【LONDON—Here’sanewwarningfromhealthexperts:Sittingisdeadly.Scientistsareincreasinglywarningthatsittingforlongperiods—evenifyoualsoexerciseregularly—couldbebadforyourhealth.Anditdoesn’tmatterwherethes】
LONDON—Here’sanewwarningfromhealthexperts:Sittingisdeadly.
Scientistsareincreasinglywarningthatsittingforlongperiods—evenifyoualsoexerciseregularly—couldbebadforyourhealth.Anditdoesn’tmatterwherethesittingtakesplace—attheoffice,atschool,inthecarorbeforeacomputerorTV—justtheoverallnumberofhoursitoccurs.Severalstudiessuggestpeoplewhospendmostoftheirdayssittingaremorelikelytobefat,haveaheartattackorevendie.
InaneditorialpublishedthisweekintheBritishJournalofSportsMedicine,ElinEkblomBakoftheSwedishSchoolofSportandHealthSciencessuggestedthatauthoritiesrethinkhowtheydefinephysicalactivitytohighlightthedangersofsitting.
Whilehealthofficialshaveissuedguidelinesrecommendingminimumamountsofphysicalactivity,theyhaven’tsuggestedpeopletrytolimithowmuchtimetheyspendinaseatedposition.
“Afterfourhoursofsitting,thebodystartstosendharmfulsignals,”saidEkblomBak.Sheexplainedthatgenesregulating(调节)theamountofglucose(葡萄糖)andfatinthebodystarttoshutdown.
Evenforpeoplewhoexercise,spendinglongperiodsoftimesittingatadeskisstillharmful.TimArmstrong,aphysicalactivityexpertattheWorldHealthOrganization,saidpeoplewhoexerciseeveryday—butstillspendalotoftimesitting—mightgetmorebenefitifthatexercisewasspreadacrosstheday,ratherthaninasinglebout(一回).
Still,inastudypublishedin2009thattrackedmorethan17000Canadiansforaboutadozenyears,researchersfoundpeoplewhosatmorehadahigherdeathrisk,whetherornottheyexercised.
“Wedon’thaveenoughevidenceyettosayhowmuchsittingisbad,”saidPeterKatzmarzykofthePenningtonBiomedicalResearchCenterinBatonRouge,wholedtheCanadianstudy.“Butitseemsthemoreyoucangetupandinterruptthissedentarybehavior,thebetter.”
FiguresfromaU.S.surveyin20032004foundAmericansspendmorethanhalftheirtimesitting,fromworkingattheirdeskstosittingincars.
Expertssaidmoreresearchisneededtofigureoutjusthowmuchsittingisdangerous,andwhatmightbepossibletooffsetthoseeffects.
“Peopleshouldkeepexercisingbecauset