简介：Purpose:Toexaminetheassociationsamongpreschoolersfundamentalmotorskills,screen-time,physicalactivity(PA),andsedentarybehavior(SB).Methods:Childrenages3-4yearswereenrolledinaprospectiveobservationaltrialofPA.TrainedassessorsconductedtheTestofGrossMotorDevelopment-3rdedition(TGMD-3),andtheMovementAssessmentBatteryforChildren-2ndedition,andparent-reportedchildscreen-timeandsociodemographicinformation.Childrenworeanaccelerometerfor7daystoexamineSBandtotalPA(TPA).TPAwasfurthercharacterizedasmoderateto-vigorousPA(MVPA)orvigorousPA(VPA).Mixedlinearmodelswerecalculated,controllingforage(forTGMD-3),sex,householdincome,andaccelerometerweartime(foraccelerometrymodels),withchildcarecenterasarandomeffect.Theprimaryanalysisreportedonthecross-sectionalbaselinedataof126childrenwithcompletefundamentalmotorskillandscreen-timedata;asubanalysisincluded88childrenwithcompleteaccelerometrydata.Results:Childrenwere3.4±0.5yearsofage(54%girls;46%white,42%AfricanAmerican,12%other).Atotalof48%livedinhouseholdsatorbelowthefederalpovertylevel.Childrenengagedin5.1±3.6h/dayofscreen-time.Children’sscreen-timewasinverselyrelatedtotheMovementAssessmentBatteryforChildren-2ndedition,manualdexterityskillspercentile(β(SE)=-1.7(0.8),p=0.049).Intheaccelerometrysubsample,childrenengagedin5.9±0.9h/dayofTPAofwhich1.7±0.6h/daywasMVPA.BoysengagedinmoreMVPAandVPAandlessSBcomparedwithgirls(allp<0.05).AhigherTGMD-3,totalscore(b(SE)=0.4(0.2),p=0.017)andlocomotorscore(β(SE)=0.7(0.3),p=0.018)wereassociatedwithmoreVPAbutnotwithTPAorMVPA.Screen-timeandtelevisioninthebedroomwerenotrelatedtoSB,TPA,MVPA,orVPA.Conclusion:Children’smotorskillswerepositivelyrelatedtoVPAbutinverselyrelatedtoscreen-time.Furtherinquiryintotheimplicationsofhighexposuretoscreen-timeinyoungchildr

简介：话题呈现假设你校英语论坛正在针对“中学生是否应该做兼职”这个话题进行讨论,请根据下面的提示写一个帖子发表在该论坛上。要求:1.词数80~100。2.文中不能出现自己真实的姓名和所在学校的名称。

简介：Background:Childrenspend70%oftheschooldaysittinginclass.Classroom-basedactivebreakscanbenefitchildren’sphysicalhealth,butifthebreaksarecognitivelydemanding(i.e.,combinephysicalexertionandmentalengagement),theymayalsoimprovefocusandcognitivefunctions.Teachersandstudentsplayacrucialroleinthesuccessfulimplementationofactivebreaks,andtheirperspectivesarecriticaltothefeasibilityofthesestrategies.Theaimofthisstudywastoassessthefeasibilityofimplementingacognitivelychallengingmotortaskasanactivebreakinmainstreamandspecialprimaryschools.Methods:Atotalof5teachersin2mainstreamschoolsand7teachersin1specialschool(attendedbychildrenwithneurodevelopmentaldisorders)attendeda20-mintrainingonhowtoimplementa4-mincognitivelychallengingactivebreak,beforeconductingafeasibilitytrial(twiceadayfor1week).Tounderstandindividualperceptions,one-on-onesemistructuredinterviewswereconductedbeforeandafterthetrialwithteachers,andfocusgroupinterviewswereconductedwithtypicallydevelopingchildrenafterthetrial.Questionswerebasedonapredefinedframeworkforfeasibilitystudies.Allinterviewswereaudiorecorded,transcribedandanalyzedinNVivo11usingaframeworkapproach.Atotalof12teachers(11females;7between20and34yearsold)and34children(16girls;9.3±1.7years,mean±SD)participatedintheinterviews.Results:Inmainstreamschools,teachersviewedthecognitivelychallengingmotortaskasappropriateandpotentiallybeneficialforchildren’shealthandfocus.Childrenreportedenjoyingtheactivebreaks.Teachersinspecialschoolsviewedthetaskascomplexandpotentiallyfrustratingforchildren.Inbothschooltypes,children’sdisruptivebehaviorandlackoftimewereseenasthemainpotentialbarrierstoimplementation.Theuseofmusic,videos,visualcards,andsupportstaffwerenotedaspotentialfacilitators.Conclusion:Thecognitivelychallen

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简介：Background:Identifyingfactorsassociatedwithphysicalactivity(PA)isusefulinplanninginterventionsandpolicies.Theaimofthisstudywastoidentifysociodemographic,biological,andpsychosocialfactorsassociatedwithPAperformedinschoolsettings.Methods:Datacollectedforthepresentstudyincludedgender,age,socioeconomicstatus,bodyfatpercentage,aerobicfitness,self-efficacy,attitudes,peerandparentalsupport,andperceptionofschoolenvironment.Dependentvariableswerelight-intensityPA(LPA)andmoderate-to-vigorousintensityPA(MVPA)performedduringschooltime,recesses,andphysicaleducation(PE)classes.Multipleregressionanalyseswereperformed.Results:Participatingadolescents(n=567,53%female,12.9±5.3years)spent5%ofschooltimeinMVPAand27%inLPA,15%ofrecessesinMVPAand44%inLPA,and16%ofPEclassesinMVPAand41%inLPA.BoysengagedinmoreMVPAinallcategories.AgewasinverselyrelatedwithMVPAandLPAinallperiods,whereasbodyfatpercentagewasinverselyrelatedwithMVPAinschooltimeandPEclasses.AttitudewasinverselyrelatedwithMVPAinallperiodsandwithLPAinrecesses.ConsideringPAtobegoodandenjoyablewaspositivelyassociatedwithMVPAinschooltime.Conclusion:AdolescentsspentlittletimeinPAduringschool.Futureinterventionsshouldimplementenjoyableactivitiesatschool.