James, MEde Lannoy, LLopes, OJohnstone, ALee, EYBakalár, PBrazo-Sayavera, JManyanga, TVanderloo, LMWentzell, EBarnett, LMBentsen, PCarson, VDuncan, SFahey, RMorrison, SAMygind, LPrioreschi, ARyu, SSikora, LTucker, PWachira, LJTremblay, MS2026-05-182026-05-182026-04-14Journal of Sport and Health Science, ISSN: 2095-2546 (Print); 2213-2961 (Online), Elsevier BV, 15, 101115-. doi: 10.1016/j.jshs.2025.1011152095-25462213-2961http://hdl.handle.net/10292/21107Background: Few individuals meet the 24-h movement guidelines for physical activity (PA), sedentary behavior, and sleep. Active outdoor play (AOP) may support healthier movement patterns, though its role is not yet established. The objective of this study was to synthesize evidence on associations between AOP and movement behaviors. Methods: A systematic review and meta-analyses were conducted using 5 databases from inception to September 2025. Studies examining AOP and movement behaviors were included with no restriction on age, ability, or geographic location. Screening and data extraction were completed in duplicate. Narrative syntheses, random-effects meta-analyses, and The Grading of Recommendations Assessment, Development, and Evaluation assessments were conducted. Results: Of 28,092 records, 61 studies met inclusion criteria, spanning 25 countries with participants aged 1.6–15.5 years. Most were cross-sectional (n = 46), with some longitudinal (n = 8), quasi-experimental (n = 5), and randomized trials (n = 3). AOP was consistently associated with greater PA, especially moderate-to-vigorous PA; meta-analysis showed a moderate positive correlation with high heterogeneity (r = 0.60, 95% confidence interval (95%CI): 0.34–0.78, p = 0.0004; I² = 99.2%). AOP was also linked to less sedentary behavior: children were sedentary 38% of the time outdoors vs. 67% indoors. Meta-analyses showed a small, significant negative correlation with sedentary time (r = –0.05, 95%CI: –0.07 to –0.02, p < 0.0043; I² = 7.0%) and a small, non-significant correlation with screen time (r = –0.19, 95%CI: –0.38 to 0.02, p = 0.0638; I² = 98.9%). Evidence on sleep was mixed, with no adverse associations found. Certainty of evidence was low to very low. Conclusion: AOP may support healthier movement behaviors in children and youth. More longitudinal and intervention research is needed to confirm causality and guide policy and practice.© 2026 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article distributed under the terms of the Creative Commons CC-BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. You are not required to obtain permission to reuse this article.https://creativecommons.org/licenses/by/4.0/ChildrenPhysical activityPublic healthSedentary behaviorSleep4206 Public Health42 Health SciencesPediatric Research InitiativeSleep ResearchBehavioral and Social SciencePreventionPhysical ActivityCardiovascularCancer1106 Human Movement and Sports Sciences4201 Allied health and rehabilitation science4206 Public health4207 Sports science and exerciseJournal ArticleOpenAccess10.1016/j.jshs.2025.101115