Measures
The participants reported travel mode to and from school, in the winter and summer seasons and answered the questionnaire on a computer. We used two items from the Health Behaviour of School-aged Children (HBSC) questionnaire [Data were categorized into two groups; those reporting cycling or walking were categorized as active travel, and car/motorcycle/moped or bus/trains/subway/ferry were categorized as motorized travel. Pupils that checked the box for “other” were not included in the analysis. Thereafter, we merged data from the pretest and posttest into one variable and categorized participants that 1) maintained active travel, 2) maintained motorized travel, 3) changed to active travel or 4) changed to motorized travel. Finally, we categorized the two groups that maintained their travel habits into one category, named “No change”.We collected data on confounding variables which were ethnicity, age, gender, mother’s education, father’s education, and geographical region. We also collected data for descriptive purposes which were height, weight and accelerometer-measured physical activity.