Bright-light exposure combined with physical exercise elevates mood

Background: Physical exercise alleviates depressive symptoms, as does exposure to bright light, especially in those with seasonal variation. Our objective was to compare the effect of exercise alone or combined with morning bright light on mood and the health-related quality of life in healthy subjects. Methods: Study subjects were working-age adults, randomized in two groups (n=80): exercise in bright light (group A), or exercise in normal indoor illumination (group B). Intervention lasted for 8 weeks and questionnaire data on mood and the health-related quality of life were collected at study entry, and at weeks 4 and 8. Results: Physical exercise both in normal indoor illumination and in bright light was effective at alleviating depressive symptoms. The exercise was significantly more effective at alleviating so-called atypical depressive symptoms when combined with bright-light exposure. Limitations: There was no active placebo condition, but a comparative, randomized trial was executed. Conclusions: Physical exercise in bright light had a positive effect on mood and health-related quality of life in a sample of healthy, working-age people. Further research is needed to explore the mechanisms of the apparent additive effect of exercise and light.