beincluded. Loads of 70-80 pounds are
standard in the community and muchheavier loads are not uncommon. Howfar must you carry this load? There is noone distance that can accurately be usedas an upper limit, but certainly 10-20miles in a 24 hour period, depending onthe difficulty of the terrain, may berequired for some operations. Walkinglong distances with a heavy load is asignificant challenge in itself, but youmay also be required to run andscramble over terrain features, walls,and fences.
Load-carrying is one of the most
important physical activities a SEALcan practice.
The ability to carry a wounded fellow
operator on your back or shoulders isalso important. Buddy shoulder carriesare critical in that they are currently theanticipated mode of transporting awounded SEAL to a secure area wheremedical care can be rendered. Thesecarries are somewhat different than longdistance hikes with equipment becausethe load is distributed quite differentlyon the body and in some cases, theweight of the wounded operator may bein addition to the basic load.
How do you train for these activities?
Long distance runs with shorts andrunning shoes are useful in promotingcardiovascular fitness, but do notadequately simulate load-bearing
activities. Similarly, the number ofbench presses you can do at a givenweight does not ensure your being ableto walk long distances with a heavyload. Moreover, some of the problemsassociated with load-carrying aremusculoskeletal injuries and blisters.These can only be avoided (orminimized) by practicing the specificactivity.
High Speed Boat Operations
The Special Boat Environmentimposes unique physical demands. Suchmissions typically include extendedperiods in transit, often at high speeds instormy seas. This type of activityrequires extraordinary stability of theknee, elbow, shoulder and ankle joints.Since maintaining a slight bend in theknees, elbows and ankles is essential for
minimizing musculoskeletal injuries,training to improve muscle strength andendurance is critical.
Combat Swimmer Operations
With the current-day SEAL teamshaving had their origin in the Scouts andRaiders, Naval Combat DemolitionUnits, and Underwater DemolitionTeams of World War II, it is notsurprising that combat swimmeroperations are still an important part ofthe Naval Special Warfare mission.These operations may last as little asone or two hours in some situations, andas long as eight to 10 hours in others.You may be swimming on the surface orswimming underwater compass courseswith the Dräeger LAR V or MK 16closed-circuit underwater breathingapparatuses. These operations are oftencarried out in very cold water; thus,hypothermia is a constant concern. In
many instances, you will be towingsomething in the water (usuallysomething with a very rapid rate ofcombustion), thereby increasing theeffort needed to accomplish the mission.Some missions involve exiting the waterand climbing up the side of a ship usinga caving ladder or other climbingapparatus. These are difficult maneuversunder any circumstances, but much moreso when your hands are numb from coldexposure and you are climbing withweapons, ammunition, and explosives.Regular exposure to cold waterimmersion will help to developphysiological adaptations so that youwill fare better when subjected to coldwater on a mission. In addition, both
upper body and leg strength areimportant for shipboarding techniques.Grip strength, in particular, is criticalfor maintaining a firm hold on the ropeor ladder. Caving ladder or rope climbsare very important to develop the musclegroups that will be used forshipboarding; you should do theseclimbs with gear whenever possible.
Swimming with fins is an activity
basic to all SEAL combat swimmermissions and should be done on aregular basis in team physical trainingevolutions. Swimming without fins,while a very good activity for promotingcardiovascular fitness, is not typicallyrequired for SEAL missions. It is
important to mention that encouragingspeed on combat swimmer operations isfine for surface swims, but should not bedone on underwater swims because ofthe reduction in the LAR V operatingrange and increased risk of centralnervous system oxygen toxicity.
High exercise rates under waterincrease the diver’s chance ofhaving an oxygen convulsion.
SDV and Dry Deck ShelterOperations
These operations are basicallycombat swimmer operations, but ones inwhich the SDV does the majority of thework. They are typically longer thanoperations in which free-swimmingdivers are used, but this is not alwaysthe case. As SDV operators, you need tobe able to accomplish the same physicaltasks noted for combat swimmers above.In addition, these operations may requiresignificant upper body strength to handlethe heavy equipment required for themission both in the Dry Deck Shelter andlater at the objective.
Urban Warfare
Some SEAL missions call for directaction operations in an urban setting.Although it is difficult to generalize,these missions might be expected torequire less of a load-bearing challenge
because some form of transportationwill often be available. In addition, thedistance to be covered on foot willtypically be less than many remotemissions. Generally, you will need tocarry less food and water than with othertypes of land warfare missions. Yourneed for weapons and ammunition,however, will not be reduced, sosignificant gear loads are still apossibility. Additionally, you may needto perform demanding physical tasks,such as sprints and rapid stair climbs, inthe urban warfare setting. Moreover,there is the potential of having toaccomplish these maneuvers whilecarrying or dragging a wounded buddyor hostage.
Winter Warfare Operations
Winter Warfare operations oftenrequire long distance cross-countryskiing or snowshoeing which willusually have to be done with a heavyequipment load. This activity requiresthe use of a different set of muscles thanwalking and running. Not all SEAL unitshave a primary mission area thatrequires the ability to operate in winterwarfare environments, but those that doshould consider cross-country skiingwith equipment when designing theirworkout programs (see Chapter 14).
Specific Mission-RelatedPhysical Tasks
In order to identify the physicaldemands of direct action SEALoperation, a study was undertaken inearly 1990 by the Naval HealthResearch Center. Missions and thephysical requirements (i.e., aerobic andanaerobic components) necessary tocomplete each mission and missionsegment were evaluated. In brief, a totalof 82 SEALs, averaging 11 years ofexperience, participated in the study.Subject matter experts from operationalplatoons were interviewed regardingmissions they had conducted as SEALs.
Information obtained during theseinterviews provided the basis for aquestionnaire which was developed andgiven to the study participants. Thequestionnaire was composed of a list ofmissions and mission segments such as“fast rope to the deck of a ship from aheight of 40 feet, carrying a 50-poundpack.” Each SEAL participant rankedmission and mission segments on scalesto rank: difficulty of performance,frequency of performance, andimportance to mission success. Theindividual scores for each scale werethen summed to obtain a “compositescore”. Mission tasks that received thehighest composite scores are providedbelow.
• Walk (i.e., hump) 15 km overuneven terrain at night carrying a125 lb pack to objective in 70°F,then retrace steps to extractionpoint.
• Serve as point person for anelement, walking a distance of42 km through dense jungle intropical heat and humidity over a3-day period carrying a 60 lbpack and weapons.
• Swim a distance of 2,000 metersin 56°F carrying a limpet mineand using a Dräeger; return toZodiac without limpet, thentravel 6 km to extraction point.
• Swim for 3 hours underwater(temperature: 70°F), wearing a
wet-suit, mask and fins, andusing a Dräeger UBA and attackboard.
• Drag a fully-loaded F470 Zodiac50 meters onto a rocky beachwith five other SEALs, then,with three of the boat crew,quickly move all equipment andsupplies across 200 meters ofrocky beach and stage/cache gearin preparation for the overlandphase of the mission.
• Perform a rescue drag of awounded comrade weighing 170lbs, dragging him by the webgear a distance of 75 meters,with the assistance of one otherSEAL.
Given the above list of missions tasks,the question “what are the physicalfitness requirements necessary tocomplete each task?” was asked. Asummary of the physical tasks data ispresented in Table 2-2 and Table 2-3.Table 2-3 presents the numerousphysical tasks associated with themissions and the physical characteristicsdemanded of the SEAL. Table 2-3extends these characteristics bydelineating specific training plans toimprove performance on the physicaltasks.
Table 2-2. Physical Requirements forSpecific Missions and Mission
Elements
Table 2-3. Specific Physical Task-Related Training
The critical point in these tables isthat your physical training program mustbe a whole body conditioning programwith upper and lower body endurance,
flexibility, and strength activities. Mostmissions involve multiple physicaltasks, therefore, an effective trainingprogram must address the physicalrequirements of all these tasks. Thetraining program provided in the lastchapter has been designed with this goalin mind.
SEAL training must be whole bodyconditioning with upper and lower
body endurance, flexibility, andstrength activities.
Summary
The most important types of SEALmission-related athletic activities arelisted below. Each of these activitiesshould be incorporated into a trainingprogram, ideally on a weekly basis. Forother/substitute activities, please refer toChapter 15: Physical Fitness andTraining Recommendations.
♦ Long distance hikes with heavyequipment loads
♦ Cross-country skiing withequipment
♦ Caving ladder climbs with gear♦ Swimming with fins♦ Sprints with gear
♦ Obstacle negotiation with gear♦ Fast-roping
For more information you may wish toconsult the Navy Technical Report: No.95-24 entitled: “Physical Demands ofU.S Navy Sea-Air-Land (SEAL)Operations,” WK Prusaczyk, JW Stuster,HW Goforth, Jr., T Sopchick Smith, andLT Meyer.
Chapter 3
CardiorespiratoryConditioning
The American College of SportsMedicine (ACSM) and the Centers forDisease Control and Prevention recentlyformulated new guidelines for theAmerican public with respect toexercise. The new recommendationsstate that “Every US adult shouldaccumulate 30 minutes or more ofmoderate intensity physical activity onmost, preferably all, days of the week”.
They defined moderate intensity physicalactivity as “activity performed at anintensity of 3 to 6 METS, or theequivalent of brisk walking at 3 to 4m.p.h. for most healthy adults”. Whereasthe previous recommendations for theUS population emphasized theimportance of extended periods ofstrenuous exercise, these new guidelinesstate that short, intermittent bouts ofmoderate exercise are important andsufficient for health benefits. The overallgoal of these organizations is to promotecardiorespiratory conditioning, animportant aspect of overall fitness,health, and disease prevention.However, activity above and beyond therecommendations for the public is
necessary for SEALs and other highlycompetitive athletes. In this chapter wewill discuss:
♦ Basic concepts ofcardiorespiratory conditioning
♦ How to estimate your maximalaerobic capacity
♦ Types of aerobic activities andbasic workouts
Many of the definitions andterminology associated withcardiorespiratory conditioning havebeen presented in Chapter 1. However,other terms are used interchangeably toreflect cardiorespiratory conditioning;these include cardiovascular,
cardiopulmonary, and aerobicconditioning. The important point is thatthis form of conditioning improveshealth and work capacity by enhancingthe circulation and overall functioning ofthe heart and lungs.
Basics Concepts ofCardiorespiratory Exercise
Cardiorespiratory conditioningconsists of both aerobic exercise, whichrequires oxygen to sustain muscleactivity, and anaerobic exercise, whichdoes not use oxygen for the short burstsof highly intense activity. Most dailywork and activities are aerobic innature, and thus, improving the deliveryof oxygen to the working skeletal musclewill improve work performance. Yourability to utilize oxygen for exercisedepends on a variety of processesincluding:
♦ Functioning of your muscles ofrespiration or pulmonaryventilation
♦ Ability of oxygen to diffuseacross lungs into your blood
♦ Ability of heart to increase rate ofbeating and amount of bloodpumped with each beat
♦ Ability of blood vessels in andsurrounding skeletal muscle toregulate blood flow
Ability of contracting skeletalmuscle to extract and use oxygenin blood
All of these factors are important indetermining your ability to sustain asubmaximal workload, and yourmaximal aerobic capacity. Two otherfactors which help determine maximalaerobic capacity are your percentage ofspecific muscle fiber types and yourgenetic makeup. Some persons areendowed with a high aerobic capacity,whereas others are not. However,everyone can and will improve if acardiorespiratory conditioning programis followed.
Terms Related to Conditioning
Many terms are used to define ordescribe exercise conditioning and workrate, also referred to as exerciseintensity or work load. The two termsused throughout this chapter fordescribing how to gauge your work ratewill be maximal oxygen uptake andenergy expenditure as calories/hour, orkcal/ hr. Other terms to describe workrate and their interrelationships will bediscussed at the end of this chapter.
Maximal Oxygen UptakeThe primary measure or predictors of
one’s capacity to sustain work
performance is maximal oxygen uptake(VO2max) or maximal aerobic(cardiorespiratory) capacity. VO2max ismeasured in milliliters per minute(ml/min), Liters/min, or after adjustingfor body weight in kilograms, as ml/kg/min; a higher value indicates a higherlevel of cardiorespiratory fitness.
Your maximal aerobic capacity or
oxygen uptake is the best indicator ofhow much work you can sustain
without fatigue.Typical VO2maxvalues range from
30 ml (of oxygen)/kg/min for an unfitperson up to 80 ml/kg/min for anexceptionally fit, endurance athlete. If
the unfit and highly fit persons bothweighed 70 kg (155 lb) then theirrespective absolute maximal aerobiccapacities would be 2.1 liters (ofoxygen)/ min and 5.6 liters (ofoxygen)/min.
Using 1 liter of oxygen/min is
equivalent to expending 5 kcal/minAs such, the unfit person can only
work at a rate of up to 10 kcal/min (2.1L x 5) whereas the highly fit could workat up to 25 kcal/min (5.6 L x 5 kcal) ifneeded. If a specific task required 2L/min, then this would amount to 10kcal/min of energy. Resting energyexpenditure requires less than onekcal/min, or about 0.200 to 0.250 L (of
oxygen)/min. In order to account fordifferent body sizes, resting energyexpenditure for an individual is usuallydefined as:
3.5 ml of oxygen/kg bodyweight/minute.
Thus, for a 70 kg (155 lb) SEAL, restingenergy expenditure would beapproximately 245 ml/min or 0.245L/min (3.5 x 70). This is equivalent toexpending around 1 to 1.25 kcal/min.
Anaerobic PowerHow much strenuous work can you
sustain without oxygen? Most people cando very little for more than a couple ofminutes. It is very important to realize
that most people cannot work for verylong at even 90% of their maximalaerobic capacity. This is becauseeveryone has a threshold at which thebalance between aerobic and anaerobicenergy systems begins to favor theanaerobic; your muscles cannot extractenough oxygen to produce the requiredenergy. This is called your anaerobicthreshold; the turning point can bemonitored by the accumulation of lactatein your blood. Of course, your body willknow when there is too much lactate,because once lactate goes above acertain value, it starts to accumulate andunless you decrease your work rate, youwill become too tired to continueworking.
This anaerobic threshold, or “break
point” varies among individuals, butranges between 60% and 100% of yourVO2max; all SEALs should be able towork at 70% of their VO2max for anextended period, and should have abreak point above 70%. Conditioningprograms for SEALs should strive toraise the anaerobic threshold or breakpoint to as high as possible, because thatmeans you can work at a higher rate fora longer period of time.
Interval workouts stress theanaerobic energy systems andwill increase your anaerobic
threshold and power.
Interval and fartlek workouts forrunning and swimming are described intheir respective chapters, and suchworkouts for other forms of exercise aredescribed later in this chapter.
Determination of Work Rate
One common denominator across alltypes of cardiorespiratory conditioningprograms is exercise intensity and workrate. The term exercise intensitytypically refers to how hard you areworking as a percent of your maximalaerobic capacity. For example, youcould work at an intensity equivalent to50% (easy), 70% (moderate), or 90%(strenuous) of your maximal aerobiccapacity or maximal heart rate. You willlearn how to estimate your maximalaerobic capacity below, but on average,a maximal capacity of 45 to 55 ml ofoxygen/kg/min and a maximal heart rateof 200 beats per min would be typical
for a 20 to 29 year old SEAL. Table 3-1presents the relation between exerciseintensity, oxygen uptake, and heart ratefor a 20 year old SEAL with a maximalheart rate of 200 and a maximal oxygenuptake of 55 ml of oxygen/kg/min. Easyexercise would use 25 to 30 ml ofoxygen/kg/min or a heart rate of about130 bpm, whereas strenuous exercisewould require a heart rate of around 180bpm. However, you must know yourmaximal capacity or your maximal heartrate to actually quantify your exerciseintensity in this way.
Table 3-1. Example of the RelationBetween Exercise Intensity, AerobicCapacity and Heart Rate
Factors Affecting the TrainingResponse
The terms duration, frequency andintensity are commonly used whentalking about training for fitness orhealth. All training programs, whetherrunning, biking, swimming, or climbing,strive to vary in duration, frequency, andintensity so as to optimize conditioningand minimize injuries. Five majorfactors determine the extent of yourmaximal aerobic capacity and themagnitude of your response to training.These include:
• Initial level of aerobic fitness• Duration of exercise
• Frequency of exercise• Intensity of exercise• Genetics/heredity
General principles apply to all typesof physical activities. Take the followinggeneral principles and apply them toyour individual program.
♦ The degree of aerobic training isclosely tied to intensity and totalwork, not to frequency oftraining. However, a minimum of3 days per week isrecommended.
♦ A greater training improvement(up to a point) will be noted ifyou exercise above 85% of
VO2max or 90% of your maximalheart rate once a week or everyother week: interval training.
♦ Aerobic capacity will improve ifexercise increases your heartrate to at least 70% of yourmaximum heart rate.
♦ A lower exercise intensity can beoffset by exercise of longerduration.
♦ Maximal heart rate for swimmingand other upper body exercise islower than maximal heart rate forleg or whole body exercise.Thus, training heart rate (THR)can be 13 to 15 bpm lower forswimming/upper body exercisethan when running, biking, or
other whole body exercises.♦ A threshold duration per workout
has not been identified tomaximize aerobic capacity.
Active Recovery
Throughout this guide, we willcontinually stress the importance ofwarming up, cooling down, andstretching. These are integral parts ofany workout, regardless of the activity.The cool down, or recovery period, isvery important because it will determinehow you feel several hours after yourworkout. There are two types ofrecovery: active and passive. Passiverecovery, in other words, just resting,was recommended many years ago, andis still recommended when you exercisebelow 50% of maximal capacity. Activerecovery is now preferred for exerciseexceeding 60% of maximal capacity to
accelerate removal of lactate. This mayhelp prevent muscle cramps, stiffness,and preserve performance duringsubsequent strenuous exercise.
Active recovery involvesexercising at 30% to 50% ofmaximal capacity for 5 to 10
minutes after a strenuousworkout.
Blood lactate removal afterstrenuous exercise is acceleratedby active recovery: mild aerobic
exercise.
How to Estimate YourMaximal Aerobic Capacity
Exercise testing is often conducted forassessment of cardiorespiratory fitness.Types of protocols currently used toassess cardiorespiratory fitness oraerobic capacity are incremental workrate tests, where the exercise work rateis increased by a uniform amount atpredetermined time intervals, andconstant work rate tests, where thesubject works at a submaximal constantwork rate for a specified time period.Your heart rate at the specific work ratesare used to estimate maximal oxygenuptake. Although the most accurate test
is conducted on a treadmill, a bicyclewill give a good estimate. If you haveaccess to a stationary bicycle, you cantest yourself by using the incremental testprotocol described. Although it is best touse a heart rate monitor, you canmanually take your pulse at varioustimes during the test.
Bicycle Exercise Test Instructions
This test is an incrementalsubmaximal test with four stages; eachstage lasts two minutes. If desired, youcan continue to increase the work rateand exercise for five to six stages. If youuse a bike that monitors revolutions permin (RPM), your RPM must bemaintained at 60. This seems like a slowpace, since you would usually bike at 70RPM, but in order to achieve the desiredwork rate, 60 RPM pace is critical.Whatever type of bike you use, you mustcheck to determine how to regulatekcal/hr.
Test Procedures
Adjust height of seat and handle barsto fit you, then if available, hook up aheart rate monitor and then start pedalingat a comfortable workload (See Table 3-2). If the bicycle permits, key in yourbody weight. This will make the testmore accurate. After a couple minutes ofwarm-up, begin to exercise at level 1 oraround 450 kcal/hr (± 25 kcal/min);record heart rate after two minutes (endof stage one). Increase the workload tolevel 2 or approximately 550 kcal/hr andcontinue for two more minutes.Remember that all stages are 2 minutes,so proceed to levels 3 (650 kcal/hr) and4 (750 kcal/hr) at the appropriate time.
The test should take no longer than 8minutes, after warming-up. Record yourheart rate at the end of each stage (Table3-3).
DO NOT STOP Pedaling WhileRecording Your Heart Rate.
Table 3-2. Stages and Work Rates forCycle Ergometer Exercise Testing
Table 3-3. Cycle Ergometer Test Form
Estimating Maximal Aerobic Capacity
Look at the example in Figure. Heartrate has been plotted against each energyexpenditure. Estimate your maximalheart rate as 220 - YOUR AGE. Plotyour heart rate values at each kcal/hr anddraw the line of best fit through yourpoints as in Figure (This should be afairly straight line). Extend the line soyou can also plot your estimatedmaximal heart rate on the line. Estimateyour maximal aerobic capacity (inL/min), and then normalize for bodyweight: divide your VO2max by yourweight in kg. For example if yourmaximal oxygen uptake was 4.2 L ofoxygen/min (4,200 ml) as in the
examples below, and you weigh 85 kg,your normalized maximal oxygen uptakewould be 4.2 L or 4,200 ml/85 = 49ml/kg/min. To convert your weight in lbto kg divide by 2.205. Normalizing forbody weight allows you to determinehow you rate relative to other persons ofyour age (Consult Table 3-4).
Table 3-4. Cardiorespiratory FitnessClassification: Maximal OxygenUptake (ml/kg/min)
Example of How to Estimate MaximalOxygen Uptake for an 85 kg, 24 year oldSEAL
Figure 3-1. Plot Your Heart Rate toEstimate Maximal Oxygen Uptake
Types of Aerobic Activitiesand Basic Workouts
Outdoor Activities
Aerobic activities, other than runningand swimming, are briefly describedbelow. More extensive discussions areprovided in the section on indooractivities, since equipment used indoorstypically has information about workrate and intensity. However, Table 3-5presents the amount of energy expendedper hour (kcal/hr) in these activities as afunction of work rate. The values are fora 70 kg male. To get a more accurateestimate for yourself, multiple thenumber by your weight in kg and divideby 70.
Table 3-5. Typical EnergyRequirements for Various OutdoorActivities
Bicycling
Bicycle riding, or biking, is an
excellent activity for improving overallcardiorespiratory fitness. Importantly,indoor bicycle ergometers have beenused for many years to study theresponses of the body to exercise. Thework rate you maintain while bikingvaries according to the terrain and yourmotivation. As such, biking outsideoffers many challenges. It is also a veryefficient means of locomotion: theenergy cost of biking is only 20% ofwalking, but you can travel almost fivetimes faster on a bicycle. Thequadriceps muscle in the front part of thethigh is the primary muscle for high ratesof power output, and seat height canmarkedly affect overall muscleinvolvement. Although pedaling rates
vary from 40 to 100 RPM, a rate of 70appears to be the most comfortable.
A high pedaling rate offersadvantages in terms of a high
power output.
All in all, biking is a great alternativeto running, and should be considered asa suitable activity for maintainingfitness, even if it is not part of a SEAL’smission. Biking complements otheractivities and is often used inrehabilitation from othermusculoskeletal injuries. More detailswith respect to biking will be providedunder the section on stationary cycles.
Cross-Country Skiing
Although cross country skiing isdiscussed in detail under winter warfarebelow, it should be noted that this is anexcellent method of training forcardiorespiratory fitness. It engagesalmost all of the major muscle groupsand thus, the overall energy expendituremay be as high or higher than whenmoving the body over the same distanceon foot. Importantly, the intensity of theeffort varies greatly as a function of theterrain: climbing uphill requirestremendous effort whereas goingdownhill represents a light load. Highcaliber cross-country skiers have someof the highest maximal oxygen uptakes
ever recorded (see Chapter 2).However, the appropriate equipment andenvironment are necessary for cross-country skiing.
Jumping Rope
Jumping rope is a great way tomaintain fitness on board a ship or inconfined spaces. It can provide a highintensity, cardiorespiratory workout ifdone long enough and fast enough. If thepace is fast, it is equivalent to running interms of energy expenditure.
Jumping rope does not have to be
boring, especially if you use differenttypes of jumps. Table 3-6 provides thenames and an explanation foralternatives to the basic jump.
Table 3-6. Different Types of Jumpsfor Jumping Rope
In terms of gear, many different typesof rope are available, and rope jumpingcan be limited by the quality of the rope.Most experts recommend lightweightleather ropes. Believe it or not, manybooks have been written about jumpingrope, with basic to advanced skills,drills and moves. Overall, jumping ropeis a great activity, especially if you arein a confined environment.
Stationary Exercise Alternatives
Rowing Ergometer
There are many types of rowing
machines on the market, and each hasdistinct advantages and disadvantages.The best rowing machine is one withvariable resistance and the ability toregulate rowing rate. Most providefeedback on either watts or kcalories perhour, as well as meters covered. Propertechnique is critical so as not harm yourlower back. If proper technique ismaintained, cardiorespiratoryconditioning can easily be achieved. Infact, both the upper and lower body areexercised, and it promotes flexibility byemphasizing maximum joint range ofmotion, so it is a total body workout. Itis also impact-free so it is a greatalternative to running! Some key pointsto remember are:
• The motion of the entire strokeshould be fluid.
• A stroke rate between 24 and 30per minute should be the goal.
• Your grip should be loose andcomfortable with wrists level.
• The rule of thumb should be alonger not a harder workout.
Just plain rowing can become a bitboring, but there are many ways to makeit fun and varied. Table 3-7 presentsdescriptions of various workouts for arowing ergometer.
Table 3-7. Various Workouts for aRowing Machine
How do you know if the workout ishard or light? Your body is the bestjudge, but knowing the kcal/hr will alsohelp. A pace of 500 meters/4 minuteswould be a light workout whereas apace of 500/2 minutes would bestrenuous. These paces equate to 385
and 970 kcal/hour for a 70 kg man.
Bicycle Ergometers
Cycle ergometers have been around along time, and are still the mainstay inexercise/fitness testing. Monitors on thebicycles available today typicallydisplay kcal per hour. Table 3-8 presentskcal/hour values for stationary bicycleworkouts at various intensities. Thesevalues can be used to gauge your workrate during indoor biking.
Table 3-8. Energy Expenditure(kcal/hr) for Stationary Cycling atVarious Intensities and Body Weights
Treadmills
Despite the fact that it is much nicer torun outside than inside, the treadmill isan extremely efficient way to maintainand/or improve cardiorespiratoryconditioning. Unlike the cycle androwing ergometer, jogging or running ona treadmill is weight dependent: theenergy expended is determined by yourbody weight. In addition, it is an impact
sport and should not be the only form ofconditioning, so joints are protected andinjuries minimized. However, if you areon a ship or in another type of confinedspace, a treadmill could maintain yourfitness!
What kind of workouts should you do
on a treadmill? Three days per week ismore than enough, if you do other typesof exercise on off days. On a treadmill,you can mix up your pace and/or changethe resistance by changing the incline.The incline and speed will determine theintensity of the workout. Remember, astrenuous workout is over 750 kcal/hr,and a moderate workout would be 450to 600 kcal/hr. Table 3-9 presents
kcal/hr values for treadmill workouts.These values can be used to determinethe speeds and grades for indoorrunning.
Table 3-9. Approximate EnergyRequirements (kcal/ hr) forHorizontal and Uphill Running on aTreadmill
Ski Machines
The simulated skiing machineprovides an excellent mode of exercisefor whole body conditioning. It uses boththe upper and lower body, and offers arange of settings so your workout can belight, moderate, vigorous or exhausting.Maintaining a comfortable rhythm ismost important during a moderateworkout, and is essential for progressingto a strenuous workout. Importantly,unlike running outside or on a treadmill,minimal stress is placed on the joints.Most models have various settings formodulating leg resistance, and typicallythe resistance ranges from four to 32 lbs.Once you have determined your desiredresistance the intensity of your workoutwill be determined by your average
speed. Numerous tables are availablewhich allow you to determine thenumber of calories expended per minuteat various resistance settings and speeds.However, they are far too detailed toinclude here. Table 3-10 presents thekcal/hr expenditures for various settingsand speeds for a 70 kg (155 lb) man.These values can be used as to estimateyour actual work rate.
Table 3-10. Energy Expenditure(kcal/hr) on a Ski Machine at VariousSettings and Speeds
Some indoor skiing machines alsohave multiple settings for arm resistance,and adjustments to these settings shouldbe made to ensure a moderate tovigorous workout. However, kcal/hrexpenditure for arm settings becomesquite complicated and will not bepresented here. All in all, ski machinesprovide great exercise, and would be
extremely beneficial for SEALsinvolved in winter warfare training.
Stair Steppers
Stair steppers provide an excellentalternative to running, biking, and otherforms of aerobic exercise. Althoughstairstepping is a weight-bearingexercise, the impact is much less thanwith running. However, to get the fulleffect, instructions must be followed.Most people hang on to the handles andthis diminishes the conditioning effect.An equally good workout could begained by actually climbing real stairs
for the same period of time; many peopleclimb stairs without holding the handles,and thus carry their full weight up thesteps. By hanging on, you allow yourarms to support a portion of your bodyweight and the energy demands are less.
Most stair steppers have a variety of
computerized, pre-designed programs tomeet the needs of devoted users. Thereare interval training programs, climbingprograms, manual programs, and manyother creative exercise programs to varythe intensity of the exercise. Althougheach manufacturer has its own energycost equations, the way to determinework intensity is to determine thenumber of steps per minute; one step is
typically 8 inches of vertical climb. Alow intensity exercise would be a steprate of less than 35 steps/minute,whereas a high intensity workout wouldrequire a step rate in excess of 95. Thisis not an easy exercise routine. Table 3-11 presents the approximate energyexpenditure in kcal/hr for a 155 lb SEALat various stepping rates.
Table 3-11. Energy Expended(kcal/hr) during Stair Stepping atVarious Step Rates
Climbers
Workouts on a climber will buildupper body strength and provideexcellent cardiovascular conditioning.Different types of climbers areavailable, and each has specificcharacteristics. Regardless of whichvariety is used, climbers have commonfeatures: weight dependent exercise thatconditions primarily the upper body.
Energy expenditure on a climber
depends on your speed of climbing andyour body weight. Some authoritieswould say that climbing results in agreater energy expenditure than most
other activities, but this depends on yourstrength and how hard you work. Table3-12 provides kcal/hr at selectedweights and ascent rates.
Table 3-12. Energy Expended(kcal/hr) on a Climber at DesignatedWeights and Feet per Minute
Basic Workouts
The most important issue with respectto workouts is recovery. Rest is anexceedingly important factor in recoveryfrom strenuous workouts, so back-to-back high intensity workouts are notencouraged. Experts recommend a hardday followed by an easy day, and at leastone day of rest over a seven day period.This can be an excellent plan, but youshould also let your body be your guide.Some days when you go to workout andfeel great, this day can and should be ahard workout day. On other days when itis an effort to even get your workoutclothes on, this should either be a restday or an easy day.
Easy days could be a run, bike, or
swim at a very comfortable pace for 60minutes or more, an easy short workout,or a short hump with a light load. A hardday may be intervals, fartleks, a fastpace for a specified period of time, along hump with a heavy load, or acompetition among team members. Thekey is to make it fun, challenging, andinteresting.
Other Terms for Work Rate
Other terms are frequently used todescribe exercise intensity and workrate. These include:
• Work• Power• METS• Watts
If these terms and concepts arelearned, they will apply to almost allexercise equipment and conditioningprograms. The terms work and powerare often used incorrectly. Because theseterms can be expressed in a variety ofways, it is useful to understand or at
least be familiar with the basic units ofmeasurement.
Work and Power
Work = Force x Distance and ismeasured in kcal
Power = Rate of Doing Work and is
measured in watts
METs and Watts
The term MET, which was used in thenational recommendations for exercise,is often used to estimate energyexpenditure and work rate.
A MET is defined as a multiple ofresting metabolic rate or energy
expenditure.
One MET is between 0.200 to 0.250liters (of oxygen)/min, or approximatelyone kcal/min, depending on the weightand body type of the person. Two METSwould be two times resting metabolicrate or approximately 0.5 liters (2 X0.200 to 0.250) of oxygen/min, or 2
kcal/min. Likewise, 3 METS would be0.75 liters (3 X 0.200 to 0.250) ofoxygen/min, or around 3 kcal/min.
Watts, as stated above, are units usedto quantify the rate of doing work, orwork/time. Most new exerciseequipment express work rate in terms ofwatts, although many use METS insteadof or as well as watts. Table 3-13presents the relationship betweenvarious terms denoting exerciseintensity. These can be used to monitorexercise intensity.
Table 3-13. Workload ConversionSheet
Summary
No doubt new modes of exercise willbe appearing in the future. What youchose to use will depend on manyfactors. The important issue is whetheryou are able to achieve the desired workrate and conditioning level. A recentstudy of indoor exercise machinesexamined energy expenditure at givenratings of perceived exertion. Theycompared a treadmill, a rowingergometer, a combination cycle/armergometer, a cycle ergometer, astairstepper and a cross-country skiingsimulator. Surprisingly they found thatrates of energy expenditure varied by asmuch as 261 kcal/hour for the exercise
machines when subjects exercised atself-selected work rates correspondingto fairly light, somewhat hard, and hard.The treadmill came out with the greatestenergy expenditures, followed by therowing and stairstepping ergometers; thecycle and combination cycle/armergometers came out with the lowestvalues. If exercise intensity isestablished by perceived effort,treadmill running/walking will result ingreater energy expenditure and astronger cardiorespiratory trainingstimulus for a given duration of exerciseas compared to other modalities.
Chapter 4
Running for Fitness
Running is a fundamental part ofyour physical training program andprovides an excellent aerobic workout.Moreover, it is not expensive; most ofthe cost of running involves buying apair of “good” running shoes. If you trainintelligently and have the right gear, youcan continue to enjoy the fitness andgeneral sense of well-being thataccompanies running while avoidingrunning injuries. In this chapter, basic
information is provided for maintaininga sound, middle distance running (20 to40 miles/week) program; this isadequate for running 10K and halfmarathon races. Some of you mayconsider running a marathon in thefuture; at such a time you may want to gettraining tips from experiencedmarathoners, trainers at a running club orrunning magazines.
Running Gear
Running Shoes
A good pair of running shoes willprovide shock absorption, cushioning,motion control and durability, andultimately help prevent injuries. Underno circumstance should you buy shoes ifthey do not fit correctly. Runningmagazines usually have a yearly reviewof various running shoes, newest modelsof shoes and the type of runner the shoesare most suited to. You can also obtaincurrent information from “RunningSites/Pages” on the worldwide web. Itis wise to try on several different shoesat a sporting goods store to determinewhich one might be best for you. This isalso important if you are planning to buy
shoes from a catalog.
Pronation
It is important to understand this termbecause the type of running shoe you buydepends on whether you are a normal,over-, or under-pronator. While running,the outside of the heel strikes the groundfirst. Next, the foot rotates inward anddownwards: this process is calledpronation. Everyone pronates to somedegree and pronation helps the footabsorb the shock of impact. However,some runners over-pronate: their feetroll too far inward. Put your running
shoes together and look at theirheels/backs; if they lean inward, you areprobably over-pronating. Another wayto check pronation is to have a friend runbehind you and have them watch theback of your heel as it makes contactwith the ground: the greater the inwardroll of your heel, the more you pronate.
Excessive pronation can lead toinjuries of the lower leg and
knee.
Other runners under-pronate or theirfeet do not have enough inward roll afterstriking the surface. Such individuals areconsidered to have “rigid” feet or feetthat absorb shock poorly. Shoes are
available to correct for either under orover-pronation.
Shoe Terminology
When buying running shoes, it ishelpful to be familiar with somecommon terms. Figure 4-1 presents thevarious parts of a running shoe.
Figure 4-1. Parts of a Running Shoe
Some General Terms
Outsole is the material on thebottom of the shoe that comes indirect contract with the runningsurface.
Midsole is the layer of cushioning
that is placed between the upperand outsoles.
Lateral is the outer-edge of theshoe.
Medial is the inner or arch side ofthe shoe.
Upper is the part of the sole thatis above the midsole.
Achilles notch is the U or V-shaped cut at the top of the heelcollar which prevents irritationof the achilles tendon.
Heel counter is a firm cupusually made of plastic that isencased in the upper andsurrounds the heel to controlexcessive rear foot motion.
External heel counter is a rigid
plastic collar that wraps aroundthe heel of the shoe to providesupport and control excesspronation.
Motion control designs ordevices control the inwardrolling or pronation of the foot.Some amount of pronation isnormal: corrective measures arenecessary only if there isexcessive rolling or under-pronation.
Terms Related to Cushioning
Cushioning is provided bymidsoles and is needed for shockabsorption.
♦Cantilever is a concave outsoledesign in which the outer edgesflare out during foot strike toprovide better shock absorption.
♦EVA is a foam-like materialwhich is used in midsoles toprovide cushioning.
Polyurethane (PU) is a syntheticrubber that is used with EVA inmidsoles. It is more durable thanEVA but provides lesscushioning. PU is used in the rearfoot for firmness and EVA in theforefoot for flexibility andlightness in many shoe models.
Metatarsal pad is a soft wedgeof EVA that is placed under theball of the foot to increase
cushioning and shock absorptionfor runners who are forefootstrikers.
Terms Related to Shape
♦ Last is a foot shaped piece ofwood, plastic or metal which isused as a frame for building ashoe. Lasts can be straight orcurved as shown in Figure 4-2.
♦ Straight-lasted shoes arerelatively straight shaped on theinner or medial side and providesupport and stability and arerecommended for runners whoover-pronate.
♦ Curve-lasted shoes are shaped
to curve inwards (see figure).This shape allows greater footmotion and such shoes can beworn by runners with normalpronation and arches.
Figure 4-2. Types of Lasts Used forRunning Shoes
Terms Related to ShoeConstruction
Board lasting increases stabilityand is good for orthotics. Aboard-lasted shoe is made bygluing the upper to fiber boardbefore it is attached to the
midsole.Slip lasting is the most flexibleshoe construction wherein theshoe upper is stitched togetherlike a moccasin before it is gluedto the midsole.
Combination lasting as the termsuggests is partly board andpartly slip lasting. Such shoesare board lasted in the rear footfor stability and slip lasted in theforefoot for greater flexibility. Ifyou removed the sockliner youwould see stitching in front and afiber-board in the rear foot.
Figure 4-3. Shoe Construction:
Lasting
Pointers for Buying RunningShoes
Maximum emphasis on shock-absorbing characteristics.
Know your foot type.
Look for shoes that come inwidths.
Do you have normal arches, higharches or are you flat footed? You canassess your foot type by what is knownas the “wet test”: simply wet your feetand briefly stand on a piece of paper oron a dark, bare floor; look at the imprintleft by your feet. Compare them to theimpressions shown in Figure 4-4 todetermine your foot type.
Figure 4-4. Types of Arches
If you have high arches you will needa shoe with more cushioning for shockabsorption whereas if you are flat footedyou will need a shoe with more supportand heel control (see Table 4-1).
Know whether you over-or under-
pronate.If you over-pronate you need shoes
that provide stability, whereas, if youunder-pronate you need shoes thatprovide shock absorption andcushioning.
Know if you are prone to running
injuries.See a sports medicine doctor if you
are predisposed to training/overuseinjuries to determine if your injuries arerelated to biomechanics. Biomechanicalconditions, such as being an over-orunder-pronator, or having one leg shorterthan the other, often result in runninginjuries. In some cases, you may benefitfrom using orthotics (see section onorthotics) in your running shoes. Also,take your running shoes with you when
you go to see your doctor.
Try on shoes towards the end ofthe day.
Feet are smallest first thing in themorning and swell slightly as the dayprogresses. Also, wear running or sportssocks while trying on shoes since theyare generally thicker than regular socks.Walk around the store in the shoes tocheck the fit, cushioning and stability ofthe shoe. If you use orthotics, lifts orother inserts, bring them with you whenyou try on shoes.
Do not buy shoes based on their
brand name.
Buy shoes that suit yourbiomechanical needs and work for yourfoot type, not shoes that a friend highlyrecommended or shoes you have seen a“good” runner wear. Consider going to aspecialty shoe store where aknowledgeable salesperson can evaluateyour running style and biomechanicalneeds, and recommend a shoe.
Replace worn out shoes in a timely
manner.Wearing worn out shoes can
eventually lead to injuries and causeknee or hip pain. It is a good idea toreplace running shoes every 400 to 500miles, or sooner if your shoes weardown quickly. One way to keep track of
your running mileage is to establish arunning log. A running log will not onlyhelp in keeping track of your runningdistance, but it will also help in trackingfactors such as sudden increases inmileage or the onset of injury.
Table 4-1. The Right Shoe for YourFoot Type
Orthotics
Individuals with biomechanical
conditions that result in pain and injurymay benefit from using orthotics in theirrunning shoes. Orthotics are shoe insertsthat are customized to an individual’sbiomechanics and foot type to providegood foot support and motion control.First, a plaster mold of the foot is madeand then inserts are developed to correctthe biomechanical problem(s). Theseinserts are usually made of cork solescovered by flexible leather or hardplastic. Orthotics should be graduallybroken in; first wear them while walkingand then progress to running. If notproperly fitted, orthotics may worsen theproblem. A podiatrist or sports medicinespecialist is required to have themcustom-made.
Sometimes low cost, over-the-counter, commercial orthotic inserts canwork as well as customized inserts. Forexample, if the amount of pronation isnot too much, over-the-counter insertsmay correct the problem. Commercialinserts are sold by shoe size. If you findthat the pain lessens, but does not goaway or that the pain returns when youincrease your mileage, you may needcustom-made orthotics.
Cleats for Cold WeatherRunning
By putting on rubber cleats over a
pair of running shoes you will be able torun outdoors under icy conditions.Personnel in the Arctic Warrior Brigadein Alaska use cleats when training infrigid weather. To obtain informationabout ordering these cleats, call Ft.Wainright (DSN 317-353-6048).
Clothes
Unlike many sports, running is notseasonal and with the right clothes, it ispossible to continue to train outdoors onvery hot or very cold days (see Chapter11: Special Considerations for Trainingto review training under adverseenvironmental conditions). Whenweather conditions are extreme, as in icestorms, blizzards or a major heat wave,outdoor training can be substituted withrunning on a treadmill in the gym. Thus,running clothes can range from a simplepair of running shorts and a singlet torunning tights and gortex jackets,depending on environmentaltemperatures. Cold weather running
requires dressing in layers. Always keepyour head and extremities warm in coldweather. Experience will teach you whatto wear when running in the cold. If youwear too much, you may get hot afterwarming up, i.e., within the first mile orso.
Running socks tend to cost a bit more,
but they are thicker and provide morecushioning than average sports socks. Inmost cases, sports socks arerecommended as they provide adequatecushioning.
Other Gear Items
Heart Rate Monitors
You may have seen these advertised inrunning and fitness magazines. Someathletes use these for monitoring theirtraining intensities. Such monitorsconsist of a wrist watch and a cheststrap: the chest strap has an electrodewhich picks up your heart beat andtransmits it to the watch which in turndisplays your heart rate in beats perminute. If you know your target trainingzone (see Chapter 1) you can check andmaintain your heart rate within that zone.
Heart rate monitors are not a trainingnecessity and can be expensive.
Reflectors
Putting reflectors on your shoes andrunning clothes is a great idea if youroutinely run late in the evening, at night,or very early in the morning whenvisibility is particularly poor. This isespecially important in urban areaswhere motorists may not be payingparticular attention to runners. Note thatyou should also run against the traffic.
Fluid Containers that Straponto Belts
As you already know, it is veryimportant to maintain fluid balance andprevent dehydration. Thus, if your longruns include running for more than 90minutes, especially in hot weather, it isadvisable to strap on a fluid containerand drink fluid (8 oz.) at 30 minuteintervals (refer to The Navy SEALNutrition Guide). If your running routeprovides access to water fountains thenyou need not carry your own fluidsupply.
