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Exercise Physiology & Fitness. Chapter 7. Exercise Physiology & Fitness. What is exercise physiology? What is the role of physical activity and exercise in achieving physical fitness and health? How do you use the FITT formula to design a fitness program? - PowerPoint PPT Presentation
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Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill/Irwin
CHAPTER 7
Exercise Physiology & Fitness
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Exercise Physiology & Fitness
What is exercise physiology?
What is the role of physical activity and exercise in achieving physical fitness and health?
How do you use the FITT formula to design a fitness program?
What are the contributors and deterrents to fitness?
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Exercise Physiology
The study of the effects of exercise on the body.
Body’s responses and adaptations to different exercises: System to subcellular level Acute (short term) to chronic
(long term) adaptations
Population served: Elite performer People of all ages and
abilities
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Historical Development
Late 1800s - the use of anthropometry to measure changes in students’ development after training programs.
Early 1900s – McKenzie ~ Investigating effects of exercise on various systems of the body and the idea of preventative medicine.
After WWII - increased interest in fitness as a result of youth fitness tests and the results of the physicals of men in the military.
1968 – Dr. Kenneth H. Cooper promotes aerobic exercise and its contribution to health; publishes Aerobics.
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Historical Development
1974: ACSM: Guidelines for Graded Exercise Testing and Prescription.
1980s and 1990s: Increased understanding of the relationship between physical activity and health. 1996:Surgeon General’s Report Physical Activity &
Health
2000: 1st certification exams for Clinical Exercise Physiologists.
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Areas of Study
Effects of various exercises on various systems of the body.
Relationship of energy metabolism to performance.
Effects of environmental factors on performance.
Effects of individual differences
Effectiveness of various rehabilitation programs.
Ergogenic aids and exercise.
Health and therapeutic effects associated with exercise.
Effects of nutrition on performance.
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Specialization
EXERCISE PHYSIOLOGY – EMERGING FIELDS OF STUDY
Cardiac Rehabilitation
Focuses on the assessments of cardiovascular functioning and on the effectiveness of various exercise programs in preventing cardiovascular disease and rehabilitating individuals suffering from the disease.
Exercise Biochemistry
Examines the effects of exercise at the cellular level, specifically within the muscle cell.
Exercise Epidemiology
Studies the relationship between physical activity and mortality.
Pediatric Exercise Studies the response of the body to exercise during childhood, including the effects of growth and maturation and how responses differ between children and adults.
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Physical Fitness
Ability of the body’s systems to function efficiently and effectively.
Individuals who are “physically fit” have the ability to: “carry out daily tasks with
vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure-time pursuits and to meet unforeseen emergencies.”
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Physical Fitness
Health Fitness Body composition
Cardiorespiratory endurance
Flexibility
Muscular endurance
Muscular strength
Performance Fitness Agility
Balance
Coordination
Speed
Reaction Time
Power
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Physical Activity and Health
Chronic Diseases Major threat to health
today
Hypokinetic Diseases Diseases caused by
insufficient physical activity, often in conjunction with inappropriate dietary practices.
Coronary heart disease, hypertension, osteoporosis, non-insulin diabetes, chronic back pain, and obesity
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Physical Inactivity & Health
Inactivity is a risk factor for several diseases.
Individuals who lead a sedentary lifestyle have increased risk of morbidity and mortality. Inactive individuals have almost twice the risk of
CHD as those who are active.
The degree of risk is similar to cigarette smoking, hypertension, and obesity.
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Dose-response Debate
What kind of activity?
How much time spent in activity?
At what intensity should it be performed?
How often in order to see benefits?
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Consensus Statement
Recommended that adults engage in 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity physical activity per week.
Recommended that adults engage in muscle-strengthening exercises on 2 or more days a week that work all the major muscle groups. Additional benefits can be derived from increasing the amount and/or intensity of physial activity.
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Health Benefits
Enhanced cardiovascular function, including reduction of many cardiovascular disease risk factors.
Increased ability to perform tasks of daily living.
Reduced risk of muscle and joint injury.
Improved work performance.
Improved physical appearance, self-image, and sound mental health.
Reduction of susceptibility to depression and anxiety
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Health Benefits
Management of stress.
Increased socialization through participation in physical activities.
Improved overall general motor performance.
Increased energy.
Resistance to fatigue.
Mitigate the debilitating effects of old-age or retain a more desirable level of health for a longer period of time.
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Energy Production for PA
Two ways to produce ATP (adenosine triphosphate) as energy to perform muscular activity:Anaerobic system
Without oxygen High energy expenditure, short time (6-60 seconds)
Aerobic system With oxygen Lower rate of energy expenditure, longer period of
time (more than 3 minutes)
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Principles of Fitness Training
Principle of Overload To gain improvements in health and fitness, an
increased workload must be placed on the body.
Principle of Specificity Training must occur with the specific muscle or
body part the person is attempting to improve.
