Grant: Travel Awards - Institute Community Support

Evidence suggests that children's physical activity (PA) levels are positively related to their friends' PA, yet few studies have investigated the effects of the changes in social networks (SN) on changes in PA. Thus, our objective was to estimate the associations between changes in children's friendship networks and their PA, and to assess whether these associations are different for boys and girls over the transition to a higher school grade. Canadian children completed in-school health and SN surveys at multiple time points, which captured their PA participation and aspects of their SN (e.g., friendships), respectively. Sociodemographic-adjusted linear regression models were used to estimate the relationships between a child's PA and SN variables before, after and across the school-grade transition. Children's PA was related to the PA of their friends prior to and following the grade transition; however, we found no association between changes in children SN and their PA over transition to a higher grade, nor did we identify any differences in the associations according to gender. More research is needed to confirm whether children's school-based friendships are related to changes in their activity over time before school-based PA interventions are implemented.