Effect of teammates on changes in physical activity in a statewide campaign

Objective: Most Americans do not meet physical activity recommendations. Statewide campaigns can effectively increase activity levels. Reported herein are physical activity outcomes from Shape Up Rhode Island (SURI) 2007, a statewide campaign to increase steps through team-based competition. Given the importance of social networks in behaviour change, this paper focused on the effects of team and team characteristics on activity outcomes. Method: For 16 weeks, 5333 adults comprising 652 teams wore pedometers and reported their steps online. Results. Participants' daily steps increased from 7029(3915) at baseline to 9393(5976) at SURI end (p<0.001). There was a significant intraclass correlation for step change among team members (ICC=0.09); thus, an individual's change in steps was influenced by what team they were on. Moreover, baseline team increases in acitivity for individual members (P<0.001), whereas being on a team with a broad range of steps was associated with smaller changes in activity for individual members (p=0.02). Conclusion: These findings are the first to suggest that team members influence indivdiual activity outcomes in team-based statewide campaigns. Future research should explore ways to use social network factors to enhance team-based physical activity programs. (C) 2010 Elsevier Inc. All rights reserved