Effects of physical exercise on Chinese workers’ job satisfaction: the chain-mediating role of social justice perception and happiness

<i>Objectives.</i> As social competition intensifies and 'involution' (a state of inefficient competition) rises in China, job satisfaction (JS) has become a key indicator of workers' quality of life. <i>Methods.</i> Using data from the China General Social Survey (CGSS) 2021, a sample of 1152 employed individuals were analyzed. Multiple linear regression and structural equation modeling (SEM) tested the direct and indirect relationships. Heterogeneity analyses were conducted across gender, household economic status and region. <i>Results.</i> Physical exercise (PE) demonstrated a significant positive direct effect on JS (<i>β</i> = 0.119, <i>p</i> < 0.01). Significant indirect effects were found through social justice perception (<i>β</i> = 0.014, 95% confidence interval [CI] [0.004, 0.033]), happiness (<i>β</i> = 0.046, 95% CI [0.023, 0.081]) and their chain-mediating pathway (<i>β</i> = 0.010, 95% CI [0.003, 0.020]). The total indirect effect accounted for 37.37% of the total effect. Heterogeneity tests revealed the impact was more pronounced among female workers, those with medium household economic status and residents in the eastern region. <i>Conclusions.</i> PE directly enhances JS and indirectly improves it by fostering social justice perception and increasing happiness. Employers should implement tailored and accessible exercise programs, while policymakers should provide targeted support for workplace physical activity.