简介：Ithasbeenknownforsometimethatstraininjuriesoccurthroughtheexcessivelengtheningofamuscle.~(1–3)However,theprecisemechanismforstraininjuryremainselusiveandhasbeenthesubjectofrecentdebateintheJournalofSportandHealthScience,~(4–9)butitseemssensibletoconsidermechanismsatthelevelofthemusclefiber.Itwaspreviouslybelievedthatdamagewastheresultofnon-uniformstretchingofsarcomeres

简介：Exercise-inducedrhabdomyolysis（exRML）,apathophysiologicalconditionofskeletalmusclecelldamagethatmaycauseacuterenalfailureandinsomecasesdeath.IncreasedCa2+levelincellsalongwithfunctionaldegradationofcellsignalingsystemandcellmatrixhavebeensuggestedasthemajorpathologicalmechanismsassociatedwithexRML.TheonsetofexRMLmaybeexhibitedinathletesaswellasingeneralpopulation.PreviousstudieshavereportedthatpossiblecausesofexRMLwereassociatedwithexcessiveeccentriccontractionsinhightemperature,abnormalelectrolytesbalance,andnutritionaldeficienciespossiblegeneticdefects.However,theunderlyingmechanismsofexRMLhavenotbeenclearlyestablishedamonghealthprofessionalsorsportsmedicinepersonnel.Therefore,wereviewedthepossiblemechanismsandcorrelatedpreventionofexRML,whileprovidingusefulandpracticalinformationfortheathleteandgeneralexercisingpopulation.

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简介：Purpose:Thepurposeofthisstudywastoexamine,usingmeta-analyticmeasures,theevidenceregardingtheoptimalexerciseintensityatwhichimprovementsinspeedofcognitivefunctionaretriggered.Specifically,itwashypothesizedthatthecatecholamine,lactate,andventilatorythresholdsisthepointatwhichsignificantimprovementsinspeedofcognitivefunctionareobserved.Methods:Wecomparedmeaneffectsizesforthresholdstudiesandforthosestudieswhereexerciseintensitywasclassedasmoderate(40%e79%VO2maxorequivalent)butinwhichthethresholdswerenotmeasured.Results:Randomeffectsmeta-analysisshowedsignificant,moderate,meaneffectsizesforstudiesatthethreshold(g=0.58,Z=2.98,p<0.003)andforthoseduringmoderateintensityexercisebutinwhichthethresholdwasnotmeasured(g=0.54,Z=5.01,p<0.001).Therewasnosignificantdifferencebetweenmeaneffectsizes,whichsuggeststhatthethresholdsareunlikelytorepresentatriggerpoint.Conclusion:Moderateintensityexercise,evenbelowthethresholds,caninduceimprovedspeedofcognition,possiblyduetoacombinationofincreasedperipheralcatecholamineconcentrationsinducingvagal/nucleustractussolitariipathwayactivationandcentralincreasesduetoperceptionsofstress.

简介：Background:Plateletrichplasma(PRP)therapyiswidelyusedinenhancingtherecoveryofskeletalmusclefrominjury.However,theimpactofintramusculardeliveryofPRPonhematologicandbiochemicalresponseshasnotbeenfullyelucidatedinexercise-inducedmuscledamage.ThepurposeofthisinvestigationtheeffectsofintramusculardeliveryofPRPonhematologicandbiochemicalresponsesandrecoverystrategymuscledamageinducedbyhighintensitymuscleexercise(exercise-inducedmuscledamage,EIMD).Methods:Moderatelyactivemalevolunteersparticipatedinthisstudyandwereassignedtoacontrolgroup(control,n=6)andPRPadministrationgroup(PRP,n=6).Thesubjectsperformedexercisewithaloadof80%onerepetitionmaximum(1RM)maximalvoluntarycontractionoftheelbowflexorsuntilpointofexhaustionofthenon-dominantarmwasreached.ThearmsweretreatedwithsalineorautologousPRPpost-24hEIMD.Venousbloodsampleswereobtainedinthemorningtoestablishabaselinevalueand1–4dayspost-exerciseandwereanalyzedforserumferritin,iron,ironbindingcapacity(IBC),creatininekinase(CK),lactatedehydrogenase(LDH),aspartateaminotransferase(AST),andalanineaminotransferase(ALT).Results:Thebaselinelevelsofplasmairon,ferritin,IBC,CK,LDH,AST,andALTweresimilarinboththecontrolandPRPgroups.However,24-hfollowingexerciseasignificantincreaseintheseparameterswasobservedinbothgroupsbetween1and4daysduringtherecoveryperiod.Interestingly,PRPadministrationdecreasedplasmaironlevelscomparedtothecontrolontheseconddaypost-exercise.PlasmaIBCincreasedinPRPgroupfromDays2to4post-exercisecomparedtothecontrolgroupwhilstPRPadministrationhadnoeffectonplasmaferritin,CK,AST,ALT,orLDH.Conclusion:Acuteexhaustiveexerciseincreasedmuscledamagemarkers,includingplasmairon,IBC,andferritinlevels,indicatingmuscledamageinducedbyexercise.PRPadministrationimprovesinflammationbyreversingtheincreaseintheironlevelspost-exercisewi