Backgroud
To evaluate the effects of chronic physical activity (PA) interventions on physical fitness (PF) in preschool children and to determine the optimal weekly PA dose for improving specific fitness components through meta-analysis and dose-response analysis.
Methods
Literature searches were conducted in PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials from database inception to January 4, 2025. Eligible randomized controlled trials (RCTs) involved healthy children aged 3-7 years, applied PA interventions lasting ≥ 4 weeks, and assessed at least one PF component, including muscular strength, cardiorespiratory fitness (CRF), flexibility, coordination, or balance. Meta-analyses used random-effects models to calculate standardized mean differences (SMDs) with 95% confidence intervals (CIs). Bayesian dose-response models with restricted cubic splines were used to explore non-linear associations.
Results
Fourteen RCTs (n = 3376) were included. PA interventions significantly improved overall PF (SMD = 0.30; 95% CI: 0.22-0.38), as well as upper muscle strength (SMD = 0.30), lower muscle strength (SMD = 0.29), flexibility (SMD = 0.27), CRF (SMD = 0.29), coordination (SMD = 0.54), and static balance (SMD = 0.38). Dose-response analysis revealed optimal weekly doses of 270 min for overall PF, 260 min for lower muscle strength, 190 min for upper muscle strength and flexibility, 300 min for coordination, and 180 min for static balance. CRF improved linearly up to 380 min/week. Subgroup analyses indicated that session frequency, length, and total duration moderated intervention effects.
Conclusions
PA interventions effectively improve physical fitness in preschool children. Optimal weekly doses range from 180 to 380 min, depending on the fitness component. Intervention effectiveness is further moderated by session frequency, duration, and total program length, highlighting the need for tailored PA strategies targeting specific physical fitness outcomes in early childhood.
Prospero Registration
CRD42025639632.