Portable Radio/CassettePlayer/Walkman
Running with headphones can reallyhelp during long runs. However, it is notadvisable to wear headphones and runon city streets as it may reduce yourawareness of your surroundings.Running with headphones on base maybe prohibited.
Running Surfaces
The ideal running surface is flat, firm,smooth and provides some shockabsorption. Surfaces in the order of mostto least desirable are listed in Table 4-2.
Table 4-2. Running Surfaces: FromBest to Worst
Source: Running Injury-Free by JoeEllis with Joe Henderson, Rodale Press,1994
Other running surfaces includetreadmills and water. Treadmills arevery popular at fitness centers and mayalso be available to you when deployed
aboard a ship. Most treadmills are stateof the art in terms of cushioning and youcan control the speed and intensity ofyour work out. Perhaps the biggestproblem when working out on atreadmill is the boredom that is oftenassociated with the monotony of theunchanging environment and theconsistent pace. A portable cassetteplayer or radio may be helpful,particularly during longer runs.
Deep water or aqua running is mainlyused for rehabilitating injured athletes asit takes the pressure off of injuredmuscles and joints while providingcardiovascular benefits similar to thoseobtained with running on surface. Thistype of running is becoming popular at
various swim centers.
Warm-Up
A warm-up to lengthen short, tightmuscles before running is crucial forpreventing injuries that may result ifmuscles are “cold”. A longer muscle isless likely to get injured than a short,tight muscle because it can exert moreforce with less effort than a shortmuscle. Another benefit of warming upis that it protects tendons. Warm up byslow jogging or walking for five to 10minutes before you run. After you warmup you need to stretch yourhamstrings, quadriceps, hip flexors,groin, calves, achilles, and the iliotibialband. Exercises to accomplish these
stretches are provided in the chapters on“Flexibility” and “Calisthenics” and areincluded in your recommended PT(Chapter 15).
Cool-Down and Stretching
After completing your run, walk for afew minutes to cool-down. It is not agood idea to sprint at the end of your runand then come to a complete stop; thispractice may result in an injury. Coolingdown helps to shift the blood flow fromthe muscles to the heart and other vitalorgans. A cool down lets your heart rateslow down and your body graduallyreturn to its pre-exercise physiologicalstate. Cooling down properly andstretching (see Chapter 7: Flexibility)after your run will go a long waytowards preventing injuries.
Running Gait or Form
Different runners may have differentrunning styles. Running is a function offootstrike, forward stride, body angle,and arm drive. The key is:
Run naturally and remainrelaxed.
Footstrike
For most runners, other than sprintersor very fast runners, the heel-ballfootstrike method works well: (1) theoutside of the heel strikes the surface;(2) the foot rolls inwards to the ball ofthe foot while the knee is slightly bent;and (3) the foot lifts off from propulsionprovided by the big toe. This methodprovides good shock absorption.
Forward Stride
The point of foot contact should occurin line with the knee which should beslightly flexed. As you improve and getfaster, the length and frequency of yourstrides will increase and you will beginlifting your knees higher. Do notoverstride such that your foot hits theground ahead of the knee flex (i.e. legshould not be straight at point of impact).Overstriding is hard on the knees, backand the hips and can cause injuries.Short, choppy strides, which usuallyresult from tight or inflexible muscles,require more energy and are inefficient.Run with a relaxed stride and do notexaggerate the knee-lift or back kick.
Body Angle
Keep your back as straight asnaturally possible, your head up andlook ahead. Of course, depending on theterrain you may have to look down toavoid tripping or landing in a hole or rut.Lean forward only when going uphill orsprinting as this motion will put stresson leg muscles and may cause back painand shin splints. Leaning back is notrecommended as this puts tremendouspressure on the back and legs and has a“braking effect”. The key is to run “tall”and remain relaxed; allow yourshoulders to hang in a relaxed mannerand let your arms drop from time to time.
Arm Drive
While running relax your shoulders,elbows, wrists and fists andoccasionally let your arms hang down atyour sides and loosely shake them out.Whereas vigorous pumping of the armshelps sprinters, it is unnecessary duringdistance running.
Building Your Mileage
Increasing mileage too quickly cancause training injuries. Your runningmileage should be gradually increasedand not by more than 10% to 20% fromone week to the next. For example, ifyou can comfortably run four miles,increase your distance by a mile andmaintain this new mileage for at leastone to two weeks or until this distance isconsistently easy for you. Also,remember consistency is more importantthan speed.
A good rule of thumb: increaseyour mileage by no more than
20% a week.
When you can continuously run for 40minutes, begin thinking about yourrunning mileage or distance. Most ofyou, unless coming back from an injuryor returning from a deployment, arealready running 30 to 40 minutes as partof your fitness routine. However, if youhave been unable to run for some timedue to reasons mentioned above or otherreasons, start out slowly; this willprevent you from getting injured andbenefit you in the long run.
Running Frequency
Run at least three to four times perweek or every other day. It is a goodidea to build in one or two rest days inyour weekly running schedule. Theserest days do not necessarily mean noexercise, but rather an alternate type ofexercise, such as biking or swimming.This allows your “running muscles” timefor rest and recovery, and helps preventoveruse training injuries.
Running Speed and Intensity
When running for exercise and notcompetition, you should run at an evenpace that allows you to talk comfortably.If you run too fast and get breathless, youmay not be able to go the distance. Also,speed work tends to tighten muscles andmust be properly stretched afterwards.Failure to stretch may lead to an injury.One way to estimate your trainingintensity is to check your heart rate andsee if it falls within your target trainingzone (See Chapter 1). As previouslymentioned, speed is not as important asbeing able to go the distanceconsistently. Figure 4-5 presents tips onhow to increase your running speed.
Figure 4-5. Ways to Increase RunningSpeed
Do not increase speed anddistance simultaneously.
Increasing both at the same time maycause an injury. Hold one constant whileyou gradually increase the other. Afteryou have been running 30 minutescontinuously 3 - 5 times per week, you
can begin increasing your runningdistance. Running 20 to 30 miles perweek is a good training distance for anintermediate runner. If you would like tofurther increase your weekly mileage,remember to increase it by no more than20% per week. Table 4-3 provides anine week program for running up to 40miles per week.
Table 4-3. A Program to Run 40 Milesper Week
The program in Table 4-3 provides abasic template for you. Based on yourown routine, you could modify thisprogram to fit your schedule andrequirements. Another way to vary yourworkout is to have one long slow runand one fast run per week. Remember ifyou feel over tired, cut back yourmileage or take a day off from running.With a running base of 40 miles perweek you can easily run a half marathon.
Training for a Marathon
If you have been running 35 to 40miles per week for 1 to 2 months, youhave a good endurance base for runninga marathon after 3 additional months (12weeks) of training (Table 4-4). To run amarathon, you must complete some longtraining runs in the weeks leading up tothe marathon. The week that you run themarathon, however, should include onlya few short runs. Your goal for your firstmarathon should be to complete it.
Table 4-4. A 12 Week MarathonTraining Program Starting at 40Miles/Week
Other Points to Consider
Make sure you eat enoughcarbohydrates and are wellhydrated before the marathon.Refer to The Navy SEAL
Nutrition Guide for informationabout high carbohydrate dietsand fluid replacement beverages.
Start out slowly and paceyourself.
♦ Walk for a while if you getcramps or feel fatigued.
♦ Consider the environmentaltemperature; if it is a hot andhumid day, it is especiallyimportant to pay attention to yourfluid and electrolyte needs(Refer to Chapter 11 and to TheNavy SEAL Nutrition Guide).
♦ After you finish, stretch and walkaround. Take a hot bath.
♦ Slowly return to running.
Interval Training
Various interval training techniquescan be used for building speed. Ideally,speed work would be done on ameasured track. Sample interval trainingworkouts are provided in Figure 4-6.Two important points are:
♦ Rest periods between reps forintervals to train the anaerobicenergy systems should be equalor slightly less than time to coverdistance (quarter mile: 60seconds; rest: 60 seconds)
♦ Rest periods to train aerobicsystem should be less than one-half time to cover distance (half-
mile: 2:50; rest: 60 seconds)
Figure 4-6. Sample Sprint andDistance Running Interval Workouts
These are not the only intervalworkouts, so you may modify them tosuit your requirements. For example, youcould do pyramids: you would start witha quarter mile, followed by a half mile,3/4 mile, and mile, then go back down inreverse. Between each speed set, it isbest to jog one quarter to one half thedistance to accelerate recovery.
Interval workouts are a greatway to improve performance.
Varying Your Workouts
It is good idea to vary your dailyrunning mileage so you have some“light” days in between heavy training.Avoid running long distances on twoconsecutive days, unless you are trainingfor a marathon, to give your body time torecover. Listen to your body and paceyourself accordingly.
Most importantly, it is good tocross-train.
Consider biking, swimming, stair-climbing or other activities that willprovide a good aerobic workout whilemainly using muscles other than those
used during running. A major benefit ofcross training is that it prevents the onsetof overuse injuries while maintainingfitness. For information about cross-training see Chapter 3:Cardiorespiratory Conditioning. Strengthtraining, especially upper body strengthworkouts, have become an importantpart of a “runner’s” overall workout. Itis recommended that you strength traintwo to three times a week (see Chapter6).
Common Running Injuriesor Problems
Most running injuries are due to “overuse” from running too much, i.e. too fast,too far, or too often. See Chapter 12:Training and Sports Related Injuries formore information about injuries. Thefollowing table shows the incidence ofvarious running injuries that werereported by male runners in a recentsurvey (Adapted from Running Injury-Free By Joe Ellis with Joe Henderson,Rodale Press, 1994).
Table 4-5. Frequency of RunningInjuries Reported by a Sample of
Male Runners
If you train sensibly there is no reasonwhy you should not be able run injury-free. Should you get injured, informationon how to go about seeking treatment fortraining related injuries is provided in
Chapter 12. Keep in mind the threeprinciples of a good running form asshown in Table 4-6.
Table 4-6. Three “Principles” of GoodRunning Form
Resources
Joe Ellis with Joe Henderson,Running Injury-Free, RodalePress, 1994.
Bob Glover and Jack Shepard,The Runner’s Handbook,Penguin Books, 1985.
Chapter 5
Swimming for Fitness
As a SEAL you are required to be aswimmer. Swimming is an excellentexercise for overall fitness; aerobicendurance, power, strength, andflexibility are all enhanced by swimtraining. It is generally gentle on thejoints and provides excellent crosstraining for running and other gravity-intensive forms of exercise by providingload-bearing joint rest. However,training must be specific for the
anticipated operational environment,including cold water acclimatization.This section will give you the tools toimprove your swimming skills, thusenhancing your fitness for combatswimmer missions.
You must primarily train for
endurance while preserving thesignificant power and strength requiredby other phases of SEAL operations.This section includes information oncompetitive swimming strokes and pooltraining, but it is important to emphasizethat most training for SEAL combatswimmer operations should consist ofopen water swims with fins. Open watertraining is essential for SEALs as a part
of a comprehensive training programunder the general principle of“specificity of training”. Surf and highsea state swimming provides specifictraining for potential operationalsituations by increasing your sense oftiming and confidence.
Swim training should focusprimarily on open water swims
with fins.
Swim training is best accomplishedwith others for a variety of safetyreasons. There should always be a guardor buddy available to you, even if youswim in a pool. You certainly should nottrain alone in open water.
Open Water Gear
In the pure sense the only gearrequired is a set of trunks. Look at thegear list for the UDT swimmers atOmaha Beach in 1944. It did not eveninclude fins and masks. However, todaythere are some significant gear issues.Goggles are necessary for any real swimtraining. Operational and open waterswimming requires more gear. There arespecific training aids that help developstrength and technique in pool training.Swimming is still an inexpensive sportwith respect to gear; a complete set ofthe most expensive training gear for pooltraining will not cost over $100.
Wet Suits
Open water swimming may requirethermal protection for safety. Males inparticular may be susceptible tohypothermia and the first symptom in anopen water swimmer may beunconsciousness from cardiacarrhythmia. Thermal protection inswimmers means a wet suit worn overan anti-chafing shirt.
Wet suits designed for open water
swimming are generally of a FarmerJohn design with the arms free forstroking. In all but the coldest water, a1/8” wet suit is best for surfaceswimming. Unlike diving, there is no
need to factor in the loss of insulationdue to compression of the neoprene withdepth. However, this is not true for thecombat swimmer operations that mayentail prolonged periods in the water.
Anti-chafing shirts are generally made
of nylon without elastic properties. Wornunder the wet suit, the nylon shirt allowsarm strokes and head rotation withoutgetting chafing from the wet suit. If youdon’t use anti-chafe shirts, then thiswould not matter.
Hood, Gloves and Booties
♦ Good open water swimminghoods allow the head to beturned with minimal chafing.Thermal protection is not asgood with the neck exposed. Agood hood preserves a great dealof the swimmer’s heat.
♦ Gloves may have webbed fingersto allow sidestroke pulling to bemore efficient. They work greatfor freestyle, too. Neoprene webgloves are popular and work likepaddles.
♦ Thin 1/8” booties without solesmaximize the power deliveredby the swimmer’s legs to the
fins.
Fins and Fin Selection
There are three factors to keep inmind when you are selecting a fin; thespecific design characteristics of the fin,the physical attributes particular to yourbody, and operational constraints. Fins,by increasing the surface area of thefoot, serve to magnify the thrustdelivered by the legs. Kicking with finsinvolves a forward stroke and abackward stroke. Several examples willillustrate how the three factors interactto influence the SEAL’s fin selection.
♦ SDV operations require anoperator to sit with fins on for along period of time. The operator
may require thermal protectionand he may have a flexible ankle.Space is limited, so a shorter finis necessary. For this situation,the operator should select ashort, wide fin with a strap thatcan be adjusted for varyingamounts of thermal wear.
♦ Surface swimming with gear willinvolve a sidestroke flutterkick.In the sidestroke, forward istoward the front of theswimmer’s body and backwardis toward the swimmer’s back.Applied force is typically muchgreater during the forwardstroke, and fins are oftendesigned with this fact in mind.
When power is needed for bothforward and backward kick, likein sidestroke, a straightsymmetrical fin may be moreefficient for you.
♦ Underwater swimming involves aface down position, where theforward stroke is down and thebackward stroke is up towardsthe surface of the water. In thisposition, gravity assists with thedownstroke and produces a lesssymmetrical type of thrust thanseen with sidestroke kick. Youshould select a high-tech divingfin with moderate flexibility andan integral type footbox. The finshould have an offset design to
allow a more efficient transfer ofpropulsion force.
♦ For bodysurfing, use short surffins.
The main principle of fins is toincrease the surface area of the
foot.
Table 5-1. Recommended Fin Types
Figure 5-1. Examples of TraditionalShort and Long Fins (Left) and NewerLong Blade Fins with InnovativeBuckles (Right)
Specific Design Characteristics ofFins:
• Size or surface area of finblade• Stiffness of fin blade• Configuration or shape of fin
blade - length and width
• Integral footbox versus strap-typefin
• “Offset” or angle of pitch betweenfootbox and fin blade
• Buoyancy of fin
Physical Attributes Influencing FinSelection:
• If your ankle range of motionis inherently limited, long fins willassist in transmitting lowerextremity forces to the water.• If your ankles are inherently
flexible, short fins may be moreefficient as well as less stressfulon relaxed ankle joints.
• Your natural kick frequency willalso influence your choice of fin
stiffness and size. Larger sizesand stiffness produces a slowerrate of kicking, while shortflexible fins allow a higher kickrate.
Operational Constraints:• Face down versus sidestroke
position• Surface versus submerged• Space limitations (SDV)• Thermal protection
The fit of the fin is critical.
If the fin is too tight, the finbox maymake your foot cramp up and moresusceptible to cold. If it is too loose,
energy is lost in the slop between footand footbox; slop also translates intofoot chafe! Booties provide grip for thefoot within the footbox and the neopreneacts to even out areas where stress isconcentrated.
Other Fin SelectionConsiderations
Fins vary slightly in buoyancy; abouthalf of sport fin models float and theremainder sink. This may be anoperational consideration. In the April1996 Rodale’s Scuba Diving fin test,fins testing as “outstanding” in the area
of power included the expensiveScubapro Gorilla, Mares/Plana Avanti,Ocean Edge Spectra, and the U.S.Divers Blades. However, so did the IDIFrog Foot and Power Fin models, whichhave been the standard fins in the Teamsfor many years.
The authors of the article reveal
honestly that, “In spite of extensiveresearch and a multiplicity of designsapplied to modern fins, there are stilltried and true fins that perform as wellas many of the top newer models.” Theolder, buckle-style strap fasteners havethe advantage of being reversible andare far less likely to foul in fishing lineor seaweed than fasteners on newer
models, many of which have quick-release buckles. The simple straps onolder models have no plastic to break,are easy and inexpensive to replace, andcan be found in almost any dive store.These fins are also not as slippery ondeck as newer designs.
As a SEAL, you will need to evaluateindividual fin performance carefully.You should not only considercharacteristics of the fin, but know yourown physical attributes and anyparticular operational constraints inmaking your decision.
When buying fins consider:
Size, stiffness, weight,buoyancy, buckles and releases.
Getting the best possible fit; tryon fins with booties or other footgear that you’ll be using with thefins.
Face Masks
A face-mask is required for swimmingas prolonged exposure to salt waterand/or stinging marine organisms maycause eye irritation or injury.
For open water swimming, youshould use your face masks.
Open Water Training
There is no substitute for ocean orlake swimming. Training in open waterwill force you to swim straight anddevelop a cycle of breathing that allowsyou to look forward in order to navigate.This is an essential skill for operationalswimming. Group swims in open waterare an excellent way to maintain fitnessand should be used extensively in SEALtraining programs. Open water trainingwill maximize the training effect of usingfins.
For operational open waterswimming, the sidestroke with a
flutterkick is superior to
freestyle.
In rough open water and underoperational circumstances you may wantto combine a scissor kick with asidestroke pulling technique to maximizeyour navigational ability and watch forbreaking waves. However, sculling is asimportant in the sidestroke as it is infreestyle. Both arms should be used toincorporate sculling motions and tostabilize the swimmer’s trunk while thekick provides the main thrust. There arestroke efficiency issues with thesidestroke just as there are in otherswimming strokes. Stroke coaching isinvaluable in developing goodtechnique.
Water Temperature Issues
Cold water is an issue to beaddressed by SEALs training in openwater. Although the work of swimminggenerates heat, there is heat loss createdby movement of the swimmer into new“unheated” cold water. Thus, open waterswimming may require variouscombinations of passive thermalprotective gear, in particular, wet suits.The three determinants for passivethermal protection are:
♦ Temperature♦ Length of the swim♦ Effort level
It is important to remember that wetsuits operate by allowing the body heatto be transferred to a layer of watercaught between the body and theneoprene material of the suit.Convective heat loss from theswimmer’s body is greatly reduced bythis mechanism and as a result,swimming at a high effort while wearinga wet suit allows the swimmer togenerate and retain heat. Guidelineshave been developed for training and arepresented in this section.
Research has established some known
“bench mark” facts about operating in acold water environment. In very coldwater (below 40° F), the unprotected
swimmer loses heat faster than animmobile person immersed in the samecold water. Heat generation simply doesnot keep up with losses. The immobileperson warms the cold waterimmediately around his body therebylimiting total heat loss. However, inmoderately cold water (around 68° F),an elite class swimmer may stay active,and the heat generated by swimmingkeeps pace with overall losses (althoughthe swimmer may develop cold feet andhands). In this situation, the activeswimmer outperforms the immobileperson with respect to maintenance ofcore body temperature. Currently we donot know the crossover temperaturepoint or the water temperature at which
it is better to remain stationary thanactive in the water for thermal balance.
Passive thermal protection modifies
this balance by reducing the convectivecomponent of heat loss. As a result, aswimmer may extend training durationsbeyond those possible without passivethermal protection. Diving medicinespecialists at BUDS have developedguidelines for use of passive thermalprotection during training in cold waterenvironments. Note that Table 5-2 islimited to high energy swims at a setdistance of 2 miles.
Table 5-2. Distance, Temperature, and
Protection Requirements
Special Open Water Training Issues
It is easy to have chafing from the wetsuit around the arms and also for the finsto chafe. Get thin booties without solesfor fin use and consider using somevaseline or aquaphor ointment for otherchafe points.
If you swim regularly in cold water,
your body will undergo some adaptivechanges. This will increase yourtolerance to some extent. You will alsobegin to actually crave fatty foods, aninstinctual tendency of cold waterswimmers to want extra body fat toprotect them! This is a natural
adaptation, but this may be undesirablefor your running and overall fitness.
Surf training is great for honing your
aquatic skills and for developingconfidence in big water. Forbodysurfing, use a medium fin, like shortsurfing fins, that permits quickacceleration but is small enough not toget caught in moving parts of the wave.Use velcro-elastic “keepers” for yourfins unless you are sponsored by a finmanufacturer!
Keep your head down and alwayssurf with an arm extended up
over your head.
It is far better if you get folded by abig chopping wave to have yourshoulder dislocated than for you tobecome quadriplegic from a cervicalspine injury. Avoid shorebreaks; thewaves are unpredictable and going overthe falls may yield a screaming descentstraight onto the beach sand. Instead tryto find a good “grab and release” breakwhere the wave stands up nicely andthen breaks back into deeper water.
Another open water issue you may be
faced with is that of sharks. Theycommonly attack solitary swimmers,particularly freestylers: the solitary,beefy organism making arm slaps againstthe surface of the water. Avoid
swimming in places where you mayresemble part of the food chain, but eventhen there appears to be protection innumbers. A good example is La JollaCove near San Diego. Here triathletesswim and Great White sharks eat smallmammals all in the same day. Avoidswimming in the evening and get out ofthe ocean if you get bloodied too muchin the surf.
Sharks virtually never attackswimmers in groups.
Swimming Pool Gear
Goggles
The most important gear for pooltraining is a good set of goggles. Getgoggles that can be adjusted across thebridge of the nose. The fog-free goggleswork better than they used to, but they dolose this quality relatively quickly underhard use and are much more expensive.
Kickboard
A kickboard is essential. They comein a wide variety of sizes and shapes,but all do basically the same thing.
Pulibuoy
A cheap, but essential, piece oftraining gear, the pullbuoy fits betweenthe swimmer’s legs for specific types ofswim drills.
Hand Paddles
These are useful to develop the feel ofsculling during freestyle pulling.
Zoomers
A unique and expensive short fin, theZoomer is helpful but not essential. Thisspecial fin is designed to allow theswimmer to use flip turns during pooltraining sessions with minimalinterference with technique. Other shortfins may be substituted, notably theshort, surf fins.
Nose Clips
Many individuals develop low gradenasal reaction to pool water. Use of anose clip will allow a swimmer tocomplete some of the backstroke drillspresented in this chapter much morecomfortably.
Pool Training: BuildingStrength and Endurance
The major reason to use a pool is thequality of training. Swim sessions maybe closely monitored and are safe.Controlled interval workouts used inpool training sessions provide goodfeedback; the pace clock doesn’t lie.Pool sessions allow you to designworkouts that vary in intensity andemphasis, which is not possible in openwater. Pool training and acquisition ofimproved stroke skills are electiveelements of a SEAL’s training program.Pool training will increase your comfortlevel in open water, thus enabling you to
significantly improve your operationalcapabilities.
Swimming is not an intuitiveactivity like running.
Warming Up
Warming-up should consist of at least400 meters of swimming, along withsome kicking and pulling drills.Warming-up is essential for swimming toavoid developing problems of theshoulder joint and upper back.
Target heart rate during warm-upshould be about 60% of maximal.
During your warm-up, work onefficient stroke “stealth” swimming!Warming-up is an appropriate time toinclude stroke drills. This serves thepurpose of providing stroke patterningalong with the warm-up.
Basic Principles of Interval Training
SEALs need to concentrate on swimtraining that will enhance endurance:interval swim training will allow this tohappen. Interval training sets (for bothstrength and endurance) are generallycomprised of repeated swims lasting 45seconds to 4 minutes. Basics of intervaltraining include the following:
• Swim at a slow to moderate pacefor five to ten minutes to warm-up muscles and cardiorespiratorysystem.
• For anaerobic training, setsshould be performed until repeattimes can no longer be held.
There is no magical number ofrepetitions for a set, but thedistance is typically 50 to 100meters, or a time of about 45seconds.
• Swimming at a prescribedintensity pace for as long aspossible is most important. Whendesired pace can no longer besustained, the set should beterminated.
• Work:recovery ratios play animportant part in the type ofadaptation that occurs. A 1:1work:recovery ratio would be toswim 45 seconds and rest 45seconds, whereas a 1:2 ratiowould be to swim 45 seconds
and rest 90 seconds.• To stimulate endurance
adaptations, recovery intervalsbetween repetitions should beless than 30 seconds. Formaximum benefit, it is best tokeep the interval less than 15seconds.
• For anaerobic adaptations tooccur, recovery intervals shouldbe in excess of one minute andup to at least twice the durationof the repetition swim. Theseeffects occur independent of therepetition distance or pace.
• The longer the rest interval,irrespective of the distance beingrepeated, the greater the use of
the anaerobic system. With longrests, it takes considerablylonger for the aerobic energysystem to be reactivated. Shortrest intervals keep the aerobicsystem functioning, particularlyduring initial recovery.
Interval training is the backboneof a swimming workout.
Figure 5-2 illustrates how thedifferent energy systems can be trainedin an interval workout. Swim 1 is a hardeffort, short distance and a lot of rest;this type of effort builds the anaerobic(CP) and transitional (Lactate-CP)energy systems. The second swim
consists of fewer sets at a longerdistance and with shorter rest intervals;this swim would challenge the aerobicsystem.
Figure 5-2. Energy Systems UsedDuring Interval Sets
A swimming pace clock is the bestway to time intervals: a diving
watch works fine.
Interval Sets - Endurance
Freestyle Swim: 10 x 50 m with only 5sec. rest
• Rest 5 seconds between eachswim.• Start with efficient “stealth”
stroke, work into distance racepace. Don’t overkick.
• Try to match your 1000 meterpace with this set.
Freestyle Swim: 50-50-100 m with 5sec. rest
• Swim 2 x 50 meters with 5seconds rest, then swim 100meters: Repeat 3X.
• This set builds into a 100 meterswim where the swimmer tries tomatch the pace set in the 50meters.
• Back off of the 50 meters a littleto save up for the 100 meters.
• If you want, add an extra 15seconds of rest between each 50-50- 100 to keep the quality up.
• A “buildup” set like this will dogreat things for your enduranceand sense of pace.
Freestyle Swim: 10 x 100 m with 10sec. rest
• Rest 10 seconds between each100 meter swim.• Swim smoothly and efficiently.
This is the set where you mayexceed your long, slowswimming 1000 meter time!
Breaststroke Swim: 50-50-100 m - 5sec. rest
♦ Done like the freestyle 50-50-100 set outlined above.♦ Concentrate on keeping effort
level up.
Interval Sets - Strength and Power
Freestyle Swim: 10 x 50 m with 30sec. rest
♦ Begin at a strong pace. Build torace pace with a strong turn andan extra strong finish. Try to bewithin 5 seconds of your race 50meters pace, usually equal toyour race 200 meter pace.♦ At first, try just 5 x 50 meters
with 30 second rest.♦ This is the most power-oriented
freestyle set. It will also allowyou to discover your truemaximal heart rate. If you start todie off at the end, increase yourrest a little to keep your pace.
♦ If you are particularly strong andwant to build more speed, do thisset with zoomers.
Freestyle Swim: 10 x 100 m with 45sec. rest
♦ Same pace approach as the 50meter interval set. This is foradvanced swimmers with arefined stroke. It will build power,but this set should be used nomore than once every two weeks.♦ The rest interval should be 45
seconds for this length of swim;adjust your interval accordingly.
Breaststroke Swim: 10 x 50 m with 30sec. rest
♦ Like backstroke, work on hardswimming with about 30 secondsof rest. Breaststroke is verytaxing when done hard but likebicycling it is easy to throttleback and have the appearancewithout the substance.
Integrated Workouts
For pool training it is necessary tointegrate your sets into a comprehensiveworkout. At first you will want to limityour hard sets, but as your fitnessimproves, hard drills can be extended. Italso worthwhile alternating betweenanaerobic and aerobic workouts. In thisway your performance for combatswimmer operations should beoptimized.
Figure 5-3. Sample Anaerobic andAerobic/ Endurance Swim IntervalWorkouts
Underwater Training
Swimming underwater requiresbreathholding. While this is an activitythat is not endorsed by the divingmanual, it may be something you willneed to do as a SEAL. Given this fact,specific training will enhance yourperformance and extend your operationalcapabilities. The following rules applyto underwater swim training:
♦ DO NOT hyperventilate prior toyour underwater swim.
♦ Use a buddy to observe duringpool drills.
Varying Your Workout
Swimming workouts should be variedbetween easy days and hard days. Forcompetitive speed, it is good to swim atleast four days a week; this will helpkeep stroke efficiency. Swimming daysprovide good relief for tight musclesgenerated by running and weighttraining.
Swimming has some specialized
weight training techniques. The primaryissue is that swimmers have full range ofmotion of their arms during exertion.Muscle contraction is fairly constantover the entire arm motion requiringbalanced power throughout. Weight
training must complement this fact, ormuscle tightness develops that actuallyworks against the swimmer (see Chapter6).
Pulley pulls are excellent weight
training techniques for a swimmer. Theclassic is the lat pull-down stationpresent in virtually all weight rooms andmulti-station machines. A betterarrangement is for weights and pulleysetups to be individualized for eachhand. Pulley pulls are “isotonic” andmimic the constant resistance of water.Weights should be kept on the low side,permitting high speed weightlifting ofbetween 1-1.5 seconds per repetition.Hold slightly at the end of each lift to
prevent banging weights and gettingthrown out of the weight room.
Swimmers use high reps, neverless than 10.
Many dedicated swimmers own anExergenie, which is a truly simple pieceof equipment that permits a realisticworkout in freestyle or backstroke. It isa nylon line rigged up through a littlecylinder that twists the line and providesresistance. This workout is possibleeven within the confines of a cramped688 class (40 - 50 reps) can be donedaily because the motion is so much likeswimming. Thus, it is a portable weightroom for swimmers.
Cross training includes canoeing,rowing, kayaking, and cross
country skiing.
All of these involve repetitive armuse in a pattern that is generallycomplementary to a swimmer’s stroke.These sports will impart strength to theshoulder and chest muscles that willhelp your swimming.
Developing Stroke Skills
Basic stroke mechanics will prohibityou from increasing your respiratory rate(except during backstroke). Because youcan’t pant, you will quickly becomelimited by not getting enough oxygen ornot getting rid of carbon dioxide beforeit starts building up. This is differentthan in running and is the reason for theuniversal use of interval training inswim training programs. Runners oftengo out for long steady runs, but aswimmer who trains this way becomes aslow and inefficient swimmer. Whileoperational SEAL swimming is a long,slow activity, it is best for you toacquire a broad base of swimming
skills. This will increase your efficiencyduring SEAL operational swimming.
This section will discuss three main
swimming strokes; crawl stroke (usuallycalled freestyle or “free”), breaststroke,and sidestroke. These particular strokesare the most useful to you as a SEAL.Most swimmers use a variety of strokesin a workout to provide cross trainingand avoid overuse injuries. Skills mustbe developed over a long period of timein order for the swimmer to becomeproficient. Good stroke mechanics arenot only necessary to develop speed;injury may occur in swimmers from poortechnique. A proper stroke may only bedeveloped by getting feedback from
others. This factor makes a buddy systemor partner coaching an essentialcomponent of your training program.Obtain periodic stroke coaching from aqualified instructor - no matter howgood you are.
General Stroke Principles
Water causes a large amount of dragon the swimmer’s body, thusstreamlining becomes extremelyimportant. The key to swimming fast isreducing drag as much as possible whilemaximizing propulsive forces. Onespecific technique includes rolling fromside to side to clear high resistance partsof the swimmer’s body for arm recovery.Swimming in salt water is faster thanswimming in fresh water because of theincreased buoyancy of the swimmer,reducing resistance. There are manyother subtle ways to reduce water dragin swimming, and learning them is one ofthe benefits of getting coaching from a
qualified instructor or swimming coach.
The Strokes
Freestyle
For beginning freestyle swimmers, apullbuoy will help the swimmerconcentrate on proper arm stroke andadditionally, help keep the hipspositioned high in the water whichminimizes drag. Approximately 90% ofthe work with the freestyle is due to thearm stroke.
The correct arm pull incorporates
several elements of sculling. In overallterms, the arm of the swimmer resembles
a turning propeller. The diagrams inFigure 5-4, Figure 5-5, and Figure 5-6outline the hand motion relative to thewater, and present front, side, below thewater views of the freestyle arm strokeof Mark Spitz, as analyzed by swimmingphysiologist, James Counsilman. Noticethe circular motion of the swimmer’sarm.
Figure 5-4. Comparing the FreeStyleStroke to the Blades Turning on aPropeller
Figure 5-5. The FreeStyle Stroke ofMark Spitz
In Figure 5-5 you can see the “catch”that a championship swimmer developsas he sculls downward at first and thensweeps his hand quickly back toward hisbody.
As shown in Figure 5-6, you can see
how the hand is used to seek out stillwater from below the swimmer. Theswimmer initially sculls outward, thenhe directs his hand inward at the sametime he is “catching” back upwardtoward his body. The freestyle stroke isthen completed with an outward scull.
This view shows best the “S” shape
of a proper pull. Keep in mind that the“S” occurs in both the horizontal andvertical planes - a very complex motionindeed! You can appreciate hownecessary coaching is in developing aproper arm stroke.
Several of the drills are designed to
break this down for you. One armfreestyle allows you to concentrate onthe arm’s motion. Catchup freestyleslows everything down so that you cancoordinate body roll with arm pulls.Using hand paddles will help you feelthe water and the sculling sensation isalso greatly accentuated.
Figure 5-6. Below the Swimmer Viewof Mark Spitz’s FreeStyle Stroke
Using hand paddles will help youdevelop a strong sculling motion.
Other views (Figure 5-7) show howthe arms move during the freestylestroke. From the front, the hand roughlydescribes a loop. Finally, you can seeagain from a side view of Mark Spitzthat there is an aggressive “catch” actionin the arm pull as he sculls back towardhis body.
Figure 5-7. Side and Front Views ofMark Spitz’s FreeStyle Stroke
Breaststroke
The key to breaststroke is the kick.Propulsion is provided by drawing thefeet up towards your body in thedirection of motion, and then sweeping
both feet backward in a circular motion,pushing motionless water backward withthe inside and bottom portions of theswimmer’s feet. Coaching is essential todevelop good technique as the kick isvery subtle.
Pulling is done by a sweeping sculling
motion. A good stroke drill to work onfor a strong sculling motion is to useonly your arms and not your legs, inother words, “pull breaststroke”. Thisdrill develops a feel for the water that isneeded for all three strokes.
Sidestroke
Sidestroke is extremely important foryou to master. SEALs are required toswim in open water under challengingconditions. Arm pulling and kickingshould be coordinated to maximize thrustand conserve energy over a long swim.It is necessary to learn sidestroke usingeither side in order to be able to faceaway from heavy ocean chop andswells. You can’t afford to have afavorite side.
Sidestroke is a “stealth” stroke, unlikefreestyle. SEALs can stay in contact witheach other over a long swim distance.The sculling motions that have beendiagrammed in this chapter for freestyle,also apply to sidestroke. Use a sweepingaction with your hand and visualize that
your upper hand is like a helicopterblade grabbing still water out in front ofyou while your bottom hand grabs waterahead and below you.
The power of fins can be used with
your flutterkick, not broaching on thesurface of the water. Sidestroke isefficient, conserving your energy over along swim. With fins, the majority ofthrust comes from the legs and armstroke is less important.
Swimming Drills
Fin Drills
Kicking with fins is fantastic training.Be careful of using a kickboard too muchwhile training with fins; this may causeback pain. Sidestroke is good but youwill need lane lines and flags to preventcareening off course and acquiring anice scalp laceration. The mainstay ofkicking strokes is still prone flutterkick.
Fin kicking drills are essential to
building leg strength and specifictraining for SEAL combat swimmer
duties. These drills are effective whenimbedded within a pool workout wherethere are swimming sets that accentuatearm and chest muscle training. This isbecause the swimmer’s legs will bewarmed up but relatively fresh andready for a strenuous workout with fins.Use high numbers of repeats in sets, 10-12, with relatively short rest intervals of10-15 seconds. A total set length ofaround 10 minutes is optimal; any longerand the set begins to degrade into a long,slow distance set which is best done inopen water.
Fin Sprints: Sprinting 25 meterswith fins will allow you to feelflaws in your arm strokes. This
drill will consume anextraordinary amount of oxygenand provide a good anaerobicand strength workout for yourlegs. It also feels great to go fast.
Fin Fartlek: Do this set without akickboard. Kick one length withan easy flutter kick, thenflutterkick the next length on yourright side with both hands out ofthe water - effort level high -then back to face down for alength of easy flutter kick, thenback at it over a hard length, thistime on your left side, againhands out of the water. Repeatseveral times. This drill isparticularly effective in a long
pool (45m). Fin Repeats: Do with akickboard. Kick flutterkick hardfor 50m, rest 10 seconds, repeatfor 10 repetitions.
Other Specific FreestyleDrills
One Arm Freestyle: May be donewith or without a pullbuoy.Emphasizes body rolling withoutcorkscrewing. This drill willallow the swimmer toconcentrate on proper pullingtechnique.
Catch-Up Freestyle: Hold arm
out in front while pulling withthe other arm. Recover thepulling arm and then touch handsout in front before initiating thepull with the other arm. Thisdrill will help timing of pull.
Fist Freestyle: Swim with fists.This will make the swimmerconcentrate on forearm sculling.Do this drill without thepullbuoy.
Finger Drag Freestyle: Recoverarm with fingers skimming thewater. This provides theswimmer with feedbackregarding arm and hand positionduring arm recovery.
Common Problems
Swimmers often develophypersensitivities and allergies withpool swimming. The source of theproblem is the inhalation of chlorinatedorganic material (guess where thiscomes from in a public pool). Thesehypersensitivity reactions may includelung conditions that are quite disabling.Prevention is the key. Ways to minimizeyour chances of such problems include:
Wearing goggles. Using a nose clip. Avoiding any situation where youmight breathe a mist or spray thatis generated from pool water.
Chapter 6
Strength Training
Muscular strength and endurancetraining enhance agility, speed, strength,and endurance, all of which are essentialto the SEAL operator. This chapter willhelp to establish an understanding of theprinciples of muscle strength andendurance training and their applicationin the use of weight equipment. Thefocus of strength training should be itsfunctional use for specific missions.Pure strength alone will not improve
mission performance, but conversion ofstrength to muscle endurance should. Themain objective of your strength trainingprogram should be to increase yourapplied strength - an increase in appliedstrength will enhance your performanceon physical tasks required duringmissions. As such, this chapterintroduces concepts and practicalinformation for achieving optimalmuscle strength and endurance for jobperformance and prevention of injuries.
Weight Training Gear andEquipment
Weight training requires minimalpersonal gear. Other than the weightsthemselves, equipment such as a pair ofsupportive shoes, fitted lifting gloves,and standard PT attire is all that isneeded. A weight lifting belt should beused for back protection.
Technology has allowed thedevelopment of exercise equipment thatefficiently adapts to the changing needsof a body in motion. Consider the choiceof free weights, machines, or acombination of both for development ofstrength and balance when starting a
weight training regimen. Table 6-1presents a comparison of free weightsand machines.
Table 6-1. Free Weight and ExerciseMachine Comparison
Strength TrainingGuidelines and Terms
Performing operational tasks requiresall muscles of the upper and lower bodyto be developed in a balanced way.Circuit weight training or Split-routineworkouts are the most common ways tomaintain a musculoskeletal balance.Circuit weight training consists of aprogression from one station to the nextsuch that over the course of the trainingperiod, both the upper and lower bodyare exercised. For split-routine training,different body areas are exercised onalternate days. For example, on Mondayand Thursday, the upper body would be
exercised whereas on Tuesday andFriday the lower body would beexercised. By having a well designedstrength program, you can expect tomaintain a high level of fitness whilereducing your risk of injury and fatigue.
Repetition Maximum or RM
One term routinely used in strengthtraining is that of repetition maximum. Arepetition maximum or RM is themaximum amount of weight you can liftfor a given number of repetitions. Forexample, your 1RM would be theamount of weight you could lift for only1 repetition. Your 5RM would be theamount of weight you could lift for 5repetitions. For example: if a SEAL cando 5 repetitions of an exercise with 50lbs., he has a 5RM of 50 lbs.
Your 1 RM would be the amountof weight you can lift for only 1
repetition
FITT: Frequency, Intensity, Time,Type
In order for the SEAL operator toperform mission-related tasks, strengthtraining is a key aspect that must not beoverlooked. Understanding the conceptsof Frequency, Intensity, Time, and Type(FITT principle) will help youunderstand and maximize your training.
The FREQUENCY of training should
be determined by the amount of time onehas to spend on strength training. AsSEAL operators, your weight trainingtime is limited due to busy schedules, sokeep this in mind when your start a
program. For example, total body circuittraining only needs to be performedtwice a week, along with other trainingmodes for optimal results. If two days oftraining cannot be achieved, one sessionwill be better than none. Split-routinetraining should be performed a minimumof two sessions per muscle groupweekly to ensure total muscular balance,and thus consumes a greater amount oftime than circuit training.
Circuit weight training optimizesthe time available for SEAL
operators.
Training INTENSITY is considered tobe the most critical aspect of strength
and conditioning. Intensity of weighttraining can be referred to as load,which is the amount of weight perrepetition. It is defined as the percentageof the RM that is being used to performan exercise. Various intensities arerecommended for optimal results. Theprogram phase focusing on muscularendurance would involve training at30% to 50% of your 1RM with 20 to 60repetitions per set, whereas the phasefocusing on strength with 20 to 60repetitions per set, whereas the phasefocusing on strength development wouldrequire training at 65% to 90% of your1RM, with 1 to 12 repetitions per set,depending on the week of training (Table6-1). SEAL training should focus on both
strength and muscular endurance, andcycle between 30 and 90% of maximalstrength. This approach will yieldmaximum results and increase yourperformance as a SEAL operator.
The TIME you spend on weight
training might vary depending on theprogram chosen. Generally, 30-60minutes is sufficient, whether a circuit orsplit routine is implemented.
The TYPE of exercise will vary
throughout your strength program andcan include free weights or machines.For platoon evolutions, circuit trainingis more adaptable, while split routines
may be used for individual strengthprograms. Figure 6-1 provides anexample of the FITT principle.
Strength training, along withvarious other mission-related
practices (such as obstaclecourses, swims, runs, jumps, andclimbs) will develop an overall
well-conditioned SEAL operator.
Figure 6-1. Applying the FITTPrinciple to Total Body Circuit WeightTraining
Muscle Balance and ExerciseSelection List
It is extremely important to considermuscle balance when designing yourworkouts. Building strength in thetriceps should be balanced bystrengthening the biceps, andstrengthening the quadriceps should bebalanced by strengthening thehamstrings. Without proper balancing ofopposing muscle groups, you becomevulnerable to injury.
