Physical Activity Characteristics And Symptoms Of Depression: Findings From The Cooper Center Longitudinal Study

Purpose: Examine the relationship between physical activity (PA) characteristics (volume, average intensity, duration, type, diversity) and depressive symptoms among a large sample of community dwelling adults. METHODS: The study consisted of 38,946 participants (n = 26,378 men, n = 12,568 women) who completed a 10-item depression screening assessment (Center for Epidemiologic Studies Depression Scale, CES-D) and reported PA (frequency, time, type) within the prior three months as part of a preventive medical examination at the Cooper Clinic in Dallas, TX. PA intensity (METs) was assigned based on activity using the Compendium of Physical Activities, and weekly PA volume (MET·hours), average intensity, duration (hours), and diversity (bits) were calculated. Activity type was classified as aerobic, strength, mixed (e.g. circuit/interval training, basketball, racket sports, etc.), and flexibility. Shannon’s diversity index was calculated using binary logarithms on the proportions of time spent in each reported activity. Depressive symptoms were determined by a CES-D score ≥ 10. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression to assess the association between PA characteristics and CES-D ≥ 10 by sex, adjusted for age, current smoking, alcohol intake, BMI, glucose, cholesterol, and systolic blood pressure. RESULTS: The mean age ± SD for women and men was 48.3 ± 10.8 and 49 ± 10.1 years, respectively. CES-D score ≥ 10 was present in 1,938 women (15.4%) and 2,399 men (9.1%). Risk of CES-D score ≥ 10 was inversely related to all PA characteristics individually and to average intensity and diversity of PA when mutually adjusted in both men and women (Table). Table: - Adjusted CES-D ≥ 10 odds ratio (95% CI)* Women Men Physical Activity, Weekly Individually Adjusted Mutually Adjusted Individually Adjusted Mutually Adjusted Volume (per MET·hour) 0.99 (0.99, 0.99) 1.00 (0.99, 1.01) 0.99 (0.99, 0.99) 1.00 (0.99, 1.01) Average intensity (per MET) 0.88 (0.86, 0.90) 0.94 (0.90, 0.99) 0.92 (0.90, 0.93) 0.96 (0.93, 1.00) Duration (per hour) 0.93 (0.91, 0.94) 1.00 (0.92, 1.08) 0.93 (0.92, 0.95) 1.01 (0.94, 1.07) Type (versus None) Aerobic 0.51 (0.45, 0.58) 0.87 (0.68, 1.12) 0.58 (0.52, 0.64) 0.86 (0.71, 1.05) Strength 0.49 (0.39, 0.60) 0.89 (0.67, 1.20) 0.61 (0.53, 0.71) 0.97 (0.77, 1.22) Mixed 0.54 (0.41, 0.70) 1.00 (0.69, 1.43) 0.48 (0.37, 0.62) 0.75 (0.55, 1.03) Flexibility 0.70 (0.57, 0.87) 1.07 (0.82, 1.40) 0.99 (0.76, 1.30) 1.30 (0.97, 1.73) Diversity (per bit) 0.71 (0.67, 0.75) 0.81 (0.75, 0.88) 0.77 (0.73, 0.81) 0.86 (0.80, 0.92) CONCLUSION: Individually, all PA variables were each negatively associated with the risk of depressive symptoms. However, when all PA characteristics were modeled together, the most important predictors of depressive symptoms were intensity and diversity of PA.