Journal of the International Society of Sports

Journal of the International
Society of Sports Nutrition
This Provisional PDF corresponds to the article as it appeared upon acceptance. Copyedited and
fully formatted PDF and full text (HTML) versions will be made available soon.
International Society of Sports Nutrition Position Stand: Protein and Exercise.
Journal of the International Society of Sports Nutrition 2007, 4:8
doi:10.1186/1550-2783-4-8
Bill Campbell ([email protected])
Richard B. Kreider ([email protected])
Tim Ziegenfuss ([email protected])
Paul La Bounty ([email protected])
Mike Roberts ([email protected])
Darren Burke ([email protected])
Jamie Landis ([email protected])
Hector Lopez ([email protected])
Jose Antonio ([email protected])
ISSN
Article type
1550-2783
Commentary
Submission date
31 August 2007
Acceptance date
26 September 2007
Publication date
26 September 2007
Article URL
http://www.jissn.com/content/4/1/8
This peer-reviewed article was published immediately upon acceptance. It can be downloaded,
printed and distributed freely for any purposes (see copyright notice below).
Articles in JISSN are listed in PubMed and archived at PubMed Central.
For information about publishing your research in JISSN or any BioMed Central journal, go to
http://www.jissn.com/info/instructions/
For information about other BioMed Central publications go to
http://www.biomedcentral.com/
© 2007 Campbell et al., licensee BioMed Central Ltd.
This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
InternationalS ocietyof S ports Nutritionp ositions tand:p roteina nde xercise
BillC ampbell1,R ichardB .K reider2*,T imZ iegenfuss3,P aulL aB ounty4, MikeR oberts5,
DarrenB urke6,J amie Landis7,H ector Lopez8,a ndJ ose Antonio9.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Exercisea ndP erformanceN utrition Laboratory, Dept.of P hysicalE ducationa nd
ExerciseS cience,U niversityo fS outhF lorida,42 02E .F owler Avenue,P ED214,
Tampa,F L33620, USA.
Exercisea ndS portN utrition Laboratory,D ept.of Health,H umanP erformance,a nd
Recreation,B aylor University, OneB earP lace97313, Waco,T X76798 -7313,
USA.
OhioR esearchG roupof ExerciseS cience &S portsN utrition,W adsworth Medical
Center,323H ighS t,S TE103A ,W adsworth,O H44281,U SA.
Exercisea ndS portN utrition Laboratory,D ept.of Health,H umanP erformance,a nd
Recreation,B aylor University, OneB earP lace97313, Waco,T X76798 -7313,
USA.
AppliedB iochemistrya ndM olecularP hysiology Laboratory,D epartmentof H ealth
andE xerciseS cience,U niversityof Oklahoma,14 01A spA venue,N orman,O K
73019,U SA.
ExerciseS cience Laboratory, Dept.of H uman Kinetics,S t.F rancisX avier
University,P .O. Box5000A ntigonish,N ovaS cotia,B 2G2W 5,C anada.
Departmentof Biology, LakelandC ommunityC ollege,7700C locktower Drive,
Kirtland,O hio44094- 5198,U SA.
Northwestern University FeinbergS choolof M edicine,D epartmentof P hysical
Medicinea ndR ehabilitation,R ehabilitation Instituteof C hicago,345E ast Superior
Street,C hicago, IL6061 1,U SA.
Departmentof E xercise Sciencea nd HealthP romotion,F loridaA tlanticU niversity,
2912C ollegeA venue,D avie,F L33314, USA.
[email protected]
[email protected].* C orrespondingA uthor
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Abstract
PositionS tatement:T hef ollowings evenpoi ntsr elatedt ot hei ntakeof pr oteinf orhe althy,
exercisingi ndividualsc onstitutet hepos itions tandof t heS ociety. Theyha vebe en approved
byt heR esearchC ommitteeof t heS ociety.1 )V astr esearchs upportst hec ontentiont hat
individualse ngagedi nr egular exerciset rainingr equirem oredi etarypr oteint hans edentary
individuals.2) P roteini ntakesof 1.4 – 2.0 g/kg/day forph ysicallya ctivei ndividualsi snot
onlys afe,but m ayi mprovet het raininga daptationst oe xerciset raining.3 ) Whenpa rtof a
balanced,nut rient-dense diet,pr oteini ntakesa tt hisl evela renot d etrimentalt oki dney
functionor bone m etabolismi nhe althy,a ctivep ersons.4) W hilei ti spos siblef orph ysically
activei ndividualst oobt aint heirda ilypr oteinr equirementst hrough ava ried,r egulardi et,
supplementalpr oteini nva riousf ormsa rea p racticalw ayof e nsuringa dequatea ndqua lity
proteini ntakef or athletes.5) D ifferentt ypesa nd qualityof pr oteinc an affecta minoa cid
bioavailabilityf ollowing proteins upplementation.T hes uperiorityof one p roteint ypeov er
anotheri nt ermsof opt imizingr ecoverya nd/ort raininga daptationsr emainst obe
convincinglyd emonstrated.6) A ppropriatelyt imedpr oteini ntakei sa ni mportant
componentof a nove rall exerciset rainingpr ogram,e ssentialf orpr operr ecovery,i mmune
function,a ndt he growth andm aintenanceof l ean bodym ass.7) Under certain
circumstances,s pecific aminoa cids upplements,s ucha sbr anched-chaina minoa cids
(BCAA’s),m ayi mprove exercisepe rformancea ndr ecoveryf rom exercise.
2
Proteini ntaker ecommendations
Controversyh ase xistedove rt hes afetya nde ffectivenessof pr oteini ntake abovet hat
currentlyr ecommended. C urrently,t heR DAf or proteini nhe althy adultsi s0.8g /kgbod y
weightp erda y[ 1].T hepur poseof t hisr ecommendationw ast oa ccount fori ndividual
differencesi npr oteinm etabolism,va riationsi nt hebi ologicalva lueof p rotein,a ndni trogen
lossesi nt heur inea ndf eces.M anyf actorsn eedt obe c onsideredw hend etermininga n
optimala mountof di etary protein fore xercisingi ndividuals.T hesef actorsi ncludepr otein
quality,e nergyi ntake, carbohydratei ntake,m ode andi ntensityof exercise,a ndt het imingof
thepr oteini ntake[ 2].T hec urrentr ecommended levelof pr oteini ntake (0.8g /kg/day)i s
estimatedt obe s ufficientt om eett hene edof n early all( 97.5%)he althym ena ndw omena ge
19 yearsa ndol der.T his amountof pr oteini ntake mayb ea ppropriatef orn on-exercising
individuals,but i ti s likely nots ufficientt oof fsett heox idationof pr otein/aminoa cidsdur ing
exercise( approximately 1-5%of t het otale nergy costof e xercise)no ri si ts ufficientt o
provides ubstratef orl eant issuea ccretionor f ort her epairof e xercisei nducedm uscle
damage[ 3,4] .