The main goal of a weighttraining regimen is to produce a
gain in overall strength foroperational tasks.
Many exercises can be incorporatedinto your strength training program.Table 6-2 presents a list of exercises byspecific body parts, all of which aredemonstrated in Appendix A. Thistranslates into a complete body workoutfrom the calves to the neck.
Table 6-2. Exercise Selection List byBody Part
Determining Repetition Maximums
The purpose of knowing your RM isto allow you to adjust the exerciseintensity. As a safety measure, it is bestto start out by determining your 5RM. Todo this, you should have not had anystrenuous activity on the day of the test,and you should be properly warmed up.A spotter should always be availablewhen conducting this test. Free weightsare the recommended form of weight forthis test.
• Select a weight you know is lightenough for 10 repetitions.
• Perform 10 - 15 repetitions withthat weight.
• Rest for two minutes.• Increase weight 2% - 10%,
depending on difficulty ofprevious set.
• Perform 6 - 8 repetitions.• Rest for two minutes.• Increase weight 2% - 10%,
depending on difficulty ofprevious set.
• Rest for three minutes.• Perform 5 repetitions - this should
be close to your 5RM.
Perform sets with increasingweights and decreasing
repetitions until a weight that canbe comfortably handled for 5 reps
is reached.
Table 6-3 provides an example ofhow you might determine your 5RM forthe bench press, starting with a weight of110 lbs. Typically, your 5RM is 87% ofyour 1RM, and your 10RM is 75% ofyour 1RM. Thus, if your 5RM is 160,your 1RM would be approximately 184lbs, and your 10 RM would be about138 lbs. After determining your 5RM, itwill be easy to establish your 1RM andloads for workouts (See Figure 6-2).See Table 6-4 for intensity as a percentof maximum strength, repetitions, energysystems, and rest intervals. Remember,the three energy systems are:
• ATP-PC System for speed workactivities, such as sprinting.
• Lactic Acid and ATP-PC Systemfor all-out exercise that continuesbeyond 30 seconds, but lasts lessthan 3 minutes.
• Oxygen system for aerobic energyto support long-term steady stateexercise, such as long distancerunning or swimming.
Multiply your 5RM times 1.15 toestablish your 1 RM.
Figure 6-2. Determining Your 1 RMfrom 5RM
Table 6-3. How to Determine Your5RM for a Bench Press
Table 6-4. Intensity Levels Relative toa 1 RM
Periodization
Periodization of training is atechnique that involves altering trainingvariables (such as the number ofrepetitions per set, the exercisesperformed, training intensity, and theamount of rest between sets) to achievewell-defined gains in muscular strength,endurance, and overall performance. Forexample, if you were working towards aparticular mission or athleticcompetition, you would want to peak atthat moment and not earlier. Yourtraining schedule would be adapted toachieve that goal.
There are several phases toperiodization and weight training ingeneral. The first phase is one ofactivation, or getting the body ready fora new activity. It would typically lastfour weeks. Most of you are alreadyweight training and thus have completedthe true activation phase, but it is okay tostart anew. The second phase is forstrength development, and it would lastabout 4 to 7 weeks, depending on howlong you have been weight training. Thenext phase is the muscular endurancephase, and lasts 8 to 12 weeks,depending on your schedule. Table 6-5presents a one year plan for training,with three seven week periods ofstrength development followed by 12
weeks of conversion to muscularendurance. Note that this schedule canbe modified, and is presented here toemphasize the concept of periodization.
The goal of the muscularendurance phase is to take
strength gains and convert theminto applied strength for
operations.
Table 6-5. An Annual Plan forActivation, Strength Development andMuscular Endurance
Training intensities should be variedweekly, depending on whether you are inthe strength or muscular endurancephase. Table 6-6 and Table 6-7 presentthe percent of maximum (%1RM) andnumber of sets for the strength andmuscular endurance phases,respectively. These templates can serveas guidelines for creating your ownperiodized program. Remember, this
program should be followed two timesper week.
Table 6-6. Strength DevelopmentPhase: 2-Day Circuit Weight Training
Routine
Table 6-7. Muscle Endurance Phase: A2-Day Circuit Weight TrainingRoutine
Although it may seem a bit foreign toyou to see up to 60 reps per set in Table6-7, this is the best way to convert yourstrength gains to applied strength, orfunctional strength. You will be amazedat your muscular endurance and ability
to perform mission-related tasks andother strenuous physical tasks, if youtruly stick with a program such as this
Weight Lifting Techniques
Correct lifting techniques are criticalfor achieving maximum benefits andpreventing injury. Lifting form, speed,and breathing techniques are allimportant for weight training. The liftshould be performed as a controlledmovement with proper form. Do notcompromise your form as it will not helpbut rather increase your chance of injury.The appropriate speed of lifting needs tobe applied to all exercise movements.When performing exercises, such as thebench press, squat, biceps curl, lat pull-down, etc., the weight should be movedat a rate of 1-2 seconds in eachdirection. This will ensure your safety
and optimize strength training.
Controlling the rate of movementaffects the muscle you intend to
strengthen.
Always make use of a spotter if youare using free weights. Refer toAppendix A for form illustrations andinstructions, so you can change yourtechnique if you are not following theproper directions.
Exhale when moving a weightagainst gravity.
Proper breathing techniques must beused during weight training. Exhaleduring positive weight movement
(moving the weight against gravity). Thishelps prevent the valsalva maneuver (anincrease in internal pressure caused byholding your breath during liftingexercises) which can result in damage tothe cardiovascular system. Never holdyour breath while performing anyexercise task.
Types of Workouts
A Circuit Routine Training for the firstweek of the strength development phaseand muscular endurance phase ispresented in Table 6-8 and Table 6-9,respectively. Workouts for the otherweeks can be obtained by reviewingTable 6-6 and Table 6-7. Remember,periodization is the key to improvingoverall muscle strength and endurance.
Table 6-8. Week 1: Circuit TrainingStrength Development Phase
Table 6-9. Week 1: Circuit TrainingMuscle Endurance Phase
Table 6-9. Week 1: Circuit TrainingMuscle Endurance Phase
Warming Up
It is imperative to warm-up prior to astrength training workout. An active anddynamic warm-up will elevate the bodytemperature so that the muscles respondbetter to the training. An increase incirculation to the joints and tissuesallow more elasticity and may decreasethe risk of injury. The warm-up shouldlast long enough to break a sweat thenstretching should be initiated. Thus, themajor component of a warm-up sessionfor weight training is a cardiovascularworkout, or a general warm-up designedto increase your circulation and directblood flow to the muscles for theupcoming workout. This should be low
intensity exercise for 10 to 20 minutes.
• Biking• Stairclimber• Treadmill/Jogging• Jumping Rope• Rowing Ergometer• Jumping Jacks/Calisthenics• One or Two Exercises with Light
Weights
Cooling Down andStretching
Upon the completion of a trainingroutine, cooling down and stretchingshould not be overlooked. The cool-down should be gradual to normalizebody temperature, prevent pooling ofblood in the muscles and returnmetabolic rates to pre-exercise levels. Italso speeds the removal of wasteproducts which tend to increase musclesoreness and prolong recovery.Stretching after weight training maintainsjoint and muscle flexibility whileminimizing muscle spasms and weighttraining injuries. In brief, the
components of a cool down include:
• Low intensity cycling or walking• Complete body stretching• Relaxation
Common Problems
You need to listen to your body and beable to recognize the signs ofproblematic conditions associated withweight training.
• Injuries - Lack of warm-up andimproper lifting techniques (form) can cause muscle damage.
• Overuse Syndrome - occurs whenyou engage in frequent repetitiveexercises to a specific area oruse an improper technique duringan exercise. The knee, elbow,and shoulder are mostsusceptible to these injuries.
• Delayed Onset Muscle Soreness
(DOMS) - potentially severepain experienced 24 to 48 hoursafter the activity.
In order to allow the body to heal, theimproper routine and/or techniques mustbe altered. Proper technique,progression, variation, rest and recoverywill minimize training related injuries.More information can be found in thetraining related injuries chapter.
Conclusions
Strength training with weights is animportant component to the complete PTprogram of the SEAL operator. Trainingwith weights 2-3 times per week canhelp optimize preparations for mission-related tasks. It is important tounderstand that one should focus on theSEAL mission when developing aweight training regimen. A properweight training routine will help preventinjuries and accelerate recovery from aninjury to the musculoskeletal system.Following the principles and examplesin this chapter will help you develop awell balanced lifting routine. Optimalconditioning can be obtained without
injury to the body if weight training isincluded in your overall “PT” program.
Resource
Fred Koch, Strength Training forSports; Applied FuturisticsSM, 1994.
Acknowledgment
The editors thank Mr. Fred Koch forsharing his expertise and experience instrength training. His comments andsuggestions were invaluable to thedevelopment of this chapter.
Chapter 7
Flexibility
Most trainers, exercisephysiologists, and health careprofessionals agree that flexibilitytraining, although often overlooked, is animportant component of a physicalfitness program. Stretching becomeseven more important as athletes and/orSEALs achieve advanced levels ofmuscle strength and endurance. Ifoptimum performance is the goal, thenadherence to a consistent flexibility
program is required.
Flexibility Benefits
Proper use of stretching increasesflexibility and provides the followingbenefits:
Improved performance Reduced potential for injury (i.e.,muscle strain or sprain)
Reduced muscle soreness Decreased risk and severity oflow-back pain
Increased agility Increased blood flow to the joints
Proper physical conditioning isnecessary for successful missionperformance. Flexibility is an integral
part of a conditioning program andenhances performance by extending therange of motion in which one canoptimally perform. SEALs are at highrisk for musculoskeletal injuries. Jointstability and consequent protectionagainst injury are best achieved througha balanced physical conditioningprogram designed to improve bothmuscle strength and flexibility. Strengthand flexibility training should beconsidered interdependent since both areinvolved in the degree and quality ofmovement across a joint.
Muscles that are strengthened should
be stretched, and vice versa. An intensestrength workout can cause microtrauma
to the muscles, and the process ofrecovery can shorten the muscles andconnective tissue. Stretching preventsthis shortening which could contribute tomuscle strains or other overuse injuries(e.g., tendonitis, fasciitis).
Flexibility training, without
concurrent strength training, weakens themuscles and connective tissue andplaces the joints and muscles at risk forsprains, partial and completedislocations, and muscle strains.Strengthening the muscles surrounding astretched joint helps stabilize the jointand improve muscular function, thusdecreasing the likelihood of injury.
Overstretching may lead to injury;
however, as long as a flexibilityprogram is well balanced with strengthtraining, this possibility is negligible.
Definition
Flexibility is the ability of a limb tomove freely about a joint through a
full range of motion.In the case of Special Warfare
Operators, flexibility refers to theoptimum range of motion surrounding aparticular joint that is necessary for peakperformance. Range of motion isspecific to each joint and dependentupon:
• Joint surfaces and capsule and thedegree of movement required forthe joint to function
• Muscles, tendons, ligaments andconnective tissue associated with
limb movement around a joint(for definitions see Chapter 1)
• Strength of the musculaturesurrounding the joint
There are two types of flexibility:dynamic and static.
Dynamic or active flexibility refers tothe speed attained within a range ofmotion at the joint during physicalperformance. This type of flexibilityinvolves the intrinsic musculaturesurrounding the joint and its ability toovercome resistance to motion. Anexample would be the flexibilityrequired to throw a baseball, punch aboxing opponent, or perform a martial
arts kick. Static or passive flexibilityrefers to the maximal range of motion ofa joint during passive movement inducedby an external source (e.g., a partner,equipment, gravity). The range of staticflexibility is always greater than that ofdynamic flexibility.
The Stretch Reflex andtheLengthening Reaction
The stretch reflex and the lengtheningreaction are joint-protective mechanismsin which sensory organs, located in themuscles and tendons surrounding a joint,are activated when muscles arestretched. As seen in Figure 7-1, the twosensory organs involved in monitoringmuscle tightness are the muscle spindlecells and golgi tendon organs (GTOs).
Figure 7-1. Graphical Representationsof Muscle Spindles and Golgi TendonOrgans
The stretch reflex involves musclespindles which lie parallel to the musclefiber. These spindles are very sensitiveto changes in muscle length. When themuscle stretches, muscle spindles sendsignals to the spinal cord, which in turn,sends signals to the muscle telling it to
contract in order to protect the musclefrom potential tissue damage. Theclassic example of the stretch reflexoccurs when a physician taps a patientjust below the kneecap. The quadricepsmuscle is quickly stretched, and themuscle spindles react by contracting thequadriceps muscle causing the knee-jerkresponse. The greater or more rapid thestretch, the greater the response of themuscle spindles and the resultant musclecontraction. Signals are high infrequency at the beginning of a stretch,but then slow down as they adapt to thenew length.
The lengthening reaction engages
GTOs, which are located in the muscle-
tendon junctions, and activates themwhen the tension in a tendon is increasedas a result of either muscularcontraction, stretching the musclebeyond its resting length, or acombination of the two. When musculartension increases, the GTOs respond bysending inhibitory signals to the muscle;this causes the muscles to relax, andprotects the muscles and tendons fromtearing due to tension overload.Knowledge of the stretch reflex and thelengthening reaction is useful foreffective stretching.
The most effective stretches areperformed slowly, and held for 15
- 30 seconds.
Performing the stretch slowly avoidsexcessive activation of the musclespindles and resultant muscularcontraction. Holding the stretch allowstime for the muscle spindles to adapt tothe new muscle length, and eventually, toachieve greater lengths. The length andduration of the stretch should also besufficient to activate the GTOs so thatthey override the muscle spindles andinduce muscular relaxation.
Flexibility TrainingMethods
There are several training methodsused to develop flexibility; however,most fall under the following generalcategories:
• Dynamic• Static• Ballistic• Proprioceptive neuromuscular
facilitation (PNF)
Dynamic Stretching
Dynamic stretching (sometimesreferred to as active stretching) consistsof controlled movements which increasein range and/or speed so that yougradually reach your full range andspeed of movement (e.g., slow,controlled leg swings or kicks,controlled arm swings, back bends).This type of stretching often mimics theactivity that is to be performed andprepares the muscles for that activity.
There is some controversy
surrounding the effectiveness of dynamicstretching and its role in thedevelopment of flexibility. Some experts
believe that the short, intermittentmovements involved in this type ofstretching activate the stretch reflex andcause the stretched muscle to contract.Others maintain that dynamic stretchingis beneficial for quick, explosiveactivities like gymnastics or martial arts.However, in general, dynamic stretchingshould not be used to develop staticflexibility or long-standing changes inrange of motion. If used at all, dynamicstretching functions best before exerciseto enhance performance. This type ofstretch is often performed after a warmup and prior to an exercise session inanticipation of a particular activity.Dynamic stretches should mimic theactivity that is to be performed.
Static Stretching
Static stretching (sometimes referredto as passive stretching) develops staticflexibility and uses slow, controlledmovements through a full range ofmotion. This type of stretch is performedby holding a position using a part of thebody, the assistance of a partner, orsome other apparatus such as a pole orthe floor (e.g., lifting one leg up andholding it with the hand, the splits).Slow, static stretching helps relievemuscle spasms due to exercise, and isused for cooling down after a workout toreduce muscle fatigue and soreness.
Ballistic Stretching
Ballistic stretching uses themomentum of the body or a limb to forcea stretch past the normal range of motionand then return to the starting position.Ballistic stretching incorporatesbouncing or jerky movements and shouldnot be confused with dynamic stretching.An example of a ballistic stretch wouldbe bouncing down to touch toes or usingthe momentum of the torso to twist thebody. Uncontrolled arms swings inwhich the arms are thrown backwardand then bounce back to the startingposition are also an example. This typeof stretching does not contribute toflexibility. Instead, the repeated
activation of the stretch reflex causesmuscles to contract which can lead toinjury. This type of stretching is notrecommended.
PNF Stretching
Proprioceptive neuromuscularfacilitation (PNF) stretching isconsidered an advanced stretchingtechnique. It is used extensively byphysical therapists or when high degreesof both passive and dynamic flexibilityare required for performance (e.g.,martial arts, ballet, gymnastics, kick-boxing). There are several PNFtechniques, but generally, PNF consistsof a passive stretch, followed by anisometric contraction, which is thenfollowed by another stretch (static ordynamic). By combining passivestretching with isometric contractions (acontraction in which there is no change
in muscle length or joint movement) witha partner or object for resistance, PNFuses the stretch reflex and lengtheningreaction to achieve a greater range ofmotion. As described in the sectionabove, when a muscle is slowlystretched and held, the resulting tensiontriggers the lengthening reaction whichprevents the stretched muscle fibersfrom contracting. When this stretched
muscle is then isometricallycontracted, the following happens:
• During an isometric contraction,some fibers will contract, butothers will stretch even further.When the contraction is stopped,the contracted fibers return to
their starting position, while thestretched fibers retain theirstretched position (due to musclespindle accommodation) and areable to lengthen even further.
• The increased tension within themuscles generated by anisometric contraction activatesthe GTO which triggers thelengthening reaction, and inhibitsfurther contraction. When theisometric contraction is stopped,the muscle is still inhibited fromfurther contraction and able tolengthen further.
The final stretch, which followsisometric contraction, takes advantage of
the muscle’s ability to elongate further,and allows the muscle, tendon, and senseorgans to adapt to greater lengths.
It is best to have a partner helpwhen using PNF techniques.
A common PNF technique is referredto as the “contract-relax method”.Instructions for and a pictorialrepresentation of this method areprovided in Figure 7-2. This techniqueuses passive stretch and isometriccontractions, followed by musclerelaxation and passive stretching to thenew range of motion. For example, ifyou are stretching your hamstrings, youfirst passively take the stretch to the
point of tightness and hold. Then youisometrically contract the hamstrings byusing this muscle to apply force againstan object or partner (See Figure 7-2).Following the contraction, the muscle isallowed to relax and the muscle is thenpassively stretched and held. Currentrecommendations suggest performingthis technique with one to fiverepetitions, but like weight training, itneeds to be done no more than three tofive times a week.
Figure 7-2. Contract-Relax PNFTechnique
It is interesting to note that manystretches (including some of thoseillustrated in this chapter) can beperformed statically, dynamically, orusing PNF, depending on the goals of astretching program.
Warming-Up and Stretching
Stretching is not the same as a warm-up.Many individuals stretch in a
misguided attempt to warm-up; however,stretching and warm-up should beconsidered distinctly different activities.A warm-up prepares the body for theactivity that is to follow. The two typesof warm-up are general and activity-specific. Physiologic changes that occuiduring warm-up include increases inmuscle temperature, blood flow, oxygendelivery to the muscles, and skeletalmuscle metabolism. Warm-up benefitsinclude injury prevention and animprovement in performance.
A warm-up should alwaysprecede any physical activity
whether it be stretching,exercise, sports, or mission-
related training.
Cold muscles don’t stretch, and thereis a high chance of injury whenstretching is performed without firstwarming up. Stretching (especiallydynamic stretching) may be part of (orfollow) a warm-up, but should notexclusively comprise the warm-up.
Stretch only after an adequatewarm-up has been performed.
General Warm-Up
General (or unrelated) warm-upinvolves movements (e.g., running inplace, jumping jacks, and othercalisthenics) that are different from, orunrelated to, the specific activity that isto follow. This type of warm-up shouldbe performed prior to high-intensityactivities (e.g., 0-Course, power-lifting,“burn-out PT,” gymnastics, etc.) whenimmediate participation in the actualactivity is likely to result in joint ormuscle injuries.
Activity-Specific Warm-Up
Activity-specific (or related) warm-up occurs with a low-intensity versionof the activity that is to follow.Examples of activity-specific warm-upinclude a slow jog prior to a long run;slow cycling in preparation for a cyclingevent; or slow karate moves prior topractice. A related warm-up starts outslowly and progresses to more intenseactivity. Depending on the intensity ofexercise to be performed, a warm-up ofanywhere between 10 - 30 minutes maybe required—the greater the intensity ofthe workout, the longer the warm-up.
All warm-ups should be of
sufficient intensity to elevatebody temperature; sweating is a
good indication that you areready to move on to the next
phase of your workout.
Both general and activity-specificwarm-ups may incorporate some type ofstretching, especially if the activity to beperformed is one of high intensity andimposes a good chance of acute injury.After a short period of warming-up,some pre-exercise stretching should bedone. Figure 7-3 provides severalexamples of warming-up for variousactivities. If time is limited, the pre-exercise stretch can be eliminated but astatic stretching program should follow
every exercise session.
Figure 7-3. Specific Warming-UpActivities
Exercise should not be endedabruptly, but gradually slowed, to avoid
pooling of blood in the skeletal muscles,and to facilitate the removal ofmetabolic end products. Exercise shouldbe followed by a cool-down andstretching session.
Since most of the benefits from
stretching occur post-exercise, a 10-15minute stretching program should followevery exercise session, and should beincorporated as part of the warm-downwhile the muscles are still warm.Stretches should be slow and static, heldfor 15-30 seconds, and taken to the pointof tightness, not pain. Static stretchingprovides a good warm-down after aworkout, reduces post-workout musclefatigue and soreness, and is useful for
relieving muscle spasms that occur as aresult of exercise. Once muscles havebeen stretched, standing in cool/coldwater, or running cool water over thelegs or muscles used during the exercise,can also reduce soreness, and seems tospeed recovery between exercise bouts.Figure 7-4 represents the idealrecommended exercise sequence.
Figure 7-4. Recommended ExerciseSequence
Recommended Stretches
Dynamic Stretching
Dynamic stretches of the musclegroups to be exercised during PT shouldbe performed following a warm-up.Dynamic stretches should not be jerkymovements. In fact, any slow, controlledmovement that simulates the activity tobe performed, executed forapproximately 2 seconds, is sufficient.Some suggested dynamic exercises areprovided in Table 7-1.
Table 7-1. Dynamic Stretch Exercisesto be Used in Physical Training
Static Stretching
Most of the benefits derived fromflexibility training are obtained with aconsistent, post-exercise, staticstretching program. The stretching that isperformed following exercise on oneday helps to prepare the muscles for thenext day’s exercise session.
The following exercises (Table 7-2)
can be incorporated into a post-exercisestretching program by selecting 1-3stretches for each anatomical locationlisted below. Remember to balance thefront of the body with the back (e.g., hipextensors with hip flexors, hamstrings
with quadriceps). Select more stretchesfor those body areas exercised (e.g., legsafter a run, shoulders after a swim).Perform 2-5 repetitions per stretch, holdfor 15-30 seconds, then relax for 10-15seconds. Note: these stretches are all nocount exercises.
Table 7-2. Static Stretch Exercises tobe Used in Physical Training
A Post-Exercise TotalBodyStretching Program
A suggested post-exercise total-bodystretching program is outlined in Figure7-5. Stretches are grouped by theposition in which they are performed. Tomake the most efficient use of time,perform stretches in the sequenceprovided. The outlined program takesten minutes if stretches are held for 15seconds and performed once on eachside of the body. Ideally, stretchesshould be performed twice on each sideof the body.
Figure 7-5. Total Body Post-Exercise
Stretching Program
Resources
Alter, MJ. Sport Stretch.Champaign, IL: Leisure Press,1990.
Anderson, B. Stretching. Bolinas,CA: Shelter, 1980.
Appleton, B. Stretching andFlexibility: Everything YouNever Wanted to Know, 1995.Available: chesapeakehttp://www.ntf.ca/NTF/papers/rma/stretching_toc.html
Tritschler, T Stretching andStrengthening Exercises. NewYork: Thieme, 1991.
Sudy, Mitchell (Ed.). PersonalTrainer Manual: The Resourcefor Fitness Instructors. Boston:
Reebok University Press, 1993.♦ Cantu, RC and Micheli, LJ.
(Eds.). ACSM’s Guidelines forthe Team Physician.Philadelphia: Lea & Febiger,1991.
Chapter 8
Calisthenics
Calisthenics are a traditional andintegral part of the SEAL’s trainingprogram because they require minimalequipment and can be performed inalmost any location. Calisthenicexercises, depending on how they areperformed, can be used to developflexibility, muscle strength, muscleendurance, and/or muscle power. Theseterms have been previously defined inChapter 1. In this chapter we will
discuss the benefits and proper use ofcalisthenics within the Special Warfaretraining environment.
The Muscle Strength-Endurance Continuum
Muscle strength and muscle enduranceexist on a continuum. Given that musclestrength is the amount of force generatedby one repetition and muscle enduranceis the ability to exert force repeatedlyover time, improving muscle strengthwill improve muscle endurance. If yourone repetition maximum weight isincreased, your submaximum multiplerepetitions can be performed with moreweight (resistance).
Muscle strength is developed by
performing low-repetition (6-12), high-
resistance exercises. When more than 12repetitions can be performed, theresistance should be increased, and therepetitions decreased. Muscle enduranceis developed by high-repetition (>12),low-resistance exercises.
A set for an exercise is thenumber of repetitions performed
per unit weight.
Increasing the number of repetitionsper set develops endurance. Forexample, if an individual can performonly 10-12 sit-ups using propertechnique, the exercise will developmuscle strength. Once an individual canperform over 15 repetitions per set,
muscle endurance is being developed.Table 8-1 outlines the strength-endurance continuum and illustrates thetraining schedules used to developvarious degrees of endurance. Note thatstrength and short-term efforts have noeffect on aerobic capacity because theaerobic/endurance system is notrecruited with maximal or heavy loads.In contrast, sustained efforts with a lightload recruit the aerobic system and haveminimal effect on strength. Generally,activities of longer duration requiremore muscle endurance. SEALs shouldmodify their training programs accordingto the principles of strength andendurance specific to missionrequirements.
Table 8-1. The Strength-EnduranceContinuum
In general, calisthenics developmuscle endurance. There are two
occasions, however, when calisthenicsdevelop muscle strength. The firstoccasion depends on individual fitnesslevel and how many repetitions can beperformed. Individuals who can onlyperform a low number of repetitions of acalisthenic exercise (less than 10-12)will develop muscle strength. Thosewho can perform a higher number (morethan 10-12) will develop muscleendurance. For example, when you firststart doing pull-ups you may only beable to perform 9 repetitions. At thispoint, you are developing musclestrength. As your performance improves,and you are able to perform over 12repetitions, you begin to develop muscleendurance.
The second occasion occurs where
calisthenics are modified to overload themuscles so that they contribute tostrength development. This can beachieved by any of the following:
♦ Adding weight (e.g., pull-ups orpush-ups while wearing aweighted pack)
♦ Using a buddy for resistance(e.g., having a buddy sit on yourhips while doing bent over calfraises; buddy-assisted legextensions)
♦ Exercising on one side of thebody only (e.g., one-leggedsquats or calf raises)
♦ Modifying the exercise (e.g.,elevating the legs during push-ups)
♦ Super sets/pyramids
These modifications can beparticularly helpful if weight trainingfacilities are not available and a strengthworkout is required.
Calisthenics in NavalSpecial Warfare
Muscle strength and endurance areboth essential for operationalperformance. Muscular strength is alsorequired for many Special Warfaremissions. Muscular endurance is neededwhen work is required over longerperiods of time (e.g., patrolling with aheavy load, climbing with equipment,swimming, or carrying a buddy).
The goal of a physical training (PT)
program for the SEAL should be todevelop complete muscular fitness (i.e.,strength, endurance, and power). Muscle
strength provides the foundation formuscle endurance and power. Anadequate strength base not onlyimproves performance, but alsodecreases the likelihood of injury. Forthis reason it is recommended that atleast two strength workouts (low-repetition [10-12 reps], high resistanceexercises per muscle group per week),as described in Chapter 6, be part of theSEAL’s physical fitness program.Traditional calisthenic exercisesperformed two to three times a weekwill develop and maintam muscleendurance. A plyometric program (SeeChapter 9) when necessary, can also beused to develop muscle power.
Mission-related training schedules,lack of exercise equipment, andinadequate nutrition can keep operatorsfrom maintaining required fitness levelsin the field. Calisthenics, however, arepractical for field situations becausethey can be performed anywhere withminimal equipment. Moreover,calisthenics can also be modified toprovide a strength workout.
A unit’s PT schedule should beflexible enough to accommodate
different training needs.
It may take one to four weeks for anoperator or platoon returning from thefield to completely regain levels of
aerobic and muscular fitness comparableto those when exercising regularly in abasic unit PT program. Allowing time togradually increase fitness will improveperformance, prevent overtraining, anddecrease the likelihood of overuse injuryor re-injury. Those returning to PTfollowing surgery and/or rehabilitationneed to return to basic PT gradually.When performing calisthenics, more isnot necessarily better, and in fact, can beharmful. Too many repetitions can causean overuse injury or worsen an existinginjury.
The goal of a PT program shouldbe to develop aerobic capacity,muscular strength, endurance,
power, and flexibility, NOT TOOUT PERFORM OTHERS.
Competitive exercise situations, suchas “Burn Out” PT and pyramid sets, canbe challenging, but if not handledcorrectly, can cause injury. SEALsshould train like elite athletes and avoidsituations that could contribute to injury.
Calisthenic sessions occasionally
include holding an exercise in thehalfway position for 2-10 seconds. Thistechnique is often applied to pull-ups,dips, or push-ups in an attempt to makethe exercise more difficult or alleviateboredom. For example, when performinga pull-up, the operator will maintain the
position halfway between the startingposition and the bar, while the chin isover the bar, and again halfway downthe bar. This technique is NOTrecommended.
Holding a mid-exercisecontraction stresses the joints,tendons, and ligaments and cancause an injury or worsen an
existing injury.
Slowing the cadence throughout theentire exercise (i.e., 10 seconds up to thebar, 10 seconds back to the startingposition), is recommended for addedstrength gains, alleviation of boredom,or to increase the difficulty.
Balancing Abs and HipFlexors and Extensors
Many calisthenics, performed tostrengthen the abdominal (Abs) muscles,are actually exercises for the hip flexors(muscles that move the hips and legstoward the chest). This causesoverdevelopment of the hip flexors andunder-development of the abdominals.Although both hip flexor and abdominalstrength is necessary for operationalperformance, overdeveloped hip flexorsplay a significant role in thedevelopment of lower back problems.Overdeveloped hip flexors not onlychange the curvature of the spine, but
also stress the front portion of thevertebral discs. Many experts contendthat much of the low-back pain in theSEAL community is due to anoverabundance of hip flexorcalisthenics. Hip flexor strength isnecessary, but it should be balanced withequally developed strength andflexibility in the hip extensors (muscleswhich move the legs away from thechest) and abdominals.
A balanced workout incorporatesabdominals, hip flexors and hip
extensors.
Therefore, it is important to identifywhich exercises are appropriate for each
muscle group (i.e., abs, hip flexors, hipextensors) and include all three in a PTprogram. A calisthenic program shouldalso incorporate a flexibility program inorder to prevent the exercised musclesfrom becoming too tight (see Chapter 7:Flexibility).
Exercises that anchor or elevate the
legs and feet off of the deck (e.g., HelloDarlings, Flutter Kicks, Leg Levers,Inboard Outboards) are actually workingthe hip flexors. When performing thesetypes of exercises, the torso and upperabdominals act to stabilize the pelvisduring the movement. For this reason itis suggested that hip flexor exercises beperformed first. Exercising the
abdominals first causes them to becomefatigued and therefore unable to stabilizethe pelvis. The followingrecommendations will strengthen theabdominals:
• Identify exercises which are trueabdominal exercises versusthose which work the hip flexors.
• Decrease the number of hip flexorexercises performed to twosessions per week with fewerrepetitions per session.
• Increase the number of trueabdominal exercises (e.g.,Crunches, Elbow to Knee/CrossOvers, Hip Rollers, Side Flex).Abdominal exercises can be
performed daily or as limited bymuscle soreness.
• Add hip extensor exercises (e.g.,Prone Back Extension, TheSuperman, Donkey Kicks).
• Incorporate a total bodyflexibility program into SpecialWarfare training and includestretches for the hip flexors,abdominals, and hamstrings.
• Focus on proper technique aspresented below.
Proper technique is importantwhen performing all calisthenics.
If the muscles are not strong enough toperform an exercise properly, other
muscles will come into play. The result:the wrong muscles get developed andcan lead to injury. For example,exercises that are too difficult for thelower abdominals will rely on the hipflexors. Hip flexors which are relativelystronger than the abdominals, result inthe stomach protruding. This may lead toinjury and low-back pain. Propertechnique is essential.
The following suggestions should
decrease mechanical stress on the lowback during hip flexor exercises:
♦ Keeping one foot on the deckminimizes the stress placed onthe lower back and spine. Many
exercises that require both legsto be off the deck simultaneouslycan be modified so that one footis constantly on the decksupporting the low back (Figure8-1 and Figure 8-2).
♦ Placing a fist under the lower partof the buttocks helps to keep thespine in a neutral position.
♦ Lifting the head and slightlyrolling the shoulders helpsmaintain the position of thespine.
♦ Performing hip flexor exercisesprior to abdominal exercises.
Figure 8-1. Modified Flutterkick:
Keeping One Foot on the Deck Protectsthe Lower Back
Figure 8-2. Modified “Knee Bender”:Keeping One Foot on the DeckProtects the Lower Back
Another change that should beincorporated in an abdominal workoutis the addition of a 2 inch thick towel oran “Ab Mat” beneath the lower spine.The anatomical range of motion for theabdominals is from 30° extension toapproximately 75-90° flexion (Figure 8-3). When performing abdominalexercises on a flat surface (i.e., the
deck) you are limiting your exercise toonly half the normal abdominal range ofmotion. In other words, when abdominalexercises are performed on a floor,deck, or mat, only half the worknecessary to develop abdominal strengthis being done. Abdominal strength isbest developed by exercises performedwithin the full anatomical range ofmotion, with some curve in the lumbarspine (i.e., towel or Ab Mat) as opposedto a flat back. By placing a towel or theAb mat beneath your lower spine youcan achieve the right form for theseexercises (see Figure 8-4).
Figure 8-3. Range of Motion forFlexion and Extension of the Upper
Body Based on Anatomy
Figure 8-4. Placing a Towel Beneath theLower Spine can Help Achieve theRight Form for Abdominal Exercises
Because of limited flexibility, it isbetter to start abdominal exercises atapproximately 15° of extension andeventually work toward 30° extension. Atowel is particularly useful because youcan adjust it to provide inclines of 15°and 30° .
Recommendations for Sit-Ups
In recent years, the sit-up techniquehas undergone many modifications.Because sit-ups compose a large portionof the SEAL training program, somespecific comments regarding theirproper use are crucial.
When performing sit-ups, the
preferred technique is to bend the legs atthe hips (at 45°) with the feet flat on thedeck shoulder width apart. Legs shouldbe slightly abducted (turned outward). Ifhands are placed behind the head, careshould be taken not to force the neck intoflexion. The fingertips of the handsshould just barely touch the back of the
head. Elbows should remain back at alltimes. Concentration on using theabdominals (not the head) to pull throughthe movement is essential. Keeping theeyes focused on the ceiling helps preventneck strain and isolate the abdominals.Lifting the torso until the shoulder bladescome off the floor engages the majorityof the abdominal musculature. Lifting thetorso further off the deck will safelyengage the internal obliques and the hipflexors, if that is the goal (see Figure 8-5).
Figure 8-5. Proper Technique for Sit-ups: Legs SlightlyTurned Outward andElbows Behind Neck at All Times
When first performing the sit-up froman extension position, you may not beable to perform as many repetitions.This should not be surprising sinceessentially, you have been performingonly half a sit-up in the past.
The focus should be on thequality, not the quantity, of sit-
ups.
The same principles that govern themuscle strength-endurance continuumapply to the abdominal musculature. Themuscular fitness component you willdevelop (i.e., strength vs. endurance) isdetermined by the number of sit-upsperformed using a towel or “Ab Mat”beginning with 15° of extension. Ifmuscle strength is the goal, you maywant to move to 30° extension. Once youare performing over 15 reps per set at30° extension, you can increase thedifficulty of the exercise by changing theposition of the arms, adding weight, or
performing sit-ups on a decline.Variations in arm positioning, from theeasiest to the most difficult, are shown inFigure 8-6:
• At the side of the body• Across the chest• Behind the head• Clasped together above the head;
weight can be added for moreresistance
Figure 8-6. Variations on Sit-UpRoutines
If the goal is to develop musclestrength, enough resistance should beadded to keep the repetitions per setbelow 15. Once there is a sufficientfoundation of muscle strength, muscleendurance can be developed. As withcalisthenics, when muscle endurance isthe goal, enough weight should be added
to keep the repetitions between 15-50per set. These principles apply to allother types of sit-ups as well (i.e.,Crunchers, Vee-Ups, Cross Overs).
Recommendations forCalisthenics
Two evolutions per week onnonconsecutive days are recommendedfor calisthenic (muscle endurance)training. Additionally, weekly PTsessions using the calisthenicmodifications for muscle strength arerecommended. Calisthenics may beperformed in conjunction withplyometrics, strength training, or aerobictraining. Static stretches for specificbody areas may be performed (fillerstretches) once the workout for that areaof the body is complete; however, asignificant drop in exercise tempo
should be avoided in order to keepexercising muscles warm.
For a 30-minute workout, choose one
to three exercises from each of thefollowing categories in Table 8-2. For a60-minute workout, choose three to sixexercises from each of the categories.Remember to balance the front of thebody with the back (e.g., hipflexors/abdominals with hip extensors,quadriceps with hamstrings, hipadductors with hip abductors). Theresting period between exercises mayvary depending on individual or groupfitness level.
Calisthenic Exercises
Table 8-2. Recommended Calisthenicsfor Physical Training
Modified Calisthenic Exercises
Calisthenic exercises can be modifiedto provide a strength workout byincreasing resistance, using a buddy, orsome other source of added weight.Many experts recommend buddy-assisted exercises for the followingreasons:
• Can be performed in any locationwith no equipment.
• Help to maintain strength base inthe field.
• Teach reliance on anotheroperator.
Most buddy-assisted exercises are
designed to develop strength, dependingon the amount of resistance one’s partnerapplies. As with regular calisthenics, themuscle strength-endurance continuumapplies. If you can only perform 4-10reps per set, you are building strength. Ifyou can perform over 10 reps per setyou are beginning to build muscleendurance. Depending on the fitnessgoal, the partner can apply as muchresistance as necessary to control thenumber of repetitions. For maximumbenefit, perform these exercises slowly.Table 8-3 provides suggestions to aid indeveloping a buddy-assisted exerciseprogram.
Table 8-3. Tips for Developing a
Buddy-Assisted Exercise Program
Some examples of buddy assistedexercises are provided in Table 8-4.Additional exercises and illustrationscan be found in Gain W., Hartmann J.Strong Together! Developing Strengthwith a Partner, 1990.
Table 8-4. Buddy Exercise Drills
Resources
♦ Gain W., Hartmann J. StrongTogether! Developing Strengthwith a Partner. Toronto: SportsBooks Publisher, 1990.
Sudy, Mitchell (Ed.). PersonalTrainer Manual: The Resourcefor Fitness Instructors. Boston:Reebok University Press, 1993.
Cantu RC and Micheli LJ. (Eds.).ACSM’S Guidelines for theTeam Physician. Philadelphia:Lea & Febiger, 1991.
Chapter 9
Plyometrics
Premature plyometric training maycause injury because plyometrics placeconsiderable stress on the body.Plyometrics is an advanced trainingtechnique that should only be performedunder the guidance of those withknowledge and experience with this typeof training. It involves explosive typesof activities (i.e., jumping onto anddown from objects, bounding up anddown stairs on one or both feet and high
speed sending and receiving) to convertmuscle strength to muscle power.Whenever you run, jump, catch or throw,you are performing a plyometricmovement.
Box Jump
Side Cone Jumps
Plyometric exercises train the musclesto reach maximal strength in the shortest
time possible. In other words, musclestrength plus speed equals musclepower. The rapid application of force isthe goal of plyometric training.Plyometric exercises will not train anenergy system as seen with aerobic orstrength conditioning; rather suchexercises train the neuromuscularsystem so that it may respond morequickly to increased loads. By makinguse of the inherent elasticity of themuscles and certain neuromuscularreflexes, plyometric exercises enhancethe speed and distance an object moves(e.g., your body, shot put).
Plyometric training is veryintense, highly specific, and if
done improperly it may beinjurious. It should not be
routinely incorporated in theNaval Special Warfare physical
training programs.
How Plyometrics Work
Plyometric exercises help to developexplosive strength and speed in fasttwitch muscle fibers. These exercisesuse the inherent stretch-recoil propertiesof muscle (i.e., eccentric tensiongenerated when the muscles arelengthened) to enhance subsequentshortening or concentric contractions.This is the dynamic action behind therapid pre-stretch or “cocking” phase to“activate” these natural recoilproperties. Examples of this phaseinclude taking the arm back into positionprior to throwing a baseball or bendingthe knees prior to jumping. Thus athletesthat rely on explosive strength and
speed, such as sprinters and basketballplayers, include plyometrics in theirtraining programs. A plyometricmovement can be broken down into threephases:
• Lengthening phase (eccentriccontraction)
• Amortization phase• Takeoff (concentric contraction)
Figure 9-1. Three Phases ofPlyometrics: Lengthening,Amortization and TakeOff
During the lengthening phase, themuscle creates tension like a springbeing stretched. This type of contraction,called an eccentric contraction, occurswhen performing movements such asjumping down from an object, running
downhill, or lowering a weight. Duringan eccentric contraction, tension is builtinto the muscle as it lengthens. Thetakeoff occurs via concentric contractionof the muscles. During this phase, themuscle shortens as it contracts, andactual work (i.e., movement of the bodythrough space) is performed.
The amortization phase is the period
of time from the beginning of thelengthening phase to the beginning of thetakeoff phase. This is the most importantphase when it comes to plyometrictraining. During this phase, the musclemust convert the muscular tensiongenerated during the lengthening phase toacceleration in a selected direction
during the takeoff phase. The elasticproperties inherent within the musclesand neuromuscular reflexes (the stretchreflex) are responsible for thisconversion. Plyometric training mayincrease the efficiency of thisconversion. The goal of plyometrictraining is to decrease the amount of timein the amortization phase and therebyincrease speed.
Preparation for PlyometricTraining
Plyometric exercises should beundertaken only once an adequatestrength base has been developed. Mostsources define an adequate strength basefor lower body plyometrics as the abilityto squat or leg press 1.5 to 2.0 timesyour body weight for one maximumrepetition. For upper body plyometrics,larger athletes (weight greater than 115kg or 250 lbs.) should be able to benchpress their body weight and athletesweighing less than 115 kg (250 lbs)should be able to bench press 1.5 timestheir body weight.
Plyometric training should neverbe undertaken if you have any
leg, hip, arm, or shoulder injury.
Safety in Plyometric Training
Several steps can be taken to ensurethat plyometrics training is safe. Thesemeasures include using an appropriatesurface, footwear, and equipment, andproper technique.
Surface
Plyometrics should not be performedon hard surfaces such as concrete orsteel, nor should they be performed onsoft surfaces such as sand. The bestsurface is a grass field, followed byartificial turf or wrestling mats.
Wrestling mats should not be too thick (>15 cm) since they will increase the timein the amortization phase. The storedenergy gained during the lengtheningphase will be lost, and this will defeatthe purpose of plyometric training.
Footwear
Recommended shoes are those thatprovide ankle and arch support, lateralstability, and have a wide, non-slip sole.
Equipment
Boxes that are used for in-depth orbox jumps should have a non-slip topand should never exceed a height of 1.2m (0.5 - 0.75 m is recommended: 1.5 to2.5 ft. and less than 4 ft.).
