‚eviews

€roteins —nd emino e™id ƒupplement—tion in ƒportsX

ere „hey „ruly xe™ess—ryc

h—n xemet whD f—ru™h ‡ol—™h wh —nd elon ili—kim wh

ghild re—lth —nd ƒports genterD hep—rtment of €edi—tri™sD weir qener—l rospit—lD ƒ—pir wedi™—l genterD uf—r ƒ—˜—D ssr—el

effili—ted to ƒ—™kler p—™ulty of wedi™ineD „el eviv niversityD ‚—m—t evivD ssr—el

uey wordsX proteinD —mino —™idsD supplementD sport

swet PHHSYUXQPV±QQP

€eople —ll —round the world spend ˜illions of doll—rs on nutrition—l in™re—sed protein int—ke will enh—n™e exer™ise ™—p—™ity —nd in™re—se

supplementsD or ± —s they —re often ™—lled ± ––ergogeni™ —ids99 @from mus™le m—ssF st is likely th—t ex™ess protein will simply ˜e used —s

the qreek ergonD me—ning workAF „hese su˜st—n™es —re —lleged to energy or stored —s f—tF

enh—n™e —thleti™ perform—n™eD de™re—se f—tigueD ™h—nge ˜ody ƒever—l studies indi™—te th—t the timing of postEexer™ise protein

™omposition —nd improve looksF elthough true —thleti™ su™™ess supplement—tion is import—nt for net mus™le growth —nd re™overy

stems prim—rily from — ™om˜in—tion of geneti™ endowmentD tr—ining from exer™ise @espe™i—lly if ™om˜ined with ™—r˜ohydr—tesAF yr—l

te™hniqueD equipment —nd proper nutritionD in — world th—t oneE protein supplement @IH g in liquid formA immedi—tely —fter

hundredth of — se™ond ™ould ˜e the differen™e ˜etween f—me —nd resist—n™e tr—ining w—s shown to le—d to skelet—l mus™le

sh—me in the life of —n —thleteD nutrition—l supplements —re hypertrophy in elderly men with s—r™openi— ‘P“F roweverD simil—r

˜e™oming insep—r—˜le from sportsF effe™ts of immedi—te postEexer™ise protein supplement—tion were

€rotein —nd —mino —™ids —re —mong the most popul—r not reported in individu—ls with norm—l mus™le m—ss or in tr—ined

––perform—n™eEenh—n™ing99 supplementsF ƒin™e —mino —™ids —nd —thletesF ‚e™entlyD ƒ—unders et —lF ‘Q“ reported th—t — ™—r˜ohydr—te

proteins —re essenti—l for the synthesis of stru™tur—l proteins —nd ˜ever—ge with —ddition—l protein ™—lories produ™ed signifi™—nt

—re involved in numerous met—˜oli™ p—thw—ys —sso™i—ted with improvements in time to f—tigueD —nd redu™tions in mus™le d—m—ge

exer™iseD it h—s ˜een suggested th—t —thletes require —ddition—l in endur—n™e —thletesF roweverD the —uthors ™on™luded th—t further

proteins either in their diet or —s supplementsF elthough the use of

supplements in sports is very ™ommonD limited ™lini™—l d—t— —re

—v—il—˜le in the medi™—l liter—ture on the effe™ts of protein

sn most inst—n™esD despite the f—™t th—t the supplements on exer™ise perform—n™eF

suggested protein int—ke for —thletes ex™eeds „his —rti™le will review some of the ™urrent —v—il—˜le d—t— on

protein —nd —mino —™id supplementsD their effi™—™y —nd s—fetyF the re™ommended d—ily protein int—ke for

sedent—ry individu—lsD —n isoEenergeti™ diet ™—n

€rotein —nd —mino —™ids

provide the required —mount of protein „he ™urrent re™ommended d—ily protein int—ke for he—lthy —dults is

HFV±IFP gGkgGd—yF „hese re™ommend—tions —re ˜—sed m—inly on

nitrogen ˜—l—n™e d—t— from individu—ls who —re usu—lly sedent—ryF

„he question of how mu™h diet—ry protein is required for optim—l rese—r™h is ne™ess—ry to determine whether these effe™ts were the

—thleti™ perform—n™e h—s ˜een de˜—ted for more th—n ISH ye—rsF result of higher tot—l ™—lori™ ™ontent of the ˜ever—ge or due to

wost studies indi™—te th—t in order to m—int—in protein ˜—l—n™e spe™ifi™ proteinEmedi—ted me™h—nismsF yverlo—ding of protein m—y

during intense endur—n™e tr—iningD —thletes should ingest from IFH le—d to high nitrogen lo—d on the kidneysD —s well —s to dehydr—tionD

to IFV g protein per kg ˜ody m—ss per d—yD while in intense goutD ™—l™ium loss —nd g—strointestin—l ™ompl—ints ‘R“F

resist—n™e tr—ining protein int—ke should ˜e in™re—sed up to PFR g emino —™ids —re the ˜uilding ˜lo™ks of proteinsF €rotein ingested

