F-11 Free Communication/Slide - Behavioral Aspects of Exercise: JUNE 4, 2010 1:00 PM - 2:30 PM: ROOM: 336
Easy access to reinforcing sedentary behaviors competes with increasing and maintaining youth physical activity. Short-term, 6 to 8 week, trials have shown that an open-loop feedback plus reinforcement paradigm where accumulated accelerometer activity counts are exchanged for access to sedentary reinforcers increases children's physical activity.
PURPOSE: To evaluate the longer-term effectiveness of open-loop feedback plus reinforcement on children's physical activity and television (TV) time.
METHODS: Normal weight boys and girls (8-12 years-old) were randomized to open-loop feedback of physical activity counts plus reinforcement intervention (open-loop, n = 21); feedback, no reinforcement (feedback, n = 20) or no feedback, no reinforcement control (control, n = 21) groups. Subjects wore a Biotrainer accelerometer with an activity count display for 16 wk. Accumulating physical activity counts gave subjects in the open-loop group access to TV time, controlled by a TV Allowance™ device, with 400 counts = 1 h of TV. The feedback group had feedback of activity counts, a goal of 400 counts/day, and free access to TV. The control group had no feedback for activity and free access to TV.
RESULTS: The open-loop group (585+41 counts/day) participated in greater (p <0.05) total physical activity during the intervention than the feedback (425+37 counts/day) or control (499+34 counts/day) groups, but their activity peaked at 8 weeks (703+67 counts/day) and returned to feedback and control group levels by week 10. The feedback and control groups did not differ in physical activity. TV time of the open-loop group was reduced by 44% to an average of 87+11 min/day and this was lower (p < 0.005) than the feedback (200+24 min/day) or control (216+28 min/day) groups across the entire intervention. Total sedentary times (e.g., TV, computer, reading) were also lower (p < 0.05) in the open-loop group (134+18 min/day) than the feedback (229+23 min/day) or control (235+29 min/day) groups.
CONCLUSION: Open-loop feedback produces a transient increase in physical activity of children that peaks at about 2 mo. The open-loop paradigm successfully reduced television time for 16 wk, which was not fully compensated for by participation in other measured sedentary activities.
Supported by NIH grant R01 HD042766 to Dr. Roemmich