Association between long working hours and cigarette smoking, leisure-time physical activity, and risky alcohol use: Findings from the Korea National Health and Nutrition Examination Survey (2014–2021)

Background: Long working hours cause adverse health outcomes; however, the precise mechanisms underlying this relationship remain unknown. We examined the association between long working hours and health behaviors, as well as gender differences in this association. Methods: A nationally representative sample of 26,385 Korean workers was analyzed. The exposure variable was self-reported weekly working hours. The outcomes examined were cigarette smoking, high-level physical activity (defined as engaging in ≥150 min/week of moderate-to-vigorous leisure-time physical activity), and risky alcohol use (defined as consuming seven glasses for men or five glasses for women of alcohol in a single sitting, twice or more per week). Logistic regression models were utilized, and gender differences were examined by incorporating interaction terms into the regression models. Results: Among 26,385 workers, 4,109 (16%) worked ≥55 h/week. The prevalence of cigarette smoking, high-level physical activity, and risky alcohol use was 19%, 18%, and 14%, respectively. The odds ratio (OR) (95% confidence interval [CI]) of the association between working ≥55 h/week and outcomes was 1.26 (1.12–1.43) for cigarette smoking, 0.73 (0.65–0.83) for high-level physical activity, and 0.95 (0.83–1.08) for risky alcohol use compared to working 35–40 h/week. A moderating effect of gender on the association between long working hours and risky alcohol use was observed. The OR (95% CI) of the association between working ≥55 h/week was 0.88 (0.76–1.02) in men and 1.51 (1.12–2.05) in women. Conclusion: Our findings emphasize the need for policy interventions aimed at reducing excessive working hours and fostering healthy lifestyle behaviors among individuals engaged in long working hours.