Associations of exercise frequency and cardiorespiratory fitness with symptoms of depression and anxiety - a cross-sectional study of 36,595 adults

Abstract Introduction Regular exercise has been associated with better mental health, but relationships of cardiorespiratory fitness (CRF) with mental health symptoms are less certain. We conducted a large cross-sectional study to examine associations of exercise frequency and objectively measured CRF with symptoms of depression and anxiety. Methods Data originates from the Swedish Health Profile Assessment (HPA) database, a general health assessment offered to all employees working for companies or organizations connected to occupational and health services. Participants reported the frequency (last 30 days) of structured exercise and completed a 6-min VO2max test on a cycle ergometer to determine CRF. Data on relevant covariates including leisure-time sedentary behavior were also collected. The study outcome was self-reported frequent (often/very often) symptoms of depression and anxiety. Results Complete data from 36,595 participants were analyzed (41% female, mean age = 42 years). In fully-adjusted models, compared to those in the lowest exercise frequency category (never/sometimes), those exercising 1–2 times/week and ≥3 times/week had 0.75 (95% CI = 0.68–0.82) and 0.72 (95% CI = 0.65–0.79) lower odds of reporting frequent symptoms of depression/anxiety, respectively. For CRF, crude models indicated a dose-response with the odds of frequent depression/anxiety symptoms reducing with higher CRF levels (low versus medium and high, respectively). No associations were found after adjustment for leisure-time sedentary behavior. Conclusions Exercising at least 1–2 times per week is associated with lower odds of depression/anxiety symptoms. Leisure-time sedentary behavior attenuates relationships of CRF with depression/anxiety symptoms.