A Study On The Daytime Variation Degree Of Adolescents' Physical Activity Level

Abstract

PURPOSE: Provide references for further exploring the possible factors that affect the daily variation characteristics of adolescents' physical activity and appropriate intervention strategies by analyzing the degree of day-time variation of vigorous physical activity (MVPA) and sitting time among adolescents. METHODS: The subjects of the study were 148 middle school and high school students in Beijing. They wore ActigraphGT3X three-axis accelerometers for one week to record the daily MVPA and sitting time. The height and weight of the subjects were also measured. RESULTS: The MVPA on school days was higher than that on weekends (49.39 min/d vs 34.24 min/d, P < 0.05). The MVPA of boys on school days and weekends was higher than that of girls (P < 0.05); The sitting time on school days and weekends was 566.48 min/d and 588.55 min/d, respectively, with no statistical difference (P > 0.05); boys’ sitting time on school days and weekends was lower than that of girls (P < 0.05); the coefficient of variation of MVPA for adolescents on school days (0.385 ± 0.168) was lower than that of weekend days (0.593 ± 0.455), and the difference was statistically significant (P < 0.01). The coefficient of variation of sitting time was not statistically different (P > 0.05) between school days (0.167 ± 0.077) and weekend days (0.145 ± 0.126). The coefficient of variation of MVPA in adolescents within one week was higher than that of sitting in one week (0.517 ± 0.177 vs 0.175 ± 0.065, P < 0.01). CONCLUSIONS: Adolescents have higher levels of physical activity on school days, and more significant insufficiency of physical activity on weekends; MVPA time variation is higher within a week, especially on weekends; sitting time is steadily at a higher level; boys are more active than girls and have a higher degree of physical activity variation. In the context of the national "double reduction" policy, in addition to the active measures taken by schools to increase the physical activity of adolescents, strengthening interventions for girls and weekends are particularly important to increase the level of physical activity for adolescents. This Study was Supported by the Planning subject for the 13th five year plan of Beijing education sciences (BEAA19045)