Medicine balls are commonly used
for many of the exercises. This is a ballthat weighs no more than 10% of yourtypical training weight. For example, ifyou regularly train with a 200 poundbench press, then the medicine ball youuse should be no more than 20 lbs.These balls can be covered with leather,plastic, rubber, or any type of fabric.
Technique
As with other exercises, attentionshould be paid to proper technique. Forexample, when performing lunges, theknee angle should not exceed 90°. Anymovement beyond this angle will placeundue stress on knee cartilage andligaments. Keeping the knee directlyover and in line with the big toe willhelp maintain technique. The step shouldbe straight out, not to the side. Theshoulders should always be over theknees during landing when performingin-depth jumps.
Fatigue from high-volume training can
compromise technique and result ininjury. When technique begins to fail, itis time to stop the exercise and rest.
Program Design and the OverloadPrinciple
Plyometrics training should betailored to account for individualcharacteristics and the activity for whichone is training. More stress will beplaced on the muscles, joints, andconnective tissue of heavier individuals,therefore, bigger operators (weightgreater than 90 kg or 198 lbs.) shouldnot perform high-intensity plyometricexercises. Persons with a previoushistory of injury should be cleared bya medical officer prior to plyometrictraining. As previously stated:
Persons with any type of
musculoskeletal injury should notconsider plyometrics training.
A plyometrics program for the specialoperations community shouldincorporate those types of movements(i.e., linear, vertical, lateral, or acombination) required for operationalperformance. For example, downhillskiing would require diagonalmovements, close-quarters battle (CQB)would require horizontal, vertical, anddiagonal movements.
The overload principal is the basis
for any training program whether it becardiovascular training or thedevelopment of muscular strength,
endurance, or power. The three basicvariables used in the overload principalinclude the frequency, volume (orduration), and intensity of training. Byincreasing any one or a combination ofthese variables within a trainingprogram, one can continuously andsafely overload the system that is to betrained (i.e., cardiovascular, muscular,neuromuscular).
Frequency
Frequency is the number of workoutsper week (or other unit of time). Forplyometric training, the range is usually
from one to three sessions per week,depending on the sport and season. Aplyometric training program for theNaval Special Warfare communityshould consist of two training sessionsper week when operational demandsrequire such training. Allow 2-3 daysfor recovery between workouts to avoidovertraining or injury.
Volume or Duration
The volume for plyometric training isdefined as the number of foot contacts orlandings per session.
• Beginners: 80-100 landings per
session• Intermediate: 100-120 landings
per session• Advanced: 120-140 landings per
session
Intensity
The intensity for plyometrics trainingis the level of stress placed on theneuromuscular system, the connectivetissue, and the joints, and is determinedby the type of exercises performed. Forexample, skipping is a low intensityexercise while in-depth box jumps are ofhigher intensity. Some guidelines areprovided as follows:
• Vertical jumps are more stressfulthan horizontal jumps.
• One leg landings are morestressful than landings on twofeet.
• The higher off the ground thebody, the more forceful thelanding and the more stressful theexercise.
• Adding external weight to thebody also increases the stress.
When designing a program, it is bestto increase only one variable per sessionto reduce the likelihood of injury.Generally frequency is held constantwhile either the volume or the intensityis increased. In advanced plyometrics,
when high intensity exercises areperformed, volume should decreasesince these exercises place significantstress on the muscles, joints, andconnective tissue. Table 9-1 provides anexample of a 10-week progressiveplyometric program. Remember:exercises that mimic the activity to beperformed during the mission taskshould be selected.
Table 9-1. A 10-Week PlyometricProgram
Table 9-2 classifies plyometricexercises by their jump direction andintensity level. This table can be used incombination with Table 9-1 to develop aspecific plyometric program. Allexercises are described in detail in thefollowing section.
Table 9-2. Plyometrics : Classified by
Jump Direction and Intensity
Plyometric Training
Plyometric training should begin witha general warm-up followed by dynamicstretching (see Chapter 7 for stretching).Stretches should mimic the activity to beperformed (e.g., 4-Way Lunges and LegSwings for lower body plyometrics; UpBack and Overs or Press-Press-Fling forupper body plyometrics). Static stretchescan also be added.
Two sessions of plyometrics perweek is sufficient for SEALs.
This statement is true when operatorshave 8-10 weeks to train prior to amission. If time is limited, a platoon may
train three times per week if adequatetime for recovery is allowed.
Heavy strength and plyometrictraining on the same body areashould not be performed on the
same day.
However, upper body strength trainingmay be combined with lower bodyplyometrics and vice versa. Adequatetime for recovery from each type oftraining is needed and can take from 1-3days, depending on the intensity. Ifschedules are tight, the intensity ofstrength and plyometric exercises shouldvary from low to high to allow sufficienttime for recovery. For instance, when
high-intensity plyometrics is required(e.g., just prior to an operation) strengthtraining should be of a lower intensity.
Plyometric Exercises
When performing jumps it often helpsto think of “hanging in the air” for aslong as possible, keeping shouldersparallel to the ground at all times.Emphasis should be on speed withoutsacrificing proper technique. Table 9-3and Table 9-4 present a variety ofplyometric exercises. Exercises arelisted in increasing order of difficultyfor each grouping in Table 9-3.
Table 9-3. Plyometric Exercises
Table 9-4. Upper Body Plyometrics
Eccentric Downhill Training
Many SEAL missions (e.g. small unitpatrolling) involve overland movement.Mountain and/or downhill hiking canresult in severe muscle soreness, injuryto muscle tissue, and strength loss thatcan last for several days, if you are notaccustomed to such activities. A recentNaval Health Research Center studyfound that as few as two downhilltraining runs (e.g., treadmill ormountainous terrain) one week apartcould greatly minimize the musclesoreness and damage. This method ofconditioning leg muscles is an effectiveway to prepare SEALs for futuremissions or events involving rugged
terrain. Uphill and downhill traininghikes with loads are also an effectivemeans for conditioning legs.
Resources
• Allerheiligen, WB. SpeedDevelopment and PlyometricTraining. In: T. R. Baechle (Ed.),Essentials of Strength Trainingand Conditioning. NationalStrength and ConditioningAssociation. Champaign IL:Human Kinetics, (pp. 314-344),1994.
• Costello, F. Training for SpeedUsing Resisted and AssistedMethods. National Strength andConditioning AssociationJournal. 1985;7(1):74-75.
• Chu, D. Plyometrics: The linkbetween Strength and Speed.
National Strength andConditioning AssociationJournal. 1983;5(2):20-21.
• Chu, D. Plyometric Exercise.National Strength andConditioning AssociationJournal. 1984;5(6):56-59, 61-64.
• Duda, M. Plyometrics: Alegitimate form of powertraining? Physician and SportsMedicine. 1988;16(3):213-218.
• Law PL et al. (1994) DownhillRunning to Enhance OperationalPerformance in MountainTerrains. NHRC TR 94-36.
• Stone, M.H. Literature review:Explosive exercises and training,National Strength and
Conditioning AssociationJournal. 1988;15(3):6-15.
• Wathen, D. Literature review:Explosive/plyometric exercises.National Strength andConditioning AssociationJournal. 1993;15(3):16-19.
Chapter 10
Load-Bearing
Extended humping with a load isone of the most physically demandingtasks for a SEAL. As a SEAL, you mustcarry loads into rivers, jungles, deserts,and mountains as well as arctic areasand be prepared to engage in variousstyles of fighting and methods ofinfiltration. In the planning phase ofthese missions, Navy SEAL platoonleaders are frequently faced withdecisions as to what type and how much
equipment and ammunition to carry on amission: common (minimum) andcritical (mission specific) equipmentneed to be chosen wisely.
The development of multiple weapon
systems and state of the art surveillanceequipment has increased the firepowerand protection of the individual warrior.However, the same equipment that isdesigned to provide a technologicaladvantage in battle may also provide aload-bearing challenge.
Much remains to be learned about
carrying heavy loads for both short andlong distances. Moreover, weather,
terrain, water discipline, acclimationstatus and other factors that impact loadrequirements must all be considered.
Both excessive fatigue andmuscle strain during long humps
can usually be explained byinadequate training for the
unique physical demands of thistask.
To assist you in maintaining readinessfor tasks that involve carrying heavyloads, the following information ispresented:
♦ Physiological and environmentalfactors
Optimizing load-bearing Physical training for load-bearing Common medical conditions
Physiological andEnvironmental Factors
Body and Load Weight
Ideally, it is best to select the load-bearing weight as a function of bodyweight rather than selecting an absoluteload-weight per man. You may not havethe flexibility to tailor the load weightper man due to mission requirements.Therefore, an upper weight limit forload-bearing should be calculated so theload will not create a higher physicaldemand (energy cost) for individualswith smaller stature and lower lean bodyweight.
Determining the maximum weight of
the load is a more important factoraffecting load-bearing than the type of
load carriage design. Numerous studieshave examined the optimal load-bearingweight you should maximally carrybefore there is a disproportionalincrease in the rate of energyexpenditure. This is calculated as apercentage of body weight. Althoughthose who are physically fit according toPhysical Fitness Test Scores cantypically carry 45% of their body weightfor 8 hours at a pace of 4 mph, a lighterload is considered optimal.
“Rule of Thumb”: A maximalload should be 40% of body
weight. Example: 40% of 170 lbs.is 68 lbs.
The energy cost of the task risessteeply beyond this percentage. It hasbeen reported that the energy cost ofhumping with a load increasesproportionally with the weight carried.For loads more than 40% of bodyweight, the energy expenditure risesdisproportionately and fatigue occurssooner. The key is to carry your loadas close as possible to your body’scenter of gravity. This will result in thelowest energy cost when you carry aload, which is evenly distributed, onyour back.
Biomechanics of Load-Bearing
The duration of time your foot is onthe ground during a normal gait does notincrease until pack loads are greater than50% of your body weight. However, thelength of time your foot is in the airduring the swing phase of your gaitdecreases with increasing load-bearingweight. This response occurs to increasethe length of time both feet are on theground for double support. As the loadweight increases, your feet increase theground force downward, forward,rearward and in lateral directions.Shorter stride lengths will increasestride frequency and help maintainnormal walking patterns during moderate
to heavy load-bearing.
Shorter strides may minimizestrain and possibly reduce lower
back and lower extremityinjuries.
Load-Bearing and Walking Pace
Self-pacing during load-bearingresults in a lower energy cost than aforced-pace. However, not all missionsallow self-pacing. When the pace isforced, a self-selected decrease inwalking pace will be observed as theload-bearing weight increases. The self-selected walking pace or exerciseintensity during load-bearing depends onmany factors. Some of the factorsaffecting the self-selected pace include:
♦ Load weight♦ Aerobic fitness level (maximal
aerobic capacity)♦ Total distance walked
You will normally self-pace at30% - 35% of your maximal
aerobic capacity when carrying amoderate load of 50 pounds.
With lighter loads, self-pacingnormally results in an exercise intensityof around 45% of your maximal aerobiccapacity. However, an exercise intensityof 60% or greater can be achieved whenthe load is light and the distance short.Remember: walking pace and loadweight carried during an infiltration orexfiltration contribute to the rate ofexhaustion. Figure 10-1 presentsestimates of when exhaustion mightoccur at various walking speeds and
loads. High rates of energy expenditure(900 to 1000 calories per hour) can besustained for only 6 to 10 minutes. To beable to move quickly at this intensity,load weight must be light.
Figure 10-1. Workload and EnergyExpenditure During Load-Bearing
Carrying a load at a walking pace thatrequires an energy expenditure in excessof 300 kcal per hour can compromise theenergy reserves you will need at thedesired destination. Figure 10-2 showsthe speeds that you can expect to sustainwith given loads at the designated paces:
note these all result in an energyexpenditure of 300 kcal per hour.
Figure 10-2. Effects of Walking Paceby Pack Weight and Terrain
Hydration Status
Appropriate water/fluid disciplinemust be observed at all times duringload-bearing. Exercise without a load isseverely compromised whendehydration occurs, and when exerciseis coupled to load-bearing,dehydration potentially becomes aneven greater threat. This is trueregardless of the environmentalconditions. The Navy SEAL NutritionGuide provides information on optimalfluid ingestion, but in brief, you shouldingest at least one to two cups of fluidevery 30 minutes during a hump.
Fluid requirements are higher
during exercise with load-bearingthan during exercise without
load-bearing.
Environmental Stress
• Hot and dry or hot and humidenvironments will increase theheat strain of individuals duringload-bearing. Thermal heat loadwill be increased due to bodyheat production from load-bearing activities, and from theheat load from the sun and otherheat sources in the environment.ALICE packs and double packscan restrict the body’s ability todissipate heat. Load-bearingvests with a nylon mesh bodywill trap less heat than backpackdesigns.
• Cold environments increase the
energy cost of walking becausethe clothing worn is usuallyheavy and cumbersome. This canresult in overheating andsweating, especially on the backwhere the load is carried.Hypothermia (drop in bodytemperature below 95°C) canalso occur rapidly in coldenvironments if the inner layersof clothing are wet when youstop exercising.
• Moderate to high altitudesdecrease exercise capacity sincethe available oxygen in blooddecreases as altitude increasesdue to lower barometricpressure.
• Sandy terrain significantlyincreases energy expenditure upto 80% or greater as comparedto walking on a firm surface. Theenergy demand increases withthe difficulty of the terrain.
Sleep Loss
Lack of sleep can compromise yourmental capacities, including attention,logical reasoning, and mentalprocessing. In contrast, physicallydemanding skills seem little affected byup to 72 to 96 hours of sleep loss.
Protective Clothing
The type of clothing worn duringload-bearing is an importantconsideration for dissipation of bodyheat. Mission Oriented PersonnelProtection (MOPP) gear for nuclear,biological and chemical environments(NBC) is a very heat-restrictivegarment.
Guidelines with estimates for
work/rest cycles and hydrationguidelines when in MOPP gear areavailable. With load-bearing activitiesin MOPP gear, work/rest guidelinesshould be adjusted downward andhydration requirements adjusted upward,
since load-bearing activities have notbeen accounted for. The use of MOPPgear will be equivalent to adding 10°Wet, Bulb, Globe, Temperature (WBGT)to the existing ambient temperature.Therefore, the medical threat of heatillness will increase substantially inMOPP clothing.
Physical Training forLoadBearing
Most regular home exercise programsand weekly NSW training programs arenot adequate for the physical demands ofmoderate to heavy load-bearing. Thissection is designed to provide you withan appreciation of the physical demandsof load-bearing and an approach toinitiating load training.
Elements of a Load-BearingConditioning Program
The key elements for conditioning forload-bearing incorporate strength, speedand endurance training while relying onthe principle of specificity of training(see Chapter 1: Overview of PhysicalFitness). These are as follows:
♦ Load-bearing progressivemarches: Specificity of trainingis one of the basic trainingprinciples. To become better ormore skilled at a particularevent, the event must bepracticed. To be able to carryheavier loads for longer periods
of time, loads must be carried intraining.
♦ Resistance strength training:Load-bearing requires strength.Strength training will helpimprove load-bearing ability andperformance.
♦ Aerobic training: Aerobiccapacity is very important withrespect to load-bearing.Individuals with the highestmaximal oxygen consumption arebetter able to tolerate thephysical demand of moderate toheavy load-bearing and walk at afaster pace for longer durationswith less fatigue than individualswith a lower aerobic capacity.
♦ Anaerobic training: Anaerobicpower and muscular strength areneeded for high intensity combatactivities. Different musclegroups are used depending on thetype of load-bearing tasks,whether it is a fast paced, shorthump or a slower paced, longhump.
Strength training or endurancerunning alone will not improve
load-bearing ability.
The best training for load-bearingis cross country marches with a
pack.
Initiating Load Training
Basic guidelines should be followedwhen beginning heavy load-bearingtraining.
♦ Start with loads 20% of yourbody weight and short distances(5 miles) once per week at thebeginning.
♦ Progressively increase packweight for each training sessionafter two weeks: Loads shouldbe increased to 25%, 30%, and40% of body weight or greater(depending on the missionrequirements).
♦ After achieving pack weight of
40% of weight, progressivelyincrease distance: 7.5, 8, 9, 10,to at least 12.5 miles. Maintaindistance for at least one month.
Maintaining Load-Bearing Fitness
To maintain fitness for humping a loadequivalent to 40% of body weight for 10miles would require at least:
♦ Upper and lower body weighttraining two days per week.
♦ Running three to four days perweek for 30 minutes per session.
♦ One hump at least every otherweek, preferably once per week.
Optimizing Load-Bearing
The decision to calculate an optimalload-bearing weight per man is adifficult task. It is challenging to definean optimal load, since no “hump” isgoing to be conducted under idealconditions. Factors such as walkingpace, weight carried, climate, grade,type of terrain and clothing, etc., will allvary on any particular mission. Table10-1 presents factors essential forensuring energy conservation andcomfort. These factors combined withproper physical training, will serve tooptimize your load-bearing.
Table 10-1. Optimizing Load Carriage
Common MedicalConditions
A number of acute medical conditionsare associated with load-bearing. Mostare minor, but any one can potentiallyaffect your ability to maneuver quicklyand ultimately slow down the walkingpace of the squad or platoon. Byunderstanding the range of medicalproblems, you will be able to betterprevent, assess and treat these injuries.These medical conditions are allcovered in Chapter 12: Training andSports Related Injuries. The mostcommon injuries incurred during load-bearing are:
♦ Foot blisters (See Appendix C)♦ Back pain♦ Stress fractures♦ Rucksack palsy♦ Dehydration♦ Other minor lower extremity
injuries, such as foot and kneepain
Conclusion
Appropriate aerobic and anaerobictraining, along with bi-monthly traininghumps, will improve your ability forload-bearing, lower energy demands,and reduce the frequency ofmusculoskeletal injuries.
Acknowledgments
BM1 Pete Vernia, USN, AdvancedTraining Department, SDV Team1 LCDRBruce Willhite, USN, J-5, SpecialOperations Command Joseph Knapik,Ph.D.
Chapter 11
Training for SpecificEnvironments
Physical training in extremeconditions, such as hot, cold, or highaltitude environments, presents specialchallenges. Even highly accomplishedathletes can be quickly overcome by“environmental exposure” injuries ifproper preparation is overlooked or ifsigns and symptoms of impending illnessare ignored. To compound matters, manyextreme environments tend to be isolated
and difficult to access. Proper planningand preparation before entering suchareas can help ensure safe and beneficialtraining.
One way of adapting to a new
environment is “acclimation”.Acclimation is defined as thecontinuous or repeated exposure toheat, cold, altitude, or some newenvironment so as to provokephysiologic or biochemical changesthat allow you to better tolerate thenew environment. Thus, acclimation isthe gradual change the body goes throughas it adapts to a new environment. Thischapter will focus on training underenvironmental conditions which require
acclimation, and also under confinedspaces.
Training in HotEnvironments
Exercising in hot, humid environmentimposes a significant challenge on thebody. The human body maintains tightcontrol of body temperature throughseveral different mechanisms. Underconditions which impose large heatloads (example: strenuous exercise orwearing protective gear in a hotenvironment), the primary mechanismfor cooling is evaporation of sweat fromthe skin or evaporative cooling. Relativehumidity is the most important factorgoverning evaporative cooling: when thehumidity is high, evaporation is greatly
limited.
Your skin is like the radiator of a car;as the temperature of the body core risesit warms the blood and pumps it to theskin to cool off. Sweat is released at theskin and absorbs the heat from thewarmed blood. As sweat is warmed, itis vaporized the same way boiling waterturns to steam and thus removes a largeamount of heat from the body. Onlysweat that evaporates can effectivelycool the body; sweat that “drips” isessentially wasted fluid and provideslittle or no cooling effect. The bodymaximizes evaporative cooling by:
♦ Increasing Heart Rate: An
increase in the heart rateincreases blood flow to the skinand results in greater heattransfer to sweat and vapor.
♦ Increasing Sweat Volume:Beginning to sweat earlier andrecruiting more sweat glandsincreases the rate of sweatproduction, therefore cooling.
How hot is too hot? The degree ofdanger posed by a hot environment isusually determined by the wet bulb-globe temperature (WB-GT). If the WB-GT is over 87° F (30.5° C) or if no WB-GT is available and the temperature isover 85° F with a relative humidity of60% or above, exercise should be
avoided or undertaken with caution.
Factors that Hinder Body Cooling inthe Heat
♦ Humid Heat: As the humidityincreases, evaporative coolingslows due to saturation of the airwith moisture.
♦ Skin Disorders: Injuries such asdeep thermal burns, sunburn orrashes will prevent or hindersweating.
♦ Clothing: Any clothing that isimpermeable to water vapor willcompromise cooling.
Heat Acclimation
Adapting to a hot environment cantake one to three weeks; for physicallyfit individuals, 75% of acclimationoccurs during the first week of heatexposure. During this time, sustainedphysical activity is more difficult andonset of fatigue occurs with minimalphysical exertion. Acclimation involvestwo parts:
♦ Cardiovascular adaptations:Changes that gradually lead to alower heart rate for a givenworkload or intensity of exerciseThis is the most rapid changeduring acclimation to heat.
♦ Sweating: Sweating beginsearlier with exertion; sweat rateis higher and can be sustained forlonger periods of time. Sweatalso becomes more dilute thussaving essential bodyelectrolytes.
Maximizing Acclimation
Maintain Aerobic FitnessA solid base of endurance training
established before you enter a hotenvironment will ease thecardiovascular strain encountered duringacclimation. Pre-acclimation endurance
training must be rigorous enough to raisecore temperatures for acclimation to bemost beneficial. Aerobically fitindividuals will retain heat acclimationlonger once removed from a hotenvironment than less fit personnel.Remember: Aerobic fitness will helpspeed the acclimation process but is nota substitute for it.
Exercise in a Hot EnvironmentAny form of physical exercise will
hasten acclimation. However, theintensity will be lower than what you areused to. Refer to your local medicalofficer for guidance. If the environmentalconditions permit, gradually increase theintensity of exercise until you reach the
desired workload or level of training.
Maintain Adequate HydrationAcclimation results in an earlier onset
of sweating as well as an increase in thesweating rate. These changes translate toan increased need for fluids. Acclimatedpersonnel may produce as much as 8 to10 liters (8.5 to 10.5 quarts) of sweatper day. Thirst cannot be used as a“measuring stick” for proper hydration.When training in hot environments, aminimum of 10 to 12 quarts of water perday should be consumed, but not morethan 5 cups per hour. Drinking atfrequent intervals will decrease the riskof a potentially fatal heat stroke.
Maintaining Acclimation
Heat acclimation cannot be maintainedunless there is repeated heat exposureand even if repeated exposure ismaintained, other factors may cause aloss of acclimation. Factors that lead toloss of heat acclimation include:
♦ Sleep loss♦ Alcohol♦ Dehydration♦ Salt depletion♦ Illness/Infections♦ Cessation of physical activity
There is some disagreement as to howlong it takes to lose acclimation to heat,
but generally speaking after 2 weeks ofworking in a hot environment, it willtake 3 to 4 weeks before most of theadaptations are lost.
Heat Injuries
There are many categories andsubcategories of heat injuries. However,there are three classes of heat-inducedinjury that will be considered here:
♦ Heat cramps are painfulcontractions of muscles (usuallyin the extremities) followingvigorous exercise. They occurmost commonly inunacclimatized personnel. Nospecific cause is known(possibly depletion ofelectrolytes), but such crampsusually resolve whenacclimation is complete.
♦ Heat exhaustion is a potentiallyserious injury resulting primarilyfrom dehydration and electrolytedepletion. The affectedindividual may feel light-headed,dizzy, nauseous, fatigued, ordevelop a headache. If heatexhaustion is suspected, theinjured individual should beplaced in a cool location ifpossible and given replacementfluids by mouth or intravenously.
♦ Heat stroke is a life threateninginjury in which the affectedindividual loses the ability toregulate temperature and isovercome by soaring body coretemperatures (greater than 104°
F). Such high temperatures canirreversibly injure vital organsand result in death if not rapidlytreated. Many factors maycontribute to heat stoke — evenwell hydrated personnel maybecome victims if they ignore thewarning signs and symptoms (seethe following Table).
Table 11-1. Warning Signs of HeatStroke
Immediate medical attention isnecessary to prevent death. Alwaysremember the basics of first aid andcheck the ABC’s first (Airway,Breathing and Circulation). If possible,move the injured person to a cool areaand remove all of the person’s clothing.Wet the body with a fine mist of water orpour cool water over the body and fan tofacilitate cooling. If ice is available,apply bags of ice to the arm pits, groinand sides of the neck. Medical personnel
should start intravenous fluids andoxygen if possible and transport theindividual to the nearest medicaltreatment facility.
Many drugs and chemicals can
decrease your ability to tolerate the heat,and knowing which ones may interferewith performance can be important onmissions in hot environments. Table 11-2presents some of the most common drugsthat should be avoided in hot weather.
Table 11-2. Drugs and Chemicals to beAvoided in Hot Environments
Summary for Hot Environments
♦ Prepare by maximizing aerobicfitness—this will greatly help insudden in-out ops where gradualacclimation is not possible.
♦ Plan workout to avoid heat of theday.
♦ Optimize acclimation by acarefully scripted exerciseprogram from the medicaldepartment.
♦ Plan for decreased physicalperformance the first two weeks.
♦ Maintain proper hydration.♦ Be aware of any illness that may
predispose to dehydration(diarrhea, vomiting, fever).
♦ Always be aware of the warningsigns of heat illness: Payattention to your body. Slowdown or stop if signs orsymptoms of heat injury becomeapparent.
♦ Avoid drugs and other substancesthat predispose to dehydration orheat injuries.
Training in ColdEnvironments
Cold climates represent the harshestenvironments and pose the greatest threatto survive that SEALs face. Anunprotected man in an extremely coldenvironment will perish much faster thanwhen exposed to extreme heat. In coldweather, the human body attempts tomaintain a warm core temperatureprimarily by physiologic mechanismsand behavioral adaptations:
♦ Increased Metabolic HeatProduction: This occurs as thebody’s fuels (carbohydrates, fats
and proteins) are metabolized or“burned” at the cellular level.Shivering represents involuntarymuscle contractions that canincrease the body’s metabolicrate five to six times abovenormal.
♦ Peripheral Vasoconstriction:Blood vessels near the surface ofthe skin constrict or narrow in aneffort to divert warm blood awayfrom the cool surface of the skin.
♦ Behavioral Adaptations: Mansgreatest asset in cold weather ishis ability to create a warmmicro-environment by wearingappropriate protective clothingor seeking shelter. He can also
increase resting metabolic heatproduction by 10 times throughvigorous exercise.
What is a cold environment? As witha hot environment, the temperature aloneis not necessarily the best indication ofcoldness. In the heat, humidity, and in thecold, the wind, can greatly change yourcomfort level. In the cold, windaccelerates heat loss by replacing thewarm layer of air surrounding the bodywith colder air. As a rule, you can besure it is a cold environment when theambient temperature is below 15° F andthe wind speed is greater than 25 mph.Such environments pose potentialdangers to those exposed for any length
of time.
Factors that Compromise Adaptationsto Cold
♦ Inadequate Energy Intake:Reduces the ability to generate“metabolic” heat.
♦ Injury or Poor PhysicalConditioning: Inhibits ability togenerate heat through vigorousexercise.
♦ Dehydration: Places greaterdemands on the heart and speedsup fatigue.
♦ Low Percentage of Body Fat:Subcutaneous fat has insulatingproperties which help protectagainst heat loss. This is aconcern for SEALs, who usually
have low body fat.♦ Excessive Sweating: Dress
appropriately using a layeringsystem and ventilate as necessaryto avoid excessive sweating.Sweat will destroy the insulatingqualities of cold weatherclothing and cause unwantedcooling by evaporation andfreezing
♦ Alcohol: Increases peripheralblood flow which promotes heatloss and causes core temperatureto fall more rapidly.
Acclimation to the Cold
Unlike acclimation to hotenvironments, there is little evidence tosuggest that in humans, there is asignificant physiologic adaptation to thecold. There is evidence to suggest thathands which are exposed to the cold for30 minutes per day for three weeks willreceive more blood flow and graduallybecome more “functional”. However,there is greater heat loss through handsconditioned in this manner.
Cold Injuries
The spectrum of cold injuriesexperienced in the SEAL community isbroad but all can be avoided by wearingappropriate clothing and paying attentionfor signs and symptoms of cold injuries.
Hypothermia
A lowering of body core temperaturebelow 95° F is not an uncommon coldinjury of SEALs and mild hypothermia isa relatively easy injury to treat.Moderate to severe hypothermia is lesscommon and should be treated as a
medical emergency. Some warning signsof a falling body core temperatureinclude:
♦ Uncontrollable shivering♦ Slurred speech♦ Clumsiness♦ Slowed thought process♦ If shivering stops but all other
signs are present - it could be anindication of severe hypothermia
If any of the above signs occur,immediate action should be taken toprevent further injury or death. Alwayshandle personnel suspected of havinghypothermia gently - do not allow themto perform vigorous exercise to warm up
as this may cause cardiac arrest.Remove wet clothing and place theindividual in dry blankets or sleepingbag with one or two other dry and warmpersonnel. Never completely immersea hypothermia patient in warm/hotwater as this may result in cardiacarrest. Passive rewarming is usuallysatisfactory for mild hypothermia, butmay not be adequate for severe cases.
Gentle rewarming is the safestmethod of restoring normal body
temperature.
Frostbite
Frostbite is a freezing injury whichmost commonly affects the hands andfeet. However, it can occur to anysurface of the body that is not adequatelyprotected. Symptoms often follow aprogressive pattern to include the initialsensation of cold followed by numbnessand eventually pain during rewarming.The skin may appear normal or appearpale. If a frostbite injury is suspected,attempts to thaw the affected tissueshould be avoided until there isabsolutely no chance of it refreezing.Frostbitten feet should not be thawed ifit is necessary for the injured to walkunassisted to the extraction or medevacsite. Rewarming is associated withsevere pain and may turn walking
wounded casualties into nonambulatorycasualties. All cases of frostbite requireevaluation at a definitive medicaltreatment facility.
How to avoid freezing injuries
♦ Dress appropriately and keephands and feet as dry aspossible.
♦ Do not touch metal with barehands/skin. Tape frequentlytouched metals to reduce thisrisk.
♦ Wear protective goggles whenexposed to high wind speedssuch as in snowmobiles, aircraft,skiers.
♦ Use the “buddy system” to checkeach other for unprotected skin.
Immersion Foot
Also known as “trench foot”, thisnonfreezing foot injury results in tissueand nerve damage after prolongedexposure of wet feet to the cold (32 to50° F). Immersion foot can be preventedby keeping feet as dry as possible and byavoiding tight fitting boots.
Nutritional Requirements
Special attention should be paid tonutritional requirements in coldenvironments. Energy requirements mayincrease several fold because of theincreased work associated withperforming physical tasks in coldweather and the caloric losses toshivering which can rapidly depleteglycogen stores. Carbohydrates are anexcellent source of energy forreplenishing depleted glycogen. Refer tothe U.S. Navy SEAL Nutrition Guide forspecific nutritional needs during coldweather operations.
Summary for a Cold Environment
♦ Check weather conditions anddress appropriately.
♦ Allow for a longer warm up.♦ Avoid profuse sweating.♦ Replenish body fuel
(carbohydrates) duringendurance events.
♦ Maintain hydration.♦ Avoid drugs that cause
dehydration: alcohol, caffeine.♦ Be aware of the signs of cold
injury.♦ Use gentle rewarming for
hypothermia victims.
Training at Altitude
An athlete’s performance can sufferdramatically when he rapidly ascends toaltitude. Several factors contribute tothis decrement in performance but themost significant factor is the relativehypoxia or lack of oxygen available todo work at higher altitudes. Manychanges occur during extended exposureto high altitudes; most occur after 2 to 3weeks. The major adaptations that affectperformance and ability to do workinclude:
♦ Increased oxygen carryingcapacity of the blood
♦ Increased density of blood supply
to and within muscle♦ Increased oxygen carrying
capacity of muscle♦ Increased respiratory rate
Decreased oxygen at altitude reducesthe maximal aerobic capacity of anathlete by 1% to 2% for every 100 meter(328 feet) rise above 1,500 meters(4,918 feet). Therefore, an eliteendurance athlete may only be able toperform at 65% to 85% of maximalaerobic capacity at 10,000 feet whencompared to sea level. Athletes thatcompete in anaerobic events, such assprinters or weight lifters who performbrief (2-3 minutes) episodes of maximaleffort events, may notice no initial
difference in performance becausesustained maximal oxygenation ofmuscle tissue is not necessary.
Acute Mountain Sickness
Acute Mountain sickness or AMS istypically a transient mild illnessresulting from ascents to altitudes above8,000 feet (2,440 meters) or ascents at arate greater than 1,000 feet (305 meters)per day above 8,000 feet. Symptomsinclude headache, nausea, vomiting,fatigue and poor appetite. The symptomsusually disappear within a few days.Some individuals, however, may have todescend to gain relief. Life threateningcomplications of AMS include HighAltitude Pulmonary Edema (HAPE) andHigh Altitude Cerebral Edema (HACE);both require immediate descent. Theincidence and severity of AMS may be
reduced by taking Acetazolamide(Diamox) 24 to 48 hours prior to andduring an ascent. The dosage is 125 mg.by mouth, twice a day for two days, butthis medication should only be givenunder the direction of a physician.
When participating in high altitude
operations, you should report any of thefollowing symptoms to your corpsman ormedical officer:
♦ Cough or progressive shortnessof breath
♦ Coughing up blood or frothy spit♦ Progressive symptoms of
headache♦ Mental confusion or difficulty
thinking♦ Visual disturbances♦ Lack of urination in excess of 8
hours♦ Excessive irregular breathing
Other Factors that HinderPerformance at Altitude
Temperature
In general, temperature decreases 6.5°C for every 1,000 meter rise in elevation(or 11.7°F/ 3,280 ft.). At extremealtitudes (above 5,000 meters or 16,400ft.), the combined effects of hypoxia andhypothermia may make sustained aerobicactivity extremely difficult if notimpossible.
Dry Air
Relative humidity falls as oneascends. Combined with the increasedventilatory rate experienced at altitude,significant water loss can occur from thenormally moist respiratory passages.Cold temperatures will also cause anincrease in urinary output and togetherthese two sources of water loss canresult in rapid dehydration. Thirst cannotbe used as a “measuring stick” forhydration status and personnel mustconstantly replace fluids with frequentwater breaks.
Weight Loss
Most people who ascend to 13,000feet (4,000 meters) or higher willexperience a weight loss of 3% to 5% inthe first 2 weeks at altitude. Some of thisloss is muscle mass and appears toresult from a decrease in the size ofindividual muscle fibers. There areseveral reasons for this weight loss:
♦ Increased energy expenditure♦ Decreased appetite due to a
direct effect of hypoxia and adecreased sense of taste
♦ Loss of body water♦ Acute Mountain Sickness - Please
refer to The Navy SEALNutrition Guide for dietaryrecommendations at altitude
Acclimation to Altitude
Prolonged exposure to altitude willbring about several physiologic changesand result in improved exercisetolerance at submaximal effort levels. Atlevels above 10,000 feet (3,050 meters),maximal aerobic capacity is limited andis lower than what would be measuredat sea level. Below 10,000 feet,maximal aerobic capacity may approachsea level values, but usually only after a2 week acclimation period. Because ofthis inability to achieve maximal aerobiccapacity above 10,000 feet, eliteendurance athletes may experience mildto moderate aerobic deconditioning withextended stays at altitude.
Training in Confined Spaces
During deployments or extendedtraining exercises it is not uncommon tobe confronted with conditions whichmay limit physical training routines.Complete cessation of physical trainingwill result in a significant and rapidreduction in both strength and endurancecapacity (see section onDeconditioning). Submarines and smallassault craft probably create the greatestchallenge, but under almost allcircumstances where time is not alimiting factor a reasonably wellbalanced training program can bemaintained with a minimal amount ofequipment. The following is a list of
both aerobic and anaerobic trainingmodalities for confined spaces:
♦ Calisthenics♦ Pull-ups and dips♦ Grip balls for grip strength♦ Resistance equipment such as the
Exergenie which imitateswimming strokes and are verylight weight
♦ Therabands, another lightweightresistance tool to maintainstrength in major muscle groups
♦ Jump rope♦ Stair stepping (monotonous but
good aerobic workout withoutneed of special equipment)
♦ Plyoball
♦ Free weights♦ Running in place
For larger platforms or forwardoperating bases with physical securitylimitations, the following equipment inaddition to weights should also beconsidered:
♦ Climbers♦ Cycle ergometer♦ Rowing machine♦ Stair climber♦ Treadmill♦ Ski machine♦ Upper arm ergometer
Physical fitness equipment on a
submarine should, at a minimum,include a cycle ergometer, a
rowing machine and free weights.
The stationary cycle and rowingmachines should have a performancemonitor to display time, distance, etc.,so that progress on stationary equipmentcan be charted and monitored. Platoonsdeployed under confined circumstancescan reduce the monotony of stationaryequipment and boost training morale bycreating competitions. Monitoring andcharting each members daily PTprogress will help demonstrate results,encourage physical training, andmaintain physical fitness.
Deconditioning
When a person is unable to maintainhis exercise program, for whateverreason, detraining or deconditioningoccurs rapidly. Numerous studies haveinvestigated the effect of detraining oncardiorespiratory fitness, and significantreductions in work capacity has beennoted within two weeks. A 25%decrease in maximal oxygen uptake hasbeen reported after three weeks, whichis equivalent to a 1% decline inphysiologic function for each day ofinactivity. In addition, the proportion andsize of the Type II fibers have beenshown to decrease with detraining. Incontrast, maximal muscle strength
appears to be more resilient to periodsof inactivity. A reduction in maximalcapacity only means that it will beharder for you to do a given task thanprior to deconditioning. You will stillbe able to do the work. Remember:
The benefits of training aretransient and reversible.
Although maximal aerobic capacity isnot maintained without training, otherkey factors can lead to a decrease inaerobic capacity which will ultimatelyreduce your work capacity. Theseinclude:
♦ Increasing age
♦ High altitude♦ Dehydration♦ Loss of lean body weight
Chapter 12
Training and Sports RelatedInjuries
One of the hazards of being a SEALor an athlete is becoming injured. InBUDS training, 1 out of 3 potentialSEALs sustain an injury that may curtailtraining or require them to drop out oftraining. Sustaining either a suddeninjury or an overuse musculoskeletalinjury can mean loss of work days,forced rest, and pain for a period of daysto weeks. More severe injuries result in
scar tissue formation at the site of injury.Thus, the purpose of this chapter is todescribe:
♦ Treatments for training-relatedinjuries
♦ Reconditioning for return to fullactivity
♦ Types of training injuries♦ Common mission-related injuries♦ When to seek medical care
The goal is NOT to have you treatyour own injuries, but rather to beinformed so that you will seekappropriate help when needed. Centralto the rapid recovery from training-related injuries is a step-wise
reconditioning program which startsimmediately after the injury. Suchprograms are designed to arrest theinflammatory process, promote healing,and accelerate the return to full duty.
Treatments forTrainingRelated Injuries
Sudden, traumatic, or acute injuries tothe musculoskeletal tissue quickly resultin inflammation, a process characterizedby localized warmth, swelling, rednessand pain. If left unchecked, however, theinflammatory process rapidly leads to:
♦ Tissue congestion♦ Stiffness♦ Weakness♦ Decreased range of motion♦ Loss of normal function
A highly successful Sports Medicineapproach to accelerate the healing of any
injury is to first decrease theinflammatory process (swelling, painand warmth), and then increase the rangeof motion at the joint. RICE and ISE arethe approaches used to achieve thesegoals.
RICE = Rest, Ice, Compression& Elevation
After decreasing inflammation by RICE,range of motion at the joint is achievedthrough continued use of ice (I),stretching of the injured ligament ortendon (S), and weight bearing exercises(E).
ISE = Ice, Stretching, & Exercise
Reduce Inflammation
RICE (rest, ice, compression,elevation) is appropriate for all strainsand sprains. In general, if an operatorcannot bear weight on the extremity, restis indicated and x-rays to rule out afracture should be completed as soon aspractical.
♦ “REST” means applying noweight or only partial weight tothe extremity; crutches should beused for locomotion. “RelativeRest” means decreasingactivities that cause pain andreplacing them with otheractivities that are pain-free.
♦ “ICE” means applying ice. Thisshould continue until swellinghas stabilized.
♦ “COMPRESSION” meansapplying an Ace wrap or similarcompression wrap to the injuredpart for periods of 2-4 hours.Never sleep with acompression wrap appliedunless medically advised.
♦ “ELEVATION” means placingthe injured part above the levelof the heart; this allows gravityto help reduce the swelling andfluid accumulation.
Application of Ice
Ice serves a variety of important rolesin the treatment of training and sportinjuries, including:
♦ Reduces swelling thataccompanies inflammation
♦ Decreases muscle spasm and pain♦ Allows for less painful range of
motion♦ Enhances blood flow back to the
site after it has been removed
The operator should not wait fora medical evaluation before using
ice.
All soft tissue or joint injuries,except open wounds, will benefit byimmediate application of ice (SeeTable 12-1). Ice can be applied eitherpassively or actively. Passiveapplication is when you take some formof ice: crushed ice, ice slush, an icepack, or snow and apply it to the injuredbody part. Active application is whenyou take the ice (perhaps in water frozenin a cup or bag) and massage the injuredpart with the ice. At home, a bag offrozen peas is an excellent way topassively ice the injured part, as thepeas easily conform to the swollen area.After 20 minutes, the bag of peas can betossed back into the freezer forreapplication later. The normal response
to ice includes cold, burning, aching andfinally numbness over the affected part.This progression occurs over 7-10minutes.
Ice can be applied eitherpassively or actively. Do notapply ice directly to the skin.
Table 12-1. Tips for Applying Ice:Passive and Active
Caution: To prevent skin ornerve damage, do not keep ice on
for more than 20 minutes,especially when applying to the
elbow, wrist, or behind/side of theknee.
Range of Motion
The term range of motion is used todescribe the extent to which a particularjoint can be moved; achieving completerange of motion is the goal, butsometimes injuries restrict the range ofmotion. During the 20 minute icingsession, you should attempt to move theinjured part through a pain-free range ofmotion. Days later you can attempt aresistance activity which stresses theinjured part while moving the jointthrough a range of motion that can betolerated. An example would be movingthe ankle up and down against resistanceapplied by holding a towel under thefoot (Figure 12-1). Continued elevation
and use of a compression wrap whiledoing these exercises will retardswelling.
Figure 12-1. Moving the AnkleThrough its Range of Motion (ROM)with Resistance
Non-Steroidal Anti-InflammatoryDrugs (NSAIDs)
All of you have taken non-steroidalanti-inflammatory drugs (NSAIDs) atsome point in your career, either asprescribed by a physician or on yourown. NSAIDs are often used as the firsttreatment for overuse injuries becausethey are effective: NSAIDs decrease thesymptoms due to inflammation (i.e.,swelling, pain, tenderness, feverassociated with injury). Although theyare usually available over-the-counter,they are not a medication to take lightly.NSAIDs are used in training relatedinjuries when there is inflammationcaused by:
♦ Tendonitis♦ Bursitis♦ Sprains/Strains
In the case of an acute injury whichinvolves bleeding (including bruising)or swelling, NSAIDs should not bestarted for 2 to 3 days or until theswelling has stabilized.
