OBJECTIVE: The present study investigated whether making access to sedentar
y activities contingent on physical activity would increase physical activi
ty.
DESIGN: Experimental.
PARTICIPANTS: Thirty-four obese children aged 8 - 12 y were randomized to o
ne of three groups in which children had to accumulate 750 or 1500 pedomete
r 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 meas
ured by electronic pedometer and triaxial accelerometer (ie TriTrac(R)). Ac
tivity liking was measured by visual analog scales. Anthropometric and demo
graphic characteristics were also assessed.
RESULTS: Children in the 750 and 1500 count contingency groups engaged in s
ignificantly more physical activity and spent more time in moderate intensi
ty activity or higher compared with controls. Children in the Contingent 15
00 group engaged in more activity and spent more time in moderate or greate
r 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.