Scr March 2012 Extract1

7/29/2019 Scr March 2012 Extract1

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MARCH2012


2/11

INTRODUCTION

BretContrerassays

Hireaders!WelcometothefirsteditionofourStrength

and Conditioning Research review service. Im very

excited about this project as I believe it fills a muchneededgapintheindustry.Ratherthantalkaboutwhat

Ilearnedthismonth,Imgoingtotaketheopportunity

toreflectonevidence-baseddecisionmaking.

ThoughIdelveheavilyintotheresearchthesedays,at

heartImalifterandastrengthcoach/personaltrainer.

Im a very curious and intrigued individual when it

comestosportsscience,butattheendofthedayweall

need to be practical and confident in our decision-

makingabilities.

Ivenoticedanalarmingtrendintheonlinestrengthandconditioningindustryasoflate-Ivebeenseeingmore

and more coaches dissing research. This is utterly

reprehensible to me. Perhaps this mind-set has

emerged on account of the hundreds of arm-chair

expertswhogiveresearchersabadname.

ThewayIseeit,ifyoutakeanycoachwhohastonsof

inthetrenchestrainingexperience,andyoubringhim

up to speedwith the research, itwillmake him even

moreeffectiveatwhathedoes.Anycoachwhodoesnt

realize this clearly hasnt spent time studying.

Considering the surmounting science in the fields ofStrength and Conditioning, Biomechanics, Physiology,

and Physical Therapy, were learning at a faster rate

thaneverbefore,anditshighlyimportanttostayup-to-

date.

Being evidence-based doesnt mean to ignore your

own experiences, anecdotes, or practical findings. It

doesnt mean you should hit the books and abandon

yourtrainingandpractice.Itdoesntmeanyoushould

be that fool who quotes some obscure study while

dismissing the experiences and opinionsof all the top

athletes and professionals. Last, it most certainlydoesntmeanyoushouldeverabandoncommonsense.

To me, being evidence-based simply means that

youre the type who considers and weighs all of the

available evidence and understands the quality and

limitationofeachpieceofevidence.

An evidence-based practitioner is curious and open-

minded, but skeptical. He questions everything. He

valueswhatthe experts know,he learns thetradition,

he understands the scientific theory, he attempts to

studytheentirebodyofknowledgebeforeformulating

anopinionorhypothesis,heexperiments,andhevaluesthescientificmethod.He realizes thatall researchhas

limitations, that all researchers have biases, and that

some typesof researcharebetter thanothers. But he

understands that controlled studies are superior to

anecdotes, logical thinking, expert opinion, intuition,

andtrialanderror.Heknowsthatthemorespecificthe

study,thebetter,andthatwhathebelievestodaywill

likelybemuchdifferenteachyearasthefieldadvances.

Ihighlyrecommendthatyoufindthetimetoreadthe

followingthreearticles:

1. A Scientific Approach to Fitness: Applying theHierarchyofKnowledgeBradSchoenfeld

2. Evidence-BasedCoachingSamLeahey3. WhyWeNeedanEvidence-BasedApproachinthe

FitnessFieldAnoopBalachandran

Hopefullythesearticleswillimpressuponyouthevalue

oftheresearchprocess.Ivebeenstudyinglikecrazyforthe past year and at the risk of soundingcocky, I can

nowpickapartnearlyallofthearticlesandvideosIsee

online.Mostexpertsareincredibleatofferingstrong

opinions,buttheyusuallylackscientificunderstanding.

Iwillwarn youthatbeingwell-versed inthe literature

and becoming scientific doesnt happen overnight.

You have to work at it. I cant begin to tell you how

much more intelligent I am after one solid year of

studyingmy butt off, and Id like for you to sharemy

experience. I would like for you to subscribe to our

research review for an entire year, Id like for you tocarefullyreadourpublicationeachmonth,andafterthe

yearisoverImcertainthatyoullbeveryproudofthe

knowledge youve gained, and youll be much more

confidentinyourunderstandingofsportsscience.

