简介:Purpose:Thepurposeofthisstudywastoinvestigatetheeffectofvariableintensitiesonasimplememoryrecognitiontaskduringexercise.Methods:Twentyactiveparticipantstookpartininitialtesting,afamiliarizationtrialandthenfour60mincyclinginterventionsinarandomizedorder.Interventionsconsistedofnoexercise(control),constantexerciseat90%ventilatorythreshold(constant)and2trialsthatinitiallymimickedtheconstanttrial,butthenincludedperiodsofhigh(90%VO2peak)andlowintensities(50%VO2peak).Cardiorespiratorymeasuresandcapillarybloodsamplesweretakenthroughout.Ashorttablet-basedcognitivetaskwascompletedpriortoandduring(50and55minintoexercise)eachintervention.Results:Theexerciseconditionsfacilitatedresponsetime(p=0.009),althoughtheextentofthiseffectwasnotasstronginthevariableexerciseconditions(p=0.011–0.089).Highintensityexerciseperiodsresultedinsomecognitiveregressionbacktowardscontroltrialperformance.Elevationsincardiorespiratorymeasuresandperiodsofhypocapniacouldnotexplainchangesincognitiveperformance.Conclusion:Changesincognitiveperformancewithvariationsinexerciseintensityarelikelytohaveimplicationsforsportandoccupationalsettings.Thetimingofcognitiveteststoexerciseintensitychangesaswellasuseofshortcognitiveassessmentswillbeimportantforfuturework.
简介:Background:Dissociativeattentionalstimuli(e.g.,music,video)areeffectiveindecreasingratingsofperceivedexertion(RPE)duringlow-tomoderateintensityexercise,buthaveinconsistentresultsduringexerciseathigherintensity.ThepurposeofthisstudywastoassessattentionalfocusandRPEduringhigh-intensityexerciseasafunctionofbeingexposedtomusic,video,both(musicandvideo),orano-treatmentcontrolcondition.Methods:Duringthefirstsession,healthymen(n=15)completedamaximalfitnesstesttodeterminetheworkloadnecessaryforhigh-intensityexercise(operationalizedas125%ventilatorythreshold)tobeperformedduringsubsequentsessions.On4subsequentdays,theycompleted20minofhigh-intensityexerciseinano-treatmentcontrolconditionorwhilelisteningtomusic,watchingavideo,orboth.Attentionalfocus,RPE,heartrate,anddistancecoveredweremeasuredevery4minduringtheexercise.Results:MusicandvideoincombinationresultedinsignificantlylowerRPEacrosstime(partialη~2=0.36)andthesizeoftheeffectincreasedovertime(partialη~2=0.14).Additionally,musicandvideoincombinationresultedinasignificantlymoredissociativefocusthantheotherconditions(partialη~2=0.29).Conclusion:Musicandvideoincombinationmayresultinlowerperceivedexertionduringhigh-intensityexercisewhencomparedtomusicorvideoinisolation.Futureresearchwillbenecessarytotestifreductionsinperceivedexertioninresponsetodissociativeattentionalstimulihaveimplicationsforexerciseadherence.
简介:InarecentissueoftheJournalofSportandHealthScience,García-Pinillosetal.~1reviewedevidenceontheeffectsofhighintensityintermittenttraining(intervaltraining)(HIIT)onmuscularandperformanceadaptationsinrecreationalrunners.
简介:Background:Theuseofnutritionalsupplements(NS)amongathletesiswidespread.However,littleisknownabouttherelationshipbetweennutritionaladequacyandNSusage.TheaimsofthisstudyweretoevaluatetheNSusageandtocomparethenutritionalintakefromfoodandprevalenceofmicronutrientinadequacy(PMI)betweenNSusersandnon-users.Methods:Portugueseathletesfrom13sportscompletedanNSusagequestionnaireandasemi-quantitativefood-frequencyquestionnaireassessinginformationovertheprevious12months.Theestimatedaveragerequirementcut-pointmethodwasusedtocalculatePMI.GenerallinearmodelswereusedtocomparenutritionalintakeandNSusage.Chi-squaredtestsandlogisticregressionwereperformedtostudy,respectively,relationshipsandassociationsbetweenPMIandNSusage.Results:Fromthe244athletes(66%males,13–37years),64%reportedNSusage.Afteradjustment,NSusersshowedahigherintakefromfood(p<0.05),foratleast1gender,forenergy,andfor7ofthe17studiednutrients.ThehighestPMIwereseenforvitaminsDandE,calcium,folate,andmagnesium.Afteradjustment,NSusers,irrespectiveofgender,reportedlowerPMIforcalcium(OR=0.28,95%CI:0.12–0.65),andfemaleusersformagnesium(OR=0.06,95%CI:0.00–0.98).Conclusion:AthletesusingNSreportedahighernutritionalintakefromfood,andalowerPMIforseveralnutrients.Perhaps,thosewhoweretakingNSwereprobablytheoneswhowouldleastbenefitfromit.