NSAIDs may cause side effects.
The most frequently reported sideeffects include:
Gastrointestinal distress such asnausea, heartburn, or vomiting
♦ Gastrointestinal ulcers/bleeding Increased blood pressure
♦ Decreased ability of blood to clot Exacerbation of asthma
♦ Potential kidney damage withlong-term use
Remember: NSAIDs should not beused, or should be used with extremecaution, in conjunction with alcohol, asboth irritate the stomach. Table 12-2provides a list of the most commonlyprescribed (or over-the-counter)NSAIDs, with their generic and commonbrand name.
Table 12-2. Generic Names (andCommon Names) for Various Non-Steroidal Anti-Inflammatory Agents
If you have stomach or othergastrointestinal tract problems, Tylenol(acetaminophen) may be a better choicefor relieving muscle soreness thanIbuprofen-and Aspirin-based products.
Reconditioning for Returnto Full Activity
After the pain and swelling arereduced and the desired range of motionis achieved, ask the physician, therapistor trainer to design a reconditioningexercise program with the overall goalof a rapid return to full activity. Theexercises prescribed will be specific tothe site and type of injury, and will worktowards the following specific goals ofmaximizing:
Flexibility Endurance Speed
Strength Power Specific Duty Tasks
Each step should be successfullycompleted in a step-wise manner beforereturning to unrestricted activity.Definitions of most of these terms can befound in Chapter 1, however, theimportance of each is described next.
♦ Strength and flexibility areclosely linked. If flexibility isnot balanced around a joint, orstrength is maintained throughonly part of the range of motion,the risk of delayed healing or re-injury is high.
♦ With respect to endurance, themuscle quickly becomesdeconditioned during the body’srepair process and fatigues.Endurance is important in aninjured ankle for example, as itmay feel strong when rested butbe prone to re-injury as themuscles and tendons around itbecome fatigued with activity.The strategies for anyrehabilitation program includeimproving individual muscleendurance while maintainingcardiovascular or total bodyendurance.
♦ In terms of power, a weak,deconditioned muscle is prone to
re-injury when called upon toperform a power move.Strategies for developing powerinclude rapid motion againstresistance, use of rubber bands,medicine balls or weightmachines.
♦ Sustained speed provides forreconditioning the injured part toanaerobic (without oxygen)activity and coordination ofmovement. Interval training (e.g.,sets of 440 yards over 90seconds) several times per weekis an excellent supplement to therehabilitation of a lowerextremity injury, provided theoperator performs the activity
below the pain threshold.
Continued use of ice and intermittentapplication of electrical stimulation,ultrasound and other therapeuticmodalities will help accelerate the rapidreturn to full activity.
Return to Mission-Related Tasks
Ultimately, the operator must return toperforming specific tasks required tocomplete the mission. This component ofreconditioning MUST NOT beoverlooked. Determine the specificmission-related tasks or training thatputs the operator at risk for re-injury.These tasks should be practiced atslower speeds in a controlled setting,and proficiency should be demonstratedprior to a return to full duty. The ultimategoal is to return the injured operator tocontrolled physical activity in 4-7 daysfor a mild to moderate injury and 1 to 2weeks for a severe strain or sprain.
General Guidelines for Returning toPhysical Activity
A number of general rules applyduring the repair and reconditioningperiod. These include the following:
♦ If the operator has pain withflexibility work, vary the degreesof motion.
♦ If there is pain with strength andpower work, vary the repetitionsand/or weight.
♦ If there is pain with endurance orspeed work, vary the distanceand/or time.
♦ If there is pain with specificmission-related tasks, vary the
quickness and/or time requiredto complete these tasks.
In summary, rehabilitation andreconditioning places its greatestemphasis on rapidly decreasing pain andincreasing range of motion about theinjured joint by using “RICE” and“ISE”, followed by specific exercisesto maximize flexibility, strength,endurance, power, and speed, and usingice as necessary.
Types of Injuries
A variety of injuries can beencountered during SEAL and otherforms of physical training. In this sectionwe will start with those problems thatmay be relatively minor and cause milddiscomfort, and then proceed to moreserious injuries that may limit youractivities.
TrainingRelated Muscle Soreness
Delayed soreness in a deconditionedmuscle is normal, and is caused bymicro-injury. Pain and tendernesstypically appear 12 to 48 hours afterbeginning a training session. Stiffnessand soreness are worse after the cooldown and resolve again after warmingup. This normal process usually persistsfor 7-12 days and then disappears.
Table 12-3. A Process of AlleviatingMuscle Soreness
Contusions
A blow to the muscle belly, tendon orbony prominence may cause swellingand bleeding into the tissue and form acontusion. The blood may coagulate andeventually form scar tissue, impedingnormal function. Passive ice therapyneeds to be started as soon as possible.After swelling has stabilized, start withactive icing and then use Cross FrictionMassage. This is a simple techniqueused to reduce the swelling andcongestion. The thumb or index and longfingers are used to apply firm pressureperpendicular to the long axis of thetendon or muscle (Figure 12-2). Theinjured part is rubbed in this manner for
10 minutes, four times a day.
Figure 12-2. Technique of Cross-Friction Massage
Sprains and Strains
Ligaments attach bone to adjacentbone and can be damaged in a fall, anaccident, or through overuse. Suchinjuries are called sprains and includeacute back sprains, knee sprains, orankle sprains. Sprains are graded asmild, moderate or severe. Mild sprainsrefer to overstretching and microtears ofthe fibers. A partial tear, with or withoutinstability or looseness, is consideredmoderate. A severe sprain implies acomplete or near complete tear of tendonfibers that results in looseness orinstability at the joint.
A sprain is a damaged ligament.
Tendons attach muscle to bone.Muscle or tendon injury is referred to asa strain or tendonitis. Tendonitis,including achilles tendonitis, shouldertendonitis, hamstring or quadricepsmuscle strains, fall into this category.
A strain or tendonitis is an injuryto a muscle or tendon.
Mild to moderate lower extremitysprains and strains heal without residualproblems if treated early. Primarytreatment includes ice and NSAIDs,partial weight bearing with crutches asnecessary, and early therapy to maintainrange of motion at the joint.
Muscle Cramps
Muscle cramps are common and maybe precipitated by prolonged physicalactivity, high heat and humidity (blackflag conditions), dehydration and/orpoor conditioning. Cramps arecharacterized by the sudden onset ofmoderately severe to incapacitating painin the muscle belly and may progress toinvolve other adjacent muscle groups.The first treatment consists of immediaterehydration with a fluid containingelectrolytes. After beginningrehydration, further treatment shouldconsist of grasping and applyingpressure to the muscle belly andimmediately putting the muscle on
stretch until the cramp resolves. The calfmuscle, for example, would be stretchedby flexing the foot toward the head,whereas a thigh cramp would be treatedby flexing the knee, bringing the foot tothe buttocks. Pictorial representations ofprocedures for treating these cramps arepresented in Figure 12-3. In addition tothese procedures, adequate rest shouldhelp prevent recurrences.
Figure 12-3. Examples for TreatingPainful Muscle Cramps in the Calf andQuadricep Muscles
Fractures
A true fracture involves a break orchip in the hard outer surface of thebone. With few exceptions, true fracturesof the lower extremity require a periodof immobilization in a cast andsupervised care by a medical officer.
Stress fractures differ from truefractures and are most commonly seen inthe load-bearing bones of the lowerextremities, i.e. pelvis, femur, tibia,fibula and bones of the foot. They arecaused by excessive strain on the bone.Bone constantly undergoes remodellingand repair in response to the stress ofweight bearing. The repair process isaccelerated by rest, and is slowed in
times of heavy exercise as with runs,hikes, marches and prolonged training.When the breakdown process exceedsthe bone’s ability to repair itself, a stressfracture may result. As the lowerextremity bone becomes weakened,weight bearing activity, such as running,may cause a vague, achy pain at or nearthe weakened site. The first symptoms ofstress fractures are initially poorlylocalized and often ignored. Later, as theprocess continues, the bone will becometender in a very localized area and willoften ache at night or at rest. Ultimately,if left untreated, continued weightbearing may cause a true fracture withinthe weakened area of bone. Physicaltraining factors which increase the risk
for stress fractures include:
♦ A change in training surface(grass to asphalt, dirt toconcrete)
♦ A change in shoe wear (worn outshoes or boots or new runningshoes or new boots)
♦ An increase in physical activity(too much, too fast, too soon)
All suspected stress fractures shouldbe evaluated and followed by themedical officer. Treatment for stressfractures include:
Reduction or avoidance of impactand load bearing activities
Partial weight bearing with
crutches and advancing to fullweight bearing when pain free
This process typically takes two tofour weeks. Stress fractures are usuallynot casted when strict non-weightbearing or partial weight-bearinginstructions can be assured. Thereconditioning process should includeswimming or water exercises (such asdeep water running) to maintainflexibility and aerobic endurance. Aprogram of lower extremitystrengthening exercises should be startedas soon as tolerated.
True fractures require a period of
immobilization which varies depending
on the bone involved. However, after thecast has been removed, the extremityshould undergo a reconditioningprogram.
After the weight-bearing restriction
has been lifted, the individual can begina reconditioning program for running. Areturn to running should ideally beinitiated on a treadmill. This allows theindividual to customize increases induration and speed while monitoringpain at the stress fracture site. A typical“return-to-running” program is presentedin Table 12-4.
Table 12-4. Return to Running Post
Injury
Common Mission andTrainin Related Injuries
Given the nature of the SEAL’soccupation, it is not surprising thatinjuries occur during training andmission-related scenarios. Clearly, thetype of injury will depend on thespecific physical tasks and theenvironments under which the tasks areperformed. Table 12-5 presents a briefsummary of some of the anticipated andcommon injuries that may occur duringmission-related platforms. Other thanthese platforms, many of the injuries area result of activities all SEALsparticipate in, namely swimming and
running.
Table 12-5. Musculoskeletal InjuriesAssociated with Mission-Elements
Swimming
Swimming is a non-impact activityinvolving maximum tension on themuscle-tendon unit. Most injuries resultfrom overuse and over training, ratherthan from one traumatic event.Consequently, once an injury occurs,healing can prove difficult.
The older, experienced operator,
despite a high skill level, faces theadded challenge of tendons and jointcapsules that are less resilient, musclesthat take longer to warm up, andflexibility which is more difficult tomaintain. All of these factors can lead to
an increased risk of overuse and acuteinjury in this age group. The mostcommon injuries arising from enduranceswimming are sprains, strains andoveruse injuries of the shoulder, kneeand back.
Stroke-Associated injuries
Freestyle, butterfly, and backstrokeplace a great amount of stress on theshoulder joint. Use alternate or bilateralbreathing on freestyle and be sure to getplenty of roll on backstroke. Beforebeginning a butterfly set, be sure you arewell warmed up. This will allow theshoulder to stay in a more neutralposition during the activity of arm
recovery and this neutral position helpsprevent what is known as“impingement syndrome” (describedlater in Table 12-8).
Freestyle swimming and kicking
with a kickboard places a great amountof stress on the low back because ofhyperextension; doing the backstrokerelieves the stress. A pullbuoy is alsohelpful as it raises the hips and allowsthe spine to assume a more neutralposture.
Kicking with fins may aggravate the
knee (especially the knee cap) and resultin a degenerative condition known as
patellofemoral syndrome, whichcommonly afflicts athletic individuals(described later in Table 12-8).
The breaststroke kick helps balance
the knee joint by increasing musculartone on the inside of the quadricepsmuscle, and serves to balance the effectthat running has: increasing musculartone on the outside portion of thequadriceps muscle. However, thebreaststroke may actually intensifyiliotibial band syndrome (describedlater in Table 12-8). Swimmers mayneed to avoid doing breaststroke if theyfeel increased pain over the outside ofthe knee.
Running and Hiking
Running and hiking work large musclegroups and enhance cardiovascularfitness in a short period of time. Hikingtransmits a force to the spine ofapproximately three times load-bearingweight. Running transmits an impactforce to the spine of up to five timesload-bearing weight. These forces areminimized with good body mechanics,shock-absorbing shoes and cross-training for overall fitness. Table 12-6outlines common running injuries.
Table 12-6. Common Running Injuries
Knee Sprains
A complete discussion of kneeinjuries is beyond the scope of this text.Medial and lateral collateral ligamentsprains can be placed in a range-ofmotion (ROM) brace to allow earlyflexion and extension while protectingthe damaged ligament.
A knee immobilizer brace that extendsand immobilizes the knee straight outshould be used with caution. Within 72hours of using this type of brace, thethigh muscle is weakened and atrophied(muscle wasting as a result of disuse).However, this type of brace must beused with patella (knee cap) fracturesand patellar dislocations. While in this
brace, strengthening exercises should bestarted as early as possible to avoidmuscle atrophy.
Ankle Sprains
Ankle sprains are ideally treated in anaircast or similar splint. Ice, crossfriction massage, partial weight-bearing,and early range of motion is allowedwhile protecting the injured ligament.Some severe sprains may requiresurgical intervention.
Overtraining Syndrome
The most common physicalconditioning error for the SEAL operatoris overtraining. Overtraining is exactlywhat the word implies, a conditioncaused by:
Too Much Physical Activity
Physical training for the operator differsfrom programs designed for eliteathletes. The athlete in professional orcollege sports has an off-season to restinjured muscles and tendons, utilizephysical therapy, maximize strength andflexibility, and finally cycle back into hissport. The SEAL team operator has no
such luxury and training is a full timejob. Typically he trains to peak levelsyear round. It is this repetitive, peakperformance conditioning schedule thatmay lead to overtraining and overuseinjuries.
The OVERTRAINING
SYNDROME can present with a widerange of physiologic or psychologicalsymptoms which vary widely amongindividuals (See Table 12-7).Overtraining is generally associatedwith endurance sports such as swimmingor running.
There is no good laboratory or
biochemical marker for overtrainingsyndrome. The BEST INDICATORSare resting heart rate in the morning andassessment of mood. Resting heart ratetaken daily just before getting out of bed,and monitored over time will give someindicator of fitness as well as fatigue.Individuals who are overtrained willshow a resting heart rate which is 10-15beats per minute higher than baselinewhen measured over a period of severaldays. A day or two of abstaining fromphysical activity should show a return tobaseline. The operator who continuesendurance activities despite the baselineelevation in heart rate will only becomemore overtrained.
Table 12-7. Characterization andSymptoms of Overtraining Syndrome
Changes in mood or mood swings mayalso be a signal that the individual isovertraining. Little data exist on mood
assessment in the SEAL community.Typically, assessment of mood isaccomplished with questionnaires.However, individuals who areovertraining and give an honestassessment of mood will consistentlyreport feelings of frustration, anger,depression or an inability to feelanything at all.
Cross-training, rest days,monitoring of morning heart rate,
mood assessment, and takingtime off from certain physical
activities will reduce overtrainingerrors.
Overtraining differs from
“overwork,” which is the temporarydeterioration of performancecapabilities due to an increase in thevolume or intensity of training.Overwork is what typically happens toBUDS students. Physical and mentalperformance deteriorates in the mostdemanding parts of the training schedule,only to rebound quickly as the schedulelightens up. Unlike overtraining, theoverworked individual is able to showan increase in physical performancewhen faced with a greater workload orphysical challenge.
When to Seek Medical Care
Table 12-8 provides the symptoms,preventive measures, and selectedtreatment modalities for commontraining and mission-relatedmusculoskeletal injuries. This list ispresented for information and to helpyou determine whether you need to seekmedical treatment. However, there arenumerous conditions which demandimmediate medical attention.
Conditions Requiring Immediate
Evaluation by Medical Personnel:
♦ Back pain that radiates into the
thigh, leg or foot♦ Severe pain♦ Numbness♦ Joint dislocation♦ Suspected fracture♦ Any lower extremity injury in
which the individual is unable tobear weight
♦ Pain which limits activity for 3 to5 days
♦ Any hip pain which causes a limp
Table 12-8. Symptomes, Prevention,and Treatment of Conmmon Training-and Mission-Related Injuries
Chapter 13
Harmful Substances thatAffect Performance
SEALs and other elite athletes arealways looking for ways to improvetheir physical performance and gain acompetitive edge to enhance theirsuccess in missions or competition.Often there is a temptation to seek otherways of increasing your capabilities,including trying various ergogenic agentsor chemical substances, either natural orman-made, that promise to give an edge.
This chapter reviews some of thosechemicals that may give you a temporaryedge, but the minor improvements youmight see in the short-term can beharmful in the long-term. The goal of thischapter is to inform you of thedetrimental effects and the legalconsequences of using chemicals asperformance enhancers. This chapter isnot intended to support or promote theuse of these chemicals for improvingyour performance.
Anabolic/AndrogenicSteroids
Anabolic/Andro genic steroids,hereafter referred to as AAS, have beenused by athletes to improve performancefor more than 30 years. The non-medicaluse of AAS is widespread amongathletes engaged in power sports such aspower-lifting, bodybuilding, footballand rugby. Their popularity stems fromtheir perceived contribution to increasemuscle bulk and strength and to improvecompetitiveness. There are more thanone million estimated users of AAS inthe United States alone. Approximately2% of athletes between the ages of 10
and 14, and 5% to 10% of high schoolathletes have used AAS, even thoughtheir use is prohibited. In addition,approximately 5% of college athletescurrently use AAS. Because of legal andadministrative issues it is difficult toestimate the number of Olympic andprofessional athletes currently using thedrugs. However, a number of OlympicGold Medalists have had their medalswithdrawn for using such substances.The use of AAS for improvedcompetitiveness violates ethicalprinciples and is strictly prohibited bythe military services as well as theUnited States Olympic Committee(USOC) and other national sportsgoverning bodies.
How do Anabolic Steroids Work?
AAS are synthetic derivatives of thehormone testosterone, which isresponsible for the development of malecharacteristics. The pituitary gland in thebrain controls the production oftestosterone in the male testes.Testosterone has both androgenic(masculinizing effects) and anabolic(tissue-building) properties. The mainfunctions of testosterone in an adult areto:
♦ Promote secondary male sexcharacteristics, such as hairpatterns and deepening of voice
♦ Increase muscle mass
♦ Initiate and maintain spermproduction
Anabolic steroids were developed bystructurally altering testosterone toreduce its breakdown, and to maximizeits tissue-building (anabolic) effects.The more commonly used anabolicsteroids are listed in Table 13-1. Thisclass of steroids was first usedtherapeutically to treat certain disordersof the blood, bone mass deterioration,protein wasting states, and as areplacement therapy for male childrendeficient in testosterone.
AAS should not be confused withcorticosteroids which act as anti-
inflammatory agents and are usedto treat a variety of medical
conditions.
Table 13-1. Commonly UsedAnabolic/Androgenic Steroids
How Anabolic Steroids AlterMetabolism
In a progressive weight trainingprogram, muscles are challenged togrow in size and strength in order tomeet the increasing workload placedupon them. The structure of muscleconsists chiefly of protein. Strength andsize gains are achieved primarily byincreasing the amount of protein insidethe muscle. Protein requirements of thehuman body are determined by acomplicated and difficult procedurecalled nitrogen balance. The body mustingest an adequate supply of protein inthe diet to process, absorb, and retainnitrogen to support the weight training.
The stress of intensive strength
training induces a catabolic state. In thisstate, muscle protein is broken down, buta state of anabolism or muscle proteinformation follows. By an unknownmechanism, AAS enhance the anabolicprocesses. Anabolic steroids improvethe body’s nitrogen balance by reversingthe catabolic state; thus muscle proteinsynthesis is supported. AAS are alsobelieved to directly stimulate the growthof new protein within muscle cells andthe cells of other tissues. A detaileddescription of protein needs is providedin The Navy SEAL Nutrition Guide. Inbrief, the daily requirement for protein is0.6 to 0.8 grams per pound of body
weight. Protein intakes in excess of 0.8grams per pound do not cause anincrease in protein stores, but suchintakes do increase the work of thekidney. The kidneys are responsible forexcreting the waste products fromdigestion of excess protein.
Purported Beneficial Effects ofAnabolic Steroids
There are several purported effects ofAAS which may be beneficial toathletes. The first is an increase in leanbody mass. In muscle cells this wouldresult in an increase in production ofproteins responsible for musclecontraction, energy production andenergy storage. The second is strength.AAS may regulate the movement ofcalcium from within the cells, whichcould lead to an increase in the speedand force of contraction. Anotherpotential benefit of AAS is an increasein aggression which may allow theathlete to do more work. At times this
may be desirable whereas in othersituations it may actually compromise amission. Overall, the potential beneficialeffects of anabolic steroids include:
♦ Increased muscle size♦ Increased muscle strength♦ Increased aggression♦ A perception of improved
performance♦ Increased motivation♦ Decreased fatigue
Adverse Effects of Anabolic Steroids
The use of anabolic steroids isstrongly associated with numerousundesirable effects, many of which maynot be predictable on the basis of thedose or frequency with which they areused. These potentially dangeroussubstances are usually taken withoutsupervision, although this is illegal, andthere have been many reports of seriousillness or deaths resulting from their use.AAS may falsely increase the perceptionof strength and cause an individual to liftheavier weights than he should. Thisoften results in torn muscle and rupturedtendons, in particular tears of the bicepsand deltoids, because the strength of
muscles increases more rapidly thanthe strength of tendons. The immunesystem may be impaired, but thisabnormality may not be detected untilafter its use. Importantly, transmission ofhepatitis B and AIDS can occur fromneedle or drug sharing. Various cancershave also been associated with AASuse. Liver, cardiovascular, hormonal,reproductive and nervous systems aremost affected, but other systems mayalso be adversely affected.
The most frequently reported negative
effects are listed in Table 13-2. Many ofthese are reversible when steroids arediscontinued, but some can be permanentor irreversible. If used in young athletes,
these agents limit final height because ofthe early termination of bone growth.Clearly, the health risks far outweigh anybenefits anabolic steroids may confer.The most common problem includesliver dysfunction. This serious medicalproblem occurs frequently in users oforal AAS and causes jaundice. Peliosishepatitis, a condition where blood filledcysts develop within the liver, has alsobeen reported.
The cardiovascular effects of AAS in
men and women include high bloodpressure, increases in serum cholesterolconcentration and serum LDL (the badcholesterol), and a decrease in serumHDL (the good cholesterol). Heart
attacks, strokes, and blood clots in thelungs have also been reported in AASusers.
The hormonal effects of AAS use in
the male include decreased naturaltestosterone production, decreasedsperm count, production of abnormalsperm and shrinkage of the testes. Breasttissue enlargement is also common, asare acne, glucose intolerance, andbaldness. Women AAS users haveslightly different hormonal responses,including thickening of the vocal cordswith resultant deepening of voice, malepattern baldness, facial hair growth andenlargement of the clitoris, all of whichare irreversible. Breast tissue shrinkage,
menstrual irregularities, infertility,glucose intolerance and acne are alsocommon in women who use AAS.
Perhaps the most significant short-
term adverse effects are the psychologicchanges associated with AAS use. Forboth men and women AAS users,increased aggression, rage reactions(“roid rage”), altered libido, anxiety andpanic disorders, psychosis(“bodybuilder’s psychosis”),depression, mania and addiction havebeen noted. Again, these effects areundesirable for tasks required bySEALs. It is extremely important to notethat:
Many of the side effects maycause permanent impairment, and
some are potentially, if notoutright, lethal.
Table 13-2. Adverse Effects ofAnabolic Steroids in Men: Physiologicand Psychological
Legalities of Steroid Use
There are also legal ramificationsassociated with AAS use. Since early1991, AAS and related compounds havebeen classified as drugs controlled bythe Food and Drug Administration.These drugs have a high potential forphysical and psychological dependenceas well as their catabolic effects onvarious body systems. Transportation ordistribution of these agents is punishableby fines of up to $500,000.00 and/or aprison sentence of up to 15 years. Themilitary, as well as most sportsgoverning bodies, (IOC, USOC, NCAA,NFL), ban the use of AAS. Users whoare detected using such agents face
significant penalties.
AAS screening is now performed in
the military along with routine randomdrug screening. Oral AAS can bedetected by urine drug screening from 2-14 days after use. Some forms may bedetected for weeks to months afterinjection. There is zero tolerance forpossession and use of AAS in themilitary, unless appropriately prescribedby medical personnel. Any violationwould be punishable under Article 92 ofthe Uniform Code of Military Justice(UCMJ). If found guilty, that individualmay also be processed foradministrative separation from themilitary.
Medical Uses of Corticosteroids
As stated previously, AAS should notbe confused with corticosteroids.Corticosteroids, or glucocorticoids, area category of synthetic hormones used torestrain inflammation and to controlitching. They are commonly usedtopically for skin disorders, and givenby injection into joints which areinflamed. Corticosteroids have beenclassified by the USOC as subject torestrictions; a physician must declare theintent to treat prior to a competition.
Other Harmful Chemicals
Growth Hormone
Human growth hormone (hGH) is ahormone produced in the brain. Thehormone is commonly used to increasethe height of very short children and untilrecently to increase strength in theelderly. Athletes have been known to usehGH at a black market cost of about$2,000 for an 8-week course. Theknown effects of hGH in the athlete areshown in Table 13-3.
Table 13-3. Physiologic Effects ofGrowth Hormone
Unfortunately, the increase in musclemass does not increase muscle strengthas much as strength training. No increasein height has been seen in a fully grownperson, however, hGH may increasehand, foot, jaw and body size. There islittle known about the adverse effects ofhGH use in the normal athlete, but theskeletal muscle growth may be abnormaland therefore the muscles may be weak.
Given that hGH use is banned by themilitary, as well as the IOC, NFL,NCAA and most sports governingbodies, it should not be used.
Clenbuterol
Clenbuterol, a drug used byveterinarians to increase muscle mass inlivestock, is being used by manyathletes, primarily those in strength-related sports. However, increases inmuscle strength have not been shown inhumans. In addition, there are numerousadverse side effects, including rapidheart rate, muscle tremors, headaches,nausea, dizziness, fever and chills.Although technically classified as a β2-agonist, it is officially considered ananabolic agent by the USOC, and is thuson their list of prohibited substances.
Stimulants
Stimulants are agents which increasearousal of the central nervous system(CNS). These agents are used medicallyin the treatment of various conditions,including depression, narcolepsy(sudden and irresistible onset of sleep),and in the treatment of diseases of thebronchial tubes. Athletes often abuse anumber of stimulants because they thinktheir performance will improve. Moststimulants are banned by the military aswell as most sport governing bodies;these agents are also measured in routinerandom drug screening tests. The majorclasses of CNS stimulants are:
♦ Amphetamines♦ Ephedrine♦ Caffeine
This section will discuss only thoseagents which are illegal and can produceharmful effects.
Amphetamines
One class of stimulants is theAmphetamines. The term amphetaminealso includes methylamphetamine,dimethyl-amphetamine, andbenzylamphetamine which aremetabolized to amphetamine afteringestion. In the 1960’s, these drugs
were widely used by athletes in thebelief that they improved strength andendurance. Stimulants such asamphetamines and many over-the-counter amphetamine “look alikes” havepronounced effects throughout the body.Taking these agents will result in thephysiologic and psychological effectsnoted in Table 13-4 and Table 13-5. Ascan be seen, these effects are the sameones which occur normally withoutstimulants when you are asked toundertake dangerous missions.
Table 13-4. Reported PhysiologicEffects of Amphetamines
Amphetamines can mask symptoms offatigue. They may restore reaction timein a weary athlete, but cannot improvereaction time or diligence in a wellrested and motivated athlete. Thepotential beneficial effect is most
marked when performance is reduced byfatigue or lack of sleep.
Exercise itself induces these same
effects, so amphetamines have not beenshown to make a net contribution to thephysiological mechanisms whichsupport athletic performance. Theyclearly make no difference in maximalaerobic capacity, but there is someevidence for small increases in speedand the time it takes to fatigue inendurance events. It could be that theprimary performance enhancementbenefit rendered by amphetamines lies intheir psychological effects as listed inTable 13-5.
Table 13-5. Psychological Effects ofAmphetamines
Perhaps more so than with manydrugs, the use of amphetamines isassociated with detrimental side-effectsthat cannot only erode athleticperformance, but can also harm healthand threaten life. These are listed in
Table 13-6. Because of these side-effects and the illegality of their use,these drugs must be avoided.
Table 13-6. Adverse Effects ofAmphetamine Use
Ephedrine andPseudoephedrine
Ephedrine, and its most notablederivative, pseudoephedrine, areadrenaline-like CNS stimulants found inmany over-the-counter cold and hayfever preparations as well as in manyherbal products, in particular the herbknown as Ma Huang. Like clenbuterol,ephedrine is a β-agonist, and hasproperties similar to that ofamphetamines. It is often combined withcaffeine. At doses higher than found inover-the-counter medications,restlessness, muscle tremors, anxiety,and headaches are frequently produced.
Ephedrine is not widely used in sports toimprove performance and there is noscientific evidence that it does.However, many people have usedephedrine and Ma Huang to lose weightthrough an increase in resting metabolicrate and metabolism of fat. Recently anumber of people have died fromdrinking tea containing ephedrine. Giventhat it is banned by the OSOC and apotentially life-threatening agent, itshould not be used.
Erythropoietin
Erythropoietin (EPO) is used byendurance athletes to improveperformance. One type of EPO, calledrEPO or rhEPO, is used to treat anumber of blood diseases. Athletes userEPO because it increases the red bloodcell count by stimulating red blood cellproduction and speeding red blood cellrelease from the bone marrow to theblood stream. The red blood cells carryoxygen to the muscles, so more red cellsmean more oxygen. The effects of rEPOare actually similar to those seen in anathlete who trains at altitude. In orderfor these changes to occur, the athletemust have an adequate iron intake and
maintain an aerobic training schedule.
The increase in red blood cellproduction can cause a number ofsignificant adverse effects. High bloodpressure, a flu-like syndrome, and asluggish bloodflow are the mostcommon. Bloodflow becomes sluggishwhen the percentage of red blood cellsreaches 55%. Normal ranges are 40% to48% in men and 36% to 45% in women.Sluggish blood flow causes a variety ofcomplaints, including headache,dizziness, ringing in the ears, visualchanges, and chest pain. Other possiblecomplications are heart attack, seizure,or stroke due to a blockage of bloodflow. Up to 18 deaths due to rEPO have
been reported in cyclists. The use ofblood doping or rEPO is prohibited byall sport governing bodies as well as themilitary.
DHEA
DHEA, or dehydroepiandrosterone, isa hormone released by your adrenalglands into your bloodstream eachmorning; from there it travels to othertissues and is converted into smallamounts of testosterone (estrogen forwomen). It has been shown that levels ofDHEA decline with age, and this findinghas created a sensation among themanufacturing world. Although DHEAhas been available for decades, it hasonly been on the market since about1994. It is now being touted as themiracle drug of the 21st century. There isno question that it is a miracle drug tothe companies producing and selling it,
but the true benefits in humans has notbeen determined. The various claimsbeing advertised for DHEA include:
♦ Lengthening of life♦ Prevention of cancer, heart
disease, and osteoporosis♦ Burning of fat stores♦ Stimulate libido♦ Boosts energy levels and mood♦ Enhances immune system
None of these claims have beendemonstrated, and there are a numberof reasons why it may be hazardous. Asstated previously, DHEA is a hormoneand it can be converted to testosterone.Increased testosterone levels could
increase your risk of prostate cancer.The other potential dangers of DHEAwill unfold as more research isconducted, and people who are taking itregularly are followed. To date it has notbeen banned by the USOC, but that maybe only because it is so new on themarket.
Summary
In conclusion, none of the chemicalagents discussed above offer anyguarantee that your performance willimprove. However, there is a goodchance you could compromise yourmilitary careers by using them. Thebenefits of these agents are limited andthe potential harmful effects are clear.Our advice is to keep up with yourtraining according to the methodsdescribed in other chapters.
Resources
♦ Catlin DH and Murray TH.Performance-enhancing drugs,fair competition, and Olympicsport. Journal of the AmericanMedical Association. Vol 276,pages 231-237, 1996
Chapter 14
Other TrainingRelatedIssues
This chapter presents other issuesimportant to SEAL training but may onlypertain to certain subgroups of EALs.For example, not all teams train forWinter Warfare and many individuals donot currently qualify as “High Mileage”SEALs (but will in the future). Alsoincluded is a section on nutritionalergogenic agents, since many athletesuse these products in an effort to
improve performance.
Winter Warfare Training
Winter warfare imposes somespecific physical training demands onSEALs. During training and deployment,winter warfare operations challenge anindividual’s skill in protection fromenvironmental factors and ability tomove efficiently over snow and ice.Thus, cross country skiing isrecommended for those involved inwinter warfare operations. This sectionreviews training issues specific to thewinter warfare mission.
Training for Skiing
A high skill level is essential if use ofskis is contemplated. Under mostoperational conditions, cross countryskiing provides the highest degree ofnon-mechanized mobility for travellingover snow and ice. Skiing becomes avery efficient form of man-poweredtransportation during long transits overflat terrain. However, the advantages ofskiing only become apparent afteracquisition of specific skills and fitness.
It is extremely easy to sustain a
serious immobilizing injury while skiingheel free in non-release bindings andfloppy loose boots. The potential for
injury is magnified further when theskier is loaded down with gear. Thus,the operator participating in winterwarfare must be a competent skier.
The overall fitness level of SEALs
may be adequate for cross country skiingbecause fitness from running and aquatictraining carry over to skiing. However,different muscle groups are used; thusSEALs should strive to customize theirtraining programs in anticipation ofwinter warfare. Use of a ski machinedoes confer training specificity andassists with developing the coordinationand muscle adaptations needed to skiefficiently. Other real training issues forskiing are skills and technique. There
are several operational considerations toconsider:
♦ Need to be able to stop and turnefficiently.in a variety of snowand ice conditions.
♦ Need to be able to ski safely witha pack and weapons.
♦ Need to be familiar with gearmodifications for maximumefficiency.
Turns, Stops, and Technique
Safe skiing with a pack demandsaggressive unweighting and the use ofparallel ski techniques. Forget abouttelemark turns while you are wearing apack; the slow forward lunge required toinitiate a turn in back-country snowswhile wearing a pack puts the skier in avulnerable body position. This is aninvitation to sustain a serious knee injuryto the lead leg, particularly because ofthe extra weight transmitted to the legdue to wearing a pack.
Telemarking is useful when used tostop while traversing a hill. Instead ofextending the uphill leg to initiate adownhill turn, extend the downhill ski
and drift up into the hill. This maneuveris easy to control and is a useful tool forchecking downhill speed while skiingheel free and wearing a pack.
Poles are essential tools for
propulsion and balance while wearing apack. It is important to use break-awaywrist straps to prevent an injury to thearm or shoulder which can occur if theski pole basket inadvertently catches ona stump or something else frozen solidlyto the ground.
The High Mileage SEAL
Chronic overuse injuries andaccumulated minor and major trauma tothe musculoskeletal system have acumulative effect on the “High-Mileage”SEAL approaching the age of 40. Themost common chronic musculoskeletalinjuries involve the neck, back, elbow,knee, ankle and foot. Table 14-1 outlinesthe sites and causes of these variouschronic conditions. It also presentsselected recommendations for treatingthese conditions. Poor flexibility can bea major contributory factor in all ofthese conditions. A lifetime program offlexibility, strengthening, and cross-training for aerobic conditioning is
essential for minimizing chronic injuriesand pain. In the event of an injury, earlyself-referral for evaluation is anessential part of avoiding chronic injury.
For those having recurrent problemsor nursing old injuries, fitness can stillbe maintained and rehabilitation canproceed. Aerobic activities that mayhelp include the stationary cycles,indoor swimming, a rowing machine, aski machine, or a climber. However, it ismost important to emphasize flexibility,with a specialized PT program thatincludes stretching. We believe that thePhysical Fitness and PT Programspresented in Table 14-2 and Table 14-3may help restore function if carried outregularly. However, you must remembernot to push yourself too hard so as toavoid a recurrence of previous injuries.
Also, it is important to remember thatyou may need a longer time to recoverthan you did when you were 18. Listento your body so it will be kind to you inthe future.
Table 14-1. Sites, Common Causes of,and Recommendations for ChronicMusculoskeletal Pain
In the long run it is better to beconservative: injuries do not always goaway. In fact, some lie dormant until youpush just a bit too hard. Then it is toolate. Seek medical care if there is anydoubt, as your job depends on yourhealth.
Table 14-2. Physical Fitness Programfor High Mileage SEALs with ChronicMusculoskeletal Pain
Table 14-3. A PT Program for HighMileage SEALs with ChronicMusculoskeletal Pain
Nutritional ErgogenicAgents
Ergogenic agents are by definition,substances or techniques that enhanceperformance. Because SEALs arerequired to perform at a high level bothmentally and physically, many arelooking for substances or techniques toimprove performance and provide “anedge”. To perform longer, to be faster, tobe stronger, and to be leaner, if not amission goal, are personal goals of manySEALs and elite athletes. People havebeen trying to accomplish these goals forcenturies through the use of ergogenicagents. It is our goal to present
information about certain productscommonly found in retail stores or bymail order, that claim performanceenhancing effects. For a detaileddiscussion refer to The Navy SEALNutrition Guide. Specifically, thissection will provide information on:
♦ Nutritional Products Advertisedas Ergogenic Agents
♦ Protein-CarbohydrateSupplements
Nutritional Products Advertised asErgogenic Agents
This section lists many of thenutritional ergogenic agents sold bymanufacturers with claims to “enhanceperformance” or have “muscle building”properties. Some have valid claimswhereas others do not. It is oftendifficult to differentiate false claimsfrom valid ones if you haven’t carefullyresearched each product individually.Many claims sound very scientific andconvincing but, unfortunately, they areoften false or unproven. For each agentdescribed in Table 14-4, the claims, theusual dose used, and a comment areprovided.
Table 14-4. Nutritional ErgogenicAgents
Summary of Ergogenic Agents
Below are brief comments on variousergogenic. agents, grouped by purportedbenefit or effect.
Protein-Carbohydrate Supplements
Go into a retail or specialty store thatcaters to athletes and you may becomeoverwhelmed by the number of differentproducts available. One of the mosthighly visible and advertised group ofproducts are the powdered protein andcarbohydrate beverages. “Weightgaining”, “anabolic”, “muscle building”— these are just a few of the variousclaims made by manufacturers. They doshare one thing in common however:they are sold as supplements to yourdiet. These products are intended tofortify your diet to meet the nutrientdemands of your body. In general, thereare three basic reasons why people take
supplements:
♦ Compensate for less thanadequate diets or life-styles
♦ Meet unusual nutrient demandsinduced by heavy exerciseand/or
♦ Produce direct positive effects onperformance
Your profession and life-style imposeunique physical demands that requirestamina, power, and strength.Consequently, your caloric (energy)expenditure is greater than the averageperson.
Supplements are a quick and
convenient means for obtaining thenutrients you need. For example, somepeople find that after eating a normalbreakfast they feel ill or nauseous duringmorning PT. If you can’t tolerateexercising on a full stomach, then apowdered beverage may be the answerfor your breakfast. You get the caloriesyou need in the morning, but don’t havethat heavy feeling in your stomach.Remember that you may not need the fullrecommended serving size. Count thecalories to suit your own energyrequirements and goals.
It is also important to realize that it is
not the supplement alone that leads tobetter performance. Success lies in
addressing your goals and analyzing andadapting your diet to meet those goals. Itwill take some work on your part tocalculate how much supplement, if any,you need to use. Read the labels andfigure out how many calories you willexpend before your next meal. Also,make sure you add up the vitamins andminerals you are getting from all thedifferent supplements you are taking.Many products provide similar nutrientsand you may be taking TOO much of oneor several nutrients.
Another decision to make is whether
or not to use a protein, carbohydrate, orcombination beverage. Once again, it alldepends on your goals. If you want to
increase lean body mass throughresistive training, then some protein maybe the way to go. Remember that:
You only need 0.6 to 0.8 grams ofprotein per pound body weight
per day.
This is equivalent to 105 to140 gramsfor a 175 lb. SEAL. Keep in mind thatthere are food sources of protein that arevery easy to come by and tend to costmuch less money. For example:
♦ One 6 oz. can of tuna fish has 48grams of protein
One 4 oz. breast of chicken has36 grams of protein
One 8 oz. glass of milk (skim)has 10 grams of protein
Resource
♦ Deuster PA, Singh A, PelletierPA. The Navy SEAL NutritionGuide, 1994.
Chapter 15
Physical Fitness andTraining Recommendations
The purpose of this final chapter is toprovide a comprehensive trainingprogram that combines all theinformation presented in the precedingchapters. This chapter has beendeveloped by group consensus, andattempts to address the specific needs ofSEALs.
The SEAL Physical FitnessProgram
The ultimate SEAL physical fitnessprogram will incorporate all aspects ofphysical training. After an initial warm-up, the overall workout will includeexercises to develop and/or maintain:
♦ Cardiovascular Fitness(Aerobic/Anaerobic Capacityand Power)
♦ Flexibility♦ Muscular Fitness (Strength,
Endurance and Power)
Aerobic fitness includes conditioningruns or swims whereas anaerobic
activities would include interval orfartlek runs/swims. Flexibility isimproved by stretching, and muscularfitness by weight training, circuittraining, or other such activities. Therelative time spent on a particular aspectof fitness each day may vary, but everyday incorporates exercises to improveor maintain: muscle strength, aerobicand anaerobic capacity, and flexibility.One point that has been stressed andshould be remembered is that:
Strength and flexibility areclosely linked.
Building strength tends to shortenmuscles and limit flexibility; thus,
stretching is essential for maintainingflexibility. The final recommendationsare shown in Table 15-1. Some of theactivities cannot accommodate the entiregroup, but rather must be done in smallergroups. For example, circuit weighttraining can be done in groups of 8 to 12,but not the entire team. These arerecommendations, but alternate activitiescan be substituted. Table 15-2 providessome suggestions for alternativeactivities.
Table 15-1. The Navy SEAL PhysicalFitness Program
Table 15-2. Alternate Activities for aFitness Program
Physical training (PT) exercises arelisted on two of the five days in theRecommended SEAL Physical FitnessProgram. The PT program recommendedfor you (shown in Table 15-3) is calleda Basic PT Program, and it willtypically serve as a prelude to the main,more rigorous, activity(ies) of the day. Itincludes warm-up activities to loosenyour muscles and exercises to increaseyour range of motion, muscle strength,muscle endurance, and power.
Depending on the number of repetitionsyou perform, this PT can take as little as10 or as many as 40 minutes.
Table 15-3. Basic Physical Training(PT) Activities for Warm-Up,Flexibility and Strength
For those interested in a moreintensive PT program, a sample TotalBody PT program is included for you.Alternatively, you can increase thenumber of repetitions of the exercises inthe “basic” PT program. Both programsare very versatile, yet complete withrespect to the whole body nature of theworkout.
Table 15-4. Total Body PhysicalTraining (PT) Activities for Warm-Up,Flexibility and Strength
You should also include strength
training at least twice per week.Details of a strength program are
provided in Chapter 6.
A Physical Fitness Programfor Confined Spaces
Maintaining fitness aboard a ship orsubmarine is possible. However, itrequires motivation and disciplinebecause usually the team spirit ismissing. It is critical to maintain fitnessso that when you reach your destinationyou have not become detrained. Table15-5 presents a potential trainingprogram that could be followed on mostships. Most ships have stationarybicycles and rowing machines.However, if the ship has some other typeof equipment, the schedule below couldbe modified to accommodate what
equipment is available.