Astimegoeson,Iwouldlikeforyoutostartpondering

thevarioushot-topicsinourindustryandbegintotryto

figure out how you couldgo aboutsolvingthem(as if

youwerearesearcher).Thesportsscientisthasvarious

tools at his disposal, such as force plates,

electromyography, motion capture, goniometers,

accelerometers,linearpositiontransducers,GPS,timinglights, radar, tape measurers, dynamometers,

ultrasound,MRI,forcetreadmills,andofcoursestrength

training equipment. He can use these tools to

investigate claims made by strength coaches or ideas

that were sparked from reading the works of other

researchers. He does this to refute or support

hypotheses, which leads to more questions and

subsequentstudies.Thisisthewayourfieldadvances.

Its time that researchersand practitioners are on the

samepage.Weneedtobridgethegapbetweenthelab

and the field. Hopefully this service will help.

Knowledgeispower!


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INTRODUCTIONcontinued

ChrisBeardsleysays

Hi, and welcome to the first edition of our monthly

StrengthandConditioningResearchpublication.Were

starting off as we mean to go on in this issue. Itsabsolutelycrammedfullofgreatresearchandwehada

great timewriting it. I hope you enjoy reading it as

much.

TheressomuchinherethatIwanttotalkaboutandwe

onlyhaveafewshortlineshereintheintroductionto

skimthesurface.Letmepickoutafewofthehighlights

formeasastrengthathleteandasapersonaltrainer.

Asastrengthathlete

Asastrengthathlete,thestudyIwasmostinterestedin

was Strength and neuromuscular adaptation following

one, four, and eight sets of high intensity resistance

exercise (page 7), inwhich the researchers concluded

that high training volumes are to be preferred over

lower or even medium volumes in order to develop

strength.

However, Iwasalso excited toreadaboutthe training

habitsofinternationalstandardpowerlifters.Inastudy

called Contemporary Training Practices in Elite British

Powerlifters(page11),itwasrevealedthat69%ofthe

powerlifters polled usedOlympic lifts or derivatives of

the Olympics lifts, such as cleans and pulls, in their

training.

Andstillonthetopicofpowerlifting,itwasgreattoread

a support of the practice of inhaling before lifts in

Musculoskeletal myths (page 48). After all, in nearly

everygym (and certainly when I trained asa personal

trainer), people are encouraged to breathe out with

exertion and told that powerlifters are an accident

waiting to happen! (Powerlifters and Olympic

weightlifters are taught toinhalepriorto the squatin

orderto increase intra-abdominal pressure inorderto

protect thespine.) However, recent researchsuggests

that even when there is good abdominal strength,

unless there is proper coordination between the

abdominalsandthediaphragm,spinalinstabilitywillbe

presentduringchallengingactivities.Sothepowerlifters

andOlympiclifterswererightallalong!

Iwasgratifiedtonotethatlow-levelgluteexercisesas

part of a warm-up caused increased glute activation

duringtraining,asfoundinLowLoadExercisesTargeting

the Gluteal Muscle Group Acutely Enhance Explosive

PowerOutputinEliteAthletes(page14).Iamabigfanof using glute exercises in my own training and have

found them to be significant in creating stability,

particularlyinmysquat.

I was intrigued to read in Effects of Unilateral and

Bilateral Lower-Body Resistance Exercise on Muscle

Activity and Testosterone Responses (page 19) that

unilateralsquatsappeartobeasefficaciousasbilateral

squatsatraisingtestosteronefollowingaworkout.Ihad

previously read how some Russian weightlifters had

made good use of additional workouts comprising

loadedstep-upsandsimilarsingle-legliftsbuthadnever

beenconvinced.Imaynowconsiderputtingtheminto

myroutines.

Asapersonaltrainer

Asapersonaltrainer,Ienjoyedlearningfromthestudy

Kinematic Analysis of Hip and Knee Angles during

Landing after Imagery in Females (page 13) howimagerycan beusedas a coachingstrategy tocorrect

faultymovementpatterns. Itwasinstructiveto seein

black and white how coaching cues can have zero

impactonperformancewithoutimagery.Manypeople

wouldregardimageryasfluffbutthisstudyshowsthat

ithasmuchgreaterimpactthanverbalcues.

