Purpose: We examined the association between depressive symptoms and physical activity (PA) in a sample of men from the Aerobics Center Longitudinal Study. Secondary analysis included stratification by age and body mass index (BMI).
Methods: Our cross-sectional analysis included 9580 men, age 20-87 yr, who completed the 10-item Center for Epidemiological Studies Depression Scale during 1996-2006. A score of 10 or higher defined depressive symptoms. Four PA categories based on the 2008 PA guidelines were created from a self-report leisure time PA questionnaire: inactive (0 MET·min·wk(-1)), low (1-499 MET·min·wk(-1)), medium (500-999 MET·min·wk(-1)), and high (≥1000 MET·min·wk(-1)).
Results: There were 727 men with depressive symptoms. Cross-sectional analyses showed a significant inverse relationship between PA categories and depressive symptoms (P for trend < 0.0001). This reduction in odds was shown across all types of measured leisure time activities (odds ratios = 0.36-0.58). Compared with the inactive group, the light, medium, and high PA categories were 24%, 51%, and 51% less likely to exhibit depressive symptoms, respectively. The inverse relationship was maintained for age and BMI groups except for those 60 yr or older, who exhibited fewer depressive symptoms than other ages. Men with a BMI of 30 kg·m(-2) or higher lowered their odds of depressive symptoms for all PA categories, whereas those with a BMI less than 30 kg·m(-2) needed at least 500 MET·min·wk(-1) to show a similar association.
Conclusions: Overall, our analyses found an inverse association between PA and depressive symptoms. Most of this benefit was seen in the medium PA category, which seemed to plateau around 500 MET·min·wk(-1). This indicates that men meeting the 2008 PA Guidelines may not only experience physical health benefits but also reduce the likelihood of depressive symptoms.