Table 15-5. Physical Fitness inConfined Spaces
A Physical Fitness Programfor Coming Off Travel
When you first come back to shore orto your home base, you are not always inas good a physical shape as you werewhen you deployed. For this reason it iscritical that you start back sensibly so asnot to injure yourself. Both the PT andendurance components need to bemodified so as to improve your overallfitness, not to put you in the doctor’soffice. Table 15-6 and Table 15-7provide a reasonable Fitness and PTprogram for those coming off of travel.When you feel like you are back to yourusual fitness level, then the Basic or
Total Body Physical Fitness Programscan be started and/or worked into yourschedule.
Table 15-6. A Re-Entry PhysicalFitness Program
Table 15-7. Re-Entry PhysicalTraining
Elimination of “Old”Exercises
As you may have noticed, some ofyour old favorites (or old foes) are nolonger recommended. In May of 1994, apanel of experts convened to look at allof the different PT exercises currently inuse by the SEAL community. A numberof exercises were considered potentiallyharmful and were therefore eliminated.In addition, many exercises weremodified to make them more effective(or potentially less harmful).Descriptions and diagrams for most ofthe exercises which are acceptable areprovided in Chapters 7 and 8
(Flexibility and Calisthenics). Table 15-8 lists exercises that were eliminatedand the reason for their elimination.
Table 15-8. Exercises Eliminated fromSEAL PT
A Short Flexibility Program
Flexibility exercises are an importantphysical fitness component and may addyears to your operational life. For thosewho have been injured, the “highmileage” SEAL (see Chapter 14), orsomeone with naturally short muscles, ashort flexibility program is provided inTable 15-9.
Table 15-9. Selected StretchingExercises for Improving Flexibility - AShort Program
The Navy SEAL PhysicalReadiness Test (PRT)
The Navy SEAL Physical ReadinessTest (PRT) is conducted in one sessionin a continuous manner, with no less thantwo minutes or greater than 15 minutesrest between exercise, and no more thana 30 minute break between the run andswim. Failure to successfully completeall events constitutes failure of the PRT.The PRT events, in order performed,include:
♦ Pull-Ups♦ Sit-Ups♦ Push-Ups
♦ 3 Mile Run 0.5 Mile Pool Swim
The first event, the pull-ups, has notime limit, whereas the sit-ups and push-ups have a three minute time limit. Allthree events are performed in clearlydesignated ways, and points areassigned to each event based on age andthe number completed. The 3 mile runand 0.5 mile swim are timed events, andthe time to completion and age are usedto assign points. When all events havebeen completed, points for individualevents are summed and an overall scoreis assigned. Table 15-10 provides asample PRT test.
Table 15-10. PRT Score for a 34 yearold SEAL
The greatest number of points for anyevent is 100; thus the highest possiblecomposite score is 500. The overallscore is used for classificationpurposes: you can fall into one of fivecategories:
In the example in Table 15-10, theoverall score was 439; this would berated as OUTSTANDING. Please referto COMNAVSPECWARCOMINST6110.1B for further information withrespect to the Navy SEAL PRT and thetables describing points for each event.
Final Comments From:RADM Smith
This manual is a superb guidecovering all the major focus areasrequired to maintain fitness as a SEAL. Ioffer as a final piece of SEAL culture,my version of “burn-out PT” in Table15-11. The progression of the program isas follows: start at Stage 1 and cyclethrough the first set of each exercise,followed by the next sets. Next, move onto Stage 2 and use the same sequence.Begin with lower reps per exercise,with the goal of eventually completingthe PT as set forth in Table 15-11. Thosewho have done it, know it is not what a
modern fitness expert would necessarilyapprove of e.g., no stretching, (do it onyour own time), over repetition of thesame exercises, and several stomachexercises clearly not beneficial for thelower back (an understatement!). Havingsaid that, you can do it practicallyanywhere, (if you have two or morehours); it exercises the vast majority ofmuscle groups; and finally, it imposesgreat pain and discomfort on the body -an instinct carefully nurtured, althoughsometimes avoided, (what’s the watertemp?) by even the most driven of us.
Its origin stems from a legendary
SCPO in UDT-12 - Frank Perry, whoreigned supreme among the West Coast
teams for at least 15 years. I haveomitted one of his favorite exercises -the eight-count body builders—invokingthe principle that if you do my PT fastenough (it’s structured to do that), youwill get the requisite cardiovascularbenefit without the 100 eight counts wedid every Friday morning (one set-non-stop). Enough is enough! While I suspectit was only Frank Perry’s way ofreminding us who WAS “the king” inthose days, I certainly don’t recall anychallenges to his reign!
I’ve also picked up many of these
exercises from working out with thevarious SEAL teams. I’ve attempted toincorporate unusual or esoteric
exercises to provide the more easily-bored SEAL with a bit of variety. I’vealso attempted to work opposing musclegroups - my one compromise to modern-day fitness.
Of course, do not feel constrained
with what I offer - add your own ormodify mine as you see fit. However, ifyou can do this program in less than 2hours 15 minutes, you might trymarketing the program to the public(plenty of former SEALS are alreadydoing so with their programs)!
More importantly, do it with your
platoon! It makes for great brotherhood
when one shares pain with one’steammates!
Hoo-Yah!RADM Smith
Table 15-11. RADM Smith’s PTProgram
Many of the exercises in the RADMSmith’s PT program have beendescribed previously in the Calisthenicschapter (Chapter 8), but some are new.So you don’t have an excuse not to trythis program, diagrams for the newexercise are provided in Table 15-12.Have fun!
Table 15-12. Examples of RADMSmith’s Exercises
Summary
Physical fitness is a criticalcomponent of SEAL training, and beingin shape is essential for missionreadiness. A comprehensive whole bodyconditioning program has been providedfor you to use in your training. Inaddition, RADM Smith’s PT programand a training program for confinedspaces and for SEALs coming off travelhave been included. Alternativeexercises have also been provided tomaintain motivation and optimize theconcept of cross-training. Try it, youmay find yourself in better “all around”shape.
Appendix A
Weight Lifting Techniques
Appendix B
Common Anatomical Termsand Diagrams
Figure B-1 . Selected Muscles of theChest
Figure B-2. Selected Muscles of theBack
Figure B-3. Selected Muscles of theFront Part (Anterior) of the Upperand Lower Leg
Figure B-4. Selected Muscles of theBack Part (Posterior) of the Upperand Lower Leg
Appendix C
Foot Care for Load-Bearing
Foot hygiene and sanitation areimportant for preventing injuries duringprolonged walking, particularly whencarrying heavy loads. Injuries to the feetthat should be considered duringprolonged load-bearing include:
♦ Blisters♦ Abrasions♦ Foot Perspiration Problems♦ Athletes’ Foot
♦ Trench Foot♦ Immersion Foot
Proper care of feet should occurbefore, during, and after load-bearingactivities. Foot care involves frequentand thorough cleaning of feet, use of footpowder, wearing properly fittedfootwear, and correctly trimmingtoenails.
Before any load-bearing hump, trim
toenails short, square, and straightacross. Keep feet clean and dry, and usefoot powder. Wear clean, dry, well-fitting socks (preferably cushioned-soled) with seams and knots outside.Socks that have been previously mended
should not be used. A nylon orpolypropylene sock liner can reducefriction and add protection. Carry anextra pair of socks. Carefully fit newboots. When getting used to new boots,alternate with another pair; tape knownhot (red skin) spots before wearing.
When possible during a rest period,lie down with feet elevated. If timepermits, massage feet, apply foot power,change socks, and medicate any blisters.Cover open blisters, cuts, or abrasionswith absorbent adhesive bandages.Obtain relief from swelling feet byloosening bootlaces where they cross thearch of the foot.
After completing the load-bearing
exercise, procedures for care of feet,wash and dry socks, and dry boots statedabove should be repeated. Medicate anyinjuries on feet. Sides of the feet candevelop red, swollen, tender skin duringprolonged humping with a load, whichcould become a blister. Thus, feetrequire airing, elevation, rest, and widerfootwear. Prevent major foot problemsby keeping feet clean. The combinationof abrasions with dirt and perspirationcan cause infection and serious injury. Ifpossible, give feet a daily foot bath. Inthe field, cool water seems to reduce thesensation of heat and irritation. Afterwashing, dry the feet well.
Part II
Nutrition
Patricia A. Deuster, Ph.D. Anita Singh, Ph.D.
Pierre A. Pelletier, ENS, MC, USNR
Preface to Part II: The NavySEAL Nutrition Guide
The demands imposed by SEALtraining are profound, and successrequires the mustering of all yourstrength - physical and mental. Onefactor that may bring you closer tosuccess is nutritional interventions. It iswell known that appropriate nutritionalhabits and interventions can enhanceyour ability to perform, and we want youto be familiar with those successfulhabits. This manual is for you to read,participate in, and use as a resourcewhen you have questions about nutritionand no one is available to get answers
from.
The first five chapters are very basic -they provide background informationabout nutrition concepts in general, andlittle to nothing about performance.However, they are very important forfully understanding the information insubsequent chapters. In the remainingchapters, we have tried to be as specificas possible in terms of what we thinkyou should and shouldn’t do, and givenyou reasons for our recommendations.For example, in Chapter 8: Restaurants,Fast Foods, and Eating Out, we havegiven you sample menus at Fast Foodsplaces so you can select a highcarbohydrate diet. In the chapter on
Mission Recovery, we target three areasyou need to focus on and provide waysto ensure a rapid recovery. In Chapter15, Ergogenic Agents, we discourage theuse of some products because not only isthere insufficient information, but theremay be potential risks and adverseeffects associated with using them.Again, our objective is to make youmore informed so you can makeeducated choices about foods andsupplements. Many commercial productssold in stores and through magazinesmake claims so you will purchase them.With some products you are wastingyour money, and with others, possiblyhurting yourself. Other products mayactually give you the “edge” and
improve your performance, but it takesinformation to make the appropriatedecision. This manual should help youdo that.
You men are a select group - we know
that from our years of working withSEALs and SEAL trainees. For thatreason you must be treated as such. Thismanual has been prepared with that inmind: we want to help you perform tothe best of your abilities under therigorous conditions you confront intraining and during missions. Wecertainly don’t have all the answers tonutritional enhancement of performance,because the answers are not allavailable yet. However, we will
continue searching for answers andencourage you to continue askingquestions that relate to nutrition andperformance so we can help you findthose answers. We wish you the best andhope you will let us know when youcan’t find answers to your questions.
Patty Deuster, Anita Singh, and PierrePelletierBethesda, MD
About the Authors
Part II: The Navy SEALNutrition Guide
Dr. Patricia Deuster is an AssociateProfessor and Director of the HumanPerformance Laboratory in theDepartment of Military and EmergencyMedicine at the Uniformed ServicesUniversity of the Health Sciences,School of Medicine in Bethesda,Maryland. Her credentials for writingthis book are many. She has beenconducting research in the area of sportsnutrition and exercise physiology forover 14 years, has published numerouspapers on the nutritional needs of U.S.Navy SEALs, and has given many sports
nutrition seminars to high school,college, and professional athletes,recreational athletes, SWAT teams,dietitians, and other healthprofessionals. She is also an athleteherself. She was a tennis professionalfor 5 years and has competed in severaltriathlons and over 20 marathons; herbest marathon time was a 2:48 in theBoston Marathon. Dr. Deuster was anationally ranked runner for severalyears and a qualifier for the FirstWomen’s Olympic Marathon Trials. Sheis an avid sportswoman and a formerskydiver who has logged in over 100jumps. Together with her athleticabilities and interests, professionaltraining, and research endeavors, she is
clearly one of the few persons to havebeen prepared to develop this guide.
Dr. Anita Singh received her Ph.D. in
Nutrition in 1986 from the University ofMaryland, where she was selected as anOutstanding Graduate. She is anAssistant Professor in the Department ofMilitary and Emergency Medicine at theUniformed Services University of theHealth Sciences, in Bethesda Maryland.She is also a registered dietitian and hasbeen working in the area of SportsNutrition for about 10 years. In additionto looking at nutritional needs of U.S.Navy SEAL trainees, she has studiedwomen who qualified for the FirstWomen’s Olympic Marathon Trials,
triathletes, ultramarathoners andrecreational athletes. Dr. Singh haspresented her research work at variousnational and international meetings andhas published extensively in scientificjournals. She is a runner, tennis playerand avid hiker.
Pierre A. Pelletier ENS, MC, USNRwill be graduating in1995 from theUniformed Services University of theHealth Sciences (USUHS), School ofMedicine, in Bethesda, MD. Hereceived his undergraduate degree fromNorwich University in Biology andChemistry. ENS Pelletier has alwaysbeen active in athletics both as aparticipant and teacher. He was acompetitive skier and instructor for eight
years and instructed kayaking in NewEngland. He is also active in thePotomac Rugby Union in Maryland andmost recently was invited to play withthe US Navy Rugby Club. His personalinterest in nutrition as it relates toathletics has been nurtured while atUSUHS and culminated in a clinicalyear of research in the HumanPerformance Laboratory at USUHSwhere he assisted in writing the manual.He plans to practice OperationalMedicine as a Diving Medical Officerwith the US Navy SEALs.
Chapter 1
Energy Balance = EnergyExpenditure - Energy
Intake
Balancing energy intake andexpenditure can be difficult whenactivity levels are very high, as inSEALtraining, and when activity levels arevery low, such as during isolation.Typically, body weight remains constantwhen energy intake equals expenditure.
Units of Energy
The unit commonly used fordescribing energy intake and energyexpenditure is the Calorie. The termKilocalorie (Kcal) is also used as ameasure of energy intake andexpenditure and 1 Kcal = 1 CalorieThroughout this book we will use theterms Kcal and calorieinterchangeably.
Sensitivity of EnergyBalance
The energy balance equation can be“unbalanced” by changing energy intake,energy expenditure, or both. To gain orlose 1 pound it takes approximately3500 extra kcal consumed or burned.Believe it or not, the energy balanceequation is very sensitive, as is shown inthe following example.
Example 1:
If you ate one extra chocolate chipcookie (65 kcal) each day for one
year, this would be 65 X 365 or 23,725
extra kcal.
This small daily increase in energyintake would result in a gain of 6.8
pounds in one year.
Example 2:If you ate one less chocolate chip cookieper day and started running 1 extra mileper day 5 days per week, you wouldlose 14 pounds. This number is obtainedby adding the 6.8 pounds from not eating
the cookie and the 7.4 pounds/year forrunning (100 kcal/mile X 5 miles/weekX 52 weeks/year = 26,000 kcal or 7.4pounds/year). You see? It works bothways!
Components of EnergyExpenditure
The three major contributors to energyexpenditure are:
♦ Resting energy expenditure Physical activity
♦ Energy for digesting foods
The first two are of interest here andwill be discussed in detail.
Resting Energy Expenditure
Resting energy expenditure (REE) isthe amount of energy required tomaintain life - such as breathing, beatingof the heart, maintenance of bodytemperature, and other life processes.Measurements are usually made in themorning after waking with the body atcomplete rest. REE can be estimated bya formula and used to predict your dailyenergy/ caloric requirements. The onlyinformation needed is your body weightin pounds.
Table 1-1. Determining Resting
Energy Expenditure (REE) of Men
From Body Weight (in pounds)
Energy Expenditure For PhysicalActivity
The amount of energy you expendduring physical activity is different eachday, depending on your training. Somedays are very strenuous and involve
running, swimming, calisthenics, coldwater exposure, sleep deprivation, andcarrying heavy loads. Some days you arein the classroom sitting a good portion ofthe day. Thus, determining your actualenergy expended during activity is moredifficult, but there are ways to estimateit. You would usually take your REE andmultiply it by a number (or factor) asshown on the next page to get a roughestimate of your total energy/calorieneeds. Lets try out an example.
Total Energy Expenditure
Table 1-2. Estimating Total DailyEnergy Needs of Men at Various
Levels of Activity
Example: You are 21, weigh 175lbs, and activity is moderate
REE = 6.95 X Weight + 679 = 6.95X 175 + 679 = 1895 kcal/day
Total Energy Needs = 1895 X 1.7 =
3222 kcal/dayThe formula for REE came from Table
1-1.
The 1.7 is the Activity Factor for“Moderate” from the table above.
Worksheet 1-1. Estimate Your TotalDaily Energy Needs
Body Size and Body MassIndex
The BODY MASS INDEX, or BMI isa measure commonly used to rapidlyassess body composition and thenclassify and identify individuals asunder-, overweight or overfat. The BMIis actually a ratio: weight/height2, withweight in kilograms and height in meters.Reference standards have beendeveloped for the United Statespopulation as a whole, broken down byrace and gender, so that individuals atrisk for obesity can be identified.However, the reference values for theU.S. population as a whole do not
always apply to special populations,such as SEALs. As a result, uniquepopulations often develop their ownstandards and references based onindividuals within that population. Areference range based on a survey ofover 800 SEALs was recentlydeveloped. For all the SEALs combined,the average BMI was 25, and theaverage body fat was 13%. What isimportant to remember, is that this indexis a screening tool. You can use the BMIto assess and keep track of changes inyour body composition. If your BMI ishigh, have your body fat checked, and ifyour body fat is more than 20%, youneed to take some action to lower yourweight. Reference BMI values for you
are provided below:
Reference BMI Values forSEALs
Use the nomogram below to find yourBMI and see where you fall relative tothe reference values. To use thenomogram, place a ruler or straight edgebetween height (right side) and bodyweight (left side); then read BMI fromthe central scale. NOTE: Even with
these reference values, the BMI canmisclassify some large frame, verystrong men as overweight. Check yourbody fat; that will be the deciding factor.
Worksheet 1-2. Normogram for Body
Mass Index
How To Calculate EnergyExpenditure
You will need a calculator to completethis exercise.
Over a 24 hour period you willexpend different amounts of energy ineach activity in which you engage, be itwatching TV, eating, running on the sand,paddling, or listening to your teammates.The objective of this activity is to makeyou aware of the energy you actually doexpend.
♦ Record your name and date onyour ENERGYEXPENDITURE ACTIVITYFORM.
♦ List all the activities youparticipated in over the last 12
hours and the approximate lengthof time (in minutes) you spent oneach activity on the form.
♦ Go through the alphabetical list ofactivities provided in Appendix4, and find the activity that mostclosely approximates each oneyou listed on the form.
♦ Write down on the form thekcal/minute (not per hour!) valuein the appropriate column(Energy Value).
♦ Multiply the energy value by thetotal time in minutes. Forexample, if you ran in the sand inboots for 25 minutes, then yourenergy expenditure for thatactivity would be 15 (energy
value) X 25 (time) = 385 kcals.♦ Do this for at least five activities,
or preferably all the events in 12hours. Then add up the numbersto get an actual energyexpenditure estimate. How didyou fare? You were probablysurprised by some of thenumbers, but this experienceshould give you a good overviewof energy balance. Keep track ofyour weight if you are in doubt -it is the most accurate way tomonitor energy balance.
Worksheet 1-3. Energy Expenditure
Activity Form
Chapter 2
Carbohydrate, Fat andProtein: The Energy-
Providing Macronutrients
You have heard the saying “You arewhat you eat”. Although this statementhas not been proven, we do know thatwhat you eat makes a difference in howyou perform, how long you survive, andthe quality of your life. Themacronutrients, or energy-providingnutrients, are extremely important in this
respect. Also, without energy you wouldstarve, and your ability to performwould be greatly reduced. Our threemain sources of energy are:
♦ Carbohydrate or CHO♦ Fat♦ Protein
These fuels are called macro becausethey are eaten in “large quantities”unlike the micronutrients we willdiscuss later. This chapter will providebasic information about thesemacronutrients.
Carbohydrate
Carbohydrates, commonlyabbreviated CHO, are foods we want tobecome very familiar with since they arethe preferred foods for enduranceactivities, competitive athletic events,and healthy living. In fact, CHOs are thebasic source of energy for humans.Luckily, CHO are also foods you areencouraged to eat, not foods you areurged to restrict, such as fat.
Definition, Composition, andClassification
Carbohydrates are composed of threeelements: carbon, hydrogen and oxygen.They exist in many forms, but the twomajor types of CHOs are simple andcomplex.
♦ Simple CHOs have one (mono)or two (disaccharides) sugarmolecules hooked together.
♦ Types of simple CHOs includeglucose (dextrose), table sugar(sucrose), honey (fructose andglucose), fructose (sugars infruit), maltose (sugars in malt),lactose (sugar in milk), brown
sugar, corn syrup, maple syrup,refined sugar products, rawsugar, corn sweeteners, high-fructose corn syrup, andmolasses.
♦ Complex CHOs have three ormore simple sugar moleculeshooked together; polysaccharidesare long strands of simplesugars.
♦ Complex CHOs are found ingrains, fruits, seeds, potatoes,pasta, macaroni, seaweed, algae,and legumes such as peas andbeans, and all other vegetables.
♦ The main forms of complexCHOs are starches and fibers;they come from plant materials.
Starches are digested by thebody whereas dietary fibercannot be. Fiber will bediscussed in Chapter 5.
♦ The only CHO stored in animalsis “glycogen” which is found inliver and muscles.
♦ The amount of glycogen stored inliver and muscle is limited:muscle glycogen stores can bedepleted after 3 to 4 hours ofheavy exercise and a 24 hour fastcould use up liver glycogenstores.
Functions of Carbohydrate in theBody
CHOs are used in the body mainly as:
♦ Fuel in the form of glucose -glucose is the most importantsource of energy in our body, andit is stored in the liver andmuscle as glycogen. Thecomplex CHOs you eat aredigested into simple sugars,mostly glucose, and then used bythe muscles, brain, heart, andother organs for energy.
♦ Building blocks to makechemicals needed by the cells ofyour body
♦ Chemical cement for repairingstructures of your body
Carbohydrate in the Diet
CHO foodstuffs are the largest part ofthe world’s food supply. In Mexico theCHO staples are corn tortilla and beans;in Brazil - black beans and rice; in India- chick peas (garbanzo), lentils, rice, andwhole grain unleavened breads; in Japan- rice, tofu and vegetables; and in theMiddle East - humus (chick peas) andtahini (sesame seeds). In the UnitedStates our classic CHOs are bread,potatoes, noodles, and macaroni.
Unfortunately, many people think
starches are unhealthy and lead to weightgain. That notion came about becausemost people add high fat toppings and/or
sauces to their starchy foods. Forexample, many individuals put lots ofbutter or margarine on their bread, sourcream on their baked potato, creamcheese on bagels and cream sauces ontheir macaroni or pasta! Look below tosee what kinds of foods provide simpleand complex CHOs.
Energy From Carbohydrate
One gram of CHO supplies 4 kcal
EXAMPLE: One Fig Newtoncontains 10 grams of CHO and provides60 calories. Calories from CHO andpercent of calories from CHO are:
4 kcal X 10 grams = 40 kcalfrom CHO
40/60 = 0.67 = 67% of energyfrom CHO
Table 2-1. Ideas For Selecting Foods/Food Combinations High In Complex
CHO
Fat
Believe it or not, fat is an essentialpart of your diet, even though you heareveryone say “Don’t eat that, it’s high infat!”. Fat adds taste to foods andsatisfies your sense of hunger. However,not all fats are created equal. By
understanding the different types ofdietary fat, how fat works in the body,and using guidelines for daily fatconsumption, you can eliminate excessfat from your diet and eat for betterhealth.
Definition, Composition, andClassification
Fat is an essential nutrient for yourbody, and is usually classified accordingto its chemical form. There are threemajor types of fats or fatty acids:
♦ Saturated♦ Monounsaturated♦ Polyunsaturated
Saturated fats (“fatty acids”) whichare solid at room temperature, have noroom for any additional hydrogen atoms.Saturated fats are found primarily inanimal foods—red meats, lard, butter,poultry with skin, and whole milk dairy
products. Palm, palm kernel and coconutoils are also highly saturated.
Mono and polyunsaturated fats, which
remain liquid at room temperature haveroom for additional hydrogen atoms.Monounsaturates have room for only onehydrogen and are found in olives, oliveoil, avocados, and peanuts.Polyunsaturated fats, which have roomfor more than one hydrogen, are foundprimarily in fish, corn, wheat, nuts,seeds, and vegetable oils, such aspeanut, sunflower, corn and saffloweroils.
Functions of Fat in the Body
Fats, or fatty acids, serve severalimportant roles in the body. Fat:
♦ Is our major form of storedenergy; it provides energy duringexercise, in cold environments,and when you don’t have enoughto eat
♦ Insulates the body♦ Helps carry other nutrients to
places in the body♦ Protects organs♦ Serves a structural role in cells
Despite its bad reputation, fat is veryimportant, and some fats/fatty acids are
essential.
How Much Fat Should We Eat?
A little of all the different types of fatsis desirable, but TOO much fat is theprimary dietary problem in our country.A high intake of fat is associated withmany diseases, including:
Heart diseaseObesity
♦ Many forms of cancer♦ Diabetes
The average American consumes 42%of his or her daily calories as fat (40%carbohydrate and 18% protein). Mosthealth experts agree that Americansshould decrease their fat intake to no
more than 30% of the total dailycalories, and saturated fat shouldprovide no more than 10% of the totaldaily calories. In our country, more than15% of our calories are from saturatedfat. The key to this is knowing whichfoods are high in fat and which are low.Once you have that information, it is upto you to start changing your dietarybehaviors.
Energy From Fat
One gram of FAT supplies 9 kcal
Fat provides more than twice theenergy supplied by carbohydrates.Example 1:A 1 ounce bag of potato chips
contains 10 grams of fat, so the caloriesfrom fat are:
9 kcal X 10 grams = 90 kcal ofenergy
Example 2:One hot dog supplies17 grams of fat,
so calories from fat would be:
9 kcal X 17 grams = 153 kcal ofenergy
Determining Your Daily Fat Allowance
Everyone talks about grams of fat, butwhat does that mean on a practicallevel? How does one translate “grams”of fat to percent fat and how many gramsof fat should you allow yourself eachday? You know that only 30% of yourcalories should come from fat, so withthat in mind, you will learn how todetermine your daily fat allowance.Let’s take an example first:
Example: DeterminingA Fat Allowance
If estimated energy need (EEN)=3222 calories
Step 1. Multiply EEN by 0.3 toget calories from fat 3222 X 0.3 =
967 fat caloriesStep 2. Divide fat calories by 9
to get grams of fat. 967/9 =107grams of FAT per day
Where Did the Numbers Come From?
Estimated energy need wasprovided in the example. Youknow your EEN from theprevious chapter.
♦ 0.3 in Step 1 is for calculating30% of calories from fat.
♦ 9 in Step 2 is the number ofcalories in one gram of fat.
♦ 107 is the number of grams of fat
that should not be exceeded toensure that the diet provides nomore than 30% of calories fromfat.
Worksheet 2-1. Figure Out Your Fat
Allowance
Now that you know how to do this,just take whatever percent fat you want,multiply it by your energy needs, andthen divide by 9.
You can also use the above method to
determine the percent of fat in particularfoods. If you read a food label and itshows the item provides 270 calories, ofwhich 15 grams are fat, then to calculatethe percent of calories from fat youwould do the following:
Total Calories = 270Total Fat = 15 grams
Calories from Fat = 15 grams X9 kcal = 135 kcal
% Calories from Fat = (135 X
100)/270 = 50%
Worksheet 2-2. Calculating Percent of
Calories From Fat
Worksheet 2-3. Select A “Lower Fat”
Alternative
Protein
Many people like to eat high proteinfoods because they think protein makesthem grow “big and strong”. Are theycorrect? Let’s take a look at protein andwhat it really does.
Definition and Composition
Unlike carbohydrates and fats whichcontain only carbon, oxygen andhydrogen, protein also contains nitrogenand other elements essential for life.Proteins are made up of several aminoacids - small building blocks that arehooked together. Although there aremany different amino acids (at least 20),only 9 are called essential amino acidsbecause the body cannot make them; theymust be obtained from the diet. That’swhy we must eat protein - to take in theessential amino acids.
Functions of Protein in the Body
Proteins vary in size, depending onhow many amino acids are linkedtogether, and each one performs differentfunctions in the body. Although they canprovide energy, they are not a mainsource of energy like carbohydrates andfat. Some functions of protein are:
♦ Form muscle, hair, nails, skin,and other tissues
♦ Direct energy production♦ Repair injuries♦ Carry fats, vitamins and minerals
to different parts of the body♦ Muscle contraction♦ Serve a structural role for every
part of the body
How Much Protein Should I Eat?
Many people eat 150 to 200 g ofprotein each day which is more proteinthan is actually needed by the body.Protein needs are determined by age,body weight, and activity level. Manyathletes think that if they eat moreprotein their muscles will get larger, butthis is not true. Excess calories fromprotein can be converted to fat andstored. Additionally, the liver and thekidneys are put under a lot of strainwhen processing large quantities ofprotein.
Table 2-2. How Much Protein Do I
Need?
ExampleSuppose you weigh 175 pounds and
are training to be a SEAL. Then you are“IN TRAINING” for sure - bothendurance and strength training. Yourprotein needs would be 0.6 to 0.8 gramsper pound body weight, as shown in the
figure above.
Protein Needs = 0.8 X 175 = 140grams
Worksheet 2-4. Calculate Your
Protein Needs
Energy from Protein
One gram of PROTEIN supplies 4kcal
Protein supplies about the sameenergy as carbohydrates.Example 1:One hard boiled egg contains 6 grams ofprotein; calories from protein are:
4 kcal X 6 grams = 24 kcal ofenergy
Example 2:One small hamburger supplies 24 gramsof protein; calories from protein wouldbe:
4 kcal X 24 grams = 96 kcal ofenergy
Chapter 3
Micronutrients: Vitaminsand Minerals
Micronutrients are substancesrequired by or essential to the body invery small amounts and include bothvitamins and minerals. Taking in eithertoo little or too much of these nutrientscan interfere with normal bodilyfunctions. It is difficult to consumeexcessive amounts through a typical diet.However, it is possible to obtain toolittle of selected vitamins and minerals if
proper food selections are not made.
Vitamin E
Vitamin C
Pro-Vitamin A
What are the RecommendedDietary Allowances?
The amounts of particular vitaminsand minerals a normal person should eatto prevent a deficiency are known as theRecommended Dietary Allowances(RDA). The RDA are periodicallyupdated to reflect new information, withthe most recent revision taking place in1989. Since there are individualvariations in nutrient requirements, theRDA are based on the average nutrientrequirements of most people with asafety factor added. Thus, the RDA areexpected to meet the nutrientrequirements of most people in a healthy
population.
The Military has its own set of RDAknown as the Military RecommendedDietary Allowances (MRDA). TheMRDA are designed to meet the nutrientneeds of most 17-50 year old moderatelyactive, military personnel. In some casesthe allowances are similar but in othersthe MRDA are slightly higher. This isbecause the last version of the MRDAwas in 1980. Neither the RDA nor theMRDA considers the nutrient needs ofspecial populations, such as SEALs whoare extremely active and train andoperate under diverse, often gruelling,environmental conditions. Therefore,both sets of recommendations can serve
only as guidelines for your minimalintake. In most instances yourmicronutrient needs will be met throughincreased food intake provided you eat avariety of foods.
What are Vitamins?
Vitamins are organic compounds thatdo not provide calories. They arebroadly classified into two categories:
♦ Fat soluble vitamins♦ Water soluble vitamins
Fat soluble vitamins, which includevitamins A, D, E and K, are absorbedwith dietary fat, can be stored in varioustissues such as the liver, and are notexcreted in the urine. In contrast, watersoluble vitamins, which include all Bvitamins and vitamin C (ascorbic acid),are not stored in the body in appreciableamounts and small amounts are excreted
in the urine each day.
What Functions Do Vitamins Serve?
Vitamins perform a wide variety offunctions, including the release of energyfrom macronutrients (carbohydrate, fatand protein), tissue growth and repair,maintenance and support of reproductivefunction, and production of an immuneresponse. Some functions may bespecific to only one vitamin, whereassome functions may require more thanone vitamin. For example, several Bvitamins and some minerals are requiredfor releasing energy from macronutrientsas shown below.
Table 3-1. Recommended Intakes and
Functions of Vitamins
Table 3-1. Recommended Intakes and
Functions of Vitamins
What Foods are Good Sources ofVitamins?
No one food is a good source of allvitamins and as such a variety of foodsshould be consumed. Some foods arevery high in selected vitamins whereassome contain precursors or substancesthat serve as building blocks for makingthe vitamin in the body. For example,beta carotene and other carotenoids fromplant foods are converted by an enzymein the body to vitamin A. Someprocessed foods provide many vitaminsbecause they have been fortified withnutrients. Other foods will contain few,if any, vitamins. Make sure you READFOOD LABELS to see how much of the
RDA the food contains.
Food preparation techniques can
affect the final amount of a particularvitamin in a food; this is specially truewhen cooking vegetables. Of allvitamins, vitamin C is most easilydestroyed during cooking and as suchraw fruits and juices are preferredsources of this vitamin. Steps you cantake to increase the retention of vitaminswhile preparing a meal include:
♦ Avoid soaking vegetables inwater
♦ Cook vegetables in just enoughwater to prevent burning
♦ Use the shortest cooking time by
cooking vegetables to a crisp andtender stage
♦ Steaming and stir frying result inthe best vitamin retention
♦ Use leftover cooking water insoups and sauces wheneverpossible to use the water solublevitamins that were leached out
♦ Cut and cook vegetables shortlybefore serving or refrigerate inan airtight storage container.
If you are not responsible for cookingyour meals or if you eat in the galley, thekey is to eat a variety of foods whenpossible. If you are eating field rationsduring training or deployment, eat theentrees as well as the other food and
beverage items provided in the pack.For example, cocoa in the MRE ration isa source of vitamin B1, calcium andmagnesium. Good food sources of thevitamins are provided in Appendix 5.
What are Minerals
Minerals are inorganic compoundsfound in all body tissues and account for4 to 5% of a persons total body weight.Typically they are classified as minerals,trace minerals and electrolytes,depending on how much is found in thebody and the functions they serve. Forexample, calcium and magnesium areminerals, whereas zinc, copper and ironare trace minerals, because the bodycontains small amounts of them. Sodium,potassium and chloride are the primaryelectrolytes.
What Functions Do Minerals Serve?
Minerals carry “charges”, eitherpositive or negative, which helpdetermine their functions. Like vitamins,minerals are essential for a variety ofimportant physiological functions, suchas regulation of fluid balance,conduction of nerve impulses, musclecontraction as well as others. Selectedfunctions and the Recommended DietaryAllowances for the most of the essentialminerals are presented in the next table.
Table 3-2. Recommended Intakes and
Functions of Minerals
What Foods are Good Sources ofMinerals?
As with vitamins, a variety of foodsshould be eaten in order to meet yourmineral requirements. The amount of aparticular mineral that will be absorbedfrom foods varies widely and dependsupon a number of factors. Absorption ofminerals can be influenced by:
Other dietary constituents, suchas dietary fiber, oxalates andphytates
♦ The amount of other minerals inthe diet
♦ Medications♦ The body’s need for the mineral
♦ Chemical form of the mineral♦ Integrity of the intestinal tract
Even though foods may contain certainminerals, other food constituents caninfluence the actual amount absorbed.For example, insoluble materials likedietary fiber, phytates (chemicals foundin high fiber foods) and oxalates(chemicals found in certain foods suchas spinach, chard, and rhubarb) bindminerals including iron, calcium andzinc to make them less available forabsorption. In contrast, the presence ofvitamin C improves the absorption ofcalcium, iron and zinc. The absorptionof iron is dependent on its particularform: heme or non-heme. Heme iron is
found in animal foods and is betterabsorbed than non-heme iron from plantfoods. Finally, excessive intakes of someminerals can interfere with theabsorption of others: high intakes ofsupplemental zinc can decrease copperabsorption and high iron intakes candecrease zinc absorption. Good foodsources of minerals are listed inAppendix 6.
What Substances MayInterfere With
Micronutrients?
Many things you take or do can affectyour losses of vitamins and minerals. Inparticular, substances that act as “ANTI”vitamins/minerals and may interfere withthe amounts of vitamins and minerals inyour body include:
CaffeineTobaccoAntibioticsAspirinAlcoholStress
Summary
The key to meeting your vitamin andmineral needs is eating a diet containinga variety of foods. Remember, foodpreparation can affect micronutrientcontent, and that simple changes, such asdrinking water or juice instead of tea orcoffee with meals can increaseabsorption of many minerals. If you donot eat alot of fresh fruits andvegetables, then try to eat fortified,ready to eat, breakfast cereals in themorning and for snacks. If you are indoubt about the nutrient content of aprocessed food, just look at food labels.Most unprocessed foods are nutritious.The following practices will help ensure
that you meet your daily vitamin andmineral needs:
Eat A Variety of FoodsBe Savvy in Your Food
SelectionsUse Good Food Preparation
Techniques
Chapter 4
Vitamin and MineralSupplements
Vitamin and mineral supplements arebeing widely used by physically activepeople because of all the performanceenhancing claims made by supplementmanufacturers. It is estimated that about40 - 50% of athletes use some form ofvitamin mineral supplements. Theseinclude single vitamins (such asvitamin C) or minerals (such as iron)and multivitamin-mineral combinations
in doses that range from amounts thatare similar to the RecommendedDietary Allowances (RDA) up to levelsmany times the RDA (see Chapter 3 forinformation on the RDAs).font>
Role of Vitamins andMinerals in Physical
Activity
Vitamins and minerals are required inmicro (very small, minute) amounts bythe body to perform vital metabolic andphysiologic functions. Some of thefunctions related to physical activity thatvitamins and minerals are involved ininclude:
♦ Production of energy: manyvitamins and minerals areinvolved in producing energyfrom carbohydrates (CHO), fatsand proteins.
♦ Formation of red blood cells:some vitamins and minerals arealso required for the formation ofred blood cells. Red blood cellscontain hemoglobin, an ironcontaining protein that carriesoxygen.
♦ Providing oxygen to theexercising muscles: hemoglobinand myoglobin are ironcontaining proteins whichtransport and deliver oxygen toexercising muscles.
♦ Maintenance of healthy musclesand joints.
♦ Recovery from exercise: somevitamins and minerals may helpin recovering from exhaustive
exercise.
Because of all the functions served byvitamins and minerals (see Chapter 3 foradditional information), the supplementindustry has embarked on a promotionalcampaign to encourage the use ofsupplements by physically activepeople. Whether all the hype aboutsupplement use and performance isjustified is discussed below.
Benefits of Supplementation
Supplements are useful under avariety of conditions. Some conditionswhere benefits of supplementation havebeen found are when:
♦ There is an existing vitamin ormineral deficiency
♦ Individuals have poor nutrientintakes and dietary habits
♦ Individuals are exposed toextreme environmentalconditions, such as altitude
Supplement Use andPerformance
Vitamin Supplements
Taking a general multivitaminsupplement appears to be withoutmeasurable performance enhancingeffects in healthy, well-nourished,physically active men on measures ofmaximal aerobic capacity, heart rate,submaximal endurance runningperformance, and muscle glycogenstores. Similarly, no improvements inmuscle strength or endurance have beennoted in strength athletes, such as bodybuilders, who tend to use megadoses ofvitamin and mineral supplements.
We don’t know yet whether
supplementation with various nutrients
will have other more subtle beneficialeffects that may allow you to perform atan optimal level for extended periods oftime. For example, supplementation withselected vitamins or minerals mayaccelerate recovery and/or reducesusceptibility to infections. Someinformation to confirm thesepossibilities is available, butconfirmatory studies have not beenconducted in military populations. Assuch, if you elect to take supplements,you should monitor your overall healthand performance to determine whetherthe expense is justified. Also, be surenot to take more than 2 to 3 times theRDA; preferably take a supplement thatprovides nutrients in amounts that meet
the RDA (see Chapter 3 for the RDAs).
Vitamin C
Supplementation with 600 mg/dayof Vitamin C may decrease theincidence of upper respiratory
infections during extendedmissions and/or prolonged
activities.
When selected individuals participatein prolonged competitive athletic events,supplementation with vitamin C has beenshown to be beneficial for reducing theincidence and or severity of upper
respiratory infections. This may help inBUD/SEAL training, especially duringthe first phase and Hell Week, whenupper respiratory tract infections andcellulitis are frequently noted.Infections, such as an outbreak ofpneumococcal pneumonia have alsobeen noted during Ranger training.
Vitamin E
Supplementation with 400 IU/dayof Vitamin E may protect cellmembranes from damage by freeradicals produced duringstrenuous exercise.
For conditions of altitude exposure,one recent study indicated thatmountaineers who took vitamin Esupplements minimized altitude-inducedperformance decrements by being ableto maintain adequate blood flow andprotect their cell membranes from“oxidative” damage.
Mineral Supplements
As with the vitamins, there is noclear-cut evidence to indicate thatmineral supplements will enhancephysical performance in normal, healthyindividuals. However, some mineralsmay be useful and others may beharmful.
Chromium
Chromium is becoming increasinglypopular among athletes because ofpurported muscle-building or anaboliceffects. The results from studies to date
are not consistent, and more work isrequired before definitiverecommendations can be made.Meanwhile, if you take chromiumsupplements, limit the amount to thecurrent recommendations (200 µg/day);do not take more than 1000 µg/day.
Zinc
Supplementation with zinc has alsobeen studied. Taking a zinc:coppersupplement (25 mg to 2 mg) twice a dayalso seems to minimize the production offree radicals generated during prolongedexercise. However, if zinc supplements
are taken, they should provide no morethan 100 mg per day, and copper shouldbe taken to prevent a copper deficiency.
Iron
Iron is commonly used by physicallyactive people looking for theperformance edge. However, ironsupplements do not improveperformance in non-deficientindividuals. If your diet provides anymeat, fish or poultry, it is unlikely youneed iron supplements. Moreover,excessive iron intakes can bedetrimental (see risks) and the use of
prenatal supplements to boost iron storesis not recommended.
Antioxidants
As SEALS, you are continuallyexposed to hazardous environments,extensive sunlight, and other situationswhich result in a process called“oxidation”. Oxidation results in theformation of “Free Radicals” or“Superoxide Anions”. Because you areexposed more than the average person,taking an antioxidant supplement may beprotective (see chapter 3 for foodsources of antioxidants). If you chewtobacco, this may be particularlyimportant to your future health.
Types of Antioxidants
Vitamin E
Beta Carotene
CysteineVitamin C
Selenium
Glutathione
Flavonoids
♦ Several multivitamin and mineral
supplements contain antioxidants- CHECK labels for amounts.
♦ Antioxidant vitamins andminerals are also available assingle nutrient supplements, e.g.,vitamin E is sold separately. Soeven if you do not takemultivitamins and minerals, youmay choose to use an antioxidant.
Risks of Supplementation
The indiscriminate use of high potencyvitamins and minerals is of concernsince excessive amounts of vitaminsand/or minerals can be harmful and mayresult in nutrient imbalances. Excessiveintake of some vitamin and mineralsupplements can result in multiple sideeffects. Harmful side effects of nutrientswhich are frequently taken in excess areprovided on the next page.
Vitamin ADaily intake of large amounts of
vitamin A over several months isextremely toxic. Symptoms ofoverdosing with retinol include nausea,vomiting, abdominal pain, weight loss,
hair loss, cerebral edema (swelling ofthe brain), and liver failure.