Proteinr ecommendationsa reba seduponni trogenba lance assessmenta nd aminoa cidt racer
studies.T heni trogenba lancet echniquei nvolves quantifyingt het otala mountof di etary
proteint hate nterst hebo dya ndt het otala mountof t heni trogent hati se xcreted[ 5].
Nitrogen balances tudies mayund erestimatet he amountof pr oteinr equiredf oropt imal
functionbe causet heses tudiesdonot di rectly relatet oe xercisepe rformance.A lso,i ti s
possiblet hatpr oteini ntakea bovet hosel evelsde emedne cessaryb yni trogenba lances tudies
mayi mprove exercisepe rformanceb ye nhancing energyut ilizationor s timulatingi ncreases
inf at-freem assi ne xercisingi ndividuals[ 2].I ndeed,a n abundanceof r esearchi ndicatest hat
thosei ndividualsw hoe ngagei nph ysicala ctivity/exerciser equirehi gherl evelsof pr otein
intaket han0.8 g/kgbod yw eightp erda y, regardlessof t hem odeof e xercise( i.e.e ndurance,
resistance, etc.)or t rainings tate (i.e.r ecreational, moderatelyor w ell-trained) [6-13].A lso,
therei sa genuiner iski nc onsumingi nsufficienta mountsof pr otein,e speciallyi nt hec ontext
ofe xercise;a ne gativen itrogenb alancew illl ikely be created,l eadingt oi ncreased
catabolisma ndi mpaired recoveryf rom exercise [14].
Relativet oe ndurancee xercise,r ecommendedpr oteini ntakesr ange fromo f1.0g /kgt o1.6
g/kgpe r day[ 2], [4,7,1 5]de pendingont hei ntensity anddur ationof t hee ndurance exercise,
asw ella st het rainings tatusof t hei ndividual.F ore xample,a ne litee ndurancea thlete
requiresa greaterl evelof pr oteini ntakea pproachingt hehi ghere ndt he aforementioned
range( 1.0t o1.6 g/kg/day). Additionally,a s endurance exercisei ncreasesi ni ntensity and
duration,t herei sa ni ncreasedox idationof br anched-chain aminoa cids,w hichc reatesa
demandw ithint hebod y forpr oteini ntakes att he uppere ndof t hisr ange. Strength/power
exercisei st houghtt oi ncreasep roteinr equirementse venm oret han endurancee xercise,
particularlydur ingt hei nitials tagesof t raining and/ors harpi ncreasesi nvo lume.
Recommendationsf ors trength/powere xerciset ypicallyr ange from1.6t o2.0g /kg/day[ 3,
11-13,16] ,a lthoughs omer esearchs uggestst hatpr oteinr equirementsm ay actuallyde crease
duringt rainingdu et obi ological adaptationst hati mprovene tpr oteinr etention[ 17].
Littler esearchha sbe enc onductedone xercise activitiest hata rei ntermittenti nna ture( e.g.,
soccer,b asketball,m ixedm artiala rts,e tc.). Ina reviewf ocusingons occerpl ayers,a pr otein
3
intakeof 1.4- 1.7 g/kgw asr ecommended[ 18].P roteini ntakesw ithint hisr ange( 1.4t o1.7
g/kg/day) are recommendedf ort hose engagingi not hert ypesof i ntermittents ports.
Ins ummary,i ti st hepos itionof t he International Societyof S portN utritiont hate xercising
individualsi ngestpr oteinr anging from1.4t o2.0 g/kg/day. Individualse ngagingi n
endurancee xercises houldi ngestl evels att hel owere ndof t hisr ange,i ndividualse ngaging
ini ntermittenta ctivitiess houldi ngestl evelsi nt hem iddleof t hisr ange,a ndt hosee ngaging
ins trength/powere xercises houldi ngestl evelsa tt heuppe re nd oft hisr ange.
Safetyof p roteini ntakesh ighert hanR DA
Iti sof ten erroneously reportedb y popularm edia thata c hronicallyhi ghpr oteini ntakei s
unhealthy andm ayr esulti nunne cessarym etabolics trainont heki dneysl eadingt oi mpaired
renalf unction.A nother concernt hati sof tenc itedi st hathi ghpr oteindi etsi ncreaset he
excretionof c alciumt herebyi ncreasingt her iskf oros teoporosis.B othof t hesec oncernsa re
unfoundeda st herei sno substantivee videncet hatpr oteini ntakesi nt her angess uggested
abovew illha ve adverse effectsi nhe althy,e xercisingi ndividuals.
Oneof t hem ainpoi ntso fde bate relativet opr oteini ntakea ndki dneyf unctioni st hebe lief
thatha bitualpr oteinc onsumptioni ne xcessof t heR DApr omotesc hronic renaldi sease
throughi ncreased glomerularpr essurea ndh yperfiltration [19,20 ].T hem ajorityof s cientific
evidence citedb yt hea uthors[ 20]w asg eneratedf roma nimalm odelsa ndp atientsw ithc oexistingr enaldi sease. Ass uch,t hee xtensionof t hisr elationshipt ohe althy individualsw ith
normalr enalf unctioni si nappropriate[ 21]. In aw ellde signedp rospective cohorts tudy,i t
wass urmisedt hathi ghp roteini ntakew asnot a ssociatedw ithr enalf unctionalde clinei n
womenw ithnor mallyop eratingki dneys[ 22].A lso,i tha sbe enr eportedt hatt herea reno
statisticallys ignificantdi fferencesi n age,s ex,w eight,a ndki dney function betweennonvegetarians andve getarians( a groupde monstratedt oha vel owerdi etarypr oteini ntakes)[ 23]
[24].B otht henon -vegetariana ndv egetarian groupspos sesseds imilarki dney function,a nd
displayedt hes amer ateo fpr ogressived eteriorationi nr enalph ysiologyw itha ge[ 24].
