Background: Physical activity (PA) in childhood contributes not only to physical health but also to psychological well-being and developmental outcomes. Yet, the psychological processes driving PA remain underexplored. Drawing on the Social Ecological Model and the Transtheoretical Model (TTM), this study examined how self-efficacy, decisional balance, and stages of change—alongside family and peer support—shape children's PA, and whether these pathways differ by gender.
Methods: A cross-sectional survey was conducted with 776 children aged 9-12 years from six primary schools in central China using random cluster sampling. Standardized questionnaires measured psychological constructs and socio-ecological factors related to PA. Multi-group structural equation modeling (SEM) tested gender differences, with model fit assessed by RMSEA, CFI, TLI, and SRMR indices.
Results: The model demonstrated good fit (RMSEA = .048, CFI = .923, TLI = .918, SRMR = .056). Distinct gender-specific pathways were observed. Among boys, PA was significantly predicted by self-efficacy (β = .241, p < .01), stages of change (β = .217, p = .002), and peer support (β = .281, p = .001). Family support primarily reduced perceived barriers (β = −.198, p = .028) but had no direct effect. Among girls, perceived benefits (β = .258, p < .001), stages of change (β = .224, p = .003), and self-efficacy (β = .139, p < .05) emerged as significant predictors, while peer support showed only marginal influence (β = .094, p = .067).
Conclusion: Children's PA behaviors are shaped by gender-specific psychological and ecological mechanisms. Interventions for boys should emphasize building self-efficacy and leveraging peer support, whereas interventions for girls should focus on enhancing perceived benefits and readiness for change. These findings underscore the value of theory-driven, gender-tailored strategies in applied psychology to promote sustainable PA engagement.