v

Piirssinen Eo' Seppi/Iii

rI! Diagnosis of Overtraining

What Tools Do We Have?

Axel Urhausen and Wi/fried Kindermann

Institute of Sports and PJ'evcntive Medicine, Faculty of CllniQl1 Medicine, University of Saarland,Saarbruecken, Germany

h familial atJCIIUlilalous pnI-(7): 557-62I. l)ana1.nl IiIJd multiplc I!C-I filldillg. in WI licrllmegalic

\ug;31(8):~76-7'tal..~crum tesIO~ICrOn()ant!'ncenlnltiml" mId the risk of

312-5.Cunaw"y Ml(. et al Scrum;tatccallccrrisk allt! hair I'at-18 (5): 495.5000" CS. ct al. Scrum slcroitisn a c".e-c'Jnt",1 "Indy. Can-

~): 632-6(cilly PH. Ana!>.']i" Me",idI.allcct 1995: 346 (8985):

ri I'. ct ai, Allabolic McroitJ.JnUr,,11999; 162(11):2089;inoma rnlluwing I'rolongcdMcd 1992; 152: 426, 429ct al. Illtr3lcSlicuiar Ici,)-

high d{JSC {t(lpillg wilhOral-19990CI15;86(8): 1571-5E,Cl al. lncre,.scd prcn111turciftcrs SUSPCCICtJ u, have ".",<1

2000;21:225-7

Abstract Thc multitude of p~lhlications rcgardillg overtraining ~yndrome (OTS or'stalcnc.'iN') or the short-term 'over-rcaching' and the severity of consequencesfurthc athlcteare in sharp contrast with the limited avnilabiJity ofvaliddiagno~lictools. Ergumctric teNts may reveal a decremelll in spurl-spccific performaJ1ce ifthey are maximal tCNts until cxhaul'tiol1. Overtrailled atillclcs usually prcsellt allimpaired 811acrobic Inctacid perfornl.\l1Ce and a reduccd timc-to-cxhuustjon instandardiscd high-intcl1sity Cl1dUraliCe exercise accompanicd by n small decreasein the maximumhcnrt ratc. Lact.tte levels are also slightly lowcrcd durillg sul}-maximal performance and tl1il' reNults in a slightly increascd anucrubic thl"CsbIJld.A reduced re.~piratory exchallgc ratio during exercise still deservcs furthcr iIIvcs-tigation. A detcrioralion of tbe mood I'Ulte and typical.~ubjeclive complaints ('hcavylegs', sleep disorders) rcprcscnt scl1silivc markerI', however, they may bc manip-ulated. AlthO~lgh measurements at rcst of Nelccted blood markers such as urca,uric acid, am!l]pnia, enzymes (crcalinc killill'c activity) or hormone.~ including thcr.tuo between (free) serum le:;to~lcronc and cortisol, may serve to reveal circum-stances which, for the long term, impair thc cxcrcisc performance, they are notuseful in the diagnosil' of established OTS. Thc nocturnal urinary catecholaminec~crction llI1d tbe dccrcIINc in the maximum exercise-induced ri!;e in pituitaryhormones, cspcciilily 1tdrcn(JCorticotropic lIonnone Itnd growth burmone, and, to:I Icsscr degrce, ill co)tisol nnd free plasma catecholamillcs, oftcl1 prnvide inter-esting diagl1oNlic iuforuuluon, but hormone measurements arc Ic££ suitable illpractical app!icntion. Prom II critic.tl review of the existing overlrnilling relOearchit must be concludcd thnt there has been little improvement ill rcccnt ycarN ill tbetools avmhlblc for tl1C diagnosil' of OTS.

!ia Piirssinrn,'ublic I Ictlltl~OO, Finland

The overmlining syndrome (OTS) or '~talcncsf;'represents one of thc most fcarcd compliclItionN in

compctitive athletes and is of real interest in SpO11S

medicine and scientific research. Althollgh in rc-

cent years the knowledge of central pathomechan-isms of the OTS ha.~ ~ignjricantly incrCClsed,f 1-31 there

i,,; still a strong demand for relevant tools tor the

early diagno~is oj' OTS.

O"S i" characterised by a sports-specific de-crellse in perfOlin.'\ncc logctllcr with disturbances inmood slate. This underpelfonnance persists despite a

period of recovery Ja."ting wecks OJ' months,13-5j The

dcfi11itive diagnosis ofOTS always rcquircs thc cx-clusion of an organic discasc, OTS is rare; how-cvcr, short-ternl over-reaching is planncd (or cul-

culatcd) in training and therefore occurs much mOJ"c

Sports Med 2002; 32 (2)

.

L.,boratory1\ Institute,

96 Urll/lllse/l & Kil/derlmmn Diagnosis of Overlraini

tensive ll'aining in nine female encillrance alhlclcs,changcs in maxima! oxygen llPtuke (\lO2m.x) weresignificantly correlated with changc~ of R-R inter-val variability dllring ~tanding: h(lwever, lhc fiveovcru"aillcd individual!\ of this group showed dif-ferent individua! rcspon,,;es, I 191 In another invC.,;li-

gadon, 6 days of ovcrlmld training resulting in over.reaching was nol accompanied by a change in hc.1rtratc variability)20] In a recent study, we found nochange in 15 Il1inutes (5 minutes sllpinc, 5 minutc.~upright,S Ininlltcs supillc position) hcarl rate !\pcc-tral allaly,~is, taken in five fatigued ~wimmers uftcra 2-weck tr!lining camp; in contra!\l, heart ralc vari-

ability decrcuse<1 in thc six tealn mates who did nol

cxperiencc over-rcaching.1211

somclimes proposed

for example, creatiru

acidI3!] and ammoni

thcsc vuriablc.~, at Ie.

ovcrcstimatcd and sy

firm chul1ge~ in over

11JcCK activity m

.~train of the training

act.'; to the intensity t

ularly lll1UCclistomC(

Some atluetes arc nor

!;mall increases in C

!;inglc bout of ccccnl

talion lasting severo

lions of CK activity

OTS bccuu~e evcn a

lo -1500 U/L, furlh

did not change CK

locports of soreness,l:

cvcr, that increascd

prcvcnt injuries rcsu

cular strcngth or COOl

clc soreness and fali!

Increa,~ing serult

lIscd as a marker of er

stimulated gluconcoj

training loads, espccance lraining.(36"17j l'

be considered, when

Follow-up studie1

urca and CK may pr

pairmcnl in exercise

phyluClic for OTS in

bccn clcscribed to be

with O'rS,!JI but this r

ing.llr.\ Uric arJd dOCf

in overtrnined athlete

~i1i of OTS. howcvcr,

possible.112,l~.32.J3.3HI

often. Even though some coachcs claim it is ncce.o;-sary to induce a state of ovcr-rcaching during thctraining process, a CUl1!1en!iUS st.ltemenl concludedthat ovcr-reaching .,;hould be avoided becau!ic of itsunpredict.lblc outcomc.161

In the diagnosis of OTS (or over-rcaching), pa-ramoter,,; that arc inexpcllsivc to mca~llre and m.IYbc nlcasurcd at rest or at Icast during 'iubmaximalcxcrci'ie, without disturbing the tt'aining p1'OCCs~, arcprcfcrred. Bccau!le it is .,;pcculatcd (hut a colltilluumcxists betwccn !rainil1g fatigue, ovcr-reaching andarS,14] it WOliid be pl"Cf'crab!e to idcl1tit'y (oo]~whichcan lead to an c,lrly diagnosis of ovcr-reaclring/OTS.Thereforc, (his flrticlc also discusses finding!) fromstudic.o; dcfining ovcr-reaching/OTS (hat have notnecessarily as!ics,,;cd a period of recovcry.

1. Tools Diagnosing OvertrainingSyndrome (OTS) at Rest

1,1 Heart Rate

An inCI-eased hcurt rate at rc.~t has bccn repol1edas a sign of OTS.17-JOI Howcver, thi~ was not con-firmed in morc rcccnt prospcctive ~tudics.rl I-Iii] An

incrcased hcart rule at rcsl (lr dUilng Nubmaximalcxcrcise may, however, indicatc an infcct1<!llsdi!;eascor glycogen depIction and thllS indicate an acl1tc!yreduced exercisc tolerance that may lead to OTS,

Rcccntly, variability in beat-to-beat changes 01'the hcart rllte havc bccl1 propo~cd a!; a too] to helpin thc diagnosis of ars. A tempting assumption isthat the sympathctic and parasympathctic forms orO'1'S arc rcl'lccted by corre~pol\ding changes in lhc]ow- and high-fTcqllcncy compol1cnts 01' thc R-){

imcrval spectral analy,..i!;. l-Iowcver, the validity ofthc hellrt ratc variability in thc diagnosis or OTS ilinot well established at prci;cnt. The cxiliting heartralc variability findings in ovcrtrained athlcte,.. arcconfllsing, III a case report, an increascd hcart ratevariability ill thc high tl.cqucncy range ~uggc~ti/1g apronounced parasympathetic modlilation was foundiu an atlllete with chl'Onic OTS,I 171 A recent study ['C-

pm'tcd a dccrcasc in sympathctic/parasympathetichal.mce in t...'\tigucd athletes nftcr J 2 wccks of in-lcnsc endurancc tmimng.118J After 6-9 wccks of in-

1.2 Mood State and Subjective Complaints

An impaircd mood slate and subjcctive com-plaints are consistently dc8cribed as ~cnsitivc andc.1rly markers (}f OT,5.116.22-2()1 Overtrained athlctc~typically show an inverscd 'iceberg profile' in theirProfile of Mood State (POMS scalc).{23,271 Simi-larly, the 'self-condition' lOcale according to Nitschl2HJrcveals II rcduccd 'capacity to act' .116,2~} With pcr-!;isting OTS, depression incre:)!;cs ~ignificantl)' unboth scalcs. Thc subjcClivc complaints are dOlni-nutcd by a pronollnccd fccling of mu~clliar sorc-nCN.o; ('heavy Icgs' in runncrs, triathlctcs and cy-clist.~), which llsllally OCCltrS during low excI"Ciscinlcnsities alld daily activitic.~. Sleep di,o;{)rdel'!i mayalso be an carly indicator sign of OTS.IJ6,291

In practice, the u!;cfulnc~~ of the:;e slIbjcctiveparamctcrs is ~()n1cwhat restricted bc:caufiC of thedifficulty ill dcl'ining a reference value that indi-cu!.c,-; OTS. Thc deterioration in mood ~latc uNuallystartN well bcfore !l1C definitive drop in pcrformnnccand parallcls the ilJCrCaNC in training !oad.I\6.2:USITn addition, it should bc kcpt in mind that athletcsmay manipulate, espc:cially if they l"car tlUlt coachcilwill makc sllbstitl1tion~ '(Ir unother team mate.

