Changes in Physical Activity and Sedentary Behavior During the Transition From Elementary to Secondary School

Background: The purpose of this study was to identify longitudinal changes in physical activity (PA) and sedentary behavior (SB) and to analyze its association with gender and weight status during the transition from elementary to secondary school. Methods: Flemish children were recruited in 6th grade of elementary school (age = 10.97 +/- 0.41) and reassessed 2 years later (age = 12.96 +/- .40). Children completed a questionnaire on moderate to vigorous PA and SB and wore pedometers to monitor habitual PA. Longitudinal data from 472 children were analyzed. Results: A significant decrease was observed in self-reported moderate to vigorous PA (-12.2%), but not in pedometer-determined PA. With respect to SB, a pronounced increase in recreational computer use was found (+3.22 hours/week), particularly in overweight boys (+8.18 hours/week). Finally, a significant increase in time spent on homework was observed in girls (+3.57 hours/week) and normal weight children (+2.83 hours/week). Conclusions: No longitudinal change in pedometer-determined PA was observed. Nevertheless, the decline in self-reported moderate-to-vigorous PA suggests that the transition to secondary school induced a change in the contribution of different types of PA. Finally, time spent on homework and recreational computer use increased during the school transition.