Abstract
Introduction
During adolescence, physical activity tends to decline, especially among girls. Adolescent inactivity is due in part to biological factors, among which pubertal development may play a role. Our aim was to study in girls, the relationship of sexual maturation based on menarche with physical activity and sedentary behaviour.
Methods
Analyses were based on a two-stage random sample of 3,911 10-15-year-old girls included in the 2018 cross-sectional Health Behaviour in School-aged Children survey carried out in French-speaking schools. Menarche, sufficient levels of physical activity (PA) (global PA: at least 60 min. of moderate- to vigorous-intensity PA daily, and vigorous PA: at least 3 times/week), sedentary week time based on all-screen use duration (SWT; categories based on tertiles), and sociodemographic characteristics were self-reported. Multilevel multiple binary (for PA) and multinomial (for SWT) logistic regressions were performed, stratified by age group (≤12.5 years vs. >12.5 years).
Results
Twenty percent of girls aged ≤ 12.5 years and 85.0% of girls aged > 12.5 years have had their first period. Within the group aged ≤12.5, post-menarcheal girls were more likely to spend long SWT (≥8h/day) than pre-menarcheal girls (vs. short SWT (<4h/day): aRRR= 1.74 [1.27-2.37]; NS for moderate SWT (4-7h/day)). Within those aged >12.5, post-menarcheal girls were less likely to engage in sufficient vigorous PA (aOR=0.76 [0.59-0.98]) than pre-menarcheal girls. Moreover, they were more likely to spend moderate (aRRR=1.70 [1.19-2.42]) and long SWT (aRRR=2.74 [1.94-3.88]) than pre-menarcheal girls of same ages. Additional adjustments for age modified the strength of associations.
Conclusions
Our results suggest that during adolescence, the physiological changes induced by sexual maturation may contribute to the decline in physical activity (in > 12.5 years), and in the increase in sedentary behaviour in girls. Potential confounding by age will be explored further.
Key messages
Development of strategies aimed at improving physical activity among adolescent girls should take into account, among other aspects, pubertal development. Specific interventions, targeting pubescent girls, should also be developed to reduce screen time in order to prevent its potential negative consequences.
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