IwasalsopleasedtoreadinKettlebellswing,snatchand

bottoms-up carry: Back and hip muscle activation,

motion, and low back loads (page 34) that the

researchers concludethatthe kettlebellswing appears

toresultinuniquecompressionandshearloadratiosinthelumbarspine.Thisuniqueratioexplainswhymany

people find the kettlebell swing to be particularly

irritatingto the lowerback,whenallelsecanbedone

painfree.Ihavecertainlyseenthisinmanypeople.

And ona completely different note, I enjoyed reading

Physically active men show better semen parameters

andhormone valuesthansedentarymen(page37). It

showed that prospective fathers would be advised to

include a level ofmoderate-hardphysicalactivity (c.1

hour,3 timesperweek)to give theirpartnerthebest

chanceofconceiving.Itsgoodtoknowthatstayingfithasmanydifferentbenefits!

ThatsallIvegotspacetotalkaboutthismonthbutIm

alreadylookingforwardtonextmonthsstudies.Weve

gotagreatline-upforyouagainandtherellbeplentyof

eye-openinginformationforyoutouseinyourtraining

oryourbusiness.

Untilnexttimeenjoythereviews.


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CONTENTS PAGE

SECTION1:STRENGTHANDCONDITIONING

EffectofCoreStrengthontheMeasureofPowerintheExtremities 2

Effectofrangeofmotiononmusclestrengthandthickness 3

Ispowertrainingorconventionalresistancetrainingbetterforfunctioninelderlypersons?Ameta-analysis 4Latespecializationthekeytosuccessincentimeters,grams,orseconds(CGS)sports 5

Relationshipsbetweennationalfootballleaguecombineperformancemeasures 6

Strengthandneuromuscularadaptationfollowingone,four,andeightsetsofhighintensityresistanceexercise 7

Theeffectivenessofresistedmovementtrainingonsprintingandjumpingperformance 8

TheEffectsofTreadmill SprintTrainingandResistanceTrainingonMaximalRunningVelocityandPower 9

Acomparisonoftheeffectsof6weeksoftraditionalresistancetraining,plyometrictrainingandcomplextraining 10

ContemporaryTrainingPracticesinEliteBritishPowerlifters 11

Effectofresistancetrainingregimensontreadmillrunningandneuromuscularperformanceinrunners 12

KinematicAnalysisofHipandKneeAnglesduringLandingafterImageryinFemales 13

LowLoadExercisesTargetingtheGlutealMuscleGroupAcutelyEnhanceExplosivePowerOutputinEliteAthletes 14

PositionalRelationshipsBetweenVariousSprintandJumpAbil it ies inEliteAmericanFootballPlayers 15

Theeffectsofplyometrictrainingonsprintperformanceameta-analysis 16

SECTION2:BIOMECHANICS

CorsethypothesisrebuttedTransversusabdominisdoesnotco-contractinunisonpriortorapidarmmovements 18

EffectsofUnilateralandBilateralLower-BodyResistanceExerciseonMuscleActivityandTestosteroneResponses 19

Kinematicchangesusingweightliftingshoesonbarbellbacksquat 20

Morphologicalandmechanicalpropertiesofmuscleandtendoninhighlytrainedsprinters 21

Realityaboutmigrationofthenucleuspulposuswithintheintervertebraldiscwithchangingpostures 22

Heelheightaffectslowerextremityfrontalplanejointmomentsduringwalking 23

WalkingonHighHeelsChangesMuscleActivityandtheDynamicsofHumanWalkingSignificantly 24

Whatistheroleoftitininactivemuscle? 25

Abdominalmuscleactivationchangesifthepurposeistocontrolpelvismotionorthoraxmotion 26

