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.