Physical activity measurements: Lessons learned from the pathways study

High obesity rates in American Indian children led to Pathways, a randomized school-and community-based childhood prevention study. Seven tribes, 5 universities, the National Institutes of Health/National Heart, Lung, and Blood Institute, and 4 elementary schools partnered in the study. Increasing physical activity (PA) was an important intervention target. The PA assessment was based on study objectives, feasibility, and tribal acceptance. A time-segmented analysis was also desired. Two methods, a new PA questionnaire and accelerometry, were developed during pilot testing. Together, the methods provided qualitative and quantitative information and showed that 3 of 4 sites were able to increase average daily PA, although overall the control versus intervention difference was not significant. The main limitation was inability to distinguish PA among individuals. Accelerometer size and some community concerns led to a protocol based on a single day of wearing time. Newer model triaxial accelerometers that are much smaller and allow sampling of multiple days of activity are recommended for future studies.