Principle of Progression Overload should be applied gradually, and steadily
increased as the body adapts.
Principle of Diminishing Returns As fitness increases, gains achieved become less
and less as individuals approach limits of adaptability.
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Principles of Fitness Training
Principle of Variation Helps maintain individuals’ interest and provides a change of
pace while continuing to make progress toward desired goals.
Principle of Reversibility “Use it or lose it” – inactivity leads to gradual erosion of
benefits achieved.
Principle of Individuality Individuals respond differently to exercise and will vary in
their rate of improvement and levels of achievement.
Principle of Recovery Rest allows the body to recover and adapt to the changes
placed on it.
Principles of Safety Safety is paramount.
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Planning a Fitness Program
Threshold of Training Minimal level of exercise
needed to achieve desired benefits.
Target Zone Defines the upper limits
of training and the optimal level of exercise.
Needs and goals of the individual Program should meet the
goals of the individual.
FITT Formula
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FITT Formula
Frequency Number of sessions each
week (i.e., how often).
Intensity Degree of effort put forth
during exercise (i.e., how hard).
Time Duration of activity (i.e.,
how long).
Type Mode of exercise being
performed.
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Cardiorespiratory Endurance
Body’s ability to deliver oxygen effectively to the working muscles to perform physical activity.
Most important component of health fitness.
Helps prevent hypokinetic disease.
Concerned with the aerobic efficiency of the body.
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Cardiorespiratory Endurance
FITT Formula
Frequency: 3 to 5 times per week
Intensity: 55% - 90% HRMAX or 40% - 85% HRR
Time: 20 - 60 minutes
Type: Aerobic activities
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Target Heart Rate Zone
HRMAX= 220 bpm – age
Target zone = 55% to 90% HRMAX
Lower threshold target HR= HRMAX x 55%
Upper threshold target HR= HRMAX x 90%
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Body Composition
Percentage of body weight composed of fat as compared with fat-free or lean tissue.
Obesity is associated with numerous health problems and earlier mortality.
Determination of the cause of obesity is important.
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Body Composition
Body composition is influenced by nutrition and physical activity.
Energy balance is important to achieving a favorable body composition.
Energy expenditure through: basal metabolism (maintenance of essential life
functions) work (including exercise) excretion of body wastes
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Body Mass Index
Estimated – Weight in pounds
X 703 divided by height in inches squared
Often used in large scale surveys because of ease of collecting large amounts of data.
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Energy Balance
Number of calories taken into the body as food minus number of calories expended.
Caloric Expenditure: Neutral balance
Caloric intake equals expenditure.
Positive balance More calories consumed than expended.
Negative balance More calories are expended than consumed.
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Body Composition Improvement
Decreasing percentage of fat. Decrease caloric intake through diet. Increase caloric expenditure through physical
activity and exercise. Moderate decrease in caloric intake and moderate
increase in caloric expenditure.
Follow sound practices. Obsession with weight loss, in conjunction with
many other factors, may contribute to the development of an eating disorder.
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Measurement of Body Composition
Hydrostatic weighing
Skinfold measurements
Body mass index (BMI)
Dual-energy x-ray absorptiometry (DXA)
Bioelectrical impedance
PERCENT BODY FAT NORMS FOR MEN AND WOMEN
Description Women MenEssential Fat Athletes Fitness Acceptable Obesity
10-13%14-20%21-24%25-31%>32%
2-5%6-13%14-17%18-24%>25%
*Source: ACE Lifestyle & Weight Management Consultant Manual
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Muscular Strength & Endurance
Muscular strength is the ability of a muscle or a muscle group to exert a single force against a resistance.
Muscular endurance is the ability of a muscle or muscle group to exert force repeatedly or over a period of time.
Maintenance of proper posture; protect joints.
Production of power to enhance performance.
Use it of lose it!
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Exercises
Isometric Exercises Muscle exerts force against an immovable object. Static contraction.
Isotonic Exercises Force is generated while the muscle is changing
in length. Concentric and eccentric contractions.
Isokinetic Exercises Contractions are performed at a constant velocity
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Development of Muscular Strength and Endurance
Principle of Overload is critical.
Repetition - performance of a movement through the full range of motion.
Set - number of repetitions performed without rest.
Strength Low number of repetitions with a heavy resistance.
Endurance High number of repetitions with a low resistance
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Muscular Strength and Endurance
FITT Formula
Frequency: 3 days per week
Intensity: Strength: 6-8 repetitions.Endurance: 12-20 repetitions.
Time: 1 – 3 sets
Type: Isotonic or progressive resistance exercises; can also use isometric and isotonic exercises.
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Flexibility
Maximum range of motion possible at a joint.
Joint specific: better range of motion in some joints than in others.
Can prevent muscle injuries & low-back pain.
Decreased flexibility can be caused by: Sedentary lifestyle (lack of use of muscles) Age High amounts of body fat Stress
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Improvement of Flexibility
Ballistic Stretching Momentum generated from repeated bouncing to
stretch. (Not recommended)
Static Stretching Slowly moving into a stretching position and holding
for a certain period of time (10-30 seconds; 5 times).
Contract-relax Technique Relaxing of the muscle to be stretched by contracting
the opposite muscle (hamstrings/quadriceps)
Measurement of Flexibility - goniometer
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Flexibility
FITT FormulaFrequency: 2 to 3 days per week
(recommended every day)
Intensity: Stretch past the normal length until resistance is felt
Time: Hold the stretch from 5 – 10 seconds initially, building to 30 – 45 seconds
Type: Static or contract-relax techniques
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Developing a Fitness Program
Medical conditions, such as heart disease, diabetes, and asthma must be taken into account.
Consider the participant’s fitness needs and goals.
Activities selected should allow participants to achieve the desired fitness goals while maintaining interested and enjoyment.
Attention must be directed to educating participants about the principles of designing a personal exercise program, assessing their own fitness, and resolving personal fitness problems.
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Effects of Training
Lower oxygen consumption
Lower pulse rate
Larger stroke volume
Lower rise in blood pressure
Slower respiration rate
Lower rate of lactic acid formation
Faster return to “normal”
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Environmental Considerations
Hot and humid weather Use extreme caution Heat cramps, heat
exhaustion, heat stroke Fluid replacement Adaptation
Extreme cold weather Heat conservation Hypothermia Frostbite
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Nutrition and Fitness
Nutrients carbohydrates fats proteins vitamins minerals water
Maintaining water balance is important.
A well-balanced diet is necessary to obtain all the nutrients required by the body.
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Nutrition
Food pyramid offers guidelines for eating a balanced diet.
Current U.S. diet is too high in fat, cholesterol, sugar, and sodium while lacking in carbohydrates and fiber.
Carefully monitor caloric intake AND caloric expenditure.
Special diets for special situations.
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US Dietary Guidelines - 2005
Consume adequate nutrients within caloric needs.
Maintain body weight within a healthy range.
Engage in regular physical activity (PA). 30 minutes of moderate-intensity PA/day to reduce
risk of chronic disease Greater health benefits can be accrued from
engaging in PA for a longer time and/or at a greater level of intensity
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US Dietary Guidelines - 2005
Consume a sufficient amount and variety of fruits and vegetables.
Consume at least half of your grains from whole grains.
Consume 3 cups/day of fat-free or low-fat milk or equivalent mild products.
Limit consumption of saturated fatty acids, trans fatty acids, and sodium.
Consume potassium-rich foods.
Drink alcoholic beverages in moderation.
Safely prepare foods to avoid illness.
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Ergogenic Aids
Work-producing substances or phenomena believed to increase performance.
Used to enhance energy use, production, and/or recovery in quest for improved performance.
Forms of Ergogenic Aids: Mechanical Psychological Pharmacological Physiological Nutritional
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Caffeine
Stimulant, restricted by IOC – standard up to 6 to 8 cups of coffee.
Enhances muscle tension development, increased alertness, decreased perception of fatigue, increased endurance performance.
Effect depends on dosage and amount of caffeine athlete typically consumes.
Side effects – very rapid heart rate, diuresis, insomnia, nervousness, diarrhea, anxiety.
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Carbohydrate Loading
Used in endurance events lasting 60 to 90 minutes or longer in order to maintain pace and delay fatigue.
Change training regimen and modify diet to eat more complex carbohydrates than normal in order to store additional glycogen in muscles and liver to provide extra energy.
Pre-event meal – 1 to 5 grams of carbohydrate per kilogram of body weight 1 to 4 hours prior to event.
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Hydration, Energy & Sports Drinks
Proper hydration is important for safety reasons and to improve performance.
Fluid replacement during exercise is associated with lower heart rate, body core temperature, and levels of perceived exertion.
Water – 4-6 ounces for every 15-20 minutes of exercise.
Sports and/or energy drinks – add fluid as well as replace lost electrolytes and supply additional carbohydrates.
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Creatine
Used in an effort to increase stores of muscle phosphocreatine and have more fuel available to support short, high intensity activity.
Used in conjunction with a resistance training program to maximize muscle strength and increase fat-free mass.
ACSM – creatine supplementation enhances exercise performance in events involving short periods of extremely powerful activity, especially during repeated efforts.
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Anabolic-Androgenic Steroids
Synthetic forms of male hormone testosterone – testosterone secreted by testes is responsible for the development of masculine characteristics and promotion of growth of tissue, muscle mass, weight, and bone growth.
Taken orally or injected in 10 to 100 times the recommended therapeutic dosage.
Banned by IOC and some sport organizations.
Serious side effects, some irreversible, associated with chronic use including: increased risk of heart disease, liver tumors, cancer, hypertension, mood swings, aggressive behavior.