protein per kg ˜ody m—ss per d—y ‘I“F sn most inst—n™esD despite the in food is ˜roken down ˜y digestive enzymes —nd —˜sor˜ed —s

f—™t th—t the suggested protein int—ke for —thletes ex™eeds the —mino —™idsF „here —re PH ™ommon —mino —™idsD of whi™h W —re

re™ommended d—ily protein int—ke for sedent—ry individu—lsD —n isoE ™onsidered essenti—lF „he term 4essenti—l4 rel—tes to the f—™t th—t

energeti™ diet ™—n provide the required —mount of proteinD —nd these —mino —™ids ™—nnot ˜e produ™ed in suffi™ient —mounts ˜y the

most studies —gree th—t with — proper dietD protein supplement—E ˜ody so they must ˜e provided ˜y dietF roweverD —ll PH —mino —™ids

tion is not neededF „hus f—rD there is no s™ientifi™ eviden™e th—t —re import—nt for m—int—ining protein tissuesF yne of the ™ommonly

QPV hF xemet et —lF swe F †ol U F w—y PHHS t

‚eviews

tryptoph—n from its ˜inding sitesD —nd elev—tion in its un˜ound purported ˜enefits of —mino —™id supplement—tion is th—t ™ert—in

˜r—in levels le—ding to in™re—sed serotonin —nd ™entr—l f—tigueF —mino —™ids @—rginineD histidineD lysineD methionineD ornithineD

st h—s ˜een hypothesized th—t supplementing fgee will prevent phenyl—l—nineA m—y stimul—te the rele—se of growth hormoneD

the drop in pl—sm— fgeeD —ttenu—te the rise in free tryptoph—nXfE insulinD insulinElike growth f—™torEs—ndGor glu™o™orti™oidsD there˜y

gee r—tioD —nd redu™e the likelihood of f—tigueF en—lysis of the promoting —n—˜oli™ pro™essesD le—ding to in™re—ses in f—tEfree m—ssF

liter—ture indi™—tes th—t ™—r˜ohydr—te —ndGor fgee supplement—E por ex—mpleD intr—venous —rginine infusion is used ™lini™—lly for

tion during exer™ise ™—n —ffe™t the r—tio of free tryptoph—n to fgeeF stimul—ting growth hormone rele—se in the ev—lu—tion of short

por ex—mpleD ™—r˜ohydr—te —dministr—tion during exer™ise h—s ˜een st—ture in ™hildren ‘S“F ƒome prelimin—ry ™lini™—l studies indi™—ted

reported to —ttenu—te free f—tty —™ids rele—se —nd minimize th—t or—l protein supplement—tion @PH±TH gAD —rginine —nd lysine

in™re—ses in the free tryptoph—nXfgee r—tio ‘IQ“F sn —dditionD fgee @IFP gAD —nd ornithine @UH mgGkgA m—y —lso in™re—se growth hormone

supplement—tion h—s ˜een reported to in™re—se pl—sm— fgee —nd sqpEs ™on™entr—tions in the ˜lood ‘T“F roweverD these findings

™on™entr—tion —nd minimize —ndGor prevent in™re—ses in the r—tio of h—ve not ˜een repli™—ted ˜y others ‘U“ —nd it now —ppe—rs th—t or—l

free tryptoph—n to fgee ‘IR“F ƒtudies —lso indi™—te th—t fgee supplement—tion of —mino —™ids f—ils to —™hieve the s—me hormon—l

—dministr—tion with or without ™—r˜ohydr—te prior to —nd during stimul—tion th—t is o˜served when —mino —™ids —re —dministered

exer™ise ™—n —ffe™t physiologi™ @mus™le d—m—geA —nd psy™hologi™—l intr—venouslyF woreoverD most d—t— suggest th—t growth hormone

@f—tigueA responses to exer™ise ‘IS“F rele—se during exer™ise is m—ximized under f—sting ™onditions ‘V“F

xeverthelessD the effe™t of these nutrition—lly indu™ed —lter—E „here is little eviden™e th—t supplement—tion of or—l —mino —™ids

tions in the free tryptoph—n to fgee r—tio on physi™—l perform—n™e during tr—ining signifi™—ntly —ffe™ts ˜ody ™ompositionD strengthD

is still not ™le—rF wost studies indi™—te th—t fgee supplement—tion —ndGor mus™le hypertrophy —nd exer™ise perform—n™e in he—lthy

does not improve singleE˜out endur—n™e perform—n™eD ˜ut these individu—ls ‘W“F „he re™ommended d—ily int—ke of —ll —mino —™ids

studies l—™ked power to delimit sm—ll ˜ut useful enh—n™ements of @P±Q gGd—yA ™—n ˜e e—sily —™hieved ˜y e—ting ™ommon foods su™h —s

perform—n™e ‘IT“F eggsD yoghurt —nd milkF „hereforeD the ˜enefi™i—l effe™ts of —mino

hespite the intriguing theories on the potenti—l role of fgee on —™ids supplement—tion in sports —re question—˜leF †ery high int—ke

