Accelerometer-determined physical activity of children during segmented school days: The Shanghai perspective

The two types of school days that are followed in China are physical education and physical exercise days. This study objectively measured the moderate-to-vigorous physical activity (MVPA) of children during the recess, lunch break, leisure time, physical education and physical exercise segments of the physical education and physical exercise days. Moreover, this research compared the gender and grade-level differences in MVPA during each segment. A total of 316 children aged 6-13 years (M = 9.28, SD = 1.87) in Grades One to Five from three elementary schools participated in this study. Accelerometers were utilised to measure the MVPA of children. The participants accumulated the most MVPA time during physical education classes, whereas the least MVPA time was recorded during lunch break. The boys were significantly more physically active than girls during recess (F (1, 316) = 4.449, p = 0.037, eta(2) = 0.030), lunch break (F (1, 316) = 4.525, p = 0.035, eta(2) = 0.030) and leisure time (F (1, 316) = 4.795, p = 0.030, eta(2) = 0.032) on physical education days, and during recess (F (1, 316) = 5.968, p = 0.017, eta(2) = 0.079) and leisure time (F (1, 316) = 5.246, p = 0.025, eta(2) = 0.070) on physical exercise days. Significant grade-level differences in the MVPA time were observed during recess (F (2, 316) = 20.209, p < 0.001, eta(2) = 0.219) on physical education days and during physical exercise classes (F (2, 316) = 3.662, p = 0.031, eta(2) = 0.095) and recess (F (2, 316) = 4.326, p = 0.017, eta(2) = 0.110) on physical exercise days. Children in Grades Two and Three engaged in the most MVPA time during the majority of segments. In conclusion, physical activity interventions during less structured or unstructured segments are recommended. Special attention should likewise be provided to girls and children in Grades One, Four and Five to increase their MVPA.