Randomized controlled trial testing an internet physical activity intervention for sedentary adults

Objective: Internet-based physical activity (PA) interventions have shown promise, although findings remain equivocal. We used formative research to enhance a previously demonstrated program (Step into Motion) with the goal of developing an Internet program poised for dissemination. Methods: We conducted focus groups to identify Internet features targeted to theoretical constructs (social cognitive theory) predictive of PA behavior and rated as "useful for increasing PA." We identified 5 theorytargeted Internet features as useful for increasing PA: (1) a PA tracking/logging calendar targeting self-monitoring and goal setting; (2) geographic mapping tools targeting perceived environment; (3) a discussion forum targeting social support; (4) exercise videos targeting observational learning; and (5) regular updates of peer PA progress targeting situation. We then tested the efficacy of the enhanced program (enhanced Internet, EI; N = 25) in relation to publicly available PA Websites (standard Internet, SI; N = 28) among 53 participants in a randomized controlled trial. Results: The EI arm increased PA in relation to the SI arm at 3 months (18.4 to 186.0 min/wk vs. 20.9 to 57.3 min/wk; p = .03) but between-groups differences were not observed at 6 months (176.8 vs. 133.5 min/wk; p = .44). EI participants maintained PA from 3 to 6 months (186.0 to 176.8 min/wk), and the SI group increased PA (57.3 to 133.5 min/wk). Conclusion: The EI program was efficacious at improving PA levels in relation to publicly available Websites initially, but differences in PA levels were not maintained at 6 months. Future research should identify Internet features that promote long-term maintenance.