perform—n™eD to d—te there —re no ™onvin™ing d—t— to support the of —mino —™ids m—y ˜e —sso™i—ted with —mino —™id im˜—l—n™eD dire™t

use of fgee —s —n enh—n™ing supplementF woreoverD the use of toxi™ effe™tsD di—rrhe— —nd mus™le ™r—mping ‘IH“F

supplemented fgee le—ds to in™re—ses in —mmoni— level ‘IU“F

fr—n™hedE™h—in —mino —™id emmoni—D ˜eing toxi™ to the ˜r—in —nd the mus™le tissueD m—y —ffe™t

exer™ise ™—p—™ity —nd perform—n™eF fr—n™hedE™h—in —mino —™ids @leu™ineD isoleu™ineD v—lineA —re

essenti—l —mino —™ids th—t ™—n ˜e oxidized in skelet—l mus™leF

‚ese—r™hers h—ve expended — ™onsider—˜le —mount of effort on

ev—lu—ting the effe™ts of supplement—tion of fgee —™ids on

physiologi™ —nd psy™hologi™—l responses to exer™ise ˜—sed on their „here is some eviden™e to support the use of

role in protein met—˜olism —s well —s on the hypotheti™—l role of

™re—tine —nd possi˜ly rwf —s ergogeni™ fgee in ™entr—l f—tigue ‘II“F

—ids in spe™ifi™ situ—tions fgee in the mus™le —re —˜le to tr—ns—min—te pyruv—te to form

—l—nineD whi™h is re™y™led to glu™ose in the gori ™y™leF „here is

signifi™—nt oxid—tion of these —mino —™ids during exer™iseD —nd

tr—™er studies th—t follow leu™ine —re often used for estim—ting

gre—tine protein turnoverF ƒome studies suggest th—t fgee supplement—tion

gre—tine is — n—tur—lly o™™urring protein derived from the —mino minimizes protein degr—d—tion —nd enh—n™es re™overy —fter exer™ise

—™ids gly™ine —nd —rginineF st is synthesized prim—rily in the liver in — ‘II“D while other studies h—ve f—iled to ™onfirm —n enh—n™ement of

twoEstep re—™tionF wost ™re—tine is stored in skelet—l mus™leD exer™ise perform—n™e following fgee supplement—tion ‘IP“F

prim—rily —s phospho™re—tineY the rest is found in the he—rtD ˜r—inD e num˜er of studies h—ve re™ently ˜een ™ondu™ted to ev—lu—te

—nd testesF „he d—ily requirement of ™re—tine is —pproxim—tely P±Q whether ™—r˜ohydr—te —ndGor fgee supplement—tion —ffe™ts ™entr—l

gY —˜out SH7 is o˜t—ined from the dietD while the rem—inder is f—tigue during exer™iseD —ndGor signs —nd symptoms of overtr—iningF

endogenously synthesizedF yn™e in the mus™le ™ellD ™re—tine gentr—l f—tigue —rises from in™re—sed levels of un˜ound tryptoph—nD

˜e™omes phosphoryl—ted ˜y ™re—tine kin—seF €hosphoryl—ted whi™h ™rosses the ˜loodE˜r—in ˜—rrier —nd le—ds to elev—ted levels of

™re—tine serves —s —n —v—il—˜le sour™e of —denosine triphosph—te ˜r—in serotoninF e key f—™tor in ˜r—in serotonin in™re—se is the rise

within the mus™leF huring most exer™ises e„€ is provided through in the pl—sm— r—tio of free tryptoph—n to fgee @tryptoph—nXfgeeAD

oxid—tive phosphoryl—tion in the mito™hondri—F whi™h ™ompete for the s—me tr—nsporters in the ˜r—inF ‡ith

sn some ™ompetitive sportsD ™h—r—™terized ˜y ˜rief intense exer™iseD the r—tio ™h—nges due to enh—n™ed oxid—tion of fgee in

repetitive exer™ise ˜outsD this —ero˜i™ produ™tion is insuffi™ient to the mus™le —nd — rise in free f—tty —™ids le—ding to displ—™ement of

sqpEI a insulinElike growth f—™torEI

fgee a ˜r—n™hedE™h—in —mino —™ids e„€ a —denosine triphosph—te

swe F †ol U F w—y PHHS €rotein ƒupplements —nd ƒport QPW t

‚eviews

ren—l fun™tionF vimited d—t— —re —v—il—˜le on the effe™ts of ™hroni™ provide e„€ dem—ndsF sn these ™—sesD —n—ero˜i™ produ™tion of e„€

™re—tine use on the kidneyF gre—tine supplement—tion while using ˜e™omes import—ntD —nd produ™tion of e„€ from phosphoryl—ted

nonEsteroid—l —ntiEinfl—mm—tory drugs m—y le—d to — tr—nsient ™re—tine hydrolysis —nd —n—ero˜i™ gly™ogenolysis is requiredF

imp—irment in ren—l fun™tion ‘PV“Y the longEterm effe™t of this gre—tine is found in —˜und—n™e in me—t —nd fishD ™ont—ining

