A comparative study between traditional and sports school uniforms on cardiorespiratory and muscular fitness and waist-height-to-ratio in adolescents

Background

Improving health of children and adolescents is crucial for their overall development. Therefore, it is essential to explore factors that may influence their health at both the public health and school system levels.

Objective

This study compares physical fitness components and waist-height-to-ratio (WHtR) in adolescents according to school uniforms, namely the traditional uniform (i.e., shirt and school necktie in boys and skirt and blouse in girls) and the sports uniform (i.e., polo shirts or t-shirts and sport or short trousers). Additionally, it seeks to investigate potential differences in these measures based on sex and school type (i.e., public, subsidized, and private).

Methods

This cross-sectional study used data from the Chilean national learning outcome assessment system (SIMCE)-2014 and involved 8,030 adolescents. Cardiorespiratory fitness (CRF) and muscular fitness (MF) were measured. WHtR was assessed as a health cardiovascular indicator. Mixed models and ANCOVA were performed to compare uniform types, adjusting for multiple covariates. value of p and effect size (ES) was used to establish significant results.

Results

Overall, sports uniforms (SU) were linked to higher CRF (p < 0.001) than the traditional uniform (TU). Boys from private schools wearing SU presented higher CRF (p = 0.016; ES = 0.37), and a positive trend was observed for MF (p = 0.645; ES = 0.21). In subsidized, a trend was found in CRF (p = 0.005; ES = 0.16). Girls wearing SU from private schools showed a positive trend in CRF (p = 0.167; ES = 0.28). Trends in WHtR were found in both sexes from private (p = 0.555; ES = 0.24; p = 0.444; ES = 0.25, respectively).

Conclusion

Wearing SU seems a promissory alternative to promote healthy physical fitness and body composition at the educational level. However, the relationship between higher physical activity and CRF, MF, and lower WHtR due to SU must be verified. Finally, when deciding to implement this measure, special attention must be paid to boys from public schools and girls from all types of schools.

Prenatal and birth predictors of objectively measured physical activity and sedentary time in three population-based birth cohorts in Brazil

Physical inactivity is a global pandemic with no signs of improvement. Prolonged sitting time is an emerging risk factor that exacerbates the health consequences of physical inactivity. Both behaviours are influenced by various individual and environmental factors but it remains unknown whether early-life exposures “program” these behaviours in later life. The current evidence is limited by a small number of studies which were primarily conducted in high-income countries, and a narrow range of early-life variables examined. Using data from three population-based Brazilian birth cohorts (analytical samples: n = 2740 for 1982 cohort, aged 30 years; n = 3592 for 1993 cohort, aged 18; n = 2603 for 2004 cohort, aged 6), we show that being female and higher family socioeconomic status at birth are strong and consistent predictors of lower physical activity and higher sedentary time from childhood to adulthood. Meanwhile, higher birth weight and lower birth order may also predict lower physical activity and higher sedentary time. Our findings are distinct from evidence from high-income countries, suggesting the importance of broader socioeconomic context in determining individual’s activity patterns through the life- course. Such evidence is essential for understanding the biological etiology and socioeconomic context of physical activity and sedentary behaviour at an early stage in life.