RESUMO
OBJECTIVE: To investigate the effect of a preschool physical activity intervention program delivered in licensed childcare settings, with or without a parent-facilitated home component, on children's daily physical activity, sedentary time, and body composition. STUDY DESIGN: For this cluster randomized controlled trial, 18 childcare centers were randomly allocated in equal numbers to the typical curriculum comparison group, childcare intervention alone (CC), or childcare intervention with parental involvement. Accelerometers were used to asses physical activity and sedentary time, and body composition was measured by bioelectrical impedance. RESULTS: Linear mixed model regression analyses showed no differences between the CC, the childcare intervention with parental involvement, and the comparison groups in changes from baseline to 6 months in total physical activity (P for time × group interaction = .665) or moderate-to-vigorous physical activity (P for time × group interaction = .164) when adjusted for baseline physical activity levels. Furthermore, no group differences were found for changes in light physical activity, sedentary time, or anthropometric variables. CONCLUSIONS: An affordable and easily scalable preschool intervention program delivered in licensed childcare settings, with or without the addition of a parent-driven home physical activity promotion, seems to have no significant effect on physical activity, sedentary time, or body composition. TRIAL REGISTRATION: ISRCTN: ISRCTN94022291.