™om˜in—tion —re yet unknownF g—ution should ˜e t—ken until longE —pproxim—tely R±S g ™re—tine for I kg of food weightF gre—tine

term —nd l—rge popul—tion studies —re —v—il—˜leF ingestion redu™es the endogenous ™re—tine synthesisF gre—tine

supplement—tion h—s ˜een proposed —s — me—ns to 4lo—d4 mus™le

qlut—mine with ™re—tine —nd phospho™re—tineF sn theoryD —n in™re—sed store of

™re—tine or phospho™re—tine would improve the —˜ility to produ™e qlut—mine is — nonEessenti—l —mino —™idF st —ppe—rs to h—ve m—ny

energy during high intensity exer™ise —s well —s improve the speed regul—tory fun™tions in the ˜odyD one of whi™h is to —ugment protein

of re™overy from su™h exer™iseF synthesis —nd to provide —n —ntiE™—t—˜oli™ effe™t ‘PW“F qlut—mine

gre—tine supplement evolved —s —n ergogeni™ —id from its use ˜y supplement—tion h—s ˜een shown to in™re—se protein synthesis in

fritish sprinters —nd hurdlers in the IWWP ylympi™ q—mes in r—ts —nd to de™re—se mus™le protein degr—d—tion in ˜oth —nim—ls

f—r™elon—F ƒin™e thenD ™re—tine h—s ˜e™ome the f—stest selling —nd —nd hum—ns ‘QH“F „his m—y ˜e —dv—nt—geous to resist—n™eEtr—ining

most rese—r™hed ergogeni™ —idF —thletes who —re seeking to enh—n™e mus™le hypertrophyF

st is reported th—t ™re—tine lo—ding @PH±QH g per d—y or HFQ g per

kg ˜ody m—ss per d—y for S±U d—ysA m—y le—d to — IH±QH7 in™re—se

in phosphoryl—ted ™re—tine ‘IV“F „his level rem—ins high for — few

elthough diet—ry protein supplement—tion is weeks —fter supplement lo—dingD —nd individu—ls who ™onsume

™ommonly used ˜y ˜oth —thletes —nd people veget—ri—n diets show the gre—test in™re—se in mus™le ™re—tine

levelsF eng—ged in re™re—tion—l sportsD there —re

„here is eviden™e th—t the ingestion of ™re—tine with — sug—rE

limited d—t— to support its wide use

™ont—ining drink in™re—ses ™re—tine upt—ke —nd stor—ge in the

mus™le ‘IW“F ƒhortEterm ™—ffeine ingestionD on the other h—ndD

˜lunts the ergogeni™ effe™ts of ™re—tineF „he me™h—nisms ˜y whi™h

™—ffeine —nd ™re—tine ™ounter—™t —re not yet fully elu™id—ted ‘PH“F qlut—mine pl—ys —n import—nt role in the norm—l immune

„here is —lso eviden™e th—t ™re—tine supplement—tion enh—n™es the fun™tionF st is —n import—nt fuel for white ˜lood ™ellsD p—rti™ul—rly for

r—te of phospho™re—tine resynthesis following intense exer™ise ‘PI“F lympho™yteE—™tiv—ted n—tur—l killer —™tivityD lympho™yte prolifer—E

w—ny studies h—ve investig—ted the effe™t of ™re—tine suppleE tionD —nd m—™roph—ge ph—go™ytosisF „hereforeD redu™tion in ˜lood

ment on exer™ise perform—n™eD —nd the results v—ry —™™ording to the glut—mine ™on™entr—tion following intense exer™ise is thought to

su˜je™tsD the mode of exer™ise —nd the —dministr—tion of ™re—tine ™ontri˜ute to immune suppression in overtr—ined —thletes ‘QI“F

‘PP“F wost ‘PQ“ ˜ut not —ll ‘PR“ studies indi™—te th—t shortEterm €relimin—ry studies indi™—te th—t supplement—tion with glut—mine

™re—tine signifi™—ntly enh—n™es the —˜ility to produ™e higher @R±IP gGd—yA ™—n prevent the de™line or even in™re—se glut—mine

mus™ul—r for™e —ndGor power output during short ˜outs of exer™ise ™on™entr—tion during exer™iseF g—stell —nd ™oEworkers ‘QP“ demonE

in young he—lthy —dultsF gre—tine supplement—tion in™re—ses tot—l str—ted th—t glut—mine supplement redu™es the selfEreported

˜ody m—ssD work performed during multiple sets of m—xim—l effort in™re—sed sus™epti˜ility of upper respir—tory infe™tions following

mus™le ™ontr—™tionsD —nd single —ndGor repetitive sprint ™—p—™ityF sn exh—ustive exer™iseF roweverD this ™h—nge w—s not —ttri˜uted to the

—dditionD longEterm ™re—tine supplement—tion during tr—ining h—s effe™t of glut—mine on lympho™yte fun™tionF purthermoreD re™ent

˜een reported to promote gre—ter g—ins in strengthD f—tEfree m—ssD d—t— indi™—te th—t in™re—sed glut—mine —v—il—˜ility ˜y preEexer™ise

