Open-loop feedback to increase physical activity in obese children

OBJECTIVE: The present study investigated whether making access to sedentary activities contingent on physical activity would increase physical activity. DESIGN: Experimental. PARTICIPANTS: Thirty-four obese children aged 8-12 y were randomized to one of three groups in which children had to accumulate 750 or 1500 pedometer counts to earn 10 min of access to video games or movies, or to a control group in which access to sedentary behaviors was provided noncontingently. MEASUREMENTS: Physical activity in the 20 min experimental session was measured by electronic pedometer and triaxial accelerometer (ie TriTrac®). Activity liking was measured by visual analog scales. Anthropometric and demographic characteristics were also assessed. RESULTS: Children in the 750 and 1500 count contingency groups engaged in significantly more physical activity and spent more time in moderate intensity activity or higher compared with controls. Children in the Contingent 1500 group engaged in more activity and spent more time in moderate or greater intensity activity compared to children in the Contingent 750 group. CONCLUSION: Findings suggest that contingent access to sedentary activities can reinforce physical activity in obese children, and changes in physical activity level depend in part on the targeted physical activity goal.