Active commuting to school in Portuguese adolescents: Using PALMS to detect trips

The declining levels of physical activity (PA) have led to active commuting to school (ACS) being seen as a key strategy to increase PA levels in school-aged children. In Portugal, no data exists on the patterns of this behavior, an essential step for developing evidence-based and effective interventions. The purpose of this study is to explore the travel to school behavior using an objective methodology. Methods 155 adolescents (mean age 15.9±1.1 years) wore an accelerometer and a GPS for 7 consecutive days. Home and school addresses were geocoded to identify home-school trips. The web-based tool PALMS was used to combine GPS and accelerometer data, categorize Moderate to Vigorous Physical Activity (MVPA) and classify trip mode of home-school trips into: walking, bicycling or vehicle. Results 609 trips were identified as home-school trips. Walking was the most frequent trip mode (68.8%) whereas bicycling was less common (14.4%). Median home–school walking trip length was 0.9 km and 96.7% of the trips were under 2.0 km. Near 80% of the total walking trip time(to or from school) was in MVPA and contributed on average with 12(±5.6) min to daily recommendations. Differences were found whether the trip started at home or at school, walking school-home trips took longer and had more minutes in MVPA than home-school trips. Regression analyses showed increasing distance to be associated with lower odds of ACS in boys (OR: 0.32; 95% CI: 0.16-0.63) and girls (OR: 0.10; 95% CI: 0.04-0.25). Conclusion Walking to school and back home can contribute with up to 40% of recommended daily MVPA, so increasing this behavior may be of particular relevance to increase PA levels. On the other hand, cycling is underused in home-school trips and strategies to promote the use of bicycle could also be of interest, especially in trips longer than 2.0 km.