Before-school physical activity patterns among adolescents using accelerometer and GPS data.

Most adolescents do not meet physical activity (PA) guidelines. The before-school segment has been identified as one promising opportunity for intervention; however, there is a need for contextual understanding of PA in this segment. This study aimed to examine: a) adolescents' PA levels across various locations before school (6:00am - school start), b) contributions of before-school PA to daily PA and PA guidelines, and c) correlates of location-specific before-school PA. A cross-sectional analysis was conducted using adolescents' (n = 148, mean age 14.7) accelerometer and GPS data. Adolescents averaged 9.7 min in before-school moderate-to-vigorous PA (MVPA), representing substantial contributions to daily activity. Most MVPA occurred away from home and school. Significant correlates included segment duration, age, socio-economic status, and PA self-efficacy. Future work should consider these patterns and correlates to support adolescents' PA through targeted interventions.