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简介：Background:Marginalchangesintheexecutionofcompetitivesportsmovementscanrepresentasignificantchangeforperformancesuccess.However,suchdifferencesmayemergeonlyatcertainexecutionintensitiesandarenoteasilydetectablethroughconventionalbiomechanicaltechniques.Thisstudyaimedtoinvestigateifandhowcompetitionstandardandprogressionspeedaffectracewalkingkinematicsfrombothaconventionalandacoordinationvariabilityperspective.Methods:Fifteenexperiencedathletesdividedintothreegroups(elite,international,andnational)werestudiedwhileracewalkingonatreadmillattwodifferentspeeds(12.0and15.5km/h).Basicgaitparameters,theangulardisplacementofthepelvisandlowerlimbs,andthevariabilityincontinuousrelativephasebetweensixdifferentjointcouplingswereanalyzed.Results:Mostofthespatio-temporal,kinematic,andcoordinationvariabilitymeasuresprovedsensitivetothechangeinspeed.Conversely,non-lineardynamicsmeasureshighlighteddifferencesbetweenathletesofdifferentcompetitionstandardwhenconventionalanalyticaltoolswerenotabletodiscriminatebetweendifferentskilllevels.Continuousrelativephasevariabilitywashigherfornationallevelathletesthaninternationalandeliteintwocouplings(pelvisobliquity—hipflex/extensionandpelvisrotation—ankledorsi/plantarflexion)andgaitphases(earlystanceforthefirstcoupling,propulsivephaseforthesecond)thataredeemedfundamentalforcorrecttechniqueandperformance.Conclusion:Measuresofcoordinationvariabilityshowedtobeamoresensitivetoolforthefinedetectionofskill-dependentfactorsincompetitiveracewalking,andshowedgoodpotentialforbeingintegratedintheassessmentandmonitoringofsportsmotorabilities.

简介：Purpose：Theaimofthisstudywastoinvestigatetheinfluenceofthecardiorespiratoryfitnesslevelontheresponsetohigh-intensityintervaltraining（HIIT）withanindividuallyadjustedrunningspeedofthesamerelativeintensity.Theevaluationfocusedonacutecardiorespiratoryresponse,postexercisecardiacautonomicmodulation（heartratevariability（HRV））andbiochemicalmarkersofinflammation,oxidativestress,andmuscledamage.Methods：Thirtyparticipantsweredividedinto3subgroups：welltrained,moderatelytrained,anduntrained.Alltheparticipantsperformed30minHIITcomposedof6×2minintervalexercisewithwork-to-reliefratio=1andworkintensity100%ofindividualvelocityatmaximaloxygenconsumption（VO2max）.Acutecardiorespiratoryvariables,postexerciseHRV,lactate,interleukin-6（IL-6）,totalantioxidantcapacity（TAC）,creatinekinase,andmyoglobinupto4hafterHIITweremonitored.Results：Thedifferencesinrelativelyexpressedcardiorespiratoryvariables（heartrate,VO2）duringHIITwereatmostmoderate,withthemostpronouncedbetween-groupdifferencesinabsoluteVO2values.ThedisruptionofthepostexerciseHRVwasthemostpronouncedinuntrainedindividuals,andthisdifferencepersisted1hafterHIIT.ThehighestpostexerciseIL-6andTACconcentrationsandthelowestchangesincreatinekinaseandmyoglobinwererevealedinwell-trainedindividuals.Conclusion：Thehigherfitnesslevelwasassociatedwiththelesspronouncedpostexercisecardiacautonomicchangesandtheirfasterrestoration,evenwhenthereweresimilaracutecardiorespiratoryresponses.ThesefindingsweresimultaneouslyaccompaniedbythehigherpostexerciseIL-6andTACconcentrationsandlesssignificantchangesinmuscledamagebiochemicalmarkersinwell-trainedindividuals.