Changes in physical activity and sedentary time during adolescence: Gender differences during weekdays and weekend days

Abstract

Objectives: The objective of this study was to determine the gender-specific and time-segmented changes in accelerometer measured physical activity (PA) and sedentary time (ST) during adolescence.

Methods: The study population (N = 970) consisted of children from nine schools throughout Finland. At the baseline, the children were in grades 4-7 (ages 10-13). Five times during the two-year follow-up period, hip-worn accelerometers (ActiGraph GT3X+) were deployed for seven consecutive days in order to monitor the pupils' PA. The daily time spent in vigorous (VPA), moderate to vigorous (MVPA), and light physical activity(LPA), as well as sedentary time(ST), were assessed.

Results: Significant gender differences were observed in terms of the changes in MVPA and ST during the follow-up period. The total MVPA declined significantly in boys (by 2.2min/day/year from 60 min/d at baseline) but not in girls (49 min/d at baseline). The total ST increased both in boys (by 20.7%-points/y) and in girls (by 16.1%-points/y, P < .001). However, when we compared the results during the weekdays and weekend days separately, we observed that the declines in MVPA and increases in ST were greater in boys than in girls during the weekend days.

Conclusion: A greater decrease in PA and a greater increase in ST during adolescence were observed among boys than among girls, especially during weekend days. In order to diminish these unfavorable behavioral changes during adolescence, we encourage the separate tailoring of interventions for boys and girls and for weekdays and weekends.

Keywords: accelerometer; adolescence; children; physical activity; school; sedentary time.

FIGURE 1

A, The development of sedentary time (ST), light physical activity (LPA), moderate to vigorous physical activity (MVPA), and vigorous physical activity (VPA) during the follow‐up for the whole week (Total), weekdays (WD), and weekends (WE) in boys (●) and girls (▲). The dotted lines represent the mean growth curves in boys and girls (estimated by using the parameters of the linear growth curve model). B, The development of sedentary time (ST), light physical activity (LPA), moderate to vigorous physical activity (MVPA), and vigorous physical activity (VPA) during the follow‐up for weekdays (WD) in boys (●) and girls (▲). The dotted lines represent the mean growth curves in boys and girls (estimated by using the parameters of the linear growth curve model). The weekdays (WD) are further divided into school time and leisure time based on the pupils’ individual curricula