Does reactivity exist in children when measuring activity levels with pedometers?

Reactivity is defined as a change in normal activity patterns when people are aware that their activity levels are being monitored. This study investigated reactivity in elementary school children. The step counts of forty-eight participants in second, fourth and sixth grades were monitored with sealed pedometers for eight days. A factorial repeated measures ANOVA revealed no significant differences among days for all participants (F-(7.294) = 1.25, p =.279) and no interactions among Sex, Grade, and Day. There is no reactivity in children monitored with a sealed pedometer. Intraclass correlations found that three to four days of monitoring are needed to determine habitual activity levels with a coefficient alpha level of .70 and five days of monitoring are needed to obtain a .80 coefficient alpha. This study demonstrates that there appears to be no reactivity period when sealed pedometers are used to measure physical activity.