Preliminary clinicala nd epidemiologicals tudiesha ves uggested abe nefitof r elativelyhi gh
proteindi etsonm ajorr iskf actorsf orc hronicki dneydi sease,s ucha sh ypertension,di abetes,
obesitya ndm etabolics yndrome.F utures tudiesa rene cessaryt of urther examinet her oleof
relativelyhi ghp roteinw eightl ossdi ets,di etaryp roteins ource (quality)a ndqua ntityont he
prevalencea ndd evelopmentof ki dneydi seasei n atr iskpa tientpopul ations[ 25,26] . While
ita ppearst hatdi etarypr oteini ntakesa bovet heR DAa renot de leteriousf orhe althy,
exercisingi ndividuals,t hosei ndividualsw ithm ildr enali nsufficiencyne ed toc losely
monitort heirpr oteini ntakea sobs ervationalda taf rome pidemiologicals tudiespr ovide
evidencet hatdi etarypr oteini ntakem aybe r elatedt ot hepr ogressionof r enaldi sease[ 21,
26].
In additiont or enalf unction,t her elationshipbe tweendi etary proteini ntakea ndbone
metabolismha sa lsos erveda st hec ausef ors ome controversy.S pecifically,t herei sc oncern
thata hi ghi ntakeof di etaryp roteinr esultsi nt hel eachingof calciumf rom bones,w hichm ay
leadt oos teopeniaa ndp redisposes omei ndividualst oos teoporosis.T hiss uppositions tems
frome arlys tudiesr eportinga ni ncreasei nur ine acidity fromi ncreaseddi etarypr oteint hat
4
appearedt obe l inkedt o drawingc alciumf romt hebone st obuf fert hea cidl oad.H owever,
studiesr eportingt hise ffectw erel imitedb ys malls amples izes,m ethodologicale rrors,a nd
theus eof hi ghdos esof p urifiedf ormsof p rotein[ 27]. Iti snow know nt hatt hephos phate
contentof pr oteinf oods( ands upplementsf ortifiedw ithc alciuma ndphos phorous)ne gates
thise ffect. In fact,s ome datas uggestt hate lderly mena ndw omen( thes egmentof t he
populationm osts usceptiblet oos teoporosis)s houldc onsumedi etarypr oteina bovec urrent
recommendations( 0.8 g/kg/day)t oopt imizebone m ass[ 28].I na ddition, dataf roms table
calciumi sotopes tudiesi se merging,w hichs uggestst hem ains ourceof t hei ncreasei n
urinaryc alciumf roma h igh-proteindi eti si ntestinal( dietary) andnot f rombone r esorption
[29].A lso,g ivent hate xerciset rainings uppliest hes timulusf ori ncreasings keletalm uscle
protein,l evelsi nt her angeof 1.4t o2.0 g/kg/da re recommendedt ot ransformt hiss timulus
intoa dditionalc ontractilet issue,w hichi sa ni mportantpr edictori nbone massa ccrualdur ing
pre-pubertal growth[ 30,31] .M orer esearchne edst obe c onductedi na dultsa ndt hee lderly
relativet oe xercise,s keletalm uscleh ypertrophya ndpr oteini ntakea ndt heirc umulative
effectsonbone m ass.O verall,t herei sa l acko fs cientifice videncel inkinghi gherdi etary
proteini ntakest oa dverseout comesi nhe althy,e xercisingi ndividuals.T herei s,how ever,a
bodyof s cientificl iteraturew hichha sdo cumenteda be nefitof p roteins upplementationt o
thehe althof m ultipleor gans ystems. Iti st hereforet hepos itionof t he InternationalS ociety
ofS portN utritiont hata ctivee lderlyi ndividualsr equirepr oteini ntakesr angingf rom1.4t o
2.0g /kg/day,a ndt hatt hisl evelof i ntakei ss afe.
Proteinq ualityan dc ommont ypesof p roteins upplements
Toobt ains upplementaldi etarypr otein,e xercising individualsof teni ngestp roteinpow ders.
Powderedpr oteini sc onvenienta nd,de pendingon t hepr oduct,c anb ec ost-efficient asw ell
[32]. Commons ourcesof pr oteini ncludem ilk,w hey, casein, egg,a nds oy-basedpow ders.
Differentpr oteins ourcesa ndpur ificationm ethodsm aya ffectt hebi oavailabilityof a mino
acids.T hea minoa cidbi oavailabilityof apr otein sourcei sbe stc onceptualizeda st he
amounta ndva rietyof aminoa cidst hata redi gesteda nda bsorbedi ntot he bloodstreama ftera
proteini si ngested. Furthermore, aminoa cidbi oavailabilitym aya lsobe r eflectedb yt he
differenceb etweent heni trogen contentf rom apr oteins ourcet hati si ngestedve rsust he
nitrogen contentt hati ss ubsequentlyp resenti nt hef eces.C onsiderationof t he
bioavailabilityof a mino acidsi ntot hebl ood,a sw ella st heirde liveryt ot het argett issue(s),i s
ofgr eatesti mportancew henpl anning ar egimeno fpr e- andpos t-exercisep roteini ngestion.
Apr oteint hatpr ovidesa na dequate circulatingpo olof a minoa cidsbe fore anda ftere xercise
isr eadilyt akenupb ys keletalm usclet oopt imize nitrogenb alancea ndm usclepr otein
kinetics[ 33].