.4 Hormones

A dccrcascd noctucholamincs h,I.~ beenof OTS in oycrtruineinterpl-ctcd a... lowel-ed

1.3 Enzyme Activities and MetabolicMarkers in Blood

McasurcmclltR ofse]ccLcd enzyme acLivitics andhlood markcr~ llnder sLandardi!;ed coJldition!; al'C

(-' Adl~ Intemoflor,a limited. AU r1Qhl$ rosorvod. SPOIlS Mod 2002; 32 (2) I) Adl$lntetnotl~ limited. ..

J

Urhal/sen & Kindermann 97Diagl1Ogig of Overtraining

emalc cndur!lllce athletes,gen uptakc (VO2m'lx) were

.wid! changc~ of R-R intcr-lmding; however, the fivcJf this group lihowed dif-

.~e8.1191 In another investi-d training.!"c.5ulting in ovcr-lanicd by uchange in hcarLeccnt sLudy, we found nominuLcs !iupine, 5 minuLcse posiLion) heart rate spec-

, e fatigued ~wimmcrs after

~n contrust, heart rate vari-;)x tcam mates who did not

g.1211r-

L Subjective Complaints

Illite and subjcctive com-[leSCribcd a!; sensitive at}d,22.26) Ovcrlrained athletes

:d 'iceberg profile' it} theirPOMS scalc)./23,27! Simi-,..-tale according to Nitschl2~1ity to act'.116.2~1 With per-increases significantly onive complaint.') are domi-feeling or muscular sore-nners, Iriathlctes and cy-;curs during low exercise'ities. Slcep di:)orders mayr sign of OTS.IJ6.29)

~Incf;s of these ...ubjcctivcrcstricted because of the

r reference value that indi...tion in mood slate USllully

nitive drop it} pcrfonl1ancec in truining load.! [6,23,25]

k~pt in mind thal athletesIy if they tear thaI coachc~'or another team malc..

In conlra8t, incrcascu rc.,ting plasma concentrations

of norcpincphrinc werc l'c.lunu in a retrospective ob-

8ervalion in threc ovcr-rc.lched uthlctc.~14()1 und a

tl'Cnd wa~ l'Cportcd in lUl0lhcr study ,1131 Further i nvcs-

tigatioll~ have not confirmcd dccrcuscu nocturnal

urine cxcrcti011 of catccholamincR nor thc incrca~ed

pla8ma levels of rl'CC c.ltccholamine.~,I2().25.3J.411

A decrease in tile ratio bctwcen le8l08lerone or

free testosterone and col1isol has beclI 8ugge81ed

as a marker of 'anabolic-catabolic balancc' and a8

a tool in the diagnosis ofOTS.142j III Filllli8h wcighl

lifters, the te8t081erone/cortisol ratio correlated with

measurement8 of stt'ellgth.l43! Howevcr, mo8t of lhc

studies were not able to colltinn changcs in thc

testoflterone/corti8o! ratio in ovcrlraincd cndur-

ancetl:l.2S.33,:~9.4tJ or strength athletes.[441

Rc..,ults concerning the behaviour of serum cor-

tisollevels ilt rest are bottl variable and equivocal in

relation to OTS. While some studies show unchallgcd

values,(2~.:l3,4o,41.441 others repol1 incI'Cases[22.42j and

even decreases,I131 or de8cribe variablc I'CSPOn."Cfl,I2U1

Some investigators have sugge..,ted thai dccrea..,cd

resting serum col1isol is a criterion for tbe diagnosifl

ofOTSl141 It has been proposed that a dccrca8C in

cortisol occurs in the mol'C chronic statc of thc

OTS.131 while an increase would represent an acutc

higher physiological strain,138.45-47J

Overall. the data lead to the conclusion that it is

not possible to diagnose an OTS based on single

hoTlllonal blood concentrations at rest. Although it

can be argued that serial blood samplings of hor-

mones, certain of which flhow a pulsatile release,

may be more helpflll, this metllod would not bc

practical.

sometimes proposed to help in the diagnosis of OTS,tor example, creatine kinase (CK),19.311] urea,19] uricacid!:!!j and ammonia.[IOI However, the validity ofthese variables, at 1e1lst in the diagnosis of OTS, isovere!)timated and systematic Stlldies could not con-fil'lTl changes in overtrnined athletes.[12.13.32,33J

Thc CK activity milTors thc mcchunical-musculurstrain of thc training in thc prcccding days and re-act.'; to thc intcl,sity al,d volumc of excrcise, partic-ularly unaccll"tomcd ccccntric form" of exercise.Somc athlctc" arc nonrc.~pondcr!) and show only verysmall incrcascs in CK activity. In udditiol', after asinglc bout of cccentric exercise, a muscular adap-tation 1.I!)ting !)everal weeks can ot:cur.134] Eleva-tions of CK .Ictivity are not .1 clear indication ofOTS bccau.'ic cvcn aftcr an il,crc.\!)c in CK activityto -I 500 tIlL, furtl,cr ccccntric !)trcngth tminingdid nol changc CK activity, musclc .~trel'gth ,uldrcportl; of !)()rcnCSS,[351 It c.m be speculated, how-cvcr, that incrcascu CK activity coliid be used toprcvent injurics rcsulting from the impaired mus-cular ~trcngth or coordin.ltion associated with mus-cle sorcne!)s .lnd fatigue.

