A social cognitive approach to influencing adolescent physical activity behavior via social media

The World Wide Web is an effective mode for delivering health behavior programs, yet major limitations remain (e.g., cost of development, time and resource intensive, limited interactivity). Web 2.0, however, has the potential to deliver highly customizable and socially interactive behavioral interventions with fewer constraints. Thus, the evaluation of social media as a means to influence health behaviors is warranted. The purpose of this randomized controlled pilot trial was to examine the efficacy of using an established social networking platform (i.e., Facebook) to deliver an eight-week physical activity intervention to a sample of low-active adolescents (N = 21; M age = 13.48 years). Participants were randomized to either a social cognitive-based condition (i.e., Behavioral group) or an attentional control (i.e., Informational group). Both conditions received access to a study-specific Facebook Group where two daily Wall Posts containing youth-based physical activity information and resources were made by the Group’s administrator. Primary outcomes included physical activity, as assessed by accelerometry and self-report, as well as self-efficacy, outcome expectations, goals, and barriers related to physical activity. Effect sizes (Cohen’s d) were calculated within groups to determine differential treatment effects on outcome variables. Results revealed that involvement in the Behavioral group generally produced greater effects on primary outcomes compared to the Informational group. Specifically, the Behavioral group experienced large and positive changes in subjectively assessed moderate-vigorous (d = 0.86) and leisure-time (d = 1.12) physical activity, as well as changes in objectively assessed moderate-vigorous (d = 0.85) and total (d = 0.81) physical activity, whereas the Informational group experienced small to moderate changes. These results suggest that a social cognitive-based intervention delivered via social media has the potential to positively influence physical activity levels in low-active adolescents