Estimated Prevalence of Compliance With Muscle-Strengthening Activity Recommendations in Children and Adolescents: A Meta-Analysis.

Aim: To estimate the prevalence of meeting the World Health Organization (WHO) guidelines for muscle-strengthening activities in children and adolescents, specifically engaging in these activities at least 3 days per week, and explore, whenever possible, this prevalence according to sociodemographic and healthy habits factors.

Methods: Four databases were systematically searched for studies published from inception to January 2025. Eligible studies included articles with samples of children and adolescents reporting the prevalence of meeting the muscle-strengthening activities guidelines.

Results: Twenty-nine studies comprising 1 273 544 children and adolescents (49.40% girls; mean age: 13.40 years) from 36 countries were included. Estimated prevalence of muscle-strengthening activities was 38.51% (95% CI, 34.35% to 42.75%), based primarily on studies involving adolescent populations, with limited data available for children aged 6 to 12 years. According to the subgroup analyses, the predictors that favour compliance with the muscle-strengthening activity guidelines are being a boy, having normal weight, meeting the aerobic physical activity recommendations and receiving high family support for engaging in physical activity.

Conclusion: Only 4 out of 10 children and adolescents meet the WHO muscle-strengthening activity guidelines. Targeted efforts are needed, particularly for girls and those with lower support or physical activity levels, to improve participation and youth fitness.

Trial registration: PROSPERO Registration Number: CRD42025648274.