CalfStretchinginNon-WeightBearingVersusWeightBearing 27

Cellphoneschangethewaywewalk 28

Directionspecificrecruitmentofrotatorcuffmusclesduringbenchpressandrow 29

EffectofAcuteStaticStretchonMaximalMusclePerformance:ASystematicReview 30

Effectsofplyometrictrainingonpassivestiffnessofgastrocnemii 31

EffectsofthepulloverexerciseonthepectoralismajorandlatissimusdorsimusclesasevaluatedbyEMG 32

HowNeuronsMakeUsJump:theNeuralControlofStretch-ShorteningCycleMovements 33

Kettlebellswing,snatchandbottoms-upcarry:Backandhipmuscleactivation,motion,andlowbackloads 34

SECTION3:PHYSIOLOGY

Insulinsensitivityaftermaximalandenduranceresistancetraining 36

Physicallyactivemenshowbettersemenparametersandhormonevaluesthansedentarymen 37

Unravelingtheneurophysiologyofmusclefatigue 38

Musclefatigue-frommotorunitstoclinicalsymptoms 39

Muscletimeundertensionstimulatesdifferentialmuscleproteinsub-fractionalsyntheticresponsesinmen 40


5/11

CONTENTS PAGE

SECTION4:PHYSICALTHERAPY

Assessmentofthedegreeofpelvictiltwithinanormalasymptomaticpopulation 42

Comparisonofhiprotationrangeofmotioninjudoathleteswithandwithouthistoryoflowbackpain 43

FasciaResearch-aNarrativeReview 44FasciaScienceandClinicalApplicationsaClinician-Researcher'sPerspectives 45

HamstringStrainInjuriesareweheadedintherightdirection? 46

Scapularpositioninginunimpairedshoulders,shoulderimpingementsyndrome,andglenohumeralinstability 47

Musculoskeletalmyths 48

TheeffectsofanisometrickneeextensionwithhipadductionexerciseonselectiveVMOmusclestrengthening 49

UsingtheFunctionalMovementScreentoEvaluatetheEffectivenessofTraining 50


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StrengthandConditioningResearch MARCH2012

ThisdocumentiscopyrightStrengthandConditioningResearchLimited,2012.BretandChrisbothworkveryhardtobringyouthis

information.Helpustocontinueourworkbynotsharingitwithyourfriends,howevertemptingitmaybe.Thankyou.Page1

SECTION1STRENGTHANDCONDITIONING


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EffectofCoreStrengthontheMeasureofPowerinthe

Extremities, by Shinkle, Nesser, Demchak and

McMannus,JSCR,2012

Background

Apopularviewisthatastrongcorepermitstheoptimaltransfer of forces from the lower body to the upper

body. Power transfer isconsidered important for key

athleticactivities,suchasrunningandjumping.

However,whilethereisgoodevidenceforcorestrength

playingaroleininjuryprevention,thereislesssupport

fortheroleofthecoreinpredictingsportperformance.

Shinkleetal.proposedthatthismightbebecauseofthe

lackof coretesting specificity to athleticperformance.

Popular core tests tend to involve static muscle

contractions for time, which are useful for predictinglow back pain. However, they may be of less use in

predictingathleticperformance,asthisismoredynamic.

Sowhatdidtheresearchersdo?

Basedon theseobservations, Shinkle et al. set out to

developafunctionaltesttoassesstheroleofthecore

anditsimpactonsportperformance,andtodetermine

howwellthecorecantransferforcesfromthelowerto

theupperbody.

To test the core dynamically, the researchers used

seated2.7kgmedicineballthrows,asfollows:

StaticForwardthrow StaticReversethrow StaticLeftandRightthrows DynamicForwardthrow DynamicReversethrow DynamicLeftandRightthrowInaddition,the researchersalsotestedthepush press

for power. This test was used so that they could

correlate the transferofpowerfromthe lower tothe

upperbodywiththevariousmeasuresofdynamiccore

strengthnotedinthemedicineballtests.

Inaddition,thestudyalsomeasured1RMsquat,bench

press, countermovement vertical jump, 40-yard dash

andanagilityrun.