Thequa lityo fa pr oteins ourceha sp reviouslybe ende terminedb yt hes omewhatout dated
proteine fficiencyr atio( PER),a ndt hem orepr ecisepr oteindi gestibility correcteda minoa cid
score( PDCAAS).T hef ormerm ethodw asus edt oe valuatet hequ alityof apr oteins ourceb y
quantifyingt he amountof bod ym assm aturing ratsa ccruew hen feda t estpr otein.T hel atter
methodw ase stablished byt he Fooda ndA gricultureO rganization( FAO1 991)a sa m ore
appropriates coringm ethodw hichut ilizedt hea minoa cidc ompositionof a testpr otein
relativet oa r eferencea minoa cidpa ttern,w hich wast henc orrected fordi fferencesi npr otein
5
digestibility[ 34].T heU .S.D airyE xportC ouncil’sR eferenceM anualf or U.S.W heya nd
LactoseP roducts( 2003) indicatest hatm ilk-derivedw heypr oteini solatepr esentst hehi ghest
PDCAASout of a llof t hec ommonpr oteins ourcesdue t oi tshi ghc ontent ofe ssentiala nd
branched chaina minoa cids.M ilk-derivedc asein,e gg whitepow der,a nds oypr oteini solate
area lso classifieda shi ghqua litypr oteins ources witha llof t hems coring ava lueof uni ty
(1.00)ont heP DCAASs cale. In contrast,l entilss corea v alueof 0.52 whilew heat gluten
scoresa m eager0.25.
Commercially,t het wom ostpopul art ypeso fpr oteinsi ns upplementalf orma rew heya nd
casein.R ecenti nvestigationsha vede tailedt hes eruma minoa cidr esponsest oi ngesting
differentp roteint ypes. Usinga minoa cidt racer methodology,i tw asde monstratedt hatw hey
proteine licitsa s harp,r apidi ncreaseo fpl asmaa minoa cidsf ollowingi ngestion,w hilet he
consumptionof c aseini nducesa m oderate,pr olongedi ncreasei npl asmaa minoa cidst hat
wass ustainedove r a7- hrpos tprandialt imepe riod [35].T hedi fferencesi n thedi gestibility
anda bsorptionof t hesep roteint ypesm ayi ndicatet hatt hei ngestionof “slow”( casein)a nd
“fast”( whey)p roteinsdi fferentiallym ediatew holebod yp roteinm etabolismdue t ot heir
digestivepr operties[ 35].O thers tudiesha ves howns imilardi fferencesi n thepe akpl asma
levelsof a minoa cidsf ollowingi ngestionof w hey andc asein fractions( i.e.,w heyf ractions
peakinge arliert hanc aseinf ractions)[ 36,37] .
Appliede xercises cience researchha s alsode monstratedt hedi fferentiale ffectst hati ngesting
differentp roteinse xertsonpos tprandialbl ooda minoa cidr esponses andm usclepr otein
synthesisa ftere xercise. Theda taa re equivocalr elativet ow hicht ypeof pr oteini ncreases
netpr oteins tatus( breakdownm inuss ynthesis)t o agr eatere xtenta fter exercise.S ome
researchha sd emonstratedt hatde spitedi fferentpa tternsof bl ooda minoa cidr esponses,
musclepr oteinne tba lancew ass imilari nt hosei ngestingc aseinor w hey [33].H owever,
additionalr esearchha si ndicatedt hatw heyp roteini nducedpr otein gaint oa g reatere xtent
thanc asein[ 38]. Inc ontrast,s everalot hers tudiesha ves hownt hatc aseini ncreasedpr otein
depositiona tl evelsg reatert hanw hey proteins[ 35,37] .
Ther ecommendationof t he InternationalS ociety ofS portN utritioni st hat individuals
engagingi ne xercisea ttemptt oobt aint heirpr oteinr equirementst hrough wholef oods.
Whens upplementsa rei ngested, wer ecommendt hatt hepr oteinc ontainbot hw heya nd
caseinc omponentsdu et ot heirhi ghpr oteindi gestibilityc orrecteda minoa cids core and
abilityt oi ncreasem usclepr oteina ccretion.
Proteint iming
Iti s generallyr ecognizedt hata ctivei ndividualsr equirem oredi etarypr oteindue t oa n
increasei ni ntramuscularpr oteinox idation [39]a ndpr oteinbr eakdown[ 40]t hatoc curs
duringe xercise,a sw ella st hene edt of urtherc omplementi ntramuscularpr oteinr esynthesis
anda ttenuatep roteolytic mechanismst hatoc curd uringt hepos t-exerciser ecoverypha ses
[41-43].T hus,a s trategicallypl annedpr oteini ntaker egiment imeda roundph ysical activity
isi ntegrali npr eserving musclem assor e liciting muscularh ypertrophy, ensuringa p roper
recoveryf rom exercise,a ndpe rhapse vens ustainingopt imali mmunef unction.P reviously,
highl evelsof bl ood aminoa cidsf ollowing about ofr esistancet rainingha vebe enf oundt o
6
bei ntegrali npr omoting musclepr oteins ynthesis[ 44].E videncei sa ccumulatingt hat
supportst hebe nefitsof t het imingof pr oteini ntakea ndi tse ffecton gainsi nl eanm ass
duringr esistance exerciset raining[ 45-49].G ivent hatm uchof t her esearcht oda teha sbe en
conductedonr esistance exercise,m orei nvestigationsa rer equiredt oa scertaint hee ffectsof
proteint imingonot her modesof e xercise.
Researchh asa lsohi ghlightedt hepos itivei mmunea ndhe alth-relatede ffectsa ssociatedw ith
post-exercisepr oteini ngestion.A pr eviousi nvestigationut ilizing130U nitedS tatesM arine
subjects[ 50]e xaminedt hee ffectsof ani ngested supplement( 8g carbohydrate,10 gpr otein,
3g f at)i mmediatelya ftere xerciseont hes tatusof varioushe althm arkers. Theseda ta were
comparedt o129s ubjectsi ngestinga non- proteins upplement( 8g carbohydrate,0 gpr otein,
3g f at),a nd128s ubjectsi ngestingpl acebot ablets( 0g carbohydrate,0 gp rotein,0g f at).
