Gender Differences in Objectively Measured Physical Activity and Sedentary Time at School and Outside of School Hours in Finnish Children Aged 7 to 12 Years

Aim This study evaluated objectively measured physical activity and sedentary time among Finnish schoolaged children from grades 1 to 6 (ages 7 to 12 years) and compared the results between boys and girls, and between different age groups.

Methods The study population consisted of 568 Finnish boys and girls from grades 1 to 6 (mean age 9.9 years, SD 1.9). The children’s physical activity was measured by using an ActiGraph accelerometer for seven consecutive days. Cut-off values of 2,296 cpm (counts per minute) for moderate-to-vigorous physical activity (MVPA), and 100 cpm for sedentary time, were used.

Results The children had, on average, 62 minutes (SD 21) of MVPA time and 490 minutes (SD 74) of sedentary time per day. The boys had 10 more minutes of MVPA time (p< 0.001) and 18 fewer minutes of sedentary time (p< 0.003) per day when compared to the girls. At school, the children had on average 4.7 minutes/hour (SD 2.0) of MVPA time, and 38.4 minutes/hour (SD 4.6) of sedentary time; boys had 0.7 more minutes/hour of MVPA time per day (p< 0.001), and 3.2 fewer minutes/hour of sedentary time (p< 0.001), per day as compared to girls. Daily MVPA time decreased and sedentary time increased linearly with increasing age; the difference between the oldest (grade 6) and youngest (grade 1) children was 15.9 minutes of MVPA time per day, and 127 minutes of sedentary time per day.

Conclusions Finnish boys aged 7 to 12 years old were physically more active and had less sedentary time than girls, both at school and outside of school hours. Interestingly, gender differences in physical activity and sedentary time seem to exit not only outside of school hours, but also during school. In addition, physical activity declined and sedentary time increased with age, both at school and outside of school hours.