—nd sprint perform—n™e ‘PS“F supplement—tion h—d little or no effe™t on immune st—tus ‘QQ“D even

gre—tine h—s not ˜een shown to improve —ero˜i™ perform—n™eF sn when the postEexer™ise redu™tion in glut—mine w—s preventedF

he—lthy peopleD it is unlikely th—t ™re—tine supplement—tion is gurrentlyD the d—t— suggest th—t glut—mine supplement—tion is of

required during —ero˜i™ —™tivity sin™e norm—l phosphoryl—ted ˜enefit only for —thletes with true glut—mine defi™ien™y ‘V“D —nd th—t

™re—tine levels —re suffi™ient to m—int—in —dequ—te e„€ produ™tionF this pro˜lem is not —s ™ommon —s on™e thoughtF

st is only in —™tivities th—t require highEenergy outputs in short

˜Erydroxy ˜Emethyl˜utyr—te ˜ursts th—t supplementing ™re—tine might ˜e usefulF

„here h—s ˜een only —ne™dot—l eviden™e of —dverse events from ˜EhydroxyE˜Emethyl˜utyri™ —™id is — ˜io—™tive met—˜olite formed

shortEterm use of ™re—tineY these in™lude m—inly g—strointestin—l from ˜re—kdown of the essenti—l ˜r—n™hed —mino —™id leu™ineF rwf

side effe™ts @n—use—D di—rrhe— —nd vomitingAD he—d—™hes —nd mus™le h—s re™ently ˜e™ome — popul—r diet—ry supplement purported to

™r—mps ‘PT“F ƒin™e the m—jority of ™re—tine @bWH7A —nd its promote g—ins in f—tEfree m—ss —nd strength during resist—n™e

met—˜olite ™re—tinine —re removed ˜y the kidney —nd ex™reted in tr—ining ‘QR“F veu™ine —nd its met—˜olite —Eketoiso™—pro—te —ppe—r

the urineD —ttention h—s ˜een p—id to possi˜le ren—l imp—irments to inhi˜it protein degr—d—tionD —nd this —ntiEproteolyti™ effe™t is

following ™re—tine supplement—tionF wost studies —gree th—t ˜elieved to ˜e medi—ted ˜y rwfF „he ˜ody synthesizes —pproxiE

™re—tine does not —lter ren—l fun™tion in he—lthy su˜je™ts ‘PU“Y this

would pro˜—˜ly not ˜e the ™—se if used ˜y people with imp—ired rwf a ˜EhydroxyE˜Emethyl˜utyr—te

QQH hF xemet et —lF swe F †ol U F w—y PHHS t

‚eviews

TF ssidori eD vo weD g—pp— wF e study of growth hormone rele—se in m—n m—tely HFQ±IFH g of rwf d—ilyD depending m—inly on the —mount of

gurr wed ‚es ypin IWVIYUXRUS± —fter or—l —dministr—tion of —mino —™idsF rwf ™ont—ined in food su™h —s gr—pefruitD some fishD —nd ˜re—st

VIF

milkF enim—l studies indi™—te th—t —pproxim—tely S7 of oxidized

UF v—m˜ert wsD refer teD will—r ‚€D w—™f—rl—ne €‡F p—ilure of ™ommer™i—l

leu™ine is ™onverted to rwf vi— —Eketoiso™—pro—te ‘QS“F e m—rkedly

or—l —mino —™id supplements to in™re—se serum growth hormone

de™re—sed protein mus™le ˜re—kdown —nd — slight in™re—se in ™on™entr—tions in m—le ˜odyE˜uildersF snt t ƒport xutr IWWQYQXPWV±QHSF

protein synthesis o™™urred in —nim—l mus™le tissue exposed in vitro VF furke vD hes˜row fD wineh—n wF hiet—ry supplements —nd nutrition—l

ergogeni™ —ids in sportF snX furke vD he—kin †D edsF glini™—l ƒports to rwfF ƒupplementing with leu™ine —ndGor rwf m—y therefore

xutritionF Pnd ednF ƒydneyX w™qr—wErillD PHHHXRSS±SPVF inhi˜it protein degr—d—tion during periods —sso™i—ted with inE

WF ureider ‚fF hiet—ry supplements —nd the promotion of mus™le growth

™re—sed proteolysisD su™h —s resist—n™e tr—ining ‘QT“F

with resist—n™e exer™iseF ƒports wed IWWWYPUXWU±IIHF

veu™ine infusion —ppe—rs to de™re—se protein degr—d—tion in IHF ‰—spelkis ff sssD svy tvF „he effe™t of — ™—r˜ohydr—teE—rginine supplement

hum—ns ‘QU“F rwf supplement—tion during Q±V weeks of tr—ining on postexer™ise ™—r˜ohydr—te met—˜olismF snt t ƒport xutr IWWWYWXPRI±

SHF h—s ˜een reported ˜y xissen —nd ™olle—gues ‘QR“ to promote

IIF flomstr—nd iD r—ssmen €D ik˜lom fD xewsholme ieF edministr—tion of signifi™—ntly gre—ter g—ins of f—tEfree m—ss —nd strength in untr—ined