Upont hec ompletionof t he54- dt rial,r esearchersr eportedt hatt hes ubjectsi ngestingt he
proteins upplementha da na verageof 33% fewert otalm edicalvi sits,i ncluding28% less
visitsdue t oba cterialor virali nfections,37% l essor thopedic-relatedvi sits,a nd83% l ess
visitsdue t ohe at exhaustion.M oreover,pos t-exercisem uscles orenessw ass ignificantly
reducedi ns ubjectsi ngestingpr oteinw hen comparedt ot hec ontrol groups.P reviouss tudies
usinga nimalm odelsha vede monstratedt hatw hey protein elicitsi mmuno-enhancing
properties,l ikelydue t oi tshi ghc ontentof cysteine;a na minoa cidt hati sn eededf or
glutathionepr oduction [51,52] .H ence,pr eviousr esearchha si ndicatedt hati ngesting a
proteins ourcet hati sr ichi ne ssentiala minoa cids andi sr eadilydi gestiblei mmediately
before andf ollowinge xerciset rainingi sbe neficialf ori ncreasingm usclem ass,r ecovery
followinge xercise, ands ustainingi mmunef unctiondur inghi gh-volumet rainingpe riods.
Whilepr oteini ngestioni se mphasizedi nt hisa rticle,t hec oncomitanti ngestionof pr oteina nd
carbohydratespr iort oa nd/orf ollowinge xerciseh asa lsobe ens hownt ob e advantageousi n
increasingm usclep roteins ynthesis;a r esultw hichi sl ikelydu et oa ni ncreasei ni nsulin
signalingf ollowingt hei ngestionof carbohydrates.
Iti st hepos itionof t he InternationalS ocietyof S portN utritiont hate xercisingi ndividuals
shouldc onsumehi ghqua lityp roteinw ithint het imepe riode ncompassing theire xercise
session( i.e.be fore,dur ing,a nd after).
Ther oleof B CAA’si ne xercise
Thebr anched-chaina minoa cids( i.e.l eucine,i soleucinea ndva line)c onstitutea pproximately
one-thirdof s keletalm usclepr otein [53].A ni ncreasing amountof l iteratures uggestst hatof
thet hree BCAAs,l eucinea ppearst opl ayt hem osts ignificantr olei ns timulatingpr otein
synthesis[ 54]. Int hisr egard,a minoa cids upplementation( particularlyt heB CAAs)m aybe
advantageous fort hee xercisingi ndividual.
Af ews tudiesr eportedt hatw hen BCAAsw erei nfusedi nhum ansa tr est,pr oteinba lance
increasesb y eitherd ecreasingt he rateof p rotein breakdown,i ncreasingt her ateo fpr otein
synthesisor a combinationof bot h[ 55,56] .F ollowingr esistance exercise inm alesi tha s
beens hownt hatt hea dditionof f reel eucine combinedw ithc arbohydrate andpr oteinl edt oa
greateri ncreasepr oteins ynthesisa s comparedt ot akingt hes amea mounto fc arbohydrate
andpr oteinw ithoutl eucine[ 57].H owever,t hem ajorityof t her esearchr elativet ol eucine
7
ingestiona ndpr oteins ynthesisha sbe enc onductedus inga nimalm odels. Similarr esearch
needst obe c onductedi n healthyi ndividualse ngagingi nr esistancee xercise.
BCAAi ngestionha sbe ens hownt obe be neficial duringa erobic exercise. WhenB CAAsa re
takendur inga erobice xerciset hene tr ateof pr oteinde gradationha sb eens hownt ode crease
[58].E quallyi mportant, BCAAa dministration givenbe forea nddu ring exhaustivea erobic
exerciset oi ndividualsw ithr educedm uscle glycogens toresm aya lsode lay muscle glycogen
depletion[ 59]. WhenB CAAsw ere givent or unnersdur inga m arathoni ti mprovedt he
performanceo f“ slower” runners( those whoc ompletedt her acei n3.05h- 3.30h) a s
comparedt o“ faster”r unners( thosew ho completedt her acei nl esst han3. 05h) [60].
Althought herea renum erousr eportedm etabolicc ausesof f atigues ucha s glycogen
depletion,pr otona ccumulation,de creasesi nphos phocreatinel evels,h ypoglycemia,a nd
increasedf reet ryptophan/BCAAr atio,i ti st hei ncreasei nt he freet ryptophan/BCAAr atio
thatm ayb ea ttenuated withB CAAs upplementation.D uringp rolongeda erobice xercise,t he
concentrationof f reet ryptophani ncreasesa ndt he uptakeof t ryptophani ntot hebr ain
increases.W hent hisoc curs,5- hydroxytryptamine( a.k.a.s erotonin),w hich ist houghtt o
play ar olei nt hes ubjectivef eelingsof fatigue,i s produced.S imilarly, BCAAsa re
transportedi ntot hebr ainb yt hes amec arriers ystema st ryptophan andt hus“ compete”w ith
tryptophant obe t ransportedi ntot hebr ain.T herefore,i ti sbe lievedt hatw henc ertaina mino
acidss ucha s BCAAsa repr esenti nt hepl asmai n sufficienta mounts,i tt heoreticallym ay
decreaset heupt akeof t ryptophani nt hebr aina ndul timatelyde creaset hef eelingso ff atigue
[61,62] .
Furthermore,t herei sa lsor esearcht os uggestt hatB CAAa dministrationt akendur ing
prolongede ndurance eventsm ayhe lpw ithm entalpe rformancei na ddition tot he
aforementionedpe rformancebe nefits[ 60].H owever,not a llr esearchi nvestigating BCAA
supplementationha sr eportedi mprovementsi ne xercisepe rformance.O ne suchs tudy[ 63]
reportedt hatl eucinei ngestiont akenbe fore anddu ringa naerobicr unningt oe xhaustion( 200
mg/kgof bod yw eight) anddur ing as trengtht rainings ession( 100m g/kgo fbod y weight)di d
noti mprovee xercisepe rformance.R easonsf ord iscrepantr esultsa renot c leara tt hist ime,
buta tt heve rym inimum,i ts eemsa pparentt hats upplementationw ithB CAAsdoe snot
impairpe rformance.