简介:WiththeRioOlympicsjustafewmonthspast,weremembertheexcitement,theincredibleperformances,andthecontroversies.Ashappenssooften,theOlympicGamesfocusattentionnotonlyonathleticachievementsbutalsoonhowathletesmayreachever-increasinglevelsofperformance.Doping,medicaldoping
简介:Purpose:Thepurposeofthisstudywastoinvestigatetheeffectsofobesityandhigh-intensityacuteexerciseonoxidant-antioxidantstatus,neurotrophicfactorexpression,andblood-brainbarrier(BBB)disruption.Methods:Twenty-fourhealthy,untrainedmen(12non-obese(mean14.9%bodyfat)and12obesesubjects(mean29.8%bodyfat))performed20minofcontinuoussubmaximalaerobicexerciseat85%maximaloxygenconsumption.Bloodsamplingwasperformedtoexaminetheoxidant-antioxidantstatus(reactiveoxygenspecies(ROS)andsuperoxidedismutase(SOD)),neurotrophicfactors(brain-derivedneurotrophicfactor(BDNF)andnervegrowthfactor(NGF)),andBBBdisruption(S100βandneuron-specificenolase)beforeandafteracuteexercise.Results:Theobesegroupshowedsignificantlyhigherpre-exerciseserumROSlevelsandsignificantlylowerpre-exerciseserumSODlevelsthanthenon-obesegroup(p<0.05).SerumROS,SOD,BDNF,NGF,andS100βlevelsweresignificantlyincreasedpost-exercisecomparedwithpre-exerciselevelsinboththenon-obeseandtheobesegroups(p<0.05).TheobesegroupshowedsignificantlyhigherserumROS,BDNF,NGF,andS100βlevelspost-exercisecomparedtothenon-obesegroup(p<0.05).Conclusion:OurstudysuggeststhatepisodicvigorousexercisecanincreaseoxidativestressandbloodneurotrophicfactorlevelsandinducedisruptionoftheBBB.Moreover,highlevelsofneurotrophicfactorinthebloodafterexerciseintheobesegroupmaybeduetoBBBdisruption,anditisassumedthatoxidativestresswasthemaincauseofthisBBBdisruption.
简介:Objective:Thissystematicreviewaimedtocriticallyanalyzetheliteraturetodeterminehowhigh-intensityintermittenttraining(HIIT)affectsrecreationalendurancerunnersintheshort-andlong-term.Methods:ElectronicdatabasesweresearchedforliteraturedatingfromJanuary2000toOctober2015.Thesearchwasconductedusingthekeywords'high-intensityintermittenttraining'or'high-intensityintervalexercise'or'intervalrunning'or'sprintintervaltraining'and'endurancerunners'or'longdistancerunners'.Asystematicapproachwasusedtoevaluatethe783articlesidentifiedforinitialreview.StudieswereincludediftheyinvestigatedHIITinrecreationalendurancerunners.ThemethodologicalqualityofthestudieswasevaluatedusingthePhysiotherapyEvidenceDatabase(PEDro)scale(forinterventionstudies)andthemodifiedDownsandBlackQualityIndex(forcross-sectionalstudies).Results:Twenty-threestudiesmettheinclusionarycriteriaforreview.Theresultsarepresentedin2parts:cross-sectional(n=15)andinterventionstudies(n=8).Inthe15cross-sectionalstudiesselected,endurancerunnersperformedatleast1HIITprotocol,andtheacuteimpactonphysiological,neuromuscular,metabolicand/orbiomechanicalvariableswasassessed.Interventionstudieslastedaminimumof4weeks,with10weeksbeingthelongestinterventionperiod,andincluded2to4HIITsessionsperweek.MostofthesestudiescombinedHIITsessionswithcontinuousrun(CR)sessions;2studies’subjectsperformedHIITexclusively.Conclusion:HIIT-basedrunningplans(2to3HIITsessionsperweek,combiningHIITandCRruns)showathleticperformanceimprovementsinendurancerunnersbyimprovingmaximaloxygenuptakeandrunningeconomyalongwithmuscularandmetabolicadaptations.Tomaximizetheadaptationstotraining,bothHIITandCRmustbepartoftrainingprogramsforendurancerunners.
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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.