Physical Activity Behavior in Swiss Secondary School Students: A Segmented Analysis

Introduction Physical activity (PA) levels decline from childhood to adolescence, and many Swiss adolescents do not achieve the WHO's recommendation of 60 minutes of daily moderate-to-vigorous physical activity (MVPA) (Bringolf-Isler et al. 2016). To design effective interventions, analyzing adolescents' PA behavior across different daily time segments is essential to better understand which segments offer the greatest potential for improving physical activity levels (Saint-Maurice et al., 2018). As adolescents spend a substantial part of their day in school, it is crucial to focus not only on leisure but also on school time. Therefore, this study examines the segmented PA behavior of Swiss adolescents during specific school and leisure time segments and evaluates their compliance with the respective recommendations. Methods The present study is based on the baseline data from the Active School project, which aims to promote physical activity behavior in Swiss secondary school students. A total of 637 students (mean age: 13.26 ± 0.55 years, 52.3% girls) from 12 secondary schools in the canton of Bern participated in the baseline assessment of the project. Physical activity behavior was measured using GENEActiv wrist-worn accelerometers over seven consecutive days. Data were segmented into school-related segments (Physical Education (PE), recess, classroom time, entire school time) and an after-school segment. Activity intensities were categorized into inactivity (IN), light intensity (LIG), and MVPA. Descriptive statistics were used to summarize the data, and differences between segments were analyzed using ANOVAs or t-tests, as appropriate. Results Swiss adolescents engage in significantly more MVPA during the after-school segment than during school time (9.60% vs. 8.53%, respectively; p < 0.001). During school hours, the proportion of time allocated to MVPA varies significantly across segments (PE = 31.2%, recess = 18.46%, classroom time = 5.45%; p < 0.001), falling well below the recommended targets for PE (50% MVPA) and recess (40% MVPA). Across all school segments, IN (PE = 38.13%, recess = 48.56%, classroom time = 76.98%) accounts for the largest proportion of time compared to LIG and MVPA. Overall, 49% of adolescents (63% boys; 37% girls) meet the school-based PA recommendation of 30 minutes of MVPA during school time. Furthermore, girls consistently show significantly lower percentages of MVPA and higher percentages of IN than boys across all school segments (all ps < 0.001). Discussion/Conclusion Adolescents are more active during their leisure time than during school hours, with only half meeting the school-based physical activity recommendation. This highlights the need for targeted interventions during school hours to reduce the high levels of IN across all school segments and increase MVPA, especially during PE and recess. Moreover, specific interventions for girls are crucial, as they consistently show lower PA levels compared to boys across all school segments. References Bringolf-Isler, B., Probst-Hensch, N., Kayser, B., & Suggs, S. (2016). Schlussbericht zur SOPHYA-Studie [Final report on the SOPHYA study]. Swiss Tropical and Public Health Institute. https://bit.ly/3MFskWj Saint-Maurice, P. F., Bai, Y., Vazou, S., & Welk, G. (2018). Youth physical activity patterns during school and out-of-school time. Children, 5(9), Article 118. https://doi.org/10.3390/children5090118