Because BCAAsha vebe ens hownt oa idi nr ecoverypr ocessesf rome xercises ucha s
stimulatingpr oteins ynthesis,a idingi n glycogen resynthesis, asw ella sde layingt heons etof
fatiguea ndhe lpingm aintainm entalf unctioni na erobic-based exercise,w e suggest
consuming BCAAs( ina dditiont oc arbohydrates)be fore,du ring,a ndf ollowinga n exercise
bout. Itha sb eens uggestedt hatt heR DAf orl eucinea lones houldbe 45m g/kg/dayf or
sedentaryi ndividuals,a nde venhi gher fora ctivei ndividuals[ 53].H owever,w hilem ore
researchi si ndicated,b ecauseB CAAsoc curi nna ture( i.e. animalpr otein)i na 2: 1:1r atio
(leucine:i soleucine:va line),one m ay consideri ngesting> 45m g/kg/dayo fl eucinea long
witha pproximately >22. 5m g/kg/dayof bot hi soleucinea ndv alinei na 24 hourt imef rame
inor dert oopt imizeove rallt raininga daptations.T hisw ille nsuret he2: 1:1r atiot hata ppears
ofteni na nimalpr otein [64]. Its houldnot be ove rlookedt hatc ompletepr oteinsi nw hole
foods,a sw ella sm ostqu alitypr oteinpow ders,c ontaina pproximately25% B CAAs.A ny
deficiencyi n BCAAi ntakef romw hole foodsc an easilyb er emediedb yc onsumingw hey
8
proteindur ingt het imef ramee ncompassingt he exercises ession;how ever,a na ttempts hould
bem adet oobt aina llr ecommendedB CAAsf romw holef oodpr oteins ources.
Conclusions
Iti st hepos itionof t he InternationalS ocietyof S portsN utritiont hate xercisingi ndividuals
needa pproximately1.4t o2.0g ramsof pr oteinpe rki logramof bod yweightpe rda y.T he
amounti sde pendentupo nt hem odea ndi ntensity oft hee xercise,t hequ ality oft hep rotein
ingested, andt hes tatuso ft hee nergya ndc arbohydratei ntakeo ft hei ndividual.C oncerns
thatpr oteini ntakew ithint hisr angei sunhe althya reunf oundedi nh ealthy, exercising
individuals.A na ttempts houldbe m adet oobt ainpr oteinr equirementsf romw holef oods,
buts upplementalpr oteini sa s afea nd convenient methodof i ngestinghi ghqua litydi etary
protein.T het imingof p roteini ntakei nt het imepe riode ncompassingt he exercises ession
hass everalbe nefitsi ncludingi mprovedr ecovery andgr eater gainsi nf atf reem ass.P rotein
residuess ucha sb ranchedc haina minoa cidsha vebe ens hownt obe b eneficialf ort he
exercisingi ndividual,i ncludingi ncreasingt her atesof pr oteins ynthesis,de creasingt he rate
ofpr oteinde gradation,a ndpos sibly aidingi n recoveryf rome xercise. Ins ummary,
exercisingi ndividualsne edm oredi etarypr oteint hant heirs edentaryc ounterparts,w hichc an
beobt ainedf romw holef oodsa sw ella sf romhi ghqua litys upplementalpr oteins ourcess uch
asw heya nd caseinp rotein.
Abbreviations
g/kg/d =
BCAAs =
gramspe rki logramof bo dyweightp erda y
branched-chaina minoa cids
Competingi nterests
Thea uthorsof t hispos itions tandde claret hatt heyha venoc ompetingi nterests.
References
1.
2.
3.
4.
Academies IoMotN: Dietaryr eferencei ntakesf ore nergy, carbohydrate,f iber,
fat,f attya cids,c holesterol,p rotein,an dam inoac ids( macronutrients).
Washington,D C:N ationalA cademiesP ress;2002.
LemonP W: Beyondt hez one:p roteinn eedsof ac tivei ndividuals. JA mC ollN utr
2000, 19(5S uppl):513S-521S.
JointP ositionS tatement:n utritionan dat hleticp erformance.A mericanC ollege
ofS portsM edicine,A mericanD ieteticA ssociation,an dD ietitianso fC anada.
MedSc iSpor tsE xerc 2000, 32(12):2130-2145.
TarnopolskyM : Protein requirementsf ore nduranceat hletes. Nutrition 2004,
20(7-8):662-668.
9
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
RandW M,P ellettP L,Y oungV R: Meta-analysisof n itrogenb alances tudiesf or
estimatingp roteinr equirementsi nh ealthyad ults. AmJ C linN utr 2003,
77(1):109-127.
ForslundA H,E l-KhouryA E,O lssonR M,S jodin AM,H ambraeus L,Y oungV R:
Effectof p roteini ntakean dp hysicalac tivityon 24 -hp atternan dr ateo f
macronutrientu tilization. AmJ P hysiol 1999, 276(5P t1) :E964-976.
MeredithC N, ZackinM J,F ronteraW R,E vansW J: Dietaryp roteinr equirements
andb odyp roteinm etabolismi ne ndurance-trainedm en. JA pplP hysiol 1989,
66(6):2850-2856.
Phillips SM,A tkinsonS A,T arnopolskyM A,M acDougallJ D: Genderd ifferencesi n
leucinek ineticsan dn itrogenb alancei ne nduranceat hletes. JA pplP hysiol 1993,
75(5):2134-2141.
Lamont LS,P atelD G,K alhanS C: Leucinek ineticsi ne ndurance-trainedh umans.
JA pplP hysiol 1990, 69(1):1-6.
FriedmanJ E, LemonP W: Effectof c hronice ndurancee xerciseon r etentionof
dietaryp rotein. IntJ Sp ortsM ed 1989, 10(2):118-123.
TarnopolskyM A,A tkinsonS A,M acDougallJ D,C hesleyA ,P hillipsS ,S chwarcz
HP: Evaluationof proteinr equirementsf ort raineds trengthat hletes. J Appl
Physiol 1992, 73(5):1986-1995.
LemonP W,T arnopolskyM A,M acDougallJ D,A tkinsonS A: Proteinr equirements
andm uscle mass/strengthc hangesd uringi ntensivet rainingi nn ovice
bodybuilders. JA pplP hysiol 1992, 73(2):767-775.
LemonP W: Proteinan dam inoac idn eedsof t hes trengthat hlete. IntJ SportN utr
1991, 1(2):127-145.
KreiderR ,A lmadaA ,A ntonioJ ,B roederC ,E arnestC ,G reenwoodM , IncledonT ,
KalmanD ,K leinerS , LeutholtzB e tal : ISSNE xercisean dS portN utrition
Review:R esearchan dR ecommendations. Journalof t heI nternationalSoc ietyof
SportsN utrition 2004, 1(1):1-44.
