Association between physical exercise and reemployment among Chinese older adults: the mediation effect of physical health, cognitive function, and social participation.

Objective: This study aims to systematically investigate the effects, mechanisms, and demographic heterogeneity of physical exercise on reemployment among older adults. To address the gaps in current studies, i.e., the lack of exploration of mediating mechanisms and the scarcity of large-sample empirical evidence, this paper provides empirical evidence and practical guidance for activating the human resources of older adults and advancing active aging strategies. Methods: Data were derived from the 2023 China Longitudinal Aging Social Survey, yielding a sample of 4,597 retired individuals aged 60 and older with complete data. The study treated reemployment as the dependent variable and physical exercise behavior as the primary independent variable, with physical health, cognitive function, and social participation selected as mediating variables. Control variables included factors related to individual and household sociodemographic characteristics. A binary logistic regression model was used to analyze main effects, and the propensity score matching method was employed to address potential endogeneity. Robustness tests were conducted using multiple methods, and the mediating effects were examined using the bias-corrected Bootstrap method, while heterogeneity analysis was also performed. Results: The baseline regression results revealed that physical exercise has a significant positive effect on reemployment among Chinese older adults. This effect remained stable and reliable after undergoing several robustness checks, including propensity score matching and other regression models. Tests of the mediating effects confirmed that physical exercise could promote reemployment among older adults through three pathways: first, by improving physical health, with an indirect effect accounting for approximately 10.3% of the total effect; second, by enhancing cognitive functions, with an indirect effect accounting for approximately 4.9% of the total effect; third, by increasing social participation, with an indirect effect accounting for approximately 11.3% of the total effect, which serves as the core mediating pathway. Heterogeneity analysis revealed significant group differences in this promotional effect. The promotional effect of physical exercise was particularly pronounced among older adults in rural areas, the eastern region, those aged 60-70 years, those with a junior middle school education or above, and those who were ordinary workers, clerks, or other before retirement. Conclusion: Physical exercise was and significantly positively associated with reemployment among older adults. This association may operate through several parallel pathways: physical exercise was associated with higher reemployment likelihood partially via improving physical health, enhancing cognitive functions, and increasing social participation, with social participation serving as the most critical mediating pathway.