Vitamin B6Chronic megadoses of vitamin B6
have resulted in neurological problems,including loss of muscle coordinationand loss of sensation in hands and feet;some individuals may develop theseneurological problems with even lowerdoses of vitamin B6 (100 mg/day).
IronChronic use of iron supplements can
be a problem, especially in individualsgenetically predisposed to iron overload(hemochromatosis); damage to multipleorgans including the liver has been
observed. Thus, supplemental iron is notindicated unless an iron deficiencyanemia has been diagnosed.
ZincHigh intakes of zinc interfere with
copper absorption. Daily zinc intakes of>150 mg/ day may increase the risk forcardiovascular disease by decreasingserum high density lipoprotein levelsand increasing low density lipoproteinlevels.
Although some people take excessive
amounts of nutrients on a regular basis, itis important to distinguish betweenexcessive and toxic. Intakes of nutrientsat their potentially toxic levels can resultin significant adverse effects quite
readily. Table 4-1 list the toxic values ofmany nutrients, and these amounts shouldnever be taken. Preferably, intakes willbe well below these number, even overa one week period.
Table 4-1. Nutrients and Their
Toxicity Values
Table 4-1. Nutrients and Their
Toxicity Values
What to Look for WhenBuying Supplements
The better informed you are aboutmarketing practices of vitamin andmineral supplements the more likely youwill be to save money and still use agood supplement. For example, did youknow that most supplementmanufacturers get their initial supply ofvitamins and minerals from the samesmall group of suppliers? After that theyformulate their various combinations,label them and sell them. Listed beloware some factors you should considerwhen buying supplements.
Natural Versus Synthetic Vitamins
Both forms are used the same way bythe body so why pay more for a“natural” product. Also manufacturersoften add a few plant extracts or a bit ofthe natural vitamin and sell the productat a higher price by labeling it as natural.
Presence of Starch, Sugar, and OtherAdditives
Many supplements contain starch,binders and other additives. Theseadditives are present in very smallamounts and in very rare instances theymay cause headaches and other reactionsin some people.
Disintegration Rate
If a supplement does not dissolve inthe gut, it won’t be absorbed and itwon’t do you any good. One way for youto insure you are taking the right kind ofsupplement is to look for supplementsthat meet the U.S. Pharmacopoeia (USP)standards which say that water solublevitamin supplements should disintegratein 30 minutes if uncoated and 45 minutesif coated. This standard does not applyto time-release or chewablesupplements. Standards for fat-solublevitamins, minerals and multivitamin arecurrently being prepared but severalcompanies are already marketingmultivitamin-mineral supplements that
dissolve within 45 minutes. Look atsupplement labels or call themanufacturer for information.
When to Take?
Fat soluble vitamins are betterabsorbed when taken with food, so ifyou take a multivitamin mineralsupplement, it is best to take it with ameal.font>
Tea or coffee will reduce theabsorption of several nutrients in
supplements.
In general, the body can only absorb anduse a certain amounts of nutrients at onetime and the rest will be excreted. Donot take a vitamin/mineral supplementwith a carbohydrate-protein drink that isalready supplemented with vitamins and
minerals as you would literally bewasting the supplement and your money
Amount of Nutrient
Be especially careful about theamount of fat soluble vitamins in thesupplement.
Daily supplements should notcontain more than 10,000 IU
(RDA is 5,000 IU) of Vitamin A asretinol palmitate or acetate.
This form of vitamin A in excess isvery toxic. If you use severalsupplements that each contain retinolpalmitate or acetate, you will veryquickly exceed safe levels. Also,excessive amounts of the water solublevitamin, vitamin B6 can be harmful.
Read labels and watch your supplementintakes.
In general, you can safely take 2-3
times the RDA of most vitamins andminerals without harming yourself.
Nutrient Balance
Besides the potential for toxicity,excessive amounts of single nutrientsupplements can upset your overallnutrient balance and cause a deficiencyin other nutrients. Iron, zinc and copperare good examples since all three areabsorbed by the same pathway. Anexcessive intake of one of these mineralscan prevent the proper absorption of theothers. This could eventually cause adeficiency and defeat the nutritionalenhancement being sought throughsupplementation.
Expiration Date
The expiration date on labels refers tothe length of time a particularsupplement is expected to hold itsvitamin and mineral potency. Check theexpiration date on the label and avoidbuying supplements that are due toexpire within 6 months since the potencyof vitamins may be on the decline.
Summary
♦ Vitamin and/or mineraldeficiencies can impairperformance. Restoration to asufficient level reversesperformance decrements.However, deficiency states arerare in otherwise healthy males.
♦ Vitamin and mineralsupplementation does notimprove aerobic capacity,endurance performance, ormuscle strength in healthy,nutritionally adequateindividuals.
♦ Megadoses of vitamins and orminerals can be harmful.font>
♦ CHECK LABELS - to make sureyou are not taking too much ofany single nutrient.
♦ Under most circumstances youshould be able to obtainadequate amounts of vitaminsand minerals from your dailydiet.
Chapter 5
Fiber and Health
Dietary fiber is a food constituentyou should be familiar with as it isimportant for health. Many of thenutritional approaches discussed in thismanual will, in fact, promote goodhealth. Although health is importantwhen performance is your end result,you should be aware that dietary fibershould assume a definite BACK SEATrole during mission and trainingoperations/scenarios. In this chapter we
will discuss the role of fiber in overallhealth and during special operations.
What is Dietary Fiber?
Dietary fiber is a form ofcarbohydrate we get from fruits,vegetables, grain products, beans, nutsand other plant foods. A moremeaningful definition of dietary fiberwould be: the structural components ofplant foods that cannot be digested bythe human body. Because fiber is neitherdigested or absorbed, it really can’t beconsidered a nutrient, like vitamins,minerals, proteins, fats and othercarbohydrates, but it is still an essentialpart of your diet.
Typically dietary fibers are classified
as soluble or insoluble, but most fiber-rich foods contain some of both types.These two types of fibers functiondifferently in the body. Insoluble fibersare known for their ability to absorbwater in the gastrointestinal tract andpromote regular elimination of stools.An increase in stool weight and a fastertransit time are common when diets highin insoluble fiber are ingested. Transittime is the time it takes for your meal tobe digested and be excreted in yourstools. Insoluble fibers are thepredominant fiber in most foods. Incontrast, soluble fibers appear to helplower serum cholesterol, a risk factorfor heart disease and they also helpregulate blood sugar levels. These
special effects of dietary fiber haveprompted many health promotionagencies to make specificrecommendations regarding how muchdietary fiber our diet should provide. Ina nutshell, fiber serves a very importantrole in health.
Why Should I Eat MoreFiber?
The National Cancer Institute, theAmerican Heart Association, theNational Academy of Sciences, and theUnited States Department of Agriculturehave all come out with dietaryrecommendation for fiber. There aremany reasons to increase your dailyintake of fiber, and they are all related torisk factors for chronic disease. A lackof fiber in the diet has been associatedwith gastrointestinal diseases,hypertension, diabetes, heart disease,and several types of cancer, includingcolon cancer, whereas a high fiber intake
is associated with a decreased risk. Forthese reasons, increasing your intake ofdietary fiber may be very important withrespect to your future health.
Recommendations for intake ofdietary fiber include:♦ Consume at least 3 - 5
servings of variousvegetables, 2 or more
servings of fruit, and 6 ormore servings of grain
products, or♦ Increase dietary fiber intake
to 20 to 35 grams per day
The first recommendation is the
easiest to follow since it is extremelydifficult to know how much fiber is ineach food. Moreover, what the abovementioned organizations use as a typicalserving is probably only a quarter ofwhat your portions are. For example,one serving of fruit would be one apple,one banana, one orange or one pear. Oneserving of grain products would be oneslice of whole wheat bread or one bagel.Furthermore, one serving of vegetableswould be 1/2 cup of peas, one smallpotato, or 1/2 cup of carrots. It is likelythat you are eating more than one servingat each meal.
How Can I Get More Fiberin My Diet?
Eating more fruits and vegetables,whole wheat breads, whole graincereals, beans, rice, nuts and seeds is thebest way to add fiber to your diet. Foodsthat provide the most soluble fiberinclude kidney beans, avocados, greenbeans, baked potatoes with their skin,sweet potatoes, oatmeal, oranges,bananas, and watermelon. A list of somefoods and their total dietary fiber ingrams (g) is provided below.
Table 5-1. Serving Sizes and DietaryFiber Content (in grams) of Selected
Foods
Table 5-1. Serving Sizes and DietaryFiber Content (in grams) of Selected
Foods
When Should I MinimizeMy Fiber Intake?
Dietary fiber is very important to yourhealth: it promotes regularity byincreasing stool bulk and weight.However, during extended operations,you will most likely want to avoid“regular eliminations” for as long aspossible. A low fiber diet may bepreferred for these occasions. Also,many high fiber foods can cause bloatingand gas if you are not accustomed toeating them or if you don’t drink enoughwater. Make sure to try such foodsduring training so you can find out howyour system reacts. That way you can
make dietary modifications wherenecessary before the actual event.
For Special Operations You MayWant to Minimize Your Intake of
Dietary Fiber
Chapter 6
Fluid Replacement: Waterand Other Beverages
Water is an essential nutrient andthe most abundant component of thehuman body. Believe it or not,approximately 60% of your total bodyweight is water. Since lean body/musclemass requires more water than fat, theleaner you are, the more body water youhave. As you may imagine, water mustbe consumed regularly to ensure normalfunctioning of your body.
Distribution and Functionsof Water
Water is found both inside and outsidecells, but most water is inside cells,especially muscle cells. The lowestconcentration of water is in bone and fat.Water in the body serves many importantroles, including:
♦ Participates in digestion andabsorption of nutrients
♦ Participates in excretion ofwastes
♦ Essential for maintaining bloodcirculation throughout the body
♦ Maintains body temperature
A loss of 20% of body water canresult in death, and if 4% of your bodyweight is lost because of sweating, largedecrements in decision-making,concentration, and physical work occur.In addition, being well hydrated duringoperations is absolutely critical, sinceadequate fluid volume will helpcompensate for blood loss whenwounded. For these reasons,consumption of water is absolutelycritical, and maintenance of waterbalance is essential to SEALperformance. Below are signs andsymptoms you might experience as youbecome dehydrated.
How to Maintain WaterBalance
Water balance is determined bywater/fluid output and input. In order tomaintain performance, it is critical that afluid deficit, or dehydration does notoccur. With dehydration, water outputexceeds input and balance becomesnegative. The average man loses 1,000ml to 2,300 ml (0.9 to 2.4 quarts) ofwater/day. This water is lost:
♦ In the urine♦ Through breathing♦ By sweating♦ Through the stools.
When activity level is low, mostfluids are lost through the urine.However, when activity level or theoutdoor temperature is high, most fluidis lost by sweating. In fact, up to 2,000ml (1.8 quarts) per hour can be lostthrough sweating, depending on outsidetemperatures.
All fluids lost must be added back to
the body each day to maintain fluidbalance. Sources of fluid for the bodyare:
Water in food Water in beverages (like orangejuice, coffee, sodas and beer)
Water from the metabolism or
chemical breakdown of foods
The easiest way to restore fluid balanceis by drinking water, and this is VERYimportant to remember. The figure on thenext page graphically depicts wateroutput and input for normal temperatureconditions, hot weather, and withprolonged exercise. Notice how sweatoutput increases dramatically with bothhot weather and prolonged exercise -these amounts would be even greater ifexercise were performed in the heat. Theonly way to match this great output is todrink fluids.
In this figure it is important to notethat exercise and heat exposure increasesweat losses and reduce urine losses. Inaddition, the only good way to replacethose “lost fluids” is by drinking fluids:fluid intake MUST go up toaccommodate losses.
Although eating fods high in water
will help restore or maintain waterbalance, drinking fluids is preferred.Some foods that are over 90% water,include watermelon, strawberries,grapefruit, cucumbers, and many otherfresh fruits and vegetables. If you eatmany of those foods and drink lots ofbeverages, it is less likely you would bein negative water balance.
What Conditions WillIncrease Water Losses?
The primary factors which couldcause dehydration are:
♦ Exercising for over 30 minutes♦ Working in a hot environment -
wet or dry♦ Working in a cold environment -
wet or dry♦ Going to high altitudes♦ Drinking too much alcohol♦ Exercising in the heat, cold, or at
altitude♦ Exercising with a hangover
How Can You Make Sure toGet Enough Fluids?
Several points about fluid intakeshould be considered:
♦ Do not rely on thirst as a goodindicator of fluid needs; bodyweight losses are better
♦ Before any exercise or simulated-mission, you should drink fluids,in anticipation of losing fluid
♦ Before you start, make sure yoururine is clear (unless you take Bvitamin supplements) - this is asign that you are well hydrated.The more dehydrated you are, the
darker (and smellier) your urinewill be
♦ Drink regularly or wheneverpossible during your workoutsand operations
♦ Weigh yourself before and afteran event to determine how muchfluid you have lost - for everypound of weight lost, you shoulddrink 16 ounces of fluid (2 cupsor 500 ml)
What You Should Drink
Many beverages - both regular andsports drinks - are commerciallyavailable. These include:
Although the type of activity youparticipate in will determine what youdrink, the beverage you select should:
♦ Taste good♦ Cause no gastrointestinal/stomach
discomfort
♦ Be rapidly absorbed♦ Contain sodium and potassium
especially when exercising for aprolonged period in the heat
♦ Have an osmolality of less than350 mOsm/L
Osmolality refers to the number ofparticles in solution. If it is high (> 350),the beverage can cause stomach distressand not be absorbed well if you drink itshortly before or during physicalactivity. Note in the chart below that theosmolality of some beverages is greaterthan 350. Thus, if you choose to drinkthose beverages as sports drinks, youshould dilute them appropriately ordrink an equal amount of water. For
example, orange juice should be mixedwith an equal amount of water.
If the exercise is of long duration, it
may be advisable to ingest a beveragethat provides energy in the form ofcarbohydrate (CHO) to the workingmuscles. Beverages with “glucosepolymers”, which are complex CHOsare usually preferred over the glucoseand sucrose drinks, which are simpleCHOs. However, the important messageis to drink. Below is a list of beverages,some of which are currently used as“fluid replacement beverages” byathletes and others that are popular withmany individuals.
Table 6-1. Comparison of Fluid
Replacement Beverages
When and How Much toDrink?
Remember: the followingrecommendations are generally soundfor most people. However, everyone isdifferent so you must learn to look forsigns alerting you to your fluid needs.Also, you need to make adjustmentsdepending on the temperature outside. Ifit is very hot, you may need to double therecommendations. Remember the moreactive you are the more fluid you need.Be careful not to drink TOO much plainwater, especially during prolongedexercise in the heat.
Table 6-2. Fluid IntakeRecommendations for Before, During
and After an Event or Mission
Table 6-2. Fluid Intake
Recommendations for Before, Duringand After an Event or Mission
Table 6-2. Fluid Intake
Recommendations for Before, During
and After an Event or Mission
Table 6-3. Typical Fluid Losses for
Various Events
Table 6-3. Typical Fluid Losses for
Various Events
Table 6-4. Determining Amounts of
Fluid and CHO to Drink DuringExercise
Chapter 7
Healthy Snacking
Snacking “eating between regularmeals”, can be extremely importantwhen it comes to performing your dutiesand assignments. Your energyexpenditure can be extremely high ongiven days and during variousoperations, and it is often difficult to eatenough at meals. Snacking becomes veryimportant during this time. In addition,you probably snack at various timesduring the day and evening anyway, so it
becomes important to look at whatconstitutes healthy snacks. Most peoplethink snacking is unhealthy and leads toweight gain, but that notion has emergedbecause most people don’t eat healthysnacks! If you don’t care about gainingweight, just about any snack will do, butif you want to maintain weight andperform well, then selection of snacks iscritical.
Tips for Healthy Snacking
Think through a typical day. Howoften and where do you usually snack?Are your snacks healthy or loaded withfat? In case you aren’t sure, here aresome tips to help promote healthsnacking!
Stock your cupboards andrefrigerator with plain popcorn,
whole grain crackers, Dutchpretzels, unsweetened fruit juices,
fresh fruits and vegetables, andlowfat yogurt and cheeses.
Carry naturally sweet fresh fruits,such as grapes, a pear, apple, or
watermelon, for a snack rather thancandy or cookies.
Limit the amount eaten so your
snack does NOT replace a meal. Ifit is tak-ing the place of a meal,
choose a salad or healthysandwich.
Choose a snack that providesdietary fiber as well as other
nutrients (unless the snack is for amission). Fresh fruits with edibleseeds (berries) or skins (apples,
peaches, plums, pears), rawvegetables, and whole grain
pretzels or crackers are all goodsources of fiber.
Try eating dried apricots, bananas,apples, figs, dates, pineapples, and
prunes.
Make a snack mix with wheat, rice,and corn ready-to-eat cereals.
Eat raw vegetables such as celery
with lowfat cheese spreads.
Table 7-1. Macronutrient Compositionof Selected Snacks
What Snacks are Best forDifferent Occasions?
In the following charts, examples ofsnacks are provided. Some of the snacksare part of military rations, and should(could) be used during training ormission maneuvers. Other snacks maynot be realistic in the field, but are goodchoices if you are able to be moreselective in what you choose.
Operations at Night
If you need to stay up at night youshould select a snack that is low in fat,high in carbohydrate (CHO), andprovides some or a moderate amount ofprotein. You want to avoid foods thatare 100% CHO. Sports bars would beideal snacks for night operations. Also,crackers (or other forms of bread) withegg salad, mashed beans, jelly, tuna, orlow fat cream cheese, would be suitable.Finally, some of the protein/CHObeverages described in Chapter 6 wouldbe suitable for night time operations.
Table 7-2. Snacks to Eat During Night
Time Operations
Exercises in the Heat
The ideal snacks consumed duringstrenuous activities in warm to hotenvironments are those which providethe body with fluid. As such, fruits,especially watermelon and oranges aregreat snack for hot weather. Otherwise,the fluid replacement beveragesdescribed in Chapter 6 are preferred.Avoid high fat and dried foods whichcan make you uncomfortable and thirsty.
Table 7-3. Snacks to Eat During
Exercises in the Heat
Exercises in the Cold
When working in cold weather, snackon foods that are high in CHO. CHOfoods produce more heat when digestedthan either fat or protein. To go alongwith your food snack, a hot beverage,like cocoa or soup, would be great.
Table 7-4. Snacks to Eat During
Exercises in the Cold
Sustained Operations
By definition, SUSTAINEDOPERATIONS are those missions ortraining sessions where you must workcontinuously for over 24 hours withminimal sleep, and few rest periods.During these times it is important toreceive adequate amounts of CHO tomaintain your “blood glucose” and fluidto maintain “hydration status”. Thespecific types of snacks will depend onthe temperature and how long you havebeen working, but in general avoid highfat foods since they take longer to digestthan CHO foods. Also, eating CHO withsome protein will help you stay awakewhen you are feeling drowsy. A
combination of the recommendationsalready made in this chapter would bebest, depending on the environmentalconditions.
Table 7-5. Snacks to Eat During
Sustained Operations
Snacking On Occasion
There comes a time when you justdon’t want to be healthy - you want toget some quick energy and nothing else.In that case it is still wise to beselective, so if you must have a candybar or other sweets, choose one that ishigh in CHO and as low in fat aspossible: like Peppermint Patties and 3Musketeers. Remember, these foods arenot encouraged because they provideONLY energy - no vitamins or minerals,which you must have to process theenergy. BUT sweets now and then willcertainly NOT hurt you.
Table 7-6. Macronutrient Compositionof Some Sweet Snacks
Snack Recipes
Fruit Shake
1 cup ice cubes 1 cup skim milk 1 ripe banana 2 Peaches or 1/2 to 1 cup of anyfresh fruit 2 Tbsp almonds 1 Tbsp honey 2 tsp wheat germPlace all ingredients in a blender orfood processor and blend untilsmooth. For extra protein add 1/4cup of non-fat dried milk. Makes 1serving.
Nutrition Information: 520 kcal,70% CHO, 12% Protein, and 18%Fat per serving.
Trail Mix
3 cup seedless raisins 1 cup dried apricots 1 cup dried apples 1 cup almonds 1 cup dry roasted peanuts 1 cup dried pineapple 1 cup dried dates 1/2 cup sunflower seeds
Mix all ingredients together in largebowl or bag. Makes 10 -1 cup
servings.Nutrition Information: 560 kcal,62% CHO, 7% Protein, and 30%Fat per 1 cup serving.
Chapter 8
Restaurants, Fast Foods andEating Out
The average American eats one ofthree meals away from home each day,and it is likely that many of you areeating 5, 6, 7 or more meals a weekaway from home. Learning how to “eatout” is very important if you want tooptimize your performance. You areprobably aware that eating out presentsdifferent problems than eating at home.When we talk about eating out we mean
eating at restaurants, fast food places, ontravel, on vacations, and at socialevents.
Most people love to eat in restaurants
or at places away from home. Eating outprovides a change in routine, anopportunity to try new foods, a chance tosocialize and a break from cooking andwashing dishes (for those who do).Restaurant and fast food meals do nothave to be unhealthy. By being informedand by asking appropriate questions, youcan stay within the guidelines of yournutrition program and still enjoy thebenefits of eating out.
Fast Food Restaurants
Although we don’t encourage you toget your meals from fast foodestablishments, we know fast foods are away of life. If you could learn to selectthe types of foods that will suit youractivity patterns and performancerequirements, then fast food restaurantsare OK. Below are selected foodstypically available at different fast foodplaces, and the energy, carbohydrate(CHO), and fat contributions of thosefoods. After providing you with thisinformation, sample breakfasts andlunch/dinners that maybe considerednutritionally adequate in terms of theirCHO and fat content are presented.
Table 8-1. Caloric Values of Selected
Fast Foods
Table 8-2. Sample High Carbohydrate
Fast Food Breakfasts, Lunches andDinners
Recommendations forSelecting High CHO Foods
at Restaurants
PLACING AN ORDER
♦ Order a clear soup, tomato juiceor V8 juice, steamed seafood, orfruit for an appetizer.
♦ Order a green salad with lightdressing on the side. Avoidsalads with cheese, eggs, meat,bacon or croutons. Avoid coleslaw or potato salad.
♦ Order broiled, roasted or bakedlean meat, poultry or fish - evenif the menu does not say broiled.
Avoid casseroles and foods withheavy sauces.
♦ Order baked potato or plain rice -not pasta with sauces or fried ordelmonico potatoes.
♦ Do not order dessert until youhave eaten your main course. Ifyou are still hungry, order sorbet,sherbet, frozen yogurt, ice milk,fruit or angel cake.
♦ Order juices - they are high incarbohydrates.
DURING THE MEAL
♦ Eat a plain roll, breadsticks orplain crackers rather thanbiscuits or croissants. Try to
avoid spreads completely or usesparingly
♦ Minimize your nibbling on nuts,buttery crackers, potato andtortilla chips.
♦ Ask the waiter to serve yoursalad immediately; use thedressing sparingly.
♦ Trim all visible fat off meat.♦ Limit portions of margarine,
butter or sour cream.♦ Moderate your intake of alcoholic
beverages.
Worksheet 8-1. Your Eating Out
Checklist
Chapter 9
Nutritional ConsiderationsFor Endurance Activities
As SEALs you must be in excellentphysical condition and be able to endurearduous physical tasks for extendedperiods of time. Your capacity to endurecan be greatly improved by regularphysical conditioning and by followingspecial dietary practices. Prolongedrunning, swimming, load carrying and/ormultiple shorter bouts of higher intensityactivity impose significant demands on
energy stores and fluid balance. Failureto replace the energy or fluids lostduring prolonged operational or trainingactivities can greatly impair yourperformance in subsequent missionactivities. Meeting daily vitamin andmineral needs is also important sincethese micronutrients play an importantpart in physical performance (seeChapter 3). In this chapter, informationon dietary interventions to enhanceendurance performance is provided. It isimportant to remember that your dailyenergy intakes will vary according toyour activity level.
Glycogen Stores andMeeting Your Energy Needs
During heavy physical training youmust increase your caloric intakeespecially from carbohydrate (CHO)foods to meet your energy demands.Failure to do so may result in:
♦ Chronic muscular fatigue♦ A feeling of staleness♦ Weight loss♦ Poor sleep patterns
Liver and muscle glycogen is theprimary source of glucose for yourmuscles during prolonged enduranceactivities. Therefore, the key to optimal
endurance performance lies inmaintaining muscle and liver glycogenstores. Once glycogen stores areexhausted, your ability to continue toperform an endurance activity willdecrease sharply. When you wake up inthe morning, your liver stores are lowfrom not eating for several hours, andyour blood glucose may be low. Thus,breakfast is critical to maintainingenergy balance and liver glycogenstores.
Keep a weight chart duringperiods of heavy training and
arduous operations to documentenergy needs
Carbohydrates andEndurance Performance
Liver and muscle glycogen stores arereplenished by eating carbohydrate(CHO) foods. Therefore:
CHO is the most importantenergy-providing nutrient for
endurance training
The endurance capacity of anindividual on a high CHO diet isapproximately three times greater thanwhen on a high fat diet. When CHOintake is low, rigorous training sessionsover several days will result in a
gradual depletion of muscle glycogenstores and eventually impairperformance. The figure belowillustrates depletion of muscle glycogenover three days of running two hours perday. Note that when subjects ate a lowCHO diet, glycogen stores graduallybecame depleted over the three dayperiod. When the high CHO diet wasconsumed, glycogen stores wererepleted between training sessions.Remember that glycogen is composed ofglucose molecules linked together. Thisfigure clearly demonstrates the need toconsume foods that are high in CHO.
You should eat 2.5 to 4 gramsCHO per pound of body weight
each day.
EXAMPLE
You weigh 175 lbs and work outtwo hours each day 2.5 X 175 lb =
437 grams of CHO 4 X 175 lb=700 grams of CHO Your CHOneeds are between 437 and 700
grams per day
Worksheet 9-1. Calculating Your Daily
CHO Needs
Another way to think about CHOneeds is in terms of energy intake.Ideally, 60 to 65% of your daily energyshould come from CHO. When energyintake is greater than 4,000 kcals then60% is the proportion of CHO kcals tostrive for. Since each gram of CHO is 4kcal we can calculate the number ofgrams needed from your energy intake.
Example
You train 3 hours and eat 3,500kcal per day 60% of calories fromCHO = 3,500 X 60/100 = 2,100
kcal from CHO Amount of CHO =2,100/4 kcal = 525 grams of CHO
List of various high CHO foods andthe grams of CHO provided by eachfood is provided in Chapters 7 and 12and Appendix 1. Complex CHO foodsare preferable since they also providevitamins and minerals in addition toCHO (see Chapter 2). Other importantrecommendations include:
Eat high CHO snacks in
between training sessions toreplace your glycogen stores.
Consume at least 50 grams ofCHO immediately after
completing your training session.For example, you could eat a banana
and drink a cup of orange juice.Commercially available high CHOliquid supplements may be beneficialduring recovery from long trainingsessions because they supply CHO,water, protein, vitamins and minerals.
Keep a log of all CHO foodseaten for several days to see if
your intake is high enough.
CHO Loading/ GlycogenSupercompensation
What is CHO Loading?
CHO loading/glycogensupercompensation is a regimen thatcombines diet and exercise to “pack”more glycogen into muscle and liver. Itis used by endurance athletes to optimizephysical performance during prolongedendurance events. Although well-trainedmuscles have the capacity to store 2 to 3times more glycogen than untrainedmuscles, CHO loading allows you tostore 2 to 4 times the usual amount ofglycogen in liver and muscle. CHOloading may be useful for long durationmissions and extended water operations.
CHO loading involves tapering or
reducing the number, duration, andintensity of your training sessions theweek prior to an event. As shown in thefigure below, 5 days before the event (onday 2), be it an extended dive, land andwater mission, or a sports competition,your training is tapered such that on days2 and 3, no more than 40 minutes isspent on physical activities (solid line).CHO intake (dotted line) would beapproximately 50% of your total energyintake. On days 4 and 5 the time spentexercising should be no more than 20minutes, and your CHO intake should beincreased to 70% of the total energyintake. Note day 6 is a rest day and CHOintake remains at 70% of the energyintake.
An accurate body weight should beobtained for reference purposes prior tomodifying CHO intake and decreasingthe intensity of training because 2.7grams of water are stored with every
gram of glycogen. Thus, on the day of thecompetition, if an additional 200 gramsof glycogen have been stored, bodyweight should have increased by 0.54 kgor 1.2 pounds.
Who Should (and shouldn’t) CHOLoad?
For most regimens of intense physicaltraining, a daily diet that provides 2.5 to4 grams of CHO/lb body weight andadequate calories is sufficient tomaintain muscle and liver glycogenreserves. However, for SDV operations,extended load-bearing marches, andother training scenarios with extremelyhigh energy demands, CHO loading mayprove to be very useful. Remember thatCHO loading is not useful for eventslasting only 60 minutes or less, and mayin fact impair performance in activitiesrequiring short bouts of maximal effortas you will weigh more from the
additional water stored.
Protein Needs
Endurance training increases proteinneeds, and to meet the increased needs:
Protein intakes should rangefrom 0.6 to 0.8 grams per pound
body weight per day.
You calculated your proteinrequirements in Chapter 2 so refer backto that chapter for more information. It islikely your regular diet provides whatyou need because rarely do Americanmen have protein intakes below therecommendations. Most men, includingathletes, typically consume protein inexcess of their actual needs.
Vitamin and Mineral Needs
Currently, the micronutrientrequirements of people engaged inendurance activities are not well-defined. Because of the nature of yourtraining, your daily overall needs may be1.5 to 3 times greater than those of theaverage man. If you eat a healthy diet,your daily vitamin and mineral needsshould be met from a variety of differentfoods (See Appendixes 5 and 6 forinformation on food sources of variousvitamins and minerals). Becauseendurance exercise may increase yourneed for antioxidants, it is recommendedthat each day you should eat severalfoods rich in antioxidants (vitamin C,
vitamin E and beta carotene), as shownin the table on the next page.
Table 9-1. Some Good Food Sources
of Selected Antioxidant Nutrients
Pay close attention to your electrolyte(sodium and potassium) needs whentraining in hot weather. You should get
more than enough sodium in the foodsyou eat, whereas potassium requires amore careful selection of foods. SeeAppendix 6 for good food sources ofpotassium.
Fluid Requirements
Ingesting fluids at regular intervalsand eating foods with a high watercontent are important for maintaininghydration and fluid status during training.Chapter 6 provides a thorough overviewof fluid requirements and different typesof beverages. In general:
Drink 1-2 cups of water 60minutes before a training session.
Drink a cup of 5-8% CHO drinkevery 30 minutes during prolonged
exercise.During exercise, do not drink
anything with a CHO contentgreater than 8% or you are likely to
get stomach cramps.Commercial fluid replacement
beverages or diluted juices arerecommended.
Consume beverages with ahigher percentage (>8%) of CHOafter exercise to replace glycogen
stores and fluids lost duringexercise.
The beverages you drink duringand after prolonged exercise should
contain sodium and potassium.
Nutritional InterventionsDuring Training Sessions
Nutritionalmanipulations/interventions can delayfatigue and prevent conditions such aslow blood sugar, dehydration, and lowblood sodium that are detrimental toperformance. These interventionsinclude:
Drink 1 to 2 cups of a beveragesupplemented with CHO (5 - 8%)and electrolytes every 30 minutes
throughout exercise to extendyour endurance.
When an activity has been maintainedfor 2 to 3 hours without a CHO source,blood glucose levels may fall and causefatigue. Ingestion of CHO beverageswill prevent the fall in blood sugar(glucose) and delay fatigue. Althoughproviding a CHO beverage 15 to 30minutes before the anticipated onset offatigue may extend performance for ashort time, ingesting CHO afterexhaustion will not allow you toimmediately resume your activities.
Consume CHO beverages atregular intervals during
prolonged exercise.
Solid CHO foods, such as fruits and
sports bars, are acceptable as CHOsources provided you are able totolerate them during the activity anddrink fluids with them. Food selectionsare personal choices and dietarymanipulations should be tested duringtraining and omitted if they provetroublesome to you. Some foods maycause stomach cramps and diarrhea ifeaten during exercise. Dietary fiberintake should be limited during exerciseto avoid gastrointestinal problems.
Summary
♦ Maintain energy balance byrepleting glycogen storesbetween training sessions.
♦ Eat at least 2.5 grams of CHO perlb body weight or at least 400grams of CHO per day tomaintain your glycogen stores.
♦ Maximize glycogen stores beforean event by ingesting 4 to 5grams of CHO per lb bodyweight (or 70% of calories fromCHO) for 2 to 3 days before theevent.
♦ Drink at least 250 to 300 ml of aCHO supplemented (5-8%)beverage containing electrolytes
every 30 minutes throughoutprolonged training sessions.
♦ Consume at least 50 grams ofCHO within 30 minutes ofcompleting an extended trainingsession and continue to eat/snackon high CHO foods every 2hours for at least 6 hours torapidly replace your glycogenstores.
Chapter 10
Nutritional ConsiderationsFor Strength Training
SEAL missions and training requirestrength. Thus, a strength trainingprogram will enhance your physicalconditioning and ability to perform andcomplete strenuous mission tasks. Inaddition, it will keep you “looking” fit!In this chapter information on strengthtraining and the unique dietaryrequirements for strength training will beprovided.
Benefits of StrengthTraining
Strength training should complementendurance training workouts. Thespecific benefits of strength traininginclude:
♦ Increased muscle strength andendurance
♦ Increased muscle fiber size♦ Increased ligament and tendon
strength♦ Greater protection against
“overuse” injury
Because strength training makes youstronger, it will also reduce your risk for
injuries that typically accompanyendurance training. Finally, strengthtraining can make you faster at tasks thatrequire quick, short bursts of activity(such as a running from a boat to land).
Factors determining MuscleMass
The various factors that “regulate” thesize of the muscle are shown below.Some, factors such as genetics, we can’tcontrol. Often we have no control overenvironmental factors either. Factors thatwe can control and play major roles indetermining muscle mass are physicalexercise and nutritional status.
Protein Requirements ForStrength Training
Research has shown that the proteinneeds of strength athletes and enduranceathletes are quite similar: You should eat0.6 to 0.8 grams of protein per pound
body weight each day to meet yourdaily protein requirements.
Worksheet 10-1. How Much Protein
Do I Need?
Table 10-1. Examples of Where YouGet Protein
It is likely your diet provides evenmore protein than shown in the example,since protein is also in milk, cheese,fish, and many other foods. Some of youmay be getting additional protein fromcommercially available sports bars,
protein powders or carbohydrate/protein supplements as well as the foodsyou eat. Commercial supplements oftenprovide considerable protein, as shownin the next table.
Table 10-2. Protein Content of Some
Commercial Protein Supplements
Table 10-2. Protein Content of SomeCommercial Protein Supplements
The High Protein Myth
The excess protein in an athlete’s diet,not required by the body, is often around100 grams per day. Because muscle is20% protein, the additional 100 gramsof protein per day should result in a gainof 500 grams of muscle per day
Or about 1 pound of muscle perday.
If we look at what muscle is actuallymade up of we see that eating a highprotein diet just doesn’t add up. Muscleis only 20% protein; the rest is waterand minerals, lactic acid, urea and high-energy phosphates.
If you ate 100 extra grams ofprotein every day for one week,
you should gain 7 pounds ofmuscle mass! CLEARLY, this is
not the case.
The extra protein results in anincrease in the formation and excretion
of the waste product “urea”; increasesyour fluid requirements; and places aconsiderable load on the liver and thekidneys.
You should avoid protein supplements
that provide excessive amounts ofprotein or selected amino acids.Although heavily advertised, and insome cases endorsed by celebrities,very high protein intakes fromsupplements are NOT needed to buildmuscle. This practice can be veryexpensive, dangerous to your health, andquite unnecessary. A regular balanceddiet can meet your protein needs veryeffectively.
Concerns With Very High ProteinIntakes
Increases the work load of thekidneys and in extreme casesresult in kidney failure. In someindividuals this practice hasresulted in hypertension.
Can be dehydrating especiallyduring endurance events ifadditional fluids are notconsumed.
High intake of free amino acidsmay cause diarrhea andabdominal cramps.
Creates imbalances of theessential amino acids.
Worksheet 10-2. How Much Protein
Do I Eat?
As you can see it is relatively easy to
meet your daily protein requirementsfrom food. You will probably find thatyour intake is far greater than your actualrequirement.
Other NutritionalRequirements
Carbohydrate Requirements
Strength training relies on glycogenstores for energy. Thus, carbohydrates(CHO) are very important.
55 to 60% of your daily energyintake should come from CHO
The CHO recommendations forstrength training are somewhat less thanfor endurance athletes since the overallenergy requirements of weight lifting areless. BUT depending on your trainingschedule and length of your aerobicworkouts, you may need 2.5 to 4 gramsof CHO per pound body weight per day.For more information on carbohydrates
see Chapters 2 and 9.
You may remember the termcarbohydrate loading from Chapter 9.This practice is discouraged for weightlifters because of the extra water storedin the muscle. In other words, CHOloading provides no additionaladvantage in increasing muscle girth.
Fat Requirements
A thorough discussion of fat wasprovided in Chapter 2. But for fats ingeneral, the recommendation is:
Less than 30% of your energyshould come from fat
Remember there are three differenttypes of fat: monounsaturated,polyunsaturated and saturated fats andeach should provide less than 10% ofthe daily energy.
Vitamins and Minerals
Meet your daily energy needs from avariety of different foods, should enableyou to easily meet you vitamin andmineral needs. See Appendixes 5 and 6for information on food sources ofvarious vitamins and minerals.
Multi-Ingredient SteroidAlternatives - The Bottom
Line
Some supplements containing herbs,glandulars, minerals such as chromiumor boron, and a number of othercompounds are being marketed as“muscle builders”. Manufacturers claimthat these products are alternatives tosteroids. The major concerns associatedwith using such products are:
Not properly tested andabsolutely no basis to substantiate
the claims.
Potential for harmful side-effects, allergic reactions and
toxicities.Metabolic pathways and waste
products formed from some of thesecompounds are not known.
Potential for testing positive forbanned substances when using suchproducts, especially those that do
not reveal their “secret”ingredients.
Expensive and unlikely toreplace the benefits of a good diet
and sound training program.If a product sounds too good to be
true, it is usually not worth trying. CheckChapter 15 for more information onselected products or contact a sports
nutritionist to verify the claims beingmade.
Summary
♦ Eat a wide variety of foods andmatch your energy intake toenergy output.
♦ Aim for 0.6 and 0.8 grams ofprotein per pound per day orbetween 120 to 150 grams perday
♦ Drink plenty of fluids.♦ Don’t get trapped into buying so
called “muscle building”powders and potions. Propertraining and a good diet willprovide the lasting EDGE whenit comes to building strength andmuscles.
♦ SAVE YOUR MONEY or spend
it on “real” foods.
Chapter 11
Nutrition for OptimumMission Performance
Nutrition is important for maximizingor optimizing mission performance.What you eat or don’t eat before aphysically demanding event could either“help” or “hurt” you. For example,eating a high fat meal before vigorousactivity can slow you down as fat takeslonger to digest than CHO. Knowingwhen to eat is also important since bothfasting or eating a heavy meal shortly
before endurance activity can decreaseperformance. Information to helpoptimize your performance duringsimulated and actual missions, includingfield deployment, is presented in thischapter. Suggestions for maximizingperformance during BUDS training arealso provided. In some instances youmay be unable to control what or whenyou eat, however, it is important to meetyour energy and fluid requirements.
Nutritional ReadinessBefore a Specific Mission
In this scenario you may already bedeployed under field conditions orlocked down on base. Regardless ofwhere you are, the two mainconsiderations to nutritional readinessbefore missions are:
♦ Maximizing glycogen stores♦ Being well-hydrated
In order to be ready, you mustconsider your pre-mission food andbeverages.
Several Days Before a Mission
The average, lean, 175 pound man hasapproximately 1800 calories ofcarbohydrate (CHO) stored as glycogenin liver and muscle, and 75,000 to150,000 calories stored as fat. In spiteof these large energy stores in fat, onceglycogen stores are exhausted, physicaland mental performance will decreaseand exhaustion will set in. A diet high inCHO for several days before a missionhas the potential to increase liver andmuscle glycogen stores, and therebyextend the time to exhaustion during amission (see Chapter 9). Sample 3-dayhigh CHO diet menus are provided inAppendix 7.
Timing and Composition of Pre-Mission Meals
A good pre-mission meal can increaseglycogen stores in muscles and liver, anddelay low blood sugar if it is correctlytimed and provides enough CHO.
You should know your own tolerance
for timing of meals and your ability toperform endurance activities. In generalallow greater time for digestion beforeevents that require intense physicalactivity.
Eat up to 2 grams of CHO perpound body weight, but no more
than 400 grams, 3 to 4 hoursbefore a sustained operation.
This meal should provide a minimumof fat and protein, since these nutrientstake longer to digest. CHO beveragesand CHO/ protein drinks are excellentchoices if taken 4 hours before the start.Avoid a high protein meal since this canincrease fluid requirements and maycause dehydration.
If you weigh 175 pounds 2 X 175= 350 grams of CHO
You may eat up to 350 grams ofCHO for your pre-mission meal
If this is not possible, eat a small high
CHO meal 2-3 hours before yourmission (400 -500 calories).
A CHO beverage 1-2 hoursbefore a mission will leave the
stomach faster than a solid meal.
Nutrition for MaintainingPerformance During
Training and Missions
Three major nutrition-related issuesencountered in the field are
♦ Inadequate ration consumption♦ Dehydration♦ Gastrointestinal complaints
Inadequate Ration Consumption
One of the biggest problems witheating rations is that it gets boring.Monotony and lack of time to eatcontribute to decreased ration intake andweight loss.
Weight loss in the field is commonand may impair mental and
physical performance.
Therefore, it is important that youcontinue to consume your daily fieldration so you can continue to perform.
Eat at least part of each rationitem to get all essential nutrients
Limit your use of non-issue food itemsas meal/ration substitutes since they maybe lacking in several important nutrients.Use these items as snacks to supplementyour daily rations. Also pack highcarbohydrate items, such as crackers,dried fruits, trail mixes, sports bars, etc.(see Chapter 7 for snack ideas).Experiment beforehand to see what suitsyou best. If you are planning to use highCHO bars check the fat content becauseif the fat content is greater than 3 g/100calories it slows down absorption andcan cause cramps.
If possible, drink 25 to 60 g ofCHO/hr to maintain blood
glucose.
Dehydration
You will become dehydrated if sweatand urine losses are not replaced bydrinking water and other beverages (seeChapters 6 and 14). Dehydration mayoccur at any temperature and even underconditions of low levels of physicalactivity. Mild dehydration can decreaseappetite and cause lethargy. Moderatedehydration decreases work capacityand severe dehydration could be fatal asshown in the figure on the next page.
Effects of Dehydration on BodyFunctions
Drink water/fluids during waterbreaks. You should drink at least
4 canteens per day, or more ifyou are in a hot environment.
See Chapters 6 and 14 for moreinformation on fluid replacement.
Monitor the color of your urine; ifyour urine is dark, increase fluidconsumption until the color becomespale yellow. If you are taking B vitaminsupplements, your urine may not be palebut bright yellow.
Gastrointestinal Complaints
Change in diet, dehydration, too muchfiber, poor sanitary conditions or stressmay result in diarrhea or constipation inthe field. Make sure you are wellhydrated at all times, and avoid tryingnew non-issue foods unless they havepassed sanitation inspection.