Increasing serum concentrations of urea areu.'icd as a marker of enhanced protein CC\tu.~olism andslin,ulated gluconeogcnc~is re..,uJting from highertraining loads, egpccially longer intcn!)iveendur.ancc trainiJ,g.136.371 Nutritional factors ~hould ul!)ohe considcrcd, when mcaguring urcu chal1ge,~.

Follow-up ~tudicg of .,;crum COI'\:cntratiuns ofurca and CK may prin,arily indic.rtc an acute im-pairmcnt in cxcrci~c tolcrancc, which muy be pro-pl,ylactic for o'rs in the long term. Ammonia hasbeen dcscril'ed to be dccrea~ed at re.~t in athlete~with OTS,I31 but thi.~ l'Cpresents an illconsistent find-ing) 16] Uric .tcid dues not show significant changes

in overtruil,ed athlete!).112, \),331 A definitive duigno-

sis ofOTS, l'uwever, using these parameters is notpossibl.C. [12,25,32;33.381

,5

Immunological Parameters

Up to now, only few data concerning thechangcs in immunological purameters in athletesdiagnosed with OTS have been reported. In oneprospcctivc controllcd .~tudy an enhanced expres-sion of T-cell surface (CD45 RO+) markers were

shown in OTS.1481 Others l-eportal'educedconcentra-lion of glutamine in peripheral blood in ovel'trainedathletesl32.491 or a decrea.~e in the glutamine/gluta-mate rutioduring trailling in five athletes.I.~1 How-

1.4 Hormonesand Metabolic

A decreased lIoctumal urinary cxcrClion of calc-cholamine~ ha~ been suggested a~ a rathcr latc signof OTS in overtrained athleteslJ3.39j and ha~ hccninterpreted as lowered inlrin~ic ~ympathclic activity.

::tcd cl11:yme activitics andlodardised condition... are

L.

Sporn Med 2002: 3~ (2) Spano Med 2002: 32 (2)D Aw Intelnotlonol LlI11teO. Atl rights reoerved.

98 Urhnll.~'!11 eo' Kl/ldeml/llll1 Diagnosis of Ovelirrnni

ever, a differentiation bctween intcnsive traillingand OiS based on the changcs of glutamine couldnot be made. In another study, lower plasma gluuI"

mine was not a con.l;istent finding in overtrained

swimmers and glutamine levcls did not nccessalily

decrease during high-intensity pha,~c~ oftraining.1511

Incrca.'icd conccntrdtions of cytokines, a~ !;pcculatcdin recent integrativc thcories about the pathomcch-anism of OTS,lS21 are awaiting confinnation via COII-

crete data in overtraillcd athletes.

lowered in overtrainis postulated a.~ an exhydrate metabolismha.-; been reported inplctioll in OTS, butis not yet well c6tabl

ve.'Jtigation.

2.2 Blood Lactate

Thc decrement of n1aximal pcrformllnce is 11ar-alleled by reduced maximal blood lactate conccn-trations, (IS described for cxamplc in middle- and

long-distallcc runnerfi,191 swjmlnc~,1~41 cycli.c;ts andtrillthlctC,'i,115,161 judokall!] and canocists,I20J How-cvel., it is intcresting to note that, in 0'1'5, the sub-maximal lactate conccnu'ations during graded cx-ercisc arc typically slightly lowcrcd and the rc.'iultingcalculations of thc anaerobic threshold tend to in-crease. Collsequcntly, a reduccd anaerobic lhrcsh-old points to 1\ training error l-nthcr than to OTS.lfthe alillcte has dcplcted glycogcn stores, which isnot tllc case in OTS,114! decl"Cascd muximal and Sllb-rnaxilnal lactatc cOilcemratioll.'( can be mcu,~ured,too. Thc illdividual anaerobic thrc,~hold, howcver.

willl1ot be infltlcnccd by carbohydrate dcricicncyand maximal heart rate is not rcdllce<I,[~8.59J

2,6 Perception o'

An incI"Ca.'icd rat«intensity exprcs.~d ilactate concentrationof effort (Bm-g-scaltcriterion for OTS.12'of percei vcd cffort,changes in ovcrtr..iruusc.fulnes~ of this tOt

2.

Tools Diagnosing CTS during Exercise

2.1 Ergometry

2.7 Hormones

Athletes with OTS

mu concentrations 0

cxhullstivc cxcrcise iI

studies. Thc differell

forlns ofOTS (symp.

.,;uch a distinction can

ai' increased 8ubmax

ncphrine was obscrvl

fcrences were too 8m

thc result was not ref

A dccrcilse<1 maxi

tion of pituitary hornli

mone (ACTH), hum;

and to a Icsser extel1

sevcl-al studie." of over

athlcLcS.12_~.33.441 Thc.~

findings with ovCl'lrr

inslliin-induced hyplACl1-[ and HGH w(

48%133\ and 24 to 26%that thc...c changes, wi

lowing max:imal exel

cat()l' of 'hormonal 0

and HGH were alrea

respcctivcly. after 2 (

cler laboratory condit

2.3 Ammonia

It ha!; bcen suggc.,;tcd that ammonia induceRexerciRc-rclated 1'aliguc by central or peripheralmechanjsm~.r60] Howcvcr" tl1e plasma .tmmonia C()n-centrations did not correlate with the time to c,,-haUSlinn in concsponding studicsl61J and wel'C foundto hcunchanged or cven decrcascd in OTs.II:i.331Howcvcr, when monitoring training, it is imporl.rntto notc tl1ut at the .,;ame absolutc wurkloud amlno-nia cOl1ccntnition8 arc increased and lactate is dc-crea~cd in state8 or glycogen dcplction. This in-crea~c in submnximal ammonia Icvcls parallcl!; thcheart rute respon.,;c.1591

