Describing patterns of physical activity in adolescents using global positioning systems and accelerometry.

This study aimed to describe the location and intensity of free-living physical activity in New Zealand adolescents during weekdays and weekend days using Global Positioning Systems (GPS), accelerometry, and Geographical Information Systems (GIS). Participants (n = 79) aged 12-17 years (M = 14.5, SD 1.6) recruited from two large metropolitan high schools each wore a GPS watch and an accelerometer for four consecutive days. GPS and accelerometer data were integrated with GIS software to map the main locations of each participant's episodes of moderate-vigorous physical activity. On average participants performed 74 (SD 36) minutes of moderate and 7.5 (SD 8) minutes of vigorous activity per day, which on weekdays was most likely to occur within a 1 km radius of their school or 150 meters of their home environment. On weekends physical activity patterns were more disparate and took place outside of the home environment. Example maps were generated to display the location of moderate to vigorous activity for weekdays and weekends.