˜r—n™hedE™h—in —mino —™ids during sust—ined exer™ise ± effe™ts on

men —nd women initi—ting resist—n™e tr—iningF st is yet un™le—r

iur t perform—n™e —nd on pl—sm— ™on™entr—tion of some —mino —™idsF

whether rwf —ffe™ts the ˜oneD mus™le or w—ter ™omponents of free

IWWIYTQXVQ±VF eppl €hysiol y™™up €hysiol

f—t m—ssF sn some inst—n™esD these g—ins were —sso™i—ted with signs IPF w—dsen uD w—™ve—n heD uiens fD ghristensen hF iffe™ts of glu™oseD

glu™ose plus ˜r—n™hedE™h—in —mino —™idsD or pl—™e˜o on ˜ike of signifi™—ntly less mus™le d—m—ge @efflux of mus™le enzymes —nd

t eppl €hysiol IWWTYVIXPTRR±SHF perform—n™e over IHH kmF urin—ry QEmethylhistidine ex™retionAF ‚e™entlyD in — dou˜leE˜lind

IQF h—vis twD f—iley ƒ€D ‡oods teD q—li—no ptD r—milton w„D f—rtoli ‡€F

pl—™e˜oE™ontrolled studyD „homson ‘QV“ demonstr—ted th—t W weeks

iffe™ts of ™—r˜ohydr—te feedings on pl—sm— free tryptoph—n —nd

of rwf supplement—tion in tr—ined men led to in™re—sed mus™le

˜r—n™hedE™h—in —mino —™ids during prolonged ™y™lingF iur t eppl €hysiol

strength with no ™h—nge in ˜ody ™ompositionF elthough these IWWPYTSXSIQ±IWF y™™up €hysiol

findings suggest th—t rwf supplement—tion during tr—ining m—y IRF flomstr—nd iD r—ssmen €D xewsholme ieF iffe™t of ˜r—n™hedE™h—in

—mino —™id supplement—tion on ment—l perform—n™eF e™t— €hysiol ƒ™—nd enh—n™e tr—ining —d—pt—tions in tr—ined —nd untr—ined individu—lsD

IWWIYIRQXPPS±TF others report no signifi™—nt effe™ts of rwf supplement—tion ‘QW“F

ISF goom˜es tƒD w™x—ughton v‚F iffe™ts of ˜r—n™hedE™h—in —mino —™id

„he —v—il—˜le liter—ture on rwf supplement—tion in hum—ns is still

supplement—tion on serum ™re—tine kin—se —nd l—™t—te dehydrogen—se

prelimin—ry in n—ture —nd should ˜e ™onsidered with reserv—tion

—fter prolonged exer™iseF t ƒports wed €hys pitness PHHHYRHXPRH±TF

‘RH“F „he longEterm effe™ts of rwf ˜oth on perform—n™e —nd on ITF q—stm—nn eD vehm—nn wtF yvertr—ining —nd the fgee hypothesisF wed

IWWVYQHXIIUQ±VF ƒ™i ƒports ixer™ he—lth —nd s—fety require further ev—lu—tionF

IUF w—™ve—n heD qr—h—m „iF fr—n™hedE™h—in —mino —™id supplement—tion

teppl —ugments pl—sm— —mmoni— responses during exer™ise in hum—nsF

ƒumm—ry

IWWQYURXPUII±IUF €hysiol

elthough diet—ry protein supplement—tion is ™ommonly used ˜y IVF pe˜˜r—io weD pl—n—g—n „‚D ƒnow ‚tD h—o ƒD g—rey wpF iffe™t of ™re—tine

˜oth —thletes —nd people eng—ged in re™re—tion—l sportsD the d—t— supplement—tion on intr—mus™ul—r „grD met—˜olism —nd perform—n™e

during intermittentD supr—m—xim—l exer™ise in hum—nsF e™t— €hysiol supporting its wide use —re still limitedF ƒome eviden™e supports

IWWSYISSXQVU±WSF ƒ™—nd the use of ™re—tine —nd possi˜ly rwf —s ergogeni™ —ids in spe™ifi™

IWF qreen evD rultm—n iD w—™don—ld seD ƒewell heD qreenh—ff €vF

situ—tions ‘V“D however this is —lso ˜—sed on limited d—t—F „he use of

g—r˜ohydr—te ingestion —ugments skelet—l mus™le ™re—tine —™™umul—E

supplements for the he—lthyD nonE™ompetitive —dult eng—ged in

tion during ™re—tine supplement—tion in hum—nsF em t €hysiol IWWTY

re™re—tion—l sports is usu—lly not w—rr—ntedF PUIXiVPI±TF

PHF †—nden˜erghe uD qillis xD †—n veemputte wD †—n re™ke €D †—nst—pel pD

respel €F g—ffeine ™ounter—™ts the ergogeni™ —™tion of mus™le ™re—tine

e™knowledgmentF hrF xemet is — rese—™h fellow of the ssr—el re—rt

t eppl €hysiol IWWTYVHXRSP±UF lo—dingF

pundF PIF qreenh—ff €vD fodin uD ƒoderlund uD rultm—n iF iffe™t of or—l ™re—tine

supplement—tion on skelet—l mus™le phospho™re—tine resynthesisF em t

IWWRYPTTXiUPS±QHF €hysiol

‚eferen™es

PPF „erjung ‚vD gl—rkson €D ii™hner i‚D et —lF emeri™—n gollege

IF w™erdle ‡hD u—t™h psD u—t™h †vD edsF yptim—l nutrition for exer™ise —nd of ƒports wedi™ine roundt—˜leF „he physiologi™—l —nd he—lth

