# When and where to intervene: identifying key school segments to enhance adolescent physical activity

## TL;DR

Swiss teenagers are not getting enough physical activity at school, especially girls, and need targeted policies to boost their activity levels.

## Contribution

The study identifies specific school segments where physical activity is lacking and highlights gender disparities in activity levels.

## Key findings

- MVPA levels in school segments like PE and recess fall below recommended thresholds.
- Girls accumulate less MVPA and more inactivity than boys across all school segments.
- Only 49.5% of adolescents meet the daily school-based MVPA recommendation.

## Abstract

Swiss adolescents fall short of the WHO's guideline of 60 min of moderate-to-vigorous physical activity (MVPA) per day. Developing targeted interventions or policies requires an understanding of adolescents’ daily activity patterns. Since adolescents spend much time at school, it is essential to consider not only leisure but also school segments when assessing physical activity (PA). Therefore, this study investigates how Swiss adolescents’ PA is distributed across different school time segments and examines to what extent they meet recommended activity levels.

This cross-sectional study uses baseline data from the Active School project. The sample included 666 7th-grade students (mean age = 13.27 ± 0.55 years, 47.7% boys, 51.8% girls, 0.5% diverse) from 12 secondary schools. PA data, gathered over five schooldays using wrist-worn GENEActiv accelerometers, were segmented into physical education (PE), recess, classroom time, entire school time, and leisure time. Activity levels were categorized into inactivity (IN), light physical activity (LPA), and MVPA. Descriptive and inferential statistics (ANOVAs, t-tests) examined differences across segments and gender.

Within school time, MVPA varied significantly by segment (PE: 30.59%, recess: 18.80%, classroom: 5.69%, p < .001) and remained below recommendations for PE (50%) and recess (40%). IN dominated all segments, especially classroom time (75.83%). Overall, only half (49.5%) of Swiss adolescents met the school-based PA recommendation of at least 30 min of MVPA per day, while girls accumulated less MVPA and more IN than boys across all school segments (all ps < .001).

Substantial opportunities for PA are lost across all school segments in the Swiss context, with girls consistently less active than boys. Based on these findings, segment-specific and gender-sensitive school PA policies are discussed, and a comprehensive school approach to PA promotion is recommended to support more effective and equitable PA promotion among adolescents.

German Clinical Trials Register (DRKS00033362). Date of registration: January 25, 2024. Retrospectively registered.