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

Abstract

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 behavior change, this paper focused on the effects of team and team characteristics on activity outcomes. For 16weeks, 5333 adults comprising 652 teams wore pedometers and reported their steps online. 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 characteristics predicted individual step change; being on a more active team was associated with greater increases in activity 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). These findings are the first to suggest that team members influence individual activity outcomes in team-based statewide campaigns. Future research should explore ways to use social network factors to enhance team-based physical activity programs.