Get access

Preliminary efficacy of prize-based contingency management to increase activity levels in healthy adults


  • This project was funded by an internal grant at the University of North Carolina Wilmington and by the UNCW Psychology Department. We report no conflicts of interest or financial disclosures. The first author thanks Carole Van Camp for providing insight and undergraduate assistants David P. King and Kelly A. Wall for help in data collection.


An estimated 30% of Americans meet the criteria for obesity. Effective, low-cost interventions to increase physical activity are needed to prevent and treat obesity. In this study, 11 healthy adults wore Fitbit accelerometers for 3 weeks. During the initial baseline, subjects earned prize draws for wearing the Fitbit. During intervention, percentile schedules were used to calculate individual prize-draw criteria. The final week was a return to baseline. Four subjects increased step counts as a result of the intervention. A bout analysis of interresponse times revealed that subjects increased overall step counts by increasing daily minutes active and within-bout response rates and decreasing pauses between bouts of activity. Strategies to improve effectiveness are suggested, such as modification of reinforcement probability and amount and identification of the function of periods of inactivity.