RESUMEN
BACKGROUND: Considering the relevant amount of time spent by children at school, it is essential to ensure that suitable levels of physical activity (PA) are guaranteed. This study aimed to assess possible changes induced in the amount and type of PA performed following the 2 schedules in Italian primary schools, namely regular and full time (30-40 h/week respectively). METHODS: A sample of 169 children wore a triaxial accelerometer 24h/day for 7 consecutive days. Raw data were processed to calculate the number of steps, amount and intensity of the PA performed in morning, afternoon and evening time slots. RESULTS: During weekday afternoon times (1:30 to 4:30 PM), children attending the full-time schedule spent significantly less time in sedentary behavior with respect to those who attend the regular time (54.7% vs. 60.0%, P < .001) and more time in moderate-to-vigorous activity (18.0% vs. 15.0%, P = .004). No differences between morning and evening times were found. CONCLUSIONS: The structure of the full time schedule, which includes a second recess, promotes higher and more intense levels of PA during the afternoon. Such information represent a useful input in planning differential PA activities for children attending the regular time to achieve similar PA levels for the whole school population.