2.4 Heart Rate

It has repeatedly bccn shoWI! thal thc maxima!heart ralc is slightly, hut significantly reduced inovertrnincd athletesI13-16,20,41) Howcvcr, the inl'l'a-individual decrease is only -3 to 5 bcat.-;/min andis rather small, which impairs the u~erulnc~s of thispurumctcr in practicc.

The assessmcnt of a dccrcment of pcrformancc

in OTS still represcnt.~ the gold slw1dard of diagno-

sis and requires a .~ports-~pccjfic testing procedllrc

that has 10 be conlinllcd IIntil exhaustion. In an ill-

crcmentai graded test procedure tho maximal pcr-

]t)rmance or the \10211101, of ovcrtl11ined alillctes tends

to be rcduced.(9,13.24,41,.~31 butunchunged values are

not unusual.III.12.16.541 Spccd-endurancc or short-

tern'! high-intensivc endllrancc cxcrcise tests seem

to rcpresenl more sensitivc too!s.19.11,15,J6,201 Espe-

cially the so-called 'stress test', which is perJ'ormcd

with the intensity of 10% ahovc the individual an-

aerobic Ihrcsho1d on a cycle ergolncter and leads !()

exl1austion after ~ 15 to 40 minute~, has rcpcatedly

been succcssful in diagnosing OTS in controllcd

prospective .'Iludic~ with reductions in cxcrci!\e du-

ration of hctween 14 10 27%.rl~,161

Thc ."hort-tcrm high-imcnsily u!actacid anaero-

bic perfonnallce wa~ unaffected in most,19.11,161 hut

not in al!r.~.'il OTS investigations,

An impainnent of coordination in overtraincd

athlctcs has been commonly rcported by Douche!;

in plaCtice[6] and in stlldjc~.II(),3RJ In additiun, dcc-

remcnts of the H-rct'lcxlj6J or Ihc Ileuromusclilar

cxcitabilityl571 have becn ob8erved, but arc difficult

to mc..1."UI'C from a mcthudical point of view. In over-

trained strength athletes, a decrea~ed l-rcpetition

maxilmlm ~trength has been described.144]

2.5 Respiratory Exchange Ratio

Thc respiratory exchange ratio during submaxi-mal and maximal cxcrcise has hccn observed to be

~ AdiS nfornatlonaillmited. 1111 rights reselVed. Sports Med :1002: 32 (2) (, Adls Internalla.al Umted. A

Urh/lllsell & Kindcr/lUllln Diagnosis of OVCI,\riumng 99

lowered in overtrained endurance athlctes, whichis posuI1ated as an cxprcs~iQn of diminishcd curbo-hydrate metabolism in OTs.114-16.541 Thi,., findinghas been reported in theabscncc or glycogen de-pletion in OTS, but the validity of Ihis purametcris not yet well established and rcquircfO furthcr in-

vestigation.

laximnl pertolmancc i.~ par-"imal blolXllactatc cuncclJ"'or example in middlc- .IndJ swjmmcrs,I.~1 cyclist.~ and

1[111 and~anoeisls.12()J How-I note that, in OTS, tile sub-IItrations during graded ex-fly lowered and thc resultingcrobic thre.o;hold tcnd to in-'I rcduced anacrubic thresh-crror rather lhun to OTS. IfJ glycogen SlOrC!;, which isdecreased maximal and sub-I1tratiolls call bc me.lsurcd,Icrobic threshold, however,

by carbohydrate deficiency: j.~ not reduccd.ISS.S9)

2.6 Perception of Effort

All increused ratio between thc actual cxcrciscilltcn."ity expressed in watts or mca..,urcd hy bloodlaculte concentration and the subjective pcrccptionof effort (Borg-scale) has bcen documented a~ acriterion for OTS.124.S31 Close analY!iis or rating1\of perceived effort, however, reveals only minorchanges ill overtrained athletes. Thu!O the practicalu8cnl1ne~s of this tool appears to be limited.

whereas the performance wa!; stillllnchunged,I621The ergmnetry 'strc,,;!; tC:it' ll:ieU fur the~e mellsure-ments was perfornlcd at 10% above the individual,!naerobic tllrcshold until cxhaustil)n, In anotherStlJdy, maximal exCl'cisc.induccd scrllm C()rti~ul con-centrations were reduced arter 4 wecks of experi-mental intcnsivc cndurancc lruining without over-training,l411 Other author,s rcpl)rt similar positiveresults with a rcpcatcd tc~ting procedure within 3hours.16:\]

'I.'he disadvantage~ of such honnonal monitor-ing of tJ1lining arc the necei\sity or highly stund-ardised conditions and the expensive mcthod,s, Pur-thermore, from a practical standpoint "y"tcmatichormonul measurements requil-c the possibility for

analy~is of ~mall cilpillary samples.

