Grant: Travel Awards - Institute Community Support

Introduction. Fewer than one in ten Canadian adolescents are sufficiently active to achieve health benefits. We aim to assess adolescents' geo-spatial physical activity behaviours to better understand when and where they are most active. Methods. Participants were from the only high school in downtown Vancouver (fall 2013; n=31; 14.4 yrs, 38% female). They wore an accelerometer (GT3X+, 1 sec epoch) and GPS (Qstarz, 1 sec epoch) for seven days. Data from the two devices were merged using time-stamps. Using a geographic information system software (ArcGIS 10.1; ESRI), participants' GPS tracks were manually coded. Indoor GPS scatter was coded using land parcels for school and home locations. Trips were assigned a mode based on distance, speed and physical activity (moderate-to-vigorous physical activity (MVPA), Evenson cut-points >=2296 CPM). We included weekday person-days with >=6 hrs of matched accelerometry/GPS data and >=1 school trip (23% of all person-days). Results. Valid days had on average 8.5 hrs of matched data. The majority of captured time was at school (4.1 hrs), followed by home (2.4 hrs) and other locations (1.1 hrs). Twenty-five minutes were spent travelling to/from school, and a further 19.1 minutes to travel elsewhere (for example, walking during lunch breaks). On average, students accrued 51.6 minutes MVPA/day, nearly half of which was achieved at school (21.4 minutes). Despite the relatively short duration spent travelling compared with time spent in other locations, travelling from place to place yielded most of the remaining daily MVPA (school-travel: 11.6 minutes, other travel: 11 minutes). Conclusion. Evidently, school is a hotspot for adolescents' physical activity. Travel - which in this sample largely comprised of walking and public transit trips - is also an important source of physical activity. Travel-related physical activity may be less susceptible to age-related declines in physical activity during adolescence.