Longitudinal Association Between Physical Exercise and Depressive Symptoms in Older Adults: The Prospective Explanatory Role of Loneliness and the Moderating Role of Cognitive Emotion Regulation

Objective: This study examined the prospective association between self-reported physical exercise and depressive symptoms among older adults, and further tested whether loneliness statistically accounted for this association and whether baseline cognitive emotion regulation strategies moderated the exercise–loneliness pathway. Methods: A two-wave prospective survey with a six-month interval was conducted among 980 community-dwelling older adults in Zhengzhou, China. Baseline data were collected in September 2024, and follow-up data were collected in March 2025. Physical exercise was assessed using the Physical Activity Rating Scale-3, depressive symptoms using the 10-item Center for Epidemiologic Studies Depression Scale, loneliness using the 8-item UCLA Loneliness Scale, and cognitive emotion regulation strategies using the short version of the Cognitive Emotion Regulation Questionnaire. Cross-lagged models were used to examine the residual prospective association between physical exercise and depressive symptoms. A two-wave prospective explanatory model was then tested to examine the role of follow-up loneliness, and moderated explanatory (half-longitudinal) analyses were conducted using baseline adaptive and maladaptive cognitive emotion regulation strategies as moderators. Results: Baseline physical exercise was significantly associated with lower depressive symptoms at follow-up after controlling for baseline depressive symptoms and covariates (β = −0.182, p < 0.001). In contrast, baseline depressive symptoms were not significantly associated with follow-up physical exercise (β = −0.016, p = 0.633). Baseline physical exercise was negatively associated with follow-up loneliness (β = −0.267, p < 0.001), and follow-up loneliness was positively associated with follow-up depressive symptoms (β = 0.324, p < 0.001). The indirect association through follow-up loneliness was significant (indirect effect = −0.087, 95% CI [−0.112, −0.065]). Baseline adaptive cognitive emotion regulation strategies strengthened the association between physical exercise and lower loneliness (interaction β = −0.076, p < 0.001), whereas baseline maladaptive strategies weakened this association (interaction β = 0.059, p = 0.004). Conclusions: Self-reported physical exercise was prospectively associated with fewer depressive symptoms among older adults six months later. This association was statistically accounted for, in part, by lower follow-up loneliness, and baseline cognitive emotion regulation strategies were associated with the strength of the exercise–loneliness association. Because this study used a two-wave observational design with the explanatory variable and outcome measured at the same follow-up wave, the findings should be interpreted as prospective associations rather than evidence of causal or temporal mediation.