3. Current Recommendations2,7 Hormones

The validity of difJ'crcnt toul8 fur the diagnosisofOTS is summariscd in tahlc I. BcforcdiagnosingOTS,

organic discascs that may mimic the symp-toms ofOTS must hc cKcludcd by a physician qual-ified in sports mcdicinc. Thc detection of OTS isbased on rcgular a.'Isc~smcnt8 of the maKimal sports-specific performance (including cuurdinative skills),which, in somc disciplines, may bc repruduced byergometric tcsts. Tbc only tools available to diag-nose OTS under resting conditions arc UI1 impairedmood state and subjcctivc complaints !iuch aH thefeeling of 'heavy Icg...' and rcportH uf sleep distllr-bances. Dccrcascd nocturnal urinary catecholamineexcretion might also bc of value but is not verypractical. In thc crgomctric laburutury,~lll impah"edmaximallactatc prl)ductiul) and perhaps a reducedmaximal heart ratc n1ight be indications of OTS.Bccausc rcduccd maximal perfOrmallCe and lactatecoJ1ccntrations al'C ulso the reslIit of musclilar gly-cogen depiction aftcr intcnsivc training, perfoffilancetesting should bc donc artcr at least 2 days of re-duced training intensity or rc~t. Decreased m~lxi-mal exercise-induced ACTA secretiun may be highlysuggestive of OTS, b~1t is nurmally reserved forresearch study conditions. The l~ck of validity ofsome blood variables in diagnosing 01'8, however,doe.~ not mean that they are not valid in the moni-

ted that ammonia indllcese by contral or peripheral~r, the pl.wma uffiJnonia ~on."relale with the timc tl> ex-19 studicsl61] atld wcrc found~n dccrcllsed in OTS.I!J,3:1]ring u'aining, it is important: absolute workload ammo-

:.ncreascd and lflctate is de-fcogcn depletion. This in-mmonia levels paralic Is the

Athletes Witll OTS also show lower maximal plas-

ma colJcentrations of ft'ee (nor)epincphrine artcr

cxhalL.,tive exercise in most,19.2S.4IJ but not all[IJ.3JI

studies. The differellces may be due to difTcrcnt

form~ of OTS (sympathetic or parasympathclic, if

such adistinctioll can be. made at all)" In OJ~C !;ludy[IJI

an increased submaximal concentration or norcpi-

ncphrine was observed: howevcr, thc absolutc dif-

rcrcnces were too small to be. used in practicc and

thc rcsult was not replicated.[33.4Ij

A decreased maximal cxcrci~c-induced ~ecre-dolI of pituitary horffi{)ncs r adrcnocorticotropic hor-

mone (ACTH), human growth hormone (HGH)],

and to a Ic~scr cxtcnt cortisol has beell found in

sevCl"al studics or ovcrtraincd endurance and 8trength

athletcs.[2;.33.44J Thcsc rcsults corroborate former

findillg~ with ovcrtrained maratllon rul1ne.rs after

insulin-induecd hypoglycaemia.1221 Secretion of

ACTH and HGH wcrc clearly reduced by 42 to

48%[331 and 24 to 26%, l'Cspcctivcly,r2;] It is probable

that these changes, which can 0111y bc observed fol-

lowing maximal exercisc, rcprcsent an early indi-

cator of 'hormonal ovcr-rcaching'. Indeed ACTH

and HGH wcrc already lowcrcd by 30 and 36%,

respectively, aftcr 2 days of intcnsivc training un-

der laboratory condilioni; compured with controls,

~[J shown that the maxima!ut significantly reduced in6,20,41) Howcver, the il1tra-

rnly -3 to 5 hcuts/min andnpairs tile u.~cfull1ess of this

)onge Ratio

angc rutio during submaKi-.sc has been observed to be

Spor/$ MOO 2002; 32 (2) t) AOls Inl~rnO1k)nol Lirnltea. All r~hts rO5&l\'oo. Sport. Med 2002; 32 (2)

100 Urhall.~en e.. Kinder!""II!1 J)jugnosig of Overtraining

Table I. Summary 01 proposer! tools with corl!tsponding changes anr! suitability lor the r!iagnosis of an overtraining syndrome (OTS)-

Tool Changes In OTS SuitabilitySports-speCific performance (Sub)maximale~erclse Gold standard; rogular testing problematic (In most

spoils)Ergomotric performance Anaerobic threshold rt> Does not diagnose OTS, but targets other training

errors

Maximal exercise J. or ( ) Incremental graded tests less sensitive than

tesls-to-exhauslion (cr time-trials)Neuromuscular excitability At resl J. Difficult method; needs more data

Mood profne At rest J. Very sonsitive; may be manipulaled

Subjoctive complaints AI rest, submaximal t 'Hoavy legs'; very common; sleep disorders: lessoxercise common; may be manipulated

Borg-scew Subma1tlmal e1terciS9 (i) Small changes

Heart rate AI rest ( ) t may indicate other probioms (infection)

variability ? Insufficient data

Maximal exorcise (J,) Rather small changes

Respiratory exchange ratio (Sub)rflaxlmal exercise J, limited data

Lactate Submaximal exercise (J.I Does not diagnose OTS, but excludes other Iralnlng

orrorsMaximal exorcise J. '. Typical change, but probably not In every sport

CK, urea At rest H t may Indicate muscular overuse or prolonged

carbohydrate depletionTesto$terone At rest (4 J. may indk:ate high physiological strain?

