简介：Background:Wearablemonitors（WMs）areusedtoestimatethetimespentinsedentarybehaviors（SBs）andlight-intensityphysicalactivities（LPAs）andtheirassociatedenergycost;however,theaccuracyofWMsinmeasuringbehaviorsonthelowerendoftheintensityspectrumisunclear.Theaimofthisstudywastoassessthevalidityof3WMs（ActiGraphGT3X+;activPAL,andSenseWear2）inestimatingtheintensityofSBandLPAinadultsascomparedwiththecriterionmeasureofoxygenuptake（VO2）measuredbyindirectcalorimetry.Methods:Sixteenparticipants（age:25.38±8.58years）woretheActiGraphGT3X+,activPAL,andSenseWear2devicesduring7sedentary-to-lightactivities.VO2（mL/kg/min）wasestimatedbymeansofaportablegasanalyzer,OxyconMobile（Carefusion,YorbaLinda,CA,USA）.Alldataweretransformedintometabolicequivalentsandanalyzedusingmeanpercentageerror,equivalenceplots,Bland-Altmanplots,kappastatistics,andsensitivity/specificity.Results:MeanpercentageerrorwaslowestfortheactivPALforSB（14.9%）andLPA（9.3%）comparedwithotherWMs,whichwere>21.2%.NoneoftheWMsfellwithintheequivalencyrangeof±10%ofthecriterionmeanvalue.Bland-AltmanplotsrevealednarrowerlevelsofagreementwithallWMsforSBthanforLPA.KappastatisticswerelowforallWMs,andsensitivityandspecificityvariedbyWMtype.Conclusion:NoneoftheWMstestedinthisstudywereequivalentwiththecriterionmeasure（VO2）inestimatingsedentary-to-lightactivities;however,theactivPALhadgreateroverallaccuracyinmeasuringSBandLPAthandidtheActiGraphandSenseWear2monitors.