“Let's get physical” — or social: The role of physical activity versus social group memberships in predicting depression and anxiety over time

Background: Physical activity is often promoted as a way to prevent and combat anxiety and depression in adolescents. However, very little research has sought to establish whether the benefits of exercise arise from the excercise itself or from the social context in which it takes place. We explore the hypothesis that it is not physical activity on its own, but rather adolescents' engagement in group life (as part of a sports group or otherwise), that accounts for positive mental health effects associated with physical activity. Methods and results: We conducted a longitudinal study that tracked 558 high-school boys and found that anxiety and depression over time was not predicted by (a) T1 physical fitness as determined by 7 speed and agility tests, or (b) engaging in multiple sports as co-curricular activies at T1. In contrast, multiple group memberships — irrespective of the activity — predicted reduced depression and anxiety over time, particularly when these were groups that adolescents identified with and experienced as compatible with each other. Limitations: Limitations relate to (a) physical fitness only being measured at T1, (b) the absence of a measure of frequency and duration of physical activity, and (c) the homogeneity of the sample. Conclusions: We conclude that group memberships and the social identities that adolescents derive from these groups (including, but not restricted to, those involving sport) function as a psychological resource to reduce anxiety and depression over time.