Association between recreational physical activity and depressive symptoms in adults with diagnosed sleep disorders: an analysis of NHANES 2007-2018 data

ObjectiveThis study aimed to examine the relationship between recreational physical activity and depressive symptoms in adults diagnosed with sleep disorders, and to explore the potential of recreational physical activity as a practical intervention to alleviate depressive symptoms.MethodsData were drawn from the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2018, including a cohort of 3,164 adults with diagnosed sleep disorders. Depressive symptoms were measured using the Patient Health Questionnaire-9 (PHQ-9), while recreational physical activity was assessed via metabolic equivalents (METs). The association between physical activity and depressive symptoms was evaluated using multiple linear regression and breakpoint regression models, adjusting for covariates such as sex, age, ethnicity, smoking status, and alcohol consumption.ResultsIn the fully adjusted model, participants in the highest quartile of recreational physical activity (Q4) exhibited significantly lower depressive symptom scores (Q4: beta = -1.01, 95% CI: -1.58 to -0.44, p = 0.0005), indicating that greater physical activity was linked to fewer depressive symptoms. Additional analyses revealed that this inverse relationship was most pronounced for activity levels below 840 MET, which corresponds to approximately 105 min of vigorous recreational physical activity per day or 210 min of moderate-intensity activity per day. The association weakened for activity levels exceeding 840 MET. Subgroup analyses further indicated that the benefits of recreational physical activity were more pronounced in men, individuals aged 40-60 years, and former smokers.ConclusionHigher levels of recreational physical activity were associated with significantly reduced depressive symptoms in adults with sleep disorders. The greatest reductions in depressive symptoms were observed at activity levels below 840 MET, which corresponds to approximately 105 min of vigorous recreational physical activity per day or 210 min of moderate-intensity activity per day. Men, individuals aged 40-60 years, and former smokers derived the most benefit from these activity levels.