Cortlso1 At rest H t may Indicate high physiological strain

Maximal exercise (J.) Differentiation botween Intensive training and OTS

may be questionabloACTH Maximal exercise J. Vory sensitive, differentiation between intensivo

training and OTS may be qulJslionable

Catooholamines Excretion (urine) J, Marked J. as late Indicator of OTS

Maximal Gxorciso (plasma) J, or ,.. Parailels changes of lactate

ACT" " adrenooorticotropic hormone; CK = creatine kinase; J, = decreased; (J,) = slightly decreas;d; '""' = unchanged; 1 = Increased; (i) =slightly increaSed; ? :0 not established.

5. Kllipcrs H, Kcl~cr HA. (

11nd dire.c\ion. for Ihe fl

6 BrillClI!la!\l G. Ci"ro.~IAI\ ]

challenge of I"event;OIl

nlla! USOC/ACSM hll

lun(kl(I'I.).AllicricRnlAvailRblc from: URL:

[Accc."..ed 2001 Nov 2:

7. Isracl S. Dio E,scltcinul1

mcdi?,in 1958: 9: 207-\1

8. Dre.'Ncnd'J,fcr I~H, W.cJe

Jllllners: II valid ~ign of

1985; 13: 77-R6

9. KilKlcrmann W. Ovcrlrall

""mil: "'KuIUll"n lin (1,

238-45

10. SII"'cMII. KcithRIi. Kcl

or Ihc NignN IInu. ~y'npl(

!\ci l~es \991; 5: 35-5()

I I. CalliSicr R. CAllislcr RJ, I

f",man"c 'e~l'nnsC' 10 ()

..,ci S!JOrts Excrc 1990;

12. !),y RW, Mnrlrn1 AI{, Oa,(

10 ovcr!oaU lnlining Inl

1992; 64: 335-44

13. 1.cnnll1nn M, GasllnAnll l

training: I'e,fnrmance,incrcase in Iraining vo]

middlc- Jlnd long-distan

233-4214. Snydcr AC. Kllipcrs Ir.c

illionsili..-ti training will

Sports Excrc 1995; 27:

1.5. Gllbricl HHW, LJrhllu,cn.

flcrlormancc CRIJacily, I:

;nll IIn inlcnsive Ir"inir

stracll. InI J Sport~ Mc(

16. Urha\Jsen A, Gabricl H, \\

logical findings dllnng (

r"ll"w-lII' stlldy in cndu

19: 114.20

17. Hcuclinl{.WiklllnulJ,1J

balance in an ovcrtraillc

32: 1.';31-3

18. Porlicr H.I.oui~y F,1.alld

"]] hell't nltc :lI1d blood

Sci ,~por!S Excrc 200];

19. Un"il"l" AI.l; Uu,ibllo J

I\rcs,urc ~rlilbilily cJllri

Ihc tcn1nlc "thlclc. Int J

20. Hcdclin l{. Kenl!a G, Wik

"ffCCI., 0]] PClfOI111I1nCC,

va,iabiJilY. Mcd Sci ~"{

21 Schwlll"/.1..UrllIIlIscnA./

rale vtlriolbililY during a

(icrmtll1]. IJt"ch 7. SpO!

22. Barron J1., N""ke. 1'!), I-

lion in ovcrlmine.clnlhlc

6(): 800-6

23. M:)rgan WP, Rrown PR.

lorill!; "r "vcrlraining a

21: 107.14

toring of training and thu~, in thc long term, in thcprevention of OTS. In .vummary, a critical roviewof existing ~cicntific literaturc leads to the disap-Ix>inting conclusion that tho louis available ror arsdillglJosis have not. improved much in the la~t year!;of overtraining research.

focll~ On the cau~a) training factors as wcll a.~ tem-poral changes during recovery. which may inducepositivI,) allaptatio/\~ artcr a preceding pcriod of over-load training.

Acknowledgements

The author.~ hav~ no (;ol1f1ict~ of imere!it.4. Future Studies

Tcst re.'iults alway~ nc~d an individual interprc-tation and thlls the nccd for initial af;SCiisment ofilldividual bClseline vaillcii. The definition of OTSshould hc re~tricted to actllal decrea.~cs in pettor-mancc. The assessment and validity of diagllostictool~ requires studics includillg largcr nllmbers ofelite competitive athletes and ob~crvutions overlongcr time intervals. Puture investigations should

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Sports Med 2002: 32 {2)Spoils Med 2002: 32 (2) I) Adls Imelnalionall.lmlled AU 'lgh1$ reserved.

, ..t probably not in every sport

JScular overuse or prolonged.lotion

Ih phySiological strain?

Jh physiological strain

ween intensNe training and OT8,biBerentiation between intonsivemay bo questionable

indicator 01 018

of lactate

REVIEW ARTICLE102 Urhnll.~1!11 Co' Kif,dermnll11

55. Flynn MG.l'ilz"FX.l3oun" 18I",t.l. Inu;ccsol'lraining Slrcs'dl'ring compclilivc running an" ,wilnming 'e.""" Jilt J~",".L,Me" 1994; 15:21.(,

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61. tJrhauscn A. K ilKlcrmal1n W. Blood IImmonia and lactatc c..",-,nlrations during cnduroncc cxcrci.c of dltTcrlng imcllsilic.\.