The subjects were 25 National Collegiate Athletic

AssociationDivisionIfootballplayers.

Whathappened?

Severalweakcorrelationswereidentified between the

static medicine ball throws and the performance

variables:

Static reverse throw correlated slightly withcountermovement jump, 40-yard dash and the

agilityrun

Static leftand right throws correlated slightlywithbenchpress,countermovementjump(leftonly),40-

yarddashandagilityrun

Dynamic forward throw correlated with the 1RMsquatand1RMbench

Dynamic left and right correlated withcountermovementjump

Push press correlated moderately well with 1RMsquat, 1RM bench, countermovement jump and

agilityrun

Whatweretheconclusions?

The relationship of the dynamic forward throw to the

1RM squat and bench press was explained by the

individuals ability to provide anterior stability while

resistingforcesofanexternalloadandextremityaction.

Itwasnotedthattheforwardandreversedynamicand

staticthrowsdidnotcorrelatewitheachotherbutthe

static and dynamic lateral throws did correlate. The

researchersconcludedthat thisimpliedthe lateralcoremuscleswereprimarilyresponsible forbothstatic and

dynamicactionsbutthatthiswasnot the casefor the

forwardandreversethrows.

Correlations were identified between the push press

andthestaticanddynamicleftandrightthrowsandthe

staticreversethrow.Thiswasinterpretedassupportfor

theideathatthesymmetryofthelateralaspectsofthe

coreisimportant

Inaddition,astepwiseregressionwasruninanattempt

todeterminewhich dependentvariable(s)bestpredictpushpresspower.Analysisidentified1RMsquatasthe

onlypredictor.

Practicalimplications

Theresearcherssuggestthatthecoreshouldbetrained

dynamically in athletic populations to assist in sports

performanceandthetransferofpowerfromthelower

totheupperbody.


8/11




Effect of range of motion on muscle strength and

thickness,byRonei,Gomes,Radelli,Botton,Brownand

Bottaro,JSCR,publishedaheadofprint

Background

There has been much debate concerning theeffectivenessof full andpartialrange-of-motion (ROM)

resistancetraining.

In a brief literature review, Ronei etal. conclude that

there is no strong consensus regarding the relative

effectiveness of full and partial ROM training for

strength. More importantly, they note that therehas

beenlittle investigation intothemuscularhypertrophy

thatresultsfromfullandpartialROMtraining.


Inconsequenceoftheirobservationsabove,Roneietal.

setouttotestthedifferencesinmuscularhypertrophy

of the elbow flexors in forty young men with no

resistancetrainingexperience.

Theytrainedthemen2-daysaweekfor10weeksusing

aperiodizedtrainingroutinewherethenumbersofsets

increased from 2 to4 over the 10-week period,while

thenumberofrepsdecreasedcorrespondinglyfrom20

downto8.

The researchers assigned the men to one of three

groups,alldoingoneelbowflexionexercise.Onegroup

usedexclusively partialROM,oneexclusively fullROM

andonedidnothing.

Theelbowflexionexercisewasabilateralpreachercurl,

used so that the degree of movement could be

controlledcarefully.ThefullROMwasconsideredtobe

from0to130degreesofflexion,whilethepartialROM

was set sothat theelbowcouldonlymove from50 to

100degreesinthesamecontinuum.

ThepartialROMwascontrolledbytheuseofmetalbars

atthestartandendpointsoftheROM.

Theweightsweresetsothatthesubjectsperformedthe

same number of repetitions in each of the full and

partial ROM groups. Obviously, this meant that the

partial ROMgroup used heavier weights than the full

ROMgroup.

Atthebeginningandendofthestudy,the1RMofallof

thesubjectswastested,aswasthemuscularthickness

oftheir upperarms. The researchersuseda sensitive

ultrasound apparatus to measure the increases in

muscularthickness.

Whathappened?

ThefullROM1RMpreachercurlincreasedby25.7%on

averageforthefullROMgroupand16.0%forthepartial

ROMgroup.Similarly,muscularthicknessincreasedby

9.52% in the full ROM group and and 7.37% in the

partialROMgroup.