GaineP C,P ikoskyM A, MartinW F,B olsterD R, MareshC M,R odriguezN R: Level
ofd ietaryp roteini mpactsw holeb odyp roteint urnoveri nt rainedm alesat r est.
Metabolism 2006, 55(4):501-507.
AntonioJ , Stout J( eds.): SportsS upplements.P hiladelphia,P A: Lippincott
Williams& W ilkins;2 001.
RennieM J,T iptonK D: Proteinan dam inoac idm etabolismd uringan daf ter
exercisean dt hee ffectsof n utrition. AnnuR evN utr 2000, 20:457-483.
LemonP W: Proteinr equirementsof s occer. JS portsSc i 1994, 12S pecN o:S17-22.
MetgesC C, BarthC A: Metabolicc onsequencesof ah ighd ietary-proteini ntakei n
adulthood:as sessment oft heavai lablee vidence. JN utr 2000, 130(4):886-889.
Brenner BM,M eyerT W,H ostetterT H: Dietaryp roteini ntakean dt hep rogressive
natureof k idneyd isease:t her oleof h emodynamically mediatedgl omerular
injuryi nt hep athogenesisof p rogressivegl omerulars clerosisi nagi ng,r enal
ablation,an di ntrinsicr enald isease. NE nglJ M ed 1982, 307(11):652-659.
MartinW F,A rmstrong LE,R odriguezN R: Dietaryp roteini ntakean dr enal
function. NutrM etab( Lond) 2005, 2:25.
10
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
KnightE L,S tampferM J,H ankinsonS E,S piegelmanD ,C urhanG C: Thei mpactof
proteini ntakeon r enalf unction declinei n womenw ithn ormalr enalf unctionor
mildr enali nsufficiency. AnnI nternM ed 2003, 138(6):460-467.
BedfordJ L,B arrS I: Dietsan ds electedl ifestylep racticesof s elf-definedad ult
vegetariansf romap opulation-baseds amples uggestt heyar e more' health
conscious'. IntJ B ehav NutrP hysA ct 2005, 2(1):4.
BlumM ,A verbuchM ,W olmanY ,A viramA : Proteini ntakean dk idneyf unction
inh umans:i tse ffecton ' normalagi ng'. ArchI nternM ed 1989, 149(1):211-212.
Pecoits-FilhoR : Dietaryp roteini ntakean dk idneyd iseasei nWe sternd iet.
ContribN ephrol 2007, 155:102-112.
Lentine K,W roneE M: Newi nsightsi ntop roteini ntakean d progressionof r enal
disease. CurrO pinN ephrolH ypertens 2004, 13(3):333-336.
GintyF : Dietaryp roteinan db oneh ealth. ProcN utrSoc 2003, 62(4):867-876.
Dawson-HughesB , HarrisS S,R asmussenH ,S ong L,D allalG E: Effectof d ietary
proteins upplementson c alcium excretioni nh ealthyol derm enan dw omen. J
ClinE ndocrinolM etab 2004, 89(3):1169-1173.
KerstetterJ E,O 'BrienK O,C aseriaD M,W allD E, InsognaK L: Thei mpactof
dietaryp roteinon c alciumab sorptionan dk inetic measuresof b onet urnoveri n
women. JC linE ndocrinolM etab 2005, 90(1):26-31.
Vicente-RodriguezG : Howd oese xerciseaf fect boned evelopmentd uringgr owth?
SportsM ed 2006, 36(7):561-569.
Vicente-RodriguezG ,A ra I,P erez-GomezJ ,D oradoC ,C albetJ A: Muscular
developmentan dp hysicalac tivityas majord eterminantsof f emoralb onem ass
acquisition duringgr owth. BrJ Spor tsM ed 2005, 39(9):611-616.
TiptonK D,W olfeR R: Proteinan dam inoac idsf orat hletes. JSpor tsSc i 2004,
22(1):65-79.
TiptonK D,E lliottT A,C reeM G,W olfS E,S anfordA P,W olfeR R: Ingestionof
caseinan dw heyp roteinsr esulti nm usclean abolismaf terr esistance exercise.
MedSc iSpor tsE xerc 2004, 36(12):2073-2081.
DarraghA J,H odgkinsonS M: Quantifyingt hed igestibilityof d ietaryp rotein. J
Nutr 2000, 130(7):1850S-1856S.
BoirieY ,D anginM ,G achonP ,V assonM P,M auboisJ L,B eaufrere B: Slowan df ast
dietaryp roteinsd ifferentlym odulatep ostprandialp roteinac cretion. ProcN atl
AcadSc iU SA 1997, 94(26):14930-14935.
BosC ,M etgesC C,G audichonC ,P etzkeK J, PueyoM E,M orensC ,E verwandJ ,
BenamouzigR ,T ome D: Postprandialk ineticsof d ietaryam inoac idsar et he
maind eterminantof t heir metabolismaf ters oyor milkp roteini ngestioni n
humans. JN utr 2003, 133(5):1308-1315.
DanginM ,B oirie Y,G arcia-RodenasC ,G achon P,F auquantJ ,C allierP ,B allevreO ,
Beaufrere B: Thed igestionr ateof p roteini san i ndependentr egulating factorof
postprandial proteinr etention. AmJ P hysiolE ndocrinolM etab 2001, 280(2):E340348.
DanginM ,G uilletC ,G arcia-RodenasC ,G achon P,B outeloup-Demange C,R eiffersMagnaniK ,F auquantJ ,B allevreO , Beaufrere B: Ther ateof p roteind igestion
affectsp roteingai nd ifferentlyd uringagi ngi n humans. JP hysiol 2003, 549(Pt
2):635-644.
11
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
RodriguezN R,V islocky L,G aineP C: Dietaryp rotein,e ndurancee xercise,an d
humans keletal-muscle proteint urnover. Curr Opin Clin Nutr Metab Care 2007,
10(1):40-45.
Phillips SM,P ariseG ,R oy BD,T iptonK D,W olfeR R,T amopolskyM A:
Resistance-training-inducedad aptationsi ns keletal musclep roteint urnoveri n
thef eds tate. CanJ P hysiolP harmacol 2002, 80(11):1045-1053.
