Introduction and Objectives: Many adolescents attain significantly less physical activity (PA) in the summer. Summer care programs (e.g., Boys and Girls Clubs) can be a source of structure and PA promotion while also providing an opportunity for adolescents to be active and foster friendships. These social environments can impact adolescent PA, which can be examined through social network analysis. This study investigated the impact of PA, skill competency, and team sport participation on the formation of friendship ties among a group of adolescents at a summer care program.

Methods: Adolescents (ages 8-12) from two summer care programs (n=100, n=32) reported demographic information, PA, perceived skill competency, and team sport participation at the beginning and end of summer. Adolescents also indicated up to five people they interacted with the most while at the program at both time points. Exponential random graph modeling was used to determine significant factors associated with friendship tie presence at each time point and separable temporal exponential random graph modeling was used to model significant changes between timepoints.

Results: Friendship ties were significantly more likely between individuals who shared a friend (transitivity) and were more likely to be reciprocated at both time points and both networks. Similarly, adolescents were significantly more likely to have connections with others of the same sex and age. Adolescents were more likely to be friends with others who shared team sport status in the larger network. Adolescents were more likely to be nominated as a friend but less likely to send friend nominations if they reported more PA during time two at site one and time one at site two. In longitudinal modeling, adolescents were more likely to form friendships with those who had similar PA over the summer at the larger program; however, the opposite effect was seen in the smaller program.

Conclusions: These data suggest team sport participation may play a role in adolescents’ friendship networks; however, the size of the summer care program may impact this association. Summer care social networks may be a promising avenue for targeted PA promotion activities.