Monitoring Children's Physical Activity With Pedometers: Reactivity Revisited

Thirty-two children (aged 7–11 years) were monitored for 4–5 consecutive days under two randomly assigned crossover treatment/non-treatment conditions (minimum of 2 days for each condition): (1) accelerometer (i.e., control or covert monitoring); and (2) accelerometer and pedometer (i.e., treatment or known monitoring). Participants were informed the accelerometer was measuring “time”—serving as the blinding condition. Paired analyses were performed between conditions for four time segments (warm-up and three activity units). A significant difference during the warm-up was observed. No other changes in activity levels were present. The findings suggest that during unrestricted play, children increase their activity when being monitored.