Exercise has long been advocated as a treatment for depression. A 2000 study published in "Psychosomatic Medicine" found that moderate aerobic exercise was as effective as medication in decreasing symptoms of major depression and that subjects who exercised had lower occurrence of relapse than medicated subjects. However, exercise has a point of diminishing returns; increasing your exercise levels too quickly without enough rest can negatively affect your emotional state and cause depressive symptoms.
Overtraining Syndrome and Depression
Overtraining syndrome is the state you reach if you exercise to this point of diminishing return. You are unable to improve your performance despite increases in training intensity or duration and you may develop overuse injuries, changes in your blood chemistry, decreased immune function, increased resting blood pressure and heart rate, and negative changes in your mood. Overtraining occurs if you engage in prolonged, intense exercise without allowing enough time for rest and recovery. According to an article from the University of Mexico's Exercise Science website, depression and chronic fatigue are the two most common symptoms recognized in overtraining syndrome.
Causes of Exercise-Induced Depression
The causes of overtraining syndrome and resulting depression are unknown, but "The Physiology of Sports and Exercise" states that the symptoms of overtraining are so similar to those of clinical depression that the etiology -- or physiological causes -- may be the same for both conditions. In both overtraining syndrome and clinical depression, there are changes in brain structures, neurotransmitters, endocrine pathways and immune function.
Treatment
Fortunately, depression caused by overtraining is easy to treat. According to a 1987 article published in the "British Journal of Sports Medicine," mood disturbances caused by overtraining subside when you reