Pedometer-assessed physical activity in young adolescents

The purpose of this study was to evaluate the physical activity (PA) patterns of children. Forty-four 7th-grade students (19 boys, 25 girls) recorded pedometer data for 2 consecutive weeks. Separate 2 x 3 repeated measures analyses of variance were used to examine differences in total steps/day between boys and girls and between after-school activity participants and nonparticipants. The relative contribution of physical education (PE) and after-school activity (ASA) to weekday steps/day was evaluated as a proportion, for example (steps taken in PE class/total daily steps taken on a PE class day) * 100. The total sample mean was 11,392 steps/day, SD = 4112; for boys, M = 12,490 steps/day, SD=3910, versus girls, M = 10,557 steps/day, SD=4142; F=(1, 42) 4.365, p = .043. The sample population averaged 2046 steps, SD=945, during PE class; boys=2379 steps, SD=1115, versus girls=1782, SD=703; t (42) = 2.15, p = .038, d = .65, which represented 18% of the total steps/day on PE days. In comparison, the participants accumulated an average of 5366 steps, SD=2590; ASA for boys=5897 steps/day, SD=2738, versus girls=4963 steps/day, SD=2450; t (42) = 1.190, p = .241, d = .36), representing 46% of the steps/day on all weekdays and 47% of the total on PE days. Expressed as a rate, the sample population took 45.5 steps/min (SD=21) during PE class and 13.1 steps/min (SD = 4.7) in ASA on all weekdays. The relative stability of day-to-day behavior in youth is a preliminary finding but noteworthy. Although the absolute contribution ofPE class to daily PA was less than ASA (i.e., 18 vs. 47%, respectively), the importance of the condensed contribution in class was evident when these two activities were expressed as rates (i.e., steps/min). These data indicate that youth involved in ASA accumulated a greater number of steps on all days, weekend days, and health education days when compared to youth not involved in ASA.