Physical Exercise and Life Satisfaction among Older Adults: Evidence from a Two-Wave Balanced Panel Survey in China

Abstract Background Population aging has elevated subjective well-being promotion to a core public health priority worldwide and in China. Physical exercise represents a low-cost, widely accessible health-promoting behavior, yet longitudinal evidence on the mechanisms and boundary conditions linking exercise to life satisfaction among older Chinese adults remains limited. Methods Drawing on balanced two-wave panel data from the 2020 and 2023 China Longitudinal Aging Social Survey (CLASS), this study included 14,046 person-year observations from 7,023 adults aged 60 years and older. Random-effects panel models were used to estimate the association between exercise frequency and life satisfaction. Instrumental variable two-stage least squares (IV-2SLS), mediation pathway analyses, moderation models, and subgroup analyses were further used to assess potential endogeneity, unpack mediating mechanisms, test digital moderators, and examine effect heterogeneity. Results Exercise frequency was positively associated with life satisfaction after adjustment for demographic, economic, health, and behavioral covariates. The IV-2SLS estimate remained positive (β = 0.0292, p < 0.05), and the first-stage F statistic was 141.20. Session duration showed positive coefficients for 30–59 min (β = 0.042, p < 0.10) and 60–120 min (β = 0.153, p < 0.05), with the larger estimate for 60–120 min; neither the frequency quadratic term nor subjective intensity was significant. Bootstrap analyses indicated indirect associations through self-rated health, social participation, and loneliness. Wearable-device ownership (βinteraction = 0.0029, p < 0.05) and Internet use (βinteraction = 0.0021, p < 0.10) strengthened the association. Formal interaction tests indicated stronger associations among women and adults aged 60–69 years, while urban-rural differences were small. Conclusions Regular, moderate-duration physical exercise was positively associated with life satisfaction among older Chinese adults, with indirect associations involving self-rated health, social participation, and loneliness. Community exercise services should adopt age- and gender-responsive designs and integrate accessible digital health support to maximize well-being gains for older populations.