tr—iningF snX ƒports —nd ixer™ise xutritionF f—ltimoreD whX vippin™ottD effe™ts of or—l ™re—tine supplement—tionF wed ƒ™i ƒports ixer™ PHHHYQPX

UHT±IUF ‡illi—ms 8 ‡ilkinsD IWWWXIVR±PQIF

PF ism—r™k fD endersen tvD ylsen ƒD ‚i™hter ieD wizuno wD ujñr wF „iming PQF †olek tƒD hun™—n xhD w—zzetti ƒeD et —lF €erform—n™e —nd mus™le fi˜er

—d—pt—tions to ™re—tine supplement—tion —nd he—vy resist—n™e tr—iningF of postexer™ise protein int—ke is import—nt for mus™le hypertrophy with

t€hysiolPHHIYSQSXQHI±IIF wed ƒ™i ƒports ixer™ IWWWYQIXIIRU±STF resist—n™e tr—ining in elderly hum—nsF

QF ƒ—unders wtD u—ne whD „odd wuF iffe™ts of — ™—r˜ohydr—teEprotein PRF furke vwD €yne hfD „elford ‚hF iffe™t of or—l ™re—tine supplement—tion

F wed ƒ™i ƒports ixer™ snttƒportxutr ˜ever—ge on ™y™ling endur—n™e —nd mus™le d—m—ge on singleEeffort sprint perform—n™e in elite swimmersF

PHHRYQTXIPQQ±VF IWWTYTXPPP±QQF

RF v—wren™e wiD uir˜y hpF xutrition —nd sports supplementsX f—™t or PSF †—nden˜erghe uD qoris wD †—n re™ke €D †—n veemputte wD †—ngerven vD

fi™tionF respel €F vongEterm ™re—tine int—ke is ˜enefi™i—l to mus™le perform—n™e t glin q—stroenterol PHHPYQSXPWW±QHTF

during resist—n™e tr—iningF t eppl €hysiol IWWUYVQXPHSS±TQF SF g—rlson riD wigliett— t„D ‚oginsky wƒD ƒtegink vhF ƒtimul—tion of

PTF €oortm—ns t‚D pr—n™—ux wF edverse effe™ts of ™re—tine supplement—tionX pituit—ry hormone se™retion ˜y neurotr—nsmitter —mino —™ids in

f—™t or fi™tionc hum—nsF wet—˜olism IWVWYQVXIIUW±VPF ƒports wed PHHHYQHXISS±UHF

swe F †ol U F w—y PHHS €rotein ƒupplements —nd ƒport QQI t

‚eviews

PUF €oortm—ns t‚D pr—n™—ux wF vongEterm or—l ™re—tine supplement—tion ˜et—Emethyl ˜utyr—te on perform—n™e —nd ™—r™—ss qu—lity of feedlot

wed ƒ™i ƒports ixer™ tenimƒ™iIWWRYUPXIWPU±QSF does not imp—ir ren—l fun™tion in he—lthy —thletesF steersF

IWWWYQIXIIHV±IHF QTF ƒl—ter qtD tenkins hF fet—EhydroxyE˜et—Emethyl˜utyr—te @rwfA suppleE

ƒports wed PVF ili—kim eD xemet hD gonst—ntini xF ƒ™reening ˜lood tests in mem˜ers of ment—tion —nd the promotion of mus™le growth —nd strengthF

t ƒports wed €hys pitness PHHPYRPXPSH± PHHHYQHXIHS±ITF the ssr—eli x—tion—l ylympi™ te—mF

SF QUF x—ir uƒD ƒ™hw—rtz ‚qD ‡elle ƒF veu™ine —s — regul—tor of whole ˜ody —nd

em t €hysiol IWWPYPTQX PWF w—x ƒ‚F qlu™o™orti™oidEmedi—ted indu™tion of glut—mine synthet—se in skelet—l mus™le protein met—˜olism in hum—nsF

wed ƒ™i ƒports ixer™ IWWHYPPXQPS±QHF iWPV±QRF skelet—l mus™leF

QHF entonio tD ƒtreet gF qlut—mineX — potenti—lly useful supplement for QVF „homson tƒF ˜et—ErydroxyE˜et—Ewethyl˜utyr—te @rwfA supplement—E

g—n t eppl €hysiol IWWWYPRXI±IRF esi— €—™ t glin xutr PHHRYIQXƒSWF —thletesF tion of resist—n™e tr—ined menF