RennieM J,B oheJ ,S mithK ,W ackerhageH ,G reenhaffP : Branched-chainam ino
acidsas f uelsa ndan abolics ignalsi nh umanm uscle. JN utr 2006, 136(1
Suppl):264S-268S.
YangY ,J emioloB ,T rappeS : Proteolytic mRNAe xpressioni nr esponset oac ute
resistancee xercisei nh umans ingles keletal musclef ibers. J Appl Physiol 2006,
101(5):1442-1450.
BioloG ,M aggiS P,W illiamsB D,T iptonK D,W olfeR R: Increasedr ates ofm uscle
proteint urnoveran dam inoac idt ransportaf terr esistancee xercisei nh umans.
AmJ P hysiol 1995, 268(3P t1) :E514-520.
BioloG ,T iptonK D,K leinS ,W olfeR R: Anab undants upplyo fam inoac ids
enhancest he metabolic effectof e xerciseon musclep rotein. AmJ P hysiol 1997,
273(1P t1) :E122-129.
WilloughbyD S,S toutJ R,W ilbornC D: Effectsof r esistancet rainingan dp rotein
plusam inoac ids upplementationon m usclean abolism, mass,an ds trength.
AminoA cids 2007, 32(4):467-477.
CribbP J,W illiamsA D, StathisC G,C areyM F,H ayesA : Effectsof w heyi solate,
creatine,an dr esistancet rainingon m uscleh ypertrophy. MedS ciSpor tsE xerc
2007, 39(2):298-307.
TiptonK D,B orsheimE , WolfS E,S anfordA P,W olfeR R: Acuter esponseof n et
musclep roteinb alancer eflects24- hb alanceaf tere xercisean da minoac id
ingestion. AmJ P hysiolE ndocrinolM etab 2003, 284(1):E76-89.
Esmarck B,A ndersenJ L,O lsenS ,R ichterE A,M izunoM ,K jaerM : Timingof
postexercisep roteini ntakei si mportantf or muscleh ypertrophyw ithr esistance
trainingi ne lderlyh umans. JP hysiol 2001, 535(Pt1) :301-311.
TiptonK D,F errandoA A,P hillips SM,D oyleD ,J r.,W olfeR R: Postexercisen et
proteins ynthesisi nh uman musclef romo rallyad ministeredam inoac ids. AmJ
Physiol 1999, 276(4P t1) :E628-634.
FlakollP J, JudyT , FlinnK ,C arrC ,F linnS : Postexercisep roteins upplementation
improvesh ealthan dm uscles orenessd uringb asicm ilitary trainingi nM arine
recruits. JA pplP hysiol 2004, 96(3):951-956.
BounousG , BatistG ,G oldP : Immunoenhancingp ropertyof d ietaryw heyp rotein
inm ice:r oleof gl utathione. ClinI nvestM ed 1989, 12(3):154-161.
BounousG ,K ongshavn PA,G oldP : Thei mmunoenhancingp ropertyof d ietary
wheyp roteinc oncentrate. ClinI nvestM ed 1988, 11(4):271-278.
MeroA : Leucines upplementationan di ntensivet raining. SportsM ed 1999,
27(6):347-358.
KimballS R, Jefferson LS: Signaling pathwaysa nd molecular mechanisms
throughw hichb ranched-chainam inoac idsm ediatet ranslationalc ontrolof
proteins ynthesis. JN utr 2006, 136(1S uppl):227S-231S.
12
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
LouardR J,B arrettE J,G elfandR A: Effectof i nfusedb ranched-chaina minoac ids
onm usclean dw hole-bodyam inoac idm etabolismi n man. ClinSc i( Lond) 1990,
79(5):457-466.
BlomstrandE ,E liassonJ ,K arlssonH K,K ohnke R: Branched-chainam inoac ids
activatek ey enzymesi np roteins ynthesisaf terp hysicale xercise. JN utr 2006,
136(1S uppl):269S-273S.
KoopmanR ,W agenmakersA J,M andersR J,Z orencA H,S endenJ M,G orselinkM ,
KeizerH A,va n Loon LJ: Combinedi ngestiono f proteinan df reel eucinew ith
carbohydratei ncreases postexercise musclep roteins ynthesisi nvi voi n male
subjects. AmJ P hysiolE ndocrinolM etab 2005, 288(4):E645-653.
BlomstrandE ,N ewsholmeE A: Effectof b ranched-chainam inoac id
supplementationon t hee xercise-inducedc hangei nar omatica minoac id
concentrationi nh umanm uscle. ActaP hysiolSc and 1992, 146(3):293-298.
BlomstrandE ,E kS ,N ewsholmeE A: Influenceof i ngestingas olutiono f
branched-chainam inoac idson p lasmaan dm usclec oncentrationsof amino
acidsd uring prolonged submaximale xercise. Nutrition 1996, 12(7-8):485-490.
BlomstrandE ,H assmen P,E kblomB ,N ewsholmeE A: Administrationof
branched-chainam inoac idsd urings ustained exercise--effectson p erformance
andon plasmac oncentrationof s omea minoac ids. EurJ A pplP hysiolO ccup
Physiol 1991, 63(2):83-88.
BlomstrandE : Ar olef orb ranched-chainam inoac idsi nr educingc entralf atigue.
JN utr 2006, 136(2):544S-547S.
NewsholmeE A, BlomstrandE ,E kblomB : Physicalan dm entalf atigue:m etabolic
mechanismsan di mportanceof p lasmaa minoac ids. BrM edB ull 1992, 48(3):477495.
PitkanenH T,O jaS S,R uskoH ,N ummelaA ,K omiP V,S aransaariP ,T akalaT ,M ero
AA: Leucines upplementationd oesn ote nhanceac utes trengthor r unning
performanceb utaf fectss eruma minoac idc oncentration. AminoA cids 2003,
25(1):85-94.
ShimomuraY ,M urakamiT ,N akaiN ,N agasaki M,H arrisR A: Exercise promotes
BCAAc atabolism:e ffectsof B CAAs upplementationon s keletalm uscled uring
exercise. JN utr 2004, 134(6S uppl):1583S-1587S.
13