Regular physical exercise and its association with depression: A population-based study short title: Exercise and depression

This study is to estimate the relation between regular physical exercise and the risk of depressive disorder and depressive symptoms. Data from the Korean Longitudinal Study of Aging (KLoSA) from 2008 to 2018 were used, and 3,070 research samples were included at baseline at 2008. To analyze the relation between physical exercise and risk of depression, a generalized estimating equation (GEE) model and chi-square test were used. The estimate of Center for Epidemiologic Studies Depression (CESD) in those with "< 3 h" of exercise per week was 0.033 higher (95% Confidence Interval [CI]: 0.001 - 0.065 p-value: 0.046) compared to those with "5 h or more" of exercise per week. In terms of exercise duration, the estimates for CESD was 0.153 higher (95% CI: 0.111 - 0.195 p-value: <0.0001) in "< 1 year" and 0.143 higher (95% CI: 0.109-0.178 p-value: <0.0001) in "1-2 year", compared to "5 years or more" of exercise duration. This study showed a negative relationship between regular exercise and depressive symptoms in community-dwelling adults aged 45 years and above. To develop the habit of regular physical exercise and to reinforce self-esteem, simple and practical strategies of effective exercise may become important but effective exercise interventions.