Associations between children's active travel and levels of physical activity and sedentary behavior

Objectives To investigate associations of children׳s active travel (i.e. walking, cycling) to school and non-school destinations with time spent in sedentary behavior and physical activity at different intensities, and associations stratified by sex. Methods Between 2011 and 2012, 375 Australian school children aged 8–13 years (61% female) were recruited into a cross-sectional study. Children׳s travel modes to school and non-school destinations, and socio-demographic information were assessed through child and parent surveys. Daily time spent in sedentary behavior and physical activity intensities was measured objectively through accelerometer counts from an Actiheart monitor worn on four consecutive days. Associations of active travel with sedentary behavior and physical activity variables were determined using linear mixed models while accounting for clustered sampling and covariates (age, sex, socio-economic factors, Actiheart wear time). Multiple imputation (MissForest method) was used to handle missing at random survey and accelerometer data in 104 (28%) children. Results Active travel modes to non-school destinations were positively associated with children׳s moderate-to-vigorous physical activity (b=0.18, p=0.01) but not with their sedentary behavior, light or total physical activity. Active travel modes to school were not associated with children׳s sedentary behavior or physical activity across intensities. No statistically significant differences by sex were detected in the observed associations. However, the positive association between active travel modes to non-school destinations and moderate-to-vigorous physical activity neared statistical significance in boys (b=0.15, p=0.07) but not in girls. Conclusions Active travel was positively associated with children׳s physical activity but not their sedentary behavior levels. Active travel to non-school destinations may have more potential to increase children׳s moderate-to-vigorous physical activity levels, than active travel to school