I ;llr J Appl Physiol 1992; 65: 209-14(;;2. Urba\Jscl1 A. Cocn B. Kindcrm.nn W. fmcnsivc lruining II.' ,..'1:

ctlecI8 on crgolnclric, hormonal. ami I).~ychoklgical rc"ult.'absultctJ. Mcd S"i Sp""1' I!xcrc 200 I; :13 .~lIppl.: S 132

63. Mccu,cn R !{c!'Catcd cxcrci.c ICSI ap]Jfonch: a5~ssmcm of 11~"'1-ing "Ialu~ by lnca""ring mculholic and homl(m~1 <li81l1rbRncc~.471h Anlilla! Mccling ACSM: Applicd L",uc, in MoniloringAlh-Ictic Training IIlId Diagnosing Ovcrlraillillg SYJlur<JlnC; 2000

Jlml;lndi~nlt1'(11i,,(IN)

Becky Kendall an(

Sclu)o! of Sport, I-lei'

ContentsAbstract1. Model of Musc

1.1 Free Rod"1.2 InitialStim1.3 Autogenk

1.3.1 Ro.le

].3.2ColJ::1 .4 Inflamma'

1.4.1 Cyto1.5 leucocytl1.6 Regenera

2. Estrogen and r2.1 Estrogen ('2.2 Estrogen (2.3 Estrogen (

3. Estrogen and r3.1 Effect of E3.2 H~topathl3.3 The Effect3.4 Estrogen.3.5 Estrogen (3.6 Estrogen (

3.6. 1 Calc3.6.2I\cjhl3.6.3 Cytc

4. Estrogen and I5. Implications fa6. Conclusion.

hornl0llC COIICClllralion,; duling pr(IIt,ngcd lJllining in cliftwcight Ij/ICr$, Int J Sports Moo 1.987;8 Suppl. 1: 61-5

44, ".,.y A(;, Krucmer WJ, Ramscy I,T, PiIIJllucy-adrernll-gun"dulrCS]XInscs h) lIigh-inlcn"ily r"-,i,,lal]cc CKcrci$C OYCl1rnillir\g IAppl Physiol 1998; ~5: 2352-9

45. Kr~lcmcr WJ, Flcck 5J, CalliSI!!r [{, cl "I. 't"raining rc"I'"n,c" (If'pl.""a beta-endllrphin, 11(lrcnOcorlicotropin. ami corli"u!.MLXI S"i Sp'lrls Excr" 1989; 21: 14(,-53

46. Urhall.,cn A. Kullmcr T, Kindcrmllun W, A 7-wcck follow.up.~Iudy of Ihc bcllaviour "f Icslo,lcr(mc .11(1 "orli.~ol during thc"ompclition pcriocl in ;owcrs. Bur J /\ppl "hysil,1 19117; 'it;:.';28-:\3

47. UrbU\l."enA.c"enB, WcilcrD,clnl.Hol'lnUnal'I\ldbilocbcluic,,1Jlar"m(\lcr,;, psy"hovcgctulivc profi]c 111111 ergomclnc pcrfor-malK:C during Irailung in rowers II\b,;lractj. Mell 5ci SpurlsI'Xl'I'C 1998; 30 ,~uppl.: S174

48. Gllbricl H, Urhauscll A, ValcIG,cl.I.Ovcrlrainingali(! inlmllllesy."ten]: II longiludinal slUlly in endurancc "llIlct,,-,. Mcd ",ciSpt,rl.,I;xerc 19')!!; II: 1151-7

49. ".ny-Rillings M. Bk,mslrl\nd Ii. McAndrcw N, ellli. A C'II11-mulnc'llimull link helwcen .,kclctal mu'iClc. blUil1,l\l1d cclls ofI)\C immune systom.lnl J Spurls Mcd 1991); II: SI22-&

.'iO. .~milh DJ, NOITis SR. Change.1 ill gllllmnillC ,uIll gllltamUlc con-ccnlrati(lns for tlucking troining lolerancc. Mcd Sci ~1](lrl'Exerc.2000; :12: (~4-9

5!. Mackillllun I;I~ I-h"'per SI.. PIII"mu glutllmine mId upper I\:'pi.ralol'Y IraCI illfcc\iUJI during intensified h.inillg;n .,w;mlncrs.Mcd Sci '~I'OrIS J!.~ere 1996; 28: 285.9()

52. .~lnilh J.I.. Cytokinc hYIJOlhosi.\ of uvL'l1rninin8: " )lIlysil1logicuJIId"platillll 10 excc~~iyc strcss'1 Med Sri Spurls Ex"rc 2000;32: 317-31

53. Jeukcndrnp AI;, Ile.""link MKC, Snyder AC. clll1. Physiulog.ical changos ill 11Ialc ""m~titive cyclist.' nf1cr two WCl'k... ofinlensificll 11..'1iniJIg.lnt J SporL.. Mcd 19')2; 1:1: _~:l4.41

54. Collin DI., FlynnM(;, Kirwlu] J)',clnl.lirfecl~ ofrepcmell clays.,(inlen."ified tmil1lng Otllnns<:le glycogcn nnd imming pcr.f"nuance. Mcd Sci Sports I,xel\: ] 98K; 20: 249..';4

CorrcspOI,dente and offprillls: Axel Urhllllsen, fnstitlile ofSportsf1rnt 1'{~VC\1Iive Medicine, f'ilClU( yofOillical Medicine,Univcrsily of Si\"rlnnd, Sn,\rbrucckcn, 66041, Germany.

Abstract

~ Adls "'ernotlonol Umllod. /lU rights reserved. Sports Med 2002: 32 (2)

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