Examination of the factor structure of physical activity behaviors

Multiple physical activity recommendations exist for behaviors that vary in type and intensity (e.g., vigorous physical activity, strengthening exercises, moderate physical activity). The present study examined underlying dimensions of physical activity behaviors and determined the extent to which factors correspond to national health recommendations. Fifteen variables were drawn from six self-report measures and subjected to factor analysis with quartimax rotation. Participants were 547 university seniors (56% female; 60% Caucasian; mean age = 25 years). TV watching, the only index of sedentary behavior, did not load highly with other items, and was analyzed separately. Three interpretable factors were found: variables related to vigorous physical activity loaded highly on Factor 1; flexibility and strengthening items loaded highly on Factor 2; and moderate and housework activity loaded highly on Factor 3. Factors corresponded closely to national recommendations. Unweighted factor scores and TV watching correlated significantly with physiological indicators of fitness, supporting construct validity.