The researchers note that this result is interesting, as

thegreaterincreaseinstrengthandmuscularthickness

inthefullROMgroupoverthepartialROMgroupwas

achievedeventhoughtheweightvolumeliftedwas36%

higherinthepartialROMgroup.

Clearly,however, the work done (as measuredby the

amountofweightliftedacertaindistance)wasnot36%

greater andmay have infactbeenless. Thiswas not

commenteduponinthestudy.

Additionally,thepartialROM1RMwasnottested,which

mayhavegivendifferentresultsfromthefull1RM.


The researchers note that full ROM training is better

thanpartial ROM training for developingstrength and

hypertrophyinuntrainedindividuals.

Furthermore,byusingtheirultrasoundapparatus, they

detected significant hypertrophy and they note that

previous studies that noted a delay in hypertrophy in

beginner lifters may have suffered from insensitive

equipment.

Ronei at al. note that their results are different from

those in other studies and observe several possible

reasonsforthis,asfollows:

The subjects used in this study were beginners,whilemanyotherpartial/fullROMstudiesaredone

withathletes

The partial ROM in this study was chosen as thecentralportionofthelift,whichistheeasiestpart,

ratherthanatastickingpoint.Otherstudieshave

chosenharderportionsofthelift,eitheratthetop

orthebottom

Theexerciseusedisanisolationmovementandnotacompoundmovement,suchasthebenchpress,as

is used in other partial/full ROM studies. In

compoundlifts,akeyissueisthetransferfromone

setofmusclestoanother


The researchers suggest using full ROM for beginner

lifterstomaximisestrengthandhypertrophy.


9/11




Is power training or conventional resistance training

betterforfunctioninelderlypersons?Ameta-analysis,

byTschopp,SattlelmeyerandHilfiker,AgeandAgeing,

2011

Background

Tschopp et al. note that in ageing populations,

important determinants of independent mobility are

musclestrengthandpower.

However strength and power are not equal when it

comes to retaining functional status with age. Power

declines earlier and faster than strength and has a

stronger relationship with functional status than

strength.

So the researchersdecided toreview the literature to

see whether power training was more effective thanstrengthatimprovingfunctionalstatusinolderpeople.


Theresearchersperformedaliteraturesearchforpower

and strength training in ageing populations. They

definedpowertrainingas trainingwheretheresistance

wasmoderateand thespeedwasas fastas possible

fortheconcentricphase.Theydefinedstrengthtraining

asexerciseswithhighormoderateresistanceandaslow

concentricphase.

As a result of their criteria, the researchers identified

641 studies. For various reasons, 598 of these were

immediately rejected as not relevant and 43 were

analysed.Ofthese43,11studieswereincludedinthe

meta-analysisasrelatingtothespecificissueconcerning

thedifference betweenstrengthand powertraining in

elderly populations. It was noted that most of the

participantsin theincluded studieswereolderpersons

withminorfunctionallimitations.

Mostofthestudiesincludedusedtrainingsessionswith

23 sets of 812 repetitions, 3-times a week over a

periodof8-16weeks,withamaximumof24weeks.As

per thecriteriaset out,the differencebetweenpower

and strength training consisted in the movement

velocity,exceptinonestudywherebothgroupsmoved

asfastaspossiblebutwithadifferentweight.

Regarding the functional outcomes of the training

modalities, seven of the studies directlyevaluatedthe

differential effects of power training versus strength

trainingonfunctionaloutcomes(e.g.chairrisetests,box

stepping,etc.).Inaddition,smallernumbersofstudies

assessed other outcomes, such as self-reported

functionalability,balance,walkingabilityandstrength.

Whatweretheresults?

The following results were noted in the case of each

outcome:

Functional outcomes the researchers note that,followinganalysis,thereisevidenceforonlya smalltomediumeffectonfunctionaloutcomesinfavour

of the power training compared with strength

training.Moreover,theyarekeentonotethatthe

width of the confidence interval indicatesthat the

dataarestillcompatiblewitha small,clinicallynon-

relevanteffectofpowertraining.

