The dynamic association between physical exercise and depressive symptoms in China: an age-period-cohort analysis using the HAPC-CCREM and the moderating role of urban–rural disparities
Background While the positive association between physical exercise and depressive symptoms (as an indicator of mental health) is well-established, existing research lacks a dynamic life-course and socio-generational perspective. It remains unclear how these associations evolve across different ages, historical periods, and birth cohorts, and how they are moderated by structural factors such as the urban–rural divide. Methods Utilizing pooled cross-sectional data from five waves (2010–2017) of the China General Social Survey (CGSS) with 28,618 valid adult samples, this study employs a Hierarchical Age-Period-Cohort Cross-Classified Random Effects Model (HAPC-CCREM) to disentangle age, period, and cohort patterns. Results The advantage associated with regular physical exercise in terms of depressive symptoms exhibits a non-linear age pattern suggestive of a U-shape, being strongest among younger and older adults but attenuated during middle age. Cohort analysis reveals that earlier-born cohorts show a stronger positive association between exercise and fewer depressive symptoms. This positive association declined with socio-economic development but shows a resurgence among the post-1990s cohort, suggesting possible links to socio-economic development and shifting values. Urban–rural disparities significantly moderate this association: urban residents exhibit a stronger positive association and more effective stress-alleviating patterns from exercise, whereas the corresponding association for rural residents is comparatively limited. Conclusion The positive psychological correlates of physical exercise with respect to depressive symptoms are not static but are dynamically shaped by individual life stages and macro-social transformations. In the context of China’s transition towards post-materialist values, the role of exercise may be shifting from a “luxury enhancer” to a “necessary support.” Future public health strategies should adopt a differentiated approach, considering life-course stages, cohort experiences, and urban–rural structural contexts to implement precise mental health promotion strategies (i.e., reducing depressive symptoms).