Active commuting to school in Finland, the potential for physical activity increase in different seasons.

Background: Active commuting to school (ACS) can be a significant source of physical activity and provide many health benefits.

Objective: This study identified the potential to increase physical activity levels by promoting ACS in Finnish schools and evaluated the effects of season, distance and age on ACS.

Design: Data were collected with a questionnaire from 5,107 students, aged 10-16, in 45 comprehensive schools in Finland.