Self-reported function the researchers note thatthere is evidence for only a smalleffect of power

training on self-reported functional outcome

compared with conventional strength training.

Again, theynote thatthis resultmightbe clinicallynon-relevant.

Balance the outcomes on balance followed thesame pattern, in that power training was slightly

favouredbutnotbyasignificantamount.

Walkingtheoutcomesonwalkingwereconflicted. Strengthinterestingly,theoutcomesformuscular

strengthwereinfavourofthepowertraining.

Powertheoutcomesforpowerwerealsoinfavourof the power training but not by a significant

interval.

Musclemassand,again,theoutcomesforpowerwerealsoinfavourofthepowertrainingbutnotby

asignificantinterval.


In summary, there was a small-to-medium effect on

most functional outcomes in favour of power training

comparedwithstrengthtraining.


Theresearchersnotethatpowertrainingwithmoderate

resistance at a fast velocity seems to be a feasible

method for older persons who are still relatively fit,

althoughsafetyshouldbeaconsideration.


10/11




Late specialization thekey tosuccess incentimeters,

grams,orseconds(CGS)sports,byMoesch,Elbe,Haube

andWikman,SJM&SS,2011

Background

A key question in the coachingofathletes iswhethersuccess follows early specialization in sports (to the

exclusion of other sports) or later specialization

followingaperiodofdiversificationearlierinlife.

Earlyspecialization

Thisapproachmaintainsthat10,000hoursofdeliberate

practicearerequiredwithinthechosensport,asthereis

a strong, positive relationship between amount of

practice hours and performance. Additionally, the

accumulation of these practice hours must match

sensitive stages of the biological and cognitivedevelopment during childhood and adolescence. An

earlyonsetinagivensportisthereforerecommendedin

ordertoreachexpertperformance.

However,thereisalsoresearchthatsuggeststheresult

of such early specialization can reduce intrinsic

motivationandleadtohigherdropoutandburnout

Earlydiversification

Thepathofearlydiversificationistheorisedtoproduce

resultsinthatitengendersbetterintrinsicmotivationin

the athletes, which pays dividends later their career.

Additionally,thewidevarietyofsport-specificskillsthat

are trained assist in reachingeliteperformance in the

mainsportlateron.Thiswidevarietyofsport-specific

skillsisthoughttobebesttrainedwhileyoung,sothat

themindcanbestassimilatethem.

Moreover,thereissomeevidencethatspecializinglater

can lead to greater cumulative hours spent in the

chosensport.Somestudiesshowthatdespitethelate

start, athletes specializing later stil l managed to

complete more hours than their peers who started

earlier.


Theresearchersdecidedtolookataspecificselectionof

sports,basedontheassumptionthatsportswithafocus

on different capabilities are different in their career

developmentandwouldthereforebeexpectedtoshow

differences in the specialization age of the successful

athletes.

Assuming, therefore, that sports sharing similar

structural conditions will lead to similar career paths,theresearchersdecidedtofocusonCGSsports.

CGSsportsarethosethataremeasuredincentimeters,

grams, or seconds and have a high focus on physical

capabilities,with lowerrequirements on technicaland

tacticalfactors.

The researchers hypothesized that the elite athletes

wouldspecializemoreintenselythannear-eliteathletes

fromadolescenceonward,resultingina higheramount

of accumulated practice hours at age 18 and 21. In

addition, they supposed that elite athletes would be

youngerthantheirnear-elitepeerswhentheyenterthe

perfection stage and would spendmore years on the

seniornationalteam.

To test these ideas, they sent out questionnaires to

athletes competing in canoeing, cycling, orienteering,

rowing, sailing, skiing, swimming, track and field,

triathlon and weightlifting. They received 459

responses.

Whathappened?