Dietary Considerations forSelected Training and
Mission Scenarios
Developing sound nutritional plansfor specific training and missionscenarios should improve yourperformance. Sample nutrition planswill be provided for the followingtraining scenarios.
♦ Platoon/compound work♦ SDV sub trips♦ Typical land warfare♦ Double dive days♦ BUDS - Phases 1, 2 and 3
For each scenario, the macronutrientrecommendation assumes an energyrequirement of 4,000 kcal/day. If yourenergy requirements are lower or higher,you will need to alter the amounts ofCHO, protein and fat accordingly. Thetiming and/or nutrient amount at anyparticular time can be modified to suityour individual needs based on thescenario and your personal experiences.Snacks refers to food and beverages thatcan be carried and consumed while onthe go.
Table 11-1. Seal Team
Platoon/Compound Work
Table 11-2. SDV Sub Trip
Table 11-3. Typical Land Warfare
Table 11-4. Double Dive Day (for 3
weeks)
Table 11-5. Typical BUDs Training
Day-1StPhase
Table 11-6. Typical BUDs Training
Day - 2ndPhase
Table 11-7. Typical BUDs Training
Day-3rdPhase
Other Considerations
For all of the sample scenarios, thefollowing recommendations apply:
♦ Eat a variety of foods♦ Maintain energy balance♦ Maintain hydration status♦ Include high CHO snacks in
between meals toreplenish/maximize glycogenstores (especially if there aretwo periods of high activity)
♦ See Chapter 14 for additionalconsiderations about training oroperating in the heat, cold, andother adverse conditions.
Dietary Composition
The breakdown of energy from CHO,protein and fat should be 60 to 65%from CHO, 10 to 15% from protein, and20 to 30% from fat. When energyrequirements are above 4000 kcal, morefat may be required since it is difficult toget sufficient calories from CHO alone.Recommendations for the approximategram amounts of CHO, protein, and fatfor various energy levels are shown inthe following table.
Table 11-8. Recommended Grams of
CHO, Protein and Fat for VariousEnergy Levels
Vitamins and Minerals
As of now there are no definitiverecommendations. If you meet yourenergy requirements from a variety offoods, by including fruits andvegetables, you should be able to meetyour vitamin and mineral requirements(see Appendixes 5 and 6). Selectedrecommendations would be to:
♦ Include foods that are good
sources of antioxidants in yourdaily diet.
♦ If you feel you need to takevitamin and mineral supplementsfollow the guidelines presentedin Chapter 4.
♦ During extended dive series youmay want to consider taking amulti-mineral supplement.
Immersion in water, especially cold,can increase urinary losses ofmagnesium, calcium, zinc and chromium(see Chapter 4 for safe amounts).
Fluid and Electrolytes
All of the scenarios require adequatefluids. Immersion increases fluid lossesand operations in a warm/hotenvironment deplete body water.Replace electrolytes lost throughsweating by consuming a fluidreplacement beverage that containselectrolytes or by eating foods thatcontain these nutrients (see Chapter 12and Appendix 6).
Forced drinking is highlyrecommended for all environments sincenormal thirst mechanisms cannot keep upwith increased requirements. SeeChapter 6 for the ideal composition offluid replacement beverages.
Chapter 12
Nutritional Interventionsfor Mission Recovery
After a mission it is important that yourecover quickly and continue to train andprepare for the next mission. A quickrecovery will enhance preparedness,boost morale and help protect you fromtraining injuries. Both rest and nutritionplay an important part in the recoveryprocess. In this chapter informationabout nutritional measures that can helpyou speed up your recovery after a
mission is provided.
Glycogen Restoration
Glycogen depletion is commonfollowing prolonged events requiringsustained physical activity. For example,an extended dive, sustained efforts onland, and prolonged shivering candeplete muscle glycogen stores. Duringrecovery it is critical that these stores berepleted, and nutritional interventionscan accelerate the process.
Glycogen repletion in muscles takesplace at a relatively constant rate as longas blood glucose remains elevated. Inother words, blood glucose must be highfor it to be made available to muscle forstorage.
To optimize glycogen restorationconsume 50 grams of
carbohydrate (CHO) soon afterthe completion of the mission, and
50 grams of CHO every twohours for six hours after the
mission.
Ingestion of greater amounts ofCHO will not further increase the
rate of glycogen resynthesis.Not all CHO foods are equally
effective in restoring glucose. Certainfoods are better at raising blood glucoseconcentrations and promoting glycogensynthesis. The term Glycemic Index isused to describe how high a particularfood will raise blood glucose levels;
foods with a high glycemic index (GI)are the most effective for glycogenrestoration. Thus, after a mission,consume foods and beverages that havea moderate to high GI. A list of foodsclassified according to their GI isprovided on the next page.
Table 12-1. A Selection of Foods witha High, Moderate, or Low Glycemic
Index
Rehydration
Begin rehydrating immediately afterthe mission.
After a mission, forced fluid ingestionis essential because the sensation ofthirst may be blunted. Typically,voluntary consumption of fluids willrestore only half of the fluid lost. Ifpossible, weigh yourself after themission and compare this weight to yourusual weight. Over a period of severalhours you should:
Drink at least two 8 oz. cups offluid for every pound of body
weight lost.
Fluid replacement beverages ingestedduring exercise are also appropriate forrehydration. Fluids used for rehydrationafter a mission can contain a higherpercentage of CHO than those usedduring exercise. A list of various fluidreplacement beverages and moreinformation on fluid replacementtechniques is provided in Chapter 6.
Sodium/ElectrolyteReplacement
Sodium and potassium losses in sweatcan be quite high during prolongedphysical activity, especially in warmweather. Replacing these electrolytes isan important part of the recoveryprocess. Most commercially availablefluid replacement beverages containelectrolytes. Also, sodium is widelypresent in a variety of foods, but if theweather is warm:
Each quart of fluid should containabout one quarter teaspoon of
salt.
A little bit of salt will speed uprehydration better than plain water.Typically, commercial fluid replacementbeverages contain both sodium andpotassium, but your recovery foodsshould also include foods rich inpotassium. Some excellent food sourcesof potassium are listed below andadditional information is provided inAppendix 6. You will notice that thesefoods are also good sources of CHO andmost have a moderate to high glycemicindex.
Table 12-2. Good Sources Of
Potassium
Summary
♦ High CHO foods and beveragesare ideal recovery foods
♦ Consume 50 grams of CHO asfood or drink immediately aftermission completion and 50grams every 2 hours for 6 hours
♦ Choose foods and drinks with amoderate to high glycemic indexto accelerate glycogen repletion
♦ Drink plenty of fluids after agruelling mission, even if you arenot thirsty
♦ Your fluid replacement beveragesshould contain sodium andpotassium
♦ Fruit juices are excellent
recovery fluids as they provideCHO, vitamins, minerals, sodiumand potassium
♦ If you can’t tolerate solid foodsafter intense physical exertion,drink a CHO containingbeverage (see chapters 6 and 9for additional information onCHO containing beverages)
Chapter 13
Food for the Field: Militaryand Other Rations
Field rations are designed to supplyadequate energy and nutrients for aparticular type of mission. Since theduration and environmental conditions ofmissions vary, different types ofoperational rations have beendeveloped. For example, there are coldweather rations for frigid conditions,and light weight rations for missionslasting no longer than 30 days. These
rations have different caloric contentswith varying proportions of fat, protein,and carbohydrate to meet the nutritionaldemands of the various conditions. Thischapter describes what rations areavailable and compares some militaryand commercially prepared foods. Youcan decide where your money wouldbest be spent after comparing theirdistribution of calories.
The Meal, Ready-to-Eat,Individual (MRE) Menus
Many people think that militaryrations are sub-optimal: Not enoughcalories, too much fat, bad taste, and toomuch salt are some claims leveledagainst military rations. The revisedMeal, Ready-To-Eat, Individual (MRE)ration consists of 12 meals (see nextpage for menus); each meal, or menu,contains an entree, crackers, a spread(cheese, peanut butter, or jelly), adessert, beverages, and an accessorypackage. No rehydration of these mealsis necessary. This ration will certainlykeep you going and based on your energy
requirements you will need to eat 2 to 4MREs per day.
Each menu provides 1300Calories 49% CHO, 15% protein,
36% fat Supplemental BreadPouch: 200 Calories 55% CHO,
12% protein, 33% fat,
It is also important to note that somecomponents of the MRE have beensupplemented with selected vitamins (A,B1, B2, niacin, B6, and C) and minerals(calcium). Fortified items include cocoabeverage powder, cheese spread, peanutbutter, crackers, oatmeal cookies
coating, and brownies coating.
Table 13-1. MRE Menus
Ration, Cold Weather(RCW)
The Ration, Cold Weather (RCW)was designed to sustain individualsduring operations in cold conditions.The six menus should provide sufficientcalories to meet energy requirementsduring strenuous exercises in extremecold. The ration is high in carbohydrate(CHO) since this macronutrientgenerates more heat, and comes as twomeal bags, Bag A and Bag B. Each menuis sufficient for a 24 hour period, butmore can be eaten when energy needsare higher. The RCW is also lower insalt and protein than the MREs to reduce
daily water requirements and lessen thepossibility of dehydration. If consumedhydrated, one day’s ration requires 90ounces (about 9 cups or 3 canteens) ofwater. Although it could get very boring,it will definitely help maintain yourperformance.
Each menu provides 4500Calories 60% CHO, 8% protein,32% fat Sodium content: 5 grams
Table 13-2. Ration, Cold Weather
Menus
Table 13-2. Ration Cold Weather
Menus
Ration Lightweight - 30Days (RLW-30)
This ration was designed forindividuals of the Special OperationForces who might participate inreconnaissance missions of up to 30days. Thus, it is as it’s name: a lowweight, low volume ration. There are sixmenus, each consisting of dehydrated,compressed, and “low water containing”foods. The foods may be eaten dry orreconstituted with water.
Each menu provides 2132Calories 52% CHO,18% protein,30% fat Sodium content: 5 grams
If this ration is used during extendedoperations, more CHO would be neededto obtain the recommended amount (atleast 400 grams); it provides only 277grams as is.
Table 13-3. Ration Lightweight Menus
Food Packet, Long RangePatrol, (Improved) (LRP[I])
This ration was designed for specialoperations and initial assaults and has ashelf life of 10 years. The eight menus,which have been revised significantlysince the ration was used during theVietnam war, consist of dehydratedentrees, cereal bars, candy and instantbeverages. Each menu requiresapproximately 28 oz. of water toprepare, although some of the foods maybe eaten dry. It is lightweight, hasproven acceptance, and is relativelyinexpensive.
Each LRP[I] menu provides 1570Calories 50% CHO,15% protein,
35% fat Sodium content: 2.6grams
To obtain adequate CHO and caloriesduring extended operations, at least twomenus would need to be eaten; one menuprovides only 195 grams of CHO as is.
Table 13-4. Long Range Patrol
(LRP[I])
Table 13-4. Long Range Patrol(LRP[I])
Commercial Freeze-DriedProducts
Light weight, freeze-dried foods arecommercially available from a numberof manufacturers. Two of the mostpopular manufacturers are MountainHouse and AlpineAire. As with any foodmanufacturer, their products differ interms of taste, caloric distribution,protein, and sodium content. Many of theitems from both companies have beentested under field conditions for up to 30days, and the acceptability varied fromperson to person. Choose a ration thatwill provide adequate calories and CHOto fit your requirements.
Table 13-5. Here’s a Look at Two
Similar Dinner Entrees From the TwoCompanies:
Note the differences in total caloriesand the distribution of calories. Forexample, Mountain House BeefStroganoff provides 8.8 grams of proteinwhereas AlpineAire’s Beef Stroganoffprovides 22 grams. This shows howimportant it is to check the nutritionallisting on the package label. A variety ofother meals and their macronutrientdistribution is provided on the followingpages.
Table 13-6. Selected Foods and Menus
From AlpineAire
Table 13-7. Selected Foods and Menus
From Mountain House
What Do You Choose?
The next question you should ask is:Given this information, which is the bestproduct for me to eat during a particularmission scenario? What foods will mostimpact my performance? The best wayto answer that question is to figure outwhat your expected caloric expenditurewill be and what kinds of foods youlike! The ration for any mission thatinvolves high activity should provide atleast 400 grams of CHO.
Look over some of the food selections
provided. What is important is that youeat and drink. Compare the military and
commercial foods, and try setting up amenu plan that fits both your personaltastes and energy requirements. Themilitary RCW caloric distribution is agood model to follow, and is anacceptable alternative to store-boughtlightweight foods. The Table belowprovides sample menus for two days;each menu supplies about 4,500 kcal.Use these menus as a template. Otherfood choices in the preceding tables canbe substituted accordingly. There aremany types of soups, breakfast products,and dinner entrees to chose from. Theimportant points to remember are:
Get enough CHODrink lots of fluid (preferably low
caffeine)Limit sodium and caffeine intake
Table 13-8. Two Sample Daily Menus
for High Activity
An advantage to the military rations isthat you don’t have to count calories onlabels to get the desired caloricdistribution. For example: If you are
training in a cold weather environment,you know that the RCW has 4,500kcal/day with an appropriate distributionof calories. There’s no need to look atlabels three times a day to figure outwhat you are eating. The time saved bynot counting calories may or may not beimportant to you. However, if you don’tlike military rations, spend some timedeveloping a meal plan that suits yourtaste buds, as indicated above. You needto eat on your missions!
Other Ration Information
How Long Will Rations Keep?
As long as the package is leftunopened, stored properly in a fairlycool environment (low humidity and lessthan 80° F), and not handled excessively,most of the military rations will beusable for at least 3 years. The MRE,RLW-30, and RCW all have shelf livesof 3 years. Most commercial foods haveexpiration dates noted on the packaging,but generally they will also keep for atleast 3 years. Mountain House promotesa shelf life of up to 5 years. The rationwith the longest shelf life is theimproved Long Range Patrol (LRP[I]),which has an estimated life of 10 yearsat 70 to 80° F.
Rations and Water Requirements
If the rations are prepared asinstructed, and you drink fluids asrecommended, freeze-dried rations willnot increase your need for water.However, if the rations you selectcontain greater amounts of sodium orprotein, you may need additional water.
Chapter 14
Nutritional ConsiderationsFor Adverse Conditions
Adverse conditions such as exposureto extreme environments imposeconsiderable physiological demands.The human body responds to adverseconditions by increasing energyexpenditure and water losses. If energyand fluid balance is not regained, thenperformance and perhaps missionintegrity can be at stake. In this chapter,information on nutritional interventions
that may improve performance oralternatively reduce performancedecrements under adverse conditions ispresented.
Heat Exposure
Clearly, the major concerns duringoperations in a warm or hot environmentare maintaining fluid and electrolytebalance. Any time you have to work orexercise in the heat, you will lose waterand electrolytes through sweating. Theamount of sweat produced depends on:
♦ Environmental temperature andhumidity
♦ Work rate♦ Fitness level and acclimatization♦ Volume and rate of fluid
replacement
Working at a high work rate in hot,
humid surroundings results in the veryhigh fluid and electrolyte losses. Youcan easily lose one to two quarts perhour and even more when specialclothing, such as chemical protectivegear, is required. The highest sweatingrate ever reported was 4 quarts per hour.
Fluid Needs
Failure to replace fluids lost throughsweating will result in dehydration andeventually heat injury (see Chapters 6and 11 for additional information ondehydration). Forced drinking isrecommended throughout training in awarm environment since your normalthirst mechanism will not ensureadequate fluid replacement.
Drink 1 to 3 cups of fluid every30 minutes. More than 3 cups per
30 minutes is TOO MUCH toabsorb.
It is a good idea to get a body weight
prior to starting a prolonged trainingmission in the heat, and weigh yourselfas time permits. This will allow you todetermine your sweat rate and helpensure adequate hydration in latertraining and simulated operations.Remember that your water needs may behigher when you wear chemicalprotective clothing or other gear whenyou work in the heat.
Drink 10 to 12 quarts of waterper day at regular intervals when
working in a hot environment.
One pound of water loss equalsapproximately 2 cups of water or
about 0.475 quarts.
It is estimated that a water loss of 2%body weight can impair physicalperformance and mood, decreaseappetite and increase the risk of heatinjuries. Below is a sample calculation:
If A SEAL weighs 175 poundsA 2% weight loss would be 175 X0.02 = 3.5 lbs Goal: To stay above
171 lbs
A 5% loss of body weight decreaseswork performance by 30%. This amountof water loss is a serious threat to yourhealth.
Worksheet 14-1. Calculate YourLower Weight for Fluid Losses
Monitor hydration status byinspecting the color of your urine.
A dark yellow or smelly urine suggestssome degree of dehydration; increasefluid consumption until the colorbecomes pale yellow. If, however, youare taking B vitamins your urine may benot be pale but bright yellow.
Excessive water weight gain can alsobe a threat to your health. This conditionresults when individuals drink largeamounts of plain water to replace fluidlosses during long duration (lasting for 8or more hours) endurance activities. Toprevent overhydration, make sure thatyou drink beverages that containelectrolytes (sodium and potassium) toreplace fluids lost during extendedmissions.
Electrolyte Balance
It is a fact of life that electrolytes arelost in the sweat, and excessive loss ofelectrolytes (example: sodium,potassium) can lead to muscle crampingor severe medical problems. However,being in excellent physical conditionwill help minimize electrolyte losses.The best way to maintain electrolytebalance over prolonged exposure to heatis to drink fluid/ electrolyte replacementbeverages.
Table 14-1. Upper Limits for Sodiumand Potassium in Fluid Replacement
Beverages During Heat Stress
Look at the label from the beverageyou have selected and be sure itprovides no more sodium and potassiumthan indicated in the chart above. TheNational Academy of Sciencesrecommends that chloride be the only“anion” (negatively charged electrolyte)accompanying sodium and potassium,and no other electrolytes are
recommended. Typically magnesium andcalcium are included, but the amountsare well below recommended upperlimits. Finally, after your operations,choose foods that are high in water(Chapter 6 - Fluid Replacement) andfoods that are rich in potassium (seeChapter 12 and Appendix 6).
Carbohydrate (CHO) Intake
Fluid replacement beverages withCHO are great during exercises in theheat, but the amount of CHO should belower than usual so that the fluid/wateris rapidly absorbed. Chapter 6 providesa chart showing the concentration ofCHO in the beverage to use formaintaining hydration status.
Beverages consumed in the heatshould be no more than 8% CHO
- 5% CHO is optimal
Energy Intake
Although appetites may be suppressedin the hot weather, especially during thefirst few days after arriving, adequatecaloric intake is very important.Inadequate food intake will lead toweight loss which can impair bothphysical and mental performance.Remember:
Dehydration can result in a lossof appetite.
When you do the same task in a hotenvironment, energy requirements areslightly increased due to the increasedwork of maintaining thermal balance.
When living/working in temperaturesranging from 86 to 104° F (30 to 40° C)caloric intakes should be increased by10% as shown below, unless activitylevel decreases accordingly.
If a SEAL requires 4000 kcal/dayA 10% increase in energy wouldbe 4000 X 0.10 = 400 kcal/day
Goal: Eat 4400 kcal/day
Worksheet 14-2. Calculate YourEnergy Requirements for a Hot
Environment
TIP: If your activity leveldecreases you do not need any
extra calories.
Other Recommendations:♦ Eat a high CHO diet as they
are absorbed more readily thanfat and protein.
Avoid fatty foods which may not
be not well tolerated in the heat.♦ Avoid high or excessive protein
intakes which will increasewater loss and can lead todehydration.
Cold Exposure
Exposure to a cold environment, be itair or water, is a challenge to be takenvery seriously; performance decrementsare common when you become cold. Thebody’s response to cold exposure is a“tightening of blood vessels” toconserve heat, and shivering to generateheat and guard against hypothermia (adangerously low core bodytemperature). Side effects of theseresponses are an increased in urineoutput and an increase in energymetabolism. Therefore, the mostimportant aspects of nutrition in a coldenvironment are:
♦ Energy intake♦ Fluid status♦ Vitamin and mineral needs
Energy Intake
Energy requirements canincrease 25 to 50% during cold
weather operations as comparedto warm weather operations.
A 3 to 4° decrease in bodytemperature can result in a two tofourfold increase in resting energyexpenditure. That’s a huge increase inthe body’s metabolic rate. Factors thatincrease calorie needs include:
♦ Added exertion due to wearingheavy gear
♦ Shivering which can increaseresting metabolic rate by two to
four times above normal♦ Increased activity associated with
traveling over snow and icyterrain
♦ Increased activity to keep warm
Many studies have shown thatsoldiers tend to progressively loseweight when conducting field exercisesin the cold for 2 to 3 weeks. Becausesignificant weight loss can result infatigue and performance decrements,energy intake must increase to meet theincreased energy demands.
Both fats and CHO are used as fuel
when exposed to a cold environment.However, a high CHO diet is preferred
as it will replenish glycogen stores thatare rapidly being used to maintain coretemperature. A high fat diet isdiscouraged as it would require aprolonged period of adaptation and mayresult in gastrointestinal problems.Ideally 60% of your energy should comefrom CHO, 30% from fat and 10% fromprotein, with high CHO snacks eaten inbetween meals. Protein supplements orhigh protein diets are not recommendedas they would increase water losses.
Table 14-2. Calculating EnergyRequirements for Cold Weather
If a SEAL requires 4000 kcal/dayA 25% increase in energy wouldbe 4000 X 0.25 =1000 kcal Goal:
Eat 4000 + 1000 or 5000 kcal/day
Eat frequent snacks during the dayand a large snack before going to bed
Fluid Status
Becoming dehydrated in coldenvironments is very easy because of thecold-induced increase in urine output,increased fluid losses through breathing,involuntary reduction in fluid intake, andsweating. Because dehydration willdecrease performance and potentiallylead to various medical problems,maintenance of fluid status by drinkingplenty of fluids and monitoring hydrationstatus is absolutely critical (see Chapter6).
Tips for Maintaining Fluid Status
♦ Force yourself to drink 2 to 4
cups of warm fluid at hourlyintervals.
♦ Avoid alcoholic beverages asalcohol tends to increase heatand urine losses.
♦ Moderate caffeine consumptionsince caffeine increases fluidlosses.
♦ Avoid consuming salty foods thatincrease fluid needs.
♦ Drink beverages with CHO toincrease energy intake.
♦ Don’t eat snow without firstmelting and purifying it.
Vitamin and Mineral Needs
When working in the cold, therequirements for some vitamins andminerals may increase to meet thedemands of increased energymetabolism (example: thiamin) orgreater urinary losses (example:magnesium, zinc). The amount by whichdaily vitamin and mineral needs mayincrease above the RDA (see Chapter 3for RDAs) during cold weatheroperations was recently proposed:suggested amounts are shown in theTable below. These amounts are basedon intake data from field studies, urinaryexcretion of nutrients and other measuresof “nutrient status”. In most cases, if you
meet your energy requirements by eatingall ration components you should be ableto meet your vitamin and mineral needs.
Table 14-3. Suggested Increases in
Daily Intakes of Vitamins andMinerals During Cold Exposure
Sustained Operations
Sustained Operations (SUSOPS) arework periods of 12 hours or more thatusually result in physical and mentalfatigue and sleep loss. In contrast,Continuous Operations (CONOPS) areperiods of uninterrupted activity of“normal shift length” followed bysufficient sleep. Your missions, whichusually include both SUSOPS andCONOPS, frequently result in fatigueand sleep loss. Nutritional interventionscan partially offset the effects of fatigueand sleep deprivation on physical andmental performance. The most effectivenutritional interventions include:
♦ CHO intake♦ Hydration status♦ Caffeine intake
CHO Intake
A high CHO diet is needed forreplacing muscle glycogen stores thatare used up during prolonged activityand for maintaining a sufficient “bloodglucose” level. Thus, your diet duringSUSOPS should provide 60 to 65% ofenergy from CHO, 10% from protein andthe remaining calories from fat.
High CHO snacks or CHO-containing
fluid replacement beverages providing15 to 30 g of CHO/hour will also help tomaintain blood glucose and delay fatigueduring strenuous prolonged missions(see Chapters 6 and 9 for additionalinformation). When blood glucose levels
fall, your performance will drop rapidly,and you will become unable to continueworking.
Table 14-4. Symptoms of
Hypoglycemia (low blood sugar)
CHO loading can be useful whenpreparing for missions that require
continuous movement such as snowshoeing, skiing, swimming, trekking overdifficult terrain etc. for a few hours inorder to reach the objective (see Chapter9 for information on CHO loading).
Caffeine
If you are a regular user of caffeine, itwill not do much to “pick you up” but ifyou discontinue caffeine use, it maycause discomfort. In general, caffeineincreases urine output and could causedehydration. However, you may want totry some caffeine to see if it increasesyour alertness and delays fatigue duringextended operations. See Chapter 15 forthe caffeine content of various beveragesand medications.
Fluid Intake
On some training and actual missionswater may not be available. Thus, priorhydration will assume a greaterimportance. When water or beveragesare available it is important to remainwell hydrated given that dehydration candecrease both mental and physicalperformance (see Chapter 6).
Forced drinking of 1 to 3 cups per30 minutes, depending on the
temperature, is recommended.
Beverages containing 5 to 8%CHO and some electrolytes are
best.
Diving and Immersion inWater
Like exposure to altitude and a coldenvironment, water operations,
especially cold water operations, areassociated with increased energyexpenditure and fluid losses. Thusnutritional concerns for diving aremaintenance of:
♦ Energy intake♦ Fluid intake♦ Replacing mineral losses
Energy Intake
When working at the same rate inwater as on land, the energy expenditureto accomplish the same task is greater inwater. The reasons for this increasedenergy expenditure during wateroperations include:
Greater resistance offered bywater
Decreased efficiency ofmovement when thermalprotective clothing are worn
This is especially true in cold water. Tomeet the increased energy requirementsyou may need to increase your intake of
CHO. If the water is cold, this is veryimportant.
Tips for maintaining performance incold water
♦ Eat a high CHO diet (seeChapters 2,9 and 11).
♦ Consider CHO loading forextended dives
Glycogen stores are rapidly used whenperforming hard work in cold water.These stores must be replaced betweenoperations to prevent performancedecrements (see Chapter 9). CHOloading before an anticipated dive hasbeen shown to improve and extendexercise performance during prolonged
dives and has been discussed in Chapter9.
Fluid Intake
Immersion in water increases urinaryoutput by 2 to 10 times above normal.Without adequate hydration a diver canquickly become dehydrated and sufferperformance decrements. For example,immersion during a single dive for 3 to 6hours can result in a 2 to 8 pound loss inbody weight by urination; this isequivalent to losing 1 to 3 quarts offluid.
Although fluid ingestion duringimmersion has not been found toimprove hydration status during shortterm dives (less than 3 hours), attemptsto drink fluids with CHO should proceedwhenever possible to maintain blood
glucose. A decline in blood glucose isknown to adversely affect performance.
Mineral Needs
Immersion in water, especially in coldwater, can increase urinary losses ofmagnesium, calcium, zinc and chromium;see Chapter 3 and Appendix 6 for goodfood sources and recommended intakes.
Altitude
Ascent to altitude can cause a varietyof disturbances, and adequate nutritioncan play a crucial role in maintainingperformance. The major nutritionalconcerns at altitude are:
♦ Weight loss♦ CHO intake♦ Dehydration♦ Disturbances in digestion♦ Vitamin and mineral needs
Weight Loss
Virtually all persons who go toaltitude experience weight loss and lossof lean body mass. At altitudes below5000 m weight loss can be prevented byincreased caloric intake, whereas above5000 m, a 5 to 10% weight loss isalmost inevitable. Some reasons forweight loss at high-altitude are:
♦ Energy requirements areincreased 15 to 50% above sealevel
♦ Decreased sense of taste causinga reduction in food intake
♦ Loss of body water fromincreased breathing rate and dry
air♦ Impaired absorption of nutrients♦ Acute Mountain Sickness (AMS)
which can result in nausea,vomiting, headache anddecreased appetite
The only way to minimize weightloss is by increasing your energy
intake.
Energy requirements canincrease 15 to 50%
above requirements at sea level.Recommended caloric intakes rangefrom 3500 to 6000 calories per day; thisis equivalent to eating at least four
MREs or one Ration,Cold Weatherdaily.
Table 14-5. Calculating EnergyRequirements at Altitude
If a SEAL requires 3000 kcal/dayA 50% increase in energy wouldbe 3000 X 0.50 = 1500 kcal Goal:
Eat 4500 kcal/day
Tips for Maintaining EnergyBalance
♦ Eat small frequent meals.♦ Protein should constitute no more
than 10% of the daily caloricintake. Higher intakes will beexcreted along with water.
♦ Fatty foods may not be welltolerated at altitude and mayexaccerbate AMS.
CHO Intake
High CHO foods are the preferredenergy source at altitude because they:
♦ Replete glycogen stores -glycogen stores are depleted in acouple of hours by strenuousphysical activity
Require less oxygen (which isdecreased at altitude) than fat toburn and are therefore, the moreefficient energy source.
♦ Can blunt and delay theprogression or severity ofsymptoms of AMS (nausea,vomiting, headache).
You should derive 60% of calories orat least 400g from CHO diet. This canbe accomplished by eating high CHOsnacks (see Chapter 7) between mealsand drinking CHO-CONTAININGbeverages during strenuous activity andrecovery (see Chapter 6 forrecommended rehydration practices).
Dehydration
Water losses are increased at altitudeand if these losses are not replaceddehydration results. As stated severaltimes before, dehydration impairsphysical and mental performance andincreases the risk of cold injury.Dehydration occurs at altitude forseveral reasons:
♦ Increased respiratory losses dueto increased ventilation
♦ Increased urine output due toaltitude and cold temperatures
♦ Possible diarrheal fluid losses♦ Failure to drink water♦ Meeting the increased fluid needs
can be a challenge since thirstdoes not always keep pace withneeds
Fluid requirements may be 4.25quarts or more per day at high
altitude
A drinking schedule must beestablished and hydration status
should be monitored daily.
Vitamin and Mineral Needs
As discussed in the section on cold,vitamin and mineral needs are likely tobe increased at altitude where it is coldand oxygen availability is decreased. Inparticular, increased metabolic rate andhypoxic conditions at altitude canincrease the production of harmful freeradicals which may slow bloodcirculation and impair physicalperformance. Preliminary findingsindicate that taking vitamin E (400IU/day) at high altitude reduces freeradical production, and helps maintainblood flow and aerobic energymetabolism in men.
Summary
Energy and fluid requirements arehigher than normal during all thescenarios described in this chapter (seeeach section for estimated increases).Importantly, weight loss due toinadequate energy intake and/ordehydration can result in fatigue andimpaired performance. Therefore, keysto being nutritionally prepared duringtraining and missions in adverseenvironments are:
♦ Meet energy needs preferably byeating a high CHO diet. Eathigh CHO snacks to meetincreased energy needs.
Be well hydrated - Follow aforced fluid replacementschedule since thirst is not agood indicator of fluid needs.
♦ Avoid protein supplements as theextra protein is excreted alongwith water and can bedehydrating.
Chapter 15
Ergogenic Agents - Lookingfor “The Edge”
Ergogenic agents are by definition,substances or techniques that enhanceperformance. Because SEALs arerequired to perform at a high level bothmentally and physically, many arelooking for substances or techniques toimprove performance and provide “anedge”. To perform longer, to be faster, tobe stronger, and to be leaner, if not amission goal, are personal goals of many
SEALs and elite athletes. People havebeen trying to accomplish these goals forcenturies through the use of ergogenicagents. It is the goal of this chapter topresent information and comments aboutcertain products commonly found inretail stores or by mail order, that claimperformance enhancing effects.
The comments in this chapter are
based on the most up-to-date objectivescientific information, although in somecases limited information is available,and most have not been tested for theirability to enhance SEAL or SpecialOperations mission-relatedperformance. Some products areunlikely to hurt you, and you will have to
decide if you want to try it, whereasother products may be harmful and youmay be strongly discouraged from tryingit. In many cases you may be usingsupplements that are a waste of money.This chapter will assist you in makinggood decisions.
Nutritional ProductsAdvertised as Ergogenic
Agents
This section lists many of thenutritional ergogenic agents sold bymanufacturers with claims to “enhanceperformance” or have “muscle building”properties. Some have valid claimswhereas others do not. It is oftendifficult to differentiate false claimsfrom valid ones if you haven’t carefullyresearched each product individually.Many claims sound very scientific andconvincing but, unfortunately, they areoften false or unproven. For each agentdescribed below, the claims, the usual
dose used, and a comment are provided.Remember, if the comment is NO, theproduct may be harmful.
Table 15-1. Nutritional Ergogenic
Agents
Table 15-2. Caffeine Content of
Selected Beverages, Products, andMedications
Table 15-3. Summary of Ergogenic
Agents
Protein-CarbohydrateSupplements
Go into a retail or specialty store thatcaters to athletes and you may becomeoverwhelmed by the number of differentproducts available. One of the mosthighly visible and advertised group ofproducts are the powdered protein andcarbohydrate beverages. “Weightgaining”, “anabolic”, “muscle building”-these are just a few of the various claimsmade by manufacturers. They do shareone thing in common however: they aresold as supplements to your diet. Theseproducts are intended to fortify your dietto meet the nutrient demands of your
body. In general, there are three basicreasons why people supplement:
♦ Compensate for less thanadequate diets or life-styles
♦ Meet unusual nutrient demandsinduced by heavy exerciseand/or
♦ Produce direct positive effects onperformance.
Your profession and life-style imposeunique physical demands that requirestamina, power, and strength.Consequently, your caloric (energy)expenditure is greater than the averageperson.
In Chapter 1 you calculated your REE
and then, based on your activity level,your total daily caloric expenditure. Doyou think your caloric intake supportsyour activity level? If not, you have twomethods to increase your energy intake:
♦ You can eat more (which can bedifficult based on your dailyschedule)
♦ You can use a supplement to makeup for the extra calories youneed.
Supplements are a quick andconvenient means for obtaining thenutrients you need. For example, somepeople find that after eating a normalbreakfast they feel ill or nauseous during
morning PT. If you can’t tolerateexercising on a full stomach, then apowdered beverage may be the answerfor your breakfast. You get the caloriesyou need in the morning, but don’t havethat heavy feeling in your stomach.Remember that you may not need the fullrecommended serving size. Count thecalories to suit your own energyrequirements and goals.
It is also important to realize that it is
not the supplement alone that leads tobetter performance. Success lies inaddressing your goals and analyzing andadapting your diet to meet those goals. Itwill take some work on your part tocalculate how much supplement, if any,
you need to use. Read the labels andfigure out how many calories you willexpend before your next meal. Also,make sure you add up the vitamins andminerals you are getting from all thedifferent supplements you are taking.Many products provide similar nutrientsand you may be taking TOO much of oneor several nutrients.
Another decision to make is whether
or not to use a protein, carbohydrate, orcombination beverage. Once again, it alldepends on your goals. If you want toincrease lean body mass throughresistive training, then some protein maybe the way to go. Remember:
All you need is 0.6 to 0.8 gramsof protein per pound body weight
per day
If you need more than you can eat,then a supplement with protein may befor you. Many powders contain bothprotein and carbohydrate in a good ratio.Find the one that has the mostappropriate amount of each to augmentyour diet (Refer to Chapter 10 for a listof Protein and CarbohydrateSupplements).
Here is an example: The goal of a 24
year old SEAL who weighs 175 lbs, isto increase his lean body mass throughweight training. He knows that he needs
between 0.6 and 0.8 and NO MORE than1.0 grams of protein per pound toachieve this goal. He decides to eat 0.8grams of protein per pound to see if he’llachieve his goals. His proteinrequirements are calculated as shown:
175 X 0.8 grams protein = desiredprotein intake 175 lbs X 0.8 =140
grams of protein daily. NOMORE THAN 175 X 1 or 175
grams of protein.
Now let’s see how much protein heeats on an average day
MET-Rx
MET-Rx is a nutritional supplementwith claims of decreasing body fat andincreasing muscle mass, if used inconjunction with a regular exerciseprogram. The exercise program isprimarily strength/resistive (weight)training. As with any supplement, it isdesigned to augment your normal diet tomeet the increased nutritional demandsof exercise. However, increasednutritional needs can also easily be metby dietary means.
The cornerstone of Met-Rx is that it isa high protein supplement (seenutritional information below). Theprotein is in the form of egg whites,
whey protein concentrate, andMetamyosin™ which is claimed to be a“unique blend of milk protein isolates”.
Table 15-4. Ingredients in One Serving
of MET-Rx
Depending on your goals, MET-Rxmay or may not be for you. For example,if you are interested in improving
aerobic endurance MET-Rx alone is apoor source of the necessarycarbohydrates for that kind of activity. If,however, increasing muscle mass is yourgoal, then this product provides proteinfor that. Remember that you don’t needmore than 0.8 grams of protein perpound body weight.
One major drawback of MET-Rx isthe cost. Each serving is roughly $3.00and the directions for use call for 2 to 4servings a day. That averages to about$9.00 a day! Keep in mind that there arealways alternative sources of proteinthat are very easy to come by and tend tobe much less money. For example,
One can of tuna fish has 36 grams
of protein, One 4 oz. breast of chicken has36 grams of protein
One 8 oz. glass of milk (skim)has 10 grams of protein.
Remember: There is nothing “magical”about this product and all theingredients are found in nature. Recordyour intake and see if it is worth yourmoney.
Chapter 16
Ergolytic Agents - “GoingBackwards”
A fter reading about agents that arepotentially beneficial to you, its nowtime to focus on substances that candestroy what you’ve been trying tobuild up. Ergolytic agents are thosesubstances which do not enhance, butrather impair, performance, be itphysical, mental, or psychological.When using these substances, you maybe undoing the benefits and successes
gained through training and the use ofergogenic agents. Here’s another wayto think of it - you may be wasting yourmoney if on one hand you are buyingergogenic agents and on the othercontinuing to use ergolytic agents.Hopefully, by staying away fromergolytic agents, you can maximallyimprove your athletic performance
Alcohol
Heavy alcohol intake can lead tosevere dehydration!
Drinking a lot of alcohol in theevening can lead to a state ofdehydration the next day if adequatefluid replacement does not occur. Therehave been incidences during road racesand regular training where people havedied after a night of heavy drinking,without adequate rehydration prior toand during exercise. Although a rareoccurrence, it can happen.
Some athlete believe that drinkingsmall amount of alcohol prior to anevent can be relaxing and instill self-
confidence. This is completely false. Infact, alcohol may compromise physicalperformance by decreasing the releaseof glucose from the liver. This willcause a decrease in blood glucose andpossibly lead to hypoglycemia.
Numerous studies on young trainedathletes have shown that performancedecreases after ingestion of alcohol. Themyth that alcohol can alter theperception of fatigue is also false. Thereis generally no effect on perception ofperformance after drinking.
Smokeless Tobacco
Many SEALs have been or arefrequent users of smokeless tobacco.Use of such products has been on therise in the past 20 years with an annualreported increase of 11% since 1974.Many athletes believe that smokelesstobacco will improve their performanceor enhance their reaction time by givingthem a quick “rush” during the event.After a brief discussion of what nicotine(the active ingredient in all tobaccoproducts) does to your body, you willunderstand why performanceenhancement and chew don’t go together.
Nicotine is the major ingredient ofsmokeless tobacco and very, very
addictive (as addicting as cocaine orheroin). It is termed a psychoactive drugwhich means it alters the normalfunctioning of the brain by stimulatingthe central nervous system and resultingin the nicotine “buzz” or “high”. It is this“mental state” that users claim enhancestheir reaction time and performance.However, studies have shown nodifferences in reaction times betweenusers and non-users of smokelesstobacco. Remember: there are NOreaction time improvements with chew.
Nicotine has some very detrimentaleffects on an athlete. Nicotine is avasoconstrictor (makes blood vesselstighten). This action on the circulatorysystem raises blood pressure and heart
rate, thereby causing a decrease incardiac efficiency. In one study of youngathletes, two parameters of cardiacperformance (stroke volume - the amountof blood pumped out of the heart witheach contraction, and cardiac output -the amount of blood the heart pumps inone minute) both showed decreaseswhile using smokeless tobacco. This isvery undesirable for an athlete and couldcause a severe decrease in performance.
Antihistamines
Antihistamine use is prevalent amongall groups of people since it is acommon over-the-counter medication.Many types of antihistamines are used,with the most common ones beingBenadryl and Seldane. One of the mostcommon side effects of manyantihistamines is drowsiness. This is nottypically seen with many of the newer,“non-sedating” types of antihistamines.
Antihistamines may compromisemental performance
Some of the detrimental mental effectsof the sedating antihistamines include:
♦ Decreased ability to concentrate Increase in reaction time
♦ Sleepiness♦ Decreased score on rifle target
practice - “more misses”
Seldane appears to have the leasteffects in terms of drowsiness andmental performance decrements, so ifyou need an antihistamine, it may be bestto take this one!
Other Side Effects of Sedating
Antihistamines
No clear cut effects on physicalperformance have been observed, butcaution should be exerted when takingany type of medication.
Appendix 1
Carbohydrate Content ofSelected Foods
Appendix 2
Fat Content of SelectedFoods
Appendix 3
Protein Content of SelectedFoods
Appendix 4
Energy Expenditure ForVarious Activities
Appendix 5
Good Food Sources ofVitamins
Appendix 6
Good Food Sources ofMinerals
Appendix 7
Sample High CarbohydrateMenus
Sample Day One
Macronutrient Analysis of Day One
Sample Day Two
Macronutrient Analysis of Day Two
Sample Day Three
Macronutrient Analysis of Day Three
Appendix 8
US Navy Special Warfare 10Commandments Of
Nutrition
1. Don’t believe anything you readabout nutrition written bysomeone trying to sell yousomething.
2. Read the labels on foodproducts. Total calories andweights of carbohydrate (CHO),protein, and fat per serving are
usually provided.3. Most Americans need no
supplemental vitamins, but usethe inexpensive “one-a-day” typeif you want to increase yourvitamin intake. Megadosequantities of costly wonder-vitamins serve mainly toincrease the vitamin content ofyour body waste products.
4. Don’t take protein and aminoacid supplements. One gram ofprotein per pound of body weightper day is the maximumrecommended protein intake,even for weight training andbody building. Most non-vegetarian athletes take in more
than this m their normal diet5. Limit fat intake to less than 30%
of total calories (1 gram of fat =9 calories). Items to watch arered meat, peanuts, solid dairyproducts, and french-friedanything.
6. For specific endurance eventssuch as prolonged missions, longcold dives, or triathalons, CHOload with 1500 extra CHOcalories a day for 3 days beforethe event and decrease fat andprotein intake. Cut back on yourtraining schedule and avoidstressful cold exposures duringthis time.
7. For prolonged intense aerobic
training schedules (BUD/s ortriathalon training), take inenough extra CHO calories tomaintain your desired weight.The best sources are pasta,fruits, breads, potatoes, and rice.
8. Eat fresh fruits, fresh vegetables,and high-fiber cereal productsevery day.
9. Short-term weight reductiondiets are generally useless andoccasionally dangerous. Lastingweight modification isaccomplished only with long-term changes in your eating andexercise habits.
10. The most common nutritionproblem in this country is too
much nutrition. Don’t eat whenyou’re not hungry and stop eatingas soon as you’ve had enough,not when your plate is empty.
Full Mission Profile, January 1992Compliments of CAPT Frank Butler