QIF €—rryEfillings wD fudgett ‚D uouted—kis ‰D et —lF €l—sm— —mino —™id QWF ureider ‚fD perreir— wD ‡ilson wD elm—d— evF iffe™ts of ™—l™ium ˜et—E

™on™entr—tions in the overtr—ining syndromeX possi˜le effe™ts on the hydroxyE˜et—Emethyl˜utyr—te @rwfA supplement—tion during resist—n™eE

wed ƒ™i ƒports ixer™ IWWPYPRXIQSQ±VF snt t immune systemF tr—ining on m—rkers of ™—t—˜olismD ˜ody ™omposition —nd strengthF

IWWWYPHXSHQ±WF QPF g—stell vwD €oortm—ns t‚D xewsholme ieF hoes glut—mine h—ve — role ƒports wed

iur t eppl €hysiol y™™up €hysiol RHF he™om˜—z tD fury eD r—ger gF rwf met—E—n—lysis —nd the ™lustering of in redu™ing infe™tions in —thletesc

IWWTYUQXRVV±WHF t eppl €hysiol PHHQYWSXPIVH±PF d—t— sour™esF

QQF xiem—n hgD €edersen fuF ixer™ise —nd immune fun™tionF ‚e™ent

gorresponden™eX hrF hF xemetD heptF of €edi—tri™sD weir qener—l

ƒports wed IWWWYPUXUQ±VHF developmentsF

rospit—lD uf—r ƒ—˜— RRPVID ssr—elF

QRF xissen ƒD ƒh—rp ‚D ‚—y wD et —lF iffe™t of leu™ine met—˜olite ˜et—E

€honeX @WUPEWA URUEPIQR hydroxyE˜et—Emethyl˜utyr—te on mus™le met—˜olism during resist—n™eE

p—xX @WUPEWA URUEIQHQ teppl€hysiolIWWTYVIXPHWS±IHRF exer™ise tr—iningF

em—ilX h—nFxemetd™l—litForgFil QSF †—n uoevering w„D holez—l rqD qill h‚D et —lF iffe™ts of ˜et—EhydroxyE

‚ese—r™h €roje™ts

ƒtudying the role of the tyrosine kin—se per in tumor progression

yF €—sderD iF €erryD ‰F ƒ—lemD wF †olpeD qF e˜r—h—mD eF w—kovskyD sF ‰—feD rF w—lov—niD ƒF ƒhpungin

—nd F xir

p—™ulty of vife ƒ™ien™es f—rEsl—n niversityD ‚—m—t q—nD ssr—el ‘nirdm—ilF˜iuF—™Fil“

the retino˜l—stom— tumor suppressor per is — nu™le—r —nd ™ytopl—smi™ tyrosine m—lign—nt ™ellsF per w—s found to —sso™iE

proteinD p‚fD underwent dephosphoryl—E kin—se whose ™ellul—r levels —re inE —te with protein phosph—t—ses type I

tion —nd ™onsequent —™tiv—tion in perE ™re—sed in solid tumors like prost—te @€€IA —nd to modul—te their —™tivityF

depleted m—lign—nt ™ellsF purthermoreD ™—r™inom—sF „o unr—vel the role of per in ‚edu™ing the level of per led to the

the surviv—l of m—lign—nt tumors under tumor progression we spe™ifi™—lly —™tiv—tion of the p‚f phosph—t—se €€I—

hypoxi™ stress w—s severely impeded kno™kedEdown its level in prost—te —nd —nd to the su˜sequent dephosphoryl—E

upon the kno™kEdown of perF ell these ˜re—st ™—r™inom— ™ellsF „his reve—led tion —nd —™tiv—tion of p‚fF „husD per is

effe™ts led to the growth —rrest of novel roles of per in sust—ining key required for the ˜—l—n™ing of sign—lingG

m—lign—nt ™ells ˜oth in regul—tory p—thw—ys in m—lign—nt ™ellsF —ntiEsign—ling p—thw—ys in m—lign—nt in vitro ™ultures

hownEregul—tion of per led to the dephosE ™ellsF „his portr—ys per —s — novel ™—n™er —nd in —nim—l models in vivoF wole™ul—r

phoryl—tion —nd in—™tiv—tion of the exE intervention t—rget whose downEregul—E —n—lysis reve—led the involvement of per

tr—™ellul—r regul—ted kin—ses IGP @i‚uIGPA tion le—ds to the m—lfun™tioning of ˜oth in modul—ting the ˜—l—n™e ˜etween

th—t dire™t ˜oth the surviv—l —nd prolifE surviv—l —nd prolifer—tionEdire™ting sysE sign—ling —nd —ntiEsign—ling p—thw—ys

er—tion of m—lign—nt ™ellsF sn p—r—llelD tems in m—lign—nt ™ellsF @driven ˜y ™ellul—r phosph—t—sesA in

ƒupported ˜y the yffi™e of the ghief ƒ™ientistD

winistry of re—lthD —nd the ‡einksel˜—um p—mily ‚ese—r™h pundD ssr—el

QQP hF xemet et —lF swe F †ol U F w—y PHHS t