Duncan J. Macfarlane|Cherry C. Y. Lee|Edmond Y. K. Ho|K.C. Chan|Dionise Chan
Convergent validity of six methods to assess physical activity in daily life
University of Hong Kong
purpose examine agreement convergent validity six common measures habitual physical activity estimate durations light moderate vigorous total activity range freeliving individuals 7 consecutive days 49 ethnic chinese 30 men 19 women aged 1555 yr wore polar heart rate monitor uniaxial mti triaxial tritrac accelerometer plus yamax pedometer 600 minday also completed daily physical activity log day 8 chinese version 7day international physical activity questionnaire level activity good agreement two questionnairederived instruments two accelerometryderived instruments wide variation across different instruments two fourfold differences mean durations often seen heart rate monitor overestimated light activity underestimated moderate activity compared measures spearman correlation coefficients low moderate 0205 across measures activity pedometer showing correlations total activity often superior movement sensors conclude use commonly accepted cut points defining light moderate vigorous total activity little convergent validity across instruments evident suggesting measures sampling different levels habitual physical activity care needed comparing results provide stable comparison activity among different people across studies accepted physical activity promotion guidelines work needed fine tune different cut points across range common activity monitors provide consistent results freeliving conditions