Thereweresignificantdifferencesintheresponsesfrom

theeliteandnear-eliteathletesinasfollows:

The near-elite athletes accumulated significantlymoretraininghoursasearlyasage9,andcontinue

tocompletemorehoursthroughearlyadolescence

untilage15

However, at age 18, the accumulated amount ofpractice hours for the two groups is roughly thesame

After age 18, the elite athletes complete morehours,showingasignificantdifferencebyage21

Elite athletes state that they pass important stepswithintheircareer (e.g.startingsport,participation

atfirst competition,etc.) ata significantolder age

thanthenear-eliteathletes

Theeliteathletesspendsignificantlyfeweryearsonthe junior national team but more years on the

seniornationalteam

Whataretheconclusions?

Theprinciplethatpracticehoursarecriticalforathletic

success isupheld. However,it alsoappears thatearly

specializationmakes the total practice hours required

more difficult to attain than late specialization.

Whether that time is better spent diversifying is not

possibletosayfromthisstudy.


Practicestillmakesperfectbutitmayalsobeusefulto

consider when that practice is done in an athletesdevelopmentalcareer.


11/11




Relationshipsbetweennationalfootballleaguecombine

performancemeasures,Robbins,JSCR,2011

Background

The National Football League (NFL) implements a test

batteryatitsannualcombine.Thetestscomprise:

9.1m,18.3mand36.6msprinttimes Verticalandhorizontaljumpmeasures 18.3mshuttleand3-conedrill 102.1kg(225lb)benchpressforrepetitionsHowever, there isstrong reason to suspect that there

aresignificantcorrelationalrelationshipsbetweensprint

ability over short distances, between sprint and jump

abilities, and between sprint ability and change-of-

directionability.

So are the above tests duplicating each other by

measuringthesamequalityseveraltimesover?

Whatdidtheresearcherdo?

Robbinsinvestigatedandanalyseddataonthecombine

tests that was publicly available for players who

attendedtheNFLcombinefrom2005to2009andwere

draftedinthesameyear.

A total of 1,136 players were included in the study,

although all combine draftees did not necessarily

complete all physical testsmaking up the combine so

notallofthetestshave1,136datapoints.

Andwhatweretheresults?

Sprint and sprint the correlations between the9.1m, 18.3m and 36.6m sprint times were nearly

perfect, suggesting that these tests are merely

duplicatingeachother

Sprint and jump the correlations between thelinearsprinttimesandjumpperformancewerelarge

toverylarge

Jumpandjumpthecorrelationbetweenthejumptaskswasverylarge

Change ofdirection thecorrelationbetween thechange-of-directiontestswasnearlyperfect

Bench press the bench press was positivelycorrelated with all running drills and inversely

correlatedwiththejumptests

Sowhatweretheconclusions?

Well,Robinsnotesthattheredoesntappeartobeany

pointindoingmorethanonesprinttestatanydistance,

asthescoreintheonetestwouldpredicttheothertwo

anyway.

Moreover,theredoesntappeartobeanypointindoing

more than one jump test, as the score in one canbe

usedtopredicttheother.

Finally, theredoesnt appear tobe any point indoing

more than one change-of-direction test, because the

scoreintheonecanpredicttheother.

However,therewasnostrongcorrelationbetweenthe

change-of-directiontestsandthesprintandjumptests.

Sosprintabilityand jumping ability cannot beusedto

predictchange-of-directionability.

Interestingly, horizontal jump score was better

correlated with sprint speed than vertical jump score,

which is in conflict with previous research. The

horizontaljumpwasalsobettercorrelatedwithchange-

of-direction ability than the vertical jump. Robbins

suggests that thismay bebecause similarmotor skills

areinvolvedinhorizontaljumpingandsprintingandthat

verticaljumpinginvolvesothermotorskills.


Robbinssuggestsswitchingoneofthesprinttestsfora

flying start so that itmeasures top speed rather than

acceleration,asallthreedoatpresent.

RobbinsalsonotesthatirrespectiveoftheNFLcombine,

thehorizontaljumpmaybeabettertestforcoachesto

assess explosive power for sprinting than the vertical

jump.

Documents

Scr March 2012 Extract1