| Online social networks, such as Facebook, have extensive reach and possess technology that could foster social support, an established determinant of physical activity. The purpose of this study was to design and test the efficacy and feasibility of a physical activity social support intervention primarily delivered through Facebook.;In aim 1 of this study, formative interviews (n=15) were conducted with female undergraduates to inform the online social network intervention design and explore behavior and perceptions related to the exchange of social support for physical activity through Facebook. In aim 2, we conducted a randomized controlled intervention trial comparing two groups of female undergraduates; education controls receiving access to an exercise focused website (n=67) and intervention participants receiving access to the same website with physical activity self-monitoring and enrollment in a physical activity themed Facebook group (n=67). Physical activity, perceived social support for physical activity, and psychosocial mediators were assessed using previously validated questionnaires. Facebook interactions were recorded during the intervention. In Aim 3, we conducted interviews (n=9) and a survey (n=120) with intervention participants to assess the acceptability of the intervention and participants' perceptions of physical activity social support exchanged through Facebook.;Results from the trial revealed no statistically significant differences between groups over time on perceived social support or physical activity. More than half (55%) of intervention participants indicated that they would recommend the program to friends. A path analysis examining the relationships between social support, psychosocial mediators, and physical activity among all participants found a significant indirect effect for companionship social support on physical activity mediated by intention (.09, p=.02). The majority of Facebook social support interactions collected during the intervention were classified as companionship. Qualitative analysis of formative and process interviews found that participants who received social support for physical activity through Facebook thought it was valuable.;The results from this study indicate that participants will join and exchange important types of social support for physical activity using online social networks. More research is needed to determine if online social network interventions can effectively increase social support or physical activity. |
