Effects of exercise adherence on subjective wellbeing in middle-aged and older adults: a three-wave longitudinal chain mediation study

Vollständiger Abstract

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Objective This study examined whether exercise identity and positive emotional expressivity statistically explain the prospective association between exercise adherence and subjective wellbeing among middle-aged and older adults. Drawing on identity theory, self-determination perspectives, and the broaden-and-build theory of positive emotions, we tested a three-wave longitudinal chain mediation model while controlling for baseline subjective wellbeing and demographic covariates. Methods Community-dwelling adults aged 45–75 years were recruited from community centers, senior universities, and public health platforms in Zhejiang Province, China. At baseline, 550 eligible participants completed measures of exercise adherence, subjective wellbeing, and covariates. Exercise identity was assessed 6 months later, and positive emotional expressivity and subjective wellbeing were assessed at 12 months. The final completer sample included 411 participants (mean age = 58.72 years, SD = 6.81; age range = 45–75 years; 180 men [43.8%] and 231 women [56.2%]). Attrition analyses, confirmatory factor analysis, longitudinal measurement invariance of subjective wellbeing, and structural equation modeling with 5,000 bootstrap samples were conducted. Results Attrition analyses indicated no significant baseline differences between retained and attrited participants. The measurement model showed acceptable reliability, convergent validity, and discriminant validity. The structural model fit the data well ( χ 2 /df = 1.89, CFI = 0.967, TLI = 0.960, RMSEA = 0.045, SRMR = 0.041). Exercise adherence at baseline was positively associated with subjective wellbeing at 12 months in the total-effect model ( β = 0.240, p < 0.001). In the mediation model, the direct path was attenuated and became non-significant ( β = 0.079, p = 0.126). The indirect paths through exercise identity ( β = 0.068), positive emotional expressivity ( β = 0.036), and the sequential path through exercise identity and positive emotional expressivity ( β = 0.057, 95% CI [0.028, 0.094]) were significant. Conclusion Findings suggest that sustained exercise adherence may be linked to later subjective wellbeing partly through the consolidation of exercise identity and the expression of positive emotions. Because the final mediator and outcome were assessed at the same wave and the design was observational, causal claims should be interpreted cautiously. Community exercise programs for aging populations may benefit from strategies that support exercise-related self-concept and positive affective expression in addition to promoting physical activity itself.