Abstract

Tai Chi, a traditional mind–body exercise, has been associated with improved emotional well-being among older adults; however, the psychological mechanisms underlying this relationship remain insufficiently explored. To address this gap, this study examined the effects of Tai Chi exercise (TCE) on mood states (MS) in older adults, with particular emphasis on the mediating role of psychological security (PS). A quantitative cross-sectional design was employed involving 416 regular Tai Chi practitioners aged 60 years and above from Weifang City, China. Participants were assessed using the Physical Activity Rating Scale (PARS-3), the Security Questionnaire, and the Profile of Mood States (POMS). Structural equation modelling with 5,000 bootstrap iterations revealed that TCE was significantly negatively associated with MS (β = -0.635, p < 0.001) and positively associated with PS (β = 0.383, p < 0.001). PS demonstrated a strong negative association with MS (β = -0.641, p < 0.001) and partially mediated the relationship between TCE and MS, accounting for 38.8% of the total effect (indirect effect: β = -0.246, 95% CI: -0.348 to -0.162). These findings suggest that TCE improves mood states in older adults both directly and indirectly through enhanced psychological security, revealing a novel psychological pathway and providing both theoretical insight and practical guidance for community health programs and mental health interventions aimed at promoting healthy aging.