A social-ecological examination of physical activity and fitness among Chinese university students: a cross-sectional path analysis

Background Physical inactivity and declining fitness among university students are pressing global public health concerns. While social-ecological frameworks are increasingly applied, few studies have quantitatively modeled the multilevel pathways linking institutional, familial, and behavioral factors to objectively measured fitness in non-Western contexts. Objective This study aimed to (1) assess trends in physical fitness among Chinese university students, (2) identify key social-ecological predictors of fitness, and (3) test a path model examining direct and indirect associations consistent with ecological theory. Methods Using a multi-source cross-sectional quantitative design, we analyzed administrative fitness records (n≈130,000) from 2019 to 2023 and a cross-sectional survey of 1,200 undergraduates in 2023. Structural equation modeling tested pathways between institutional factors, family support, physical activity (PA), and fitness. Results Fitness scores consistently fell within the “Pass” range (60–79.9) with significant gender disparities. PA demonstrated the strongest direct association with fitness ( β =0.38, p < .001). Institutional and family factors showed significant indirect effects via PA ( β =0.18 and 0.10, respectively), while direct effects were non-significant. Lifestyle risks (screen time, sleep irregularity) negatively impacted fitness ( β =−0.22, p < .001). Conclusion Findings align with social-ecological theory, positioning PA as a key mediator between contextual factors and fitness. The study underscores the need for integrated, multilevel interventions in campus health promotion. Methodological limitations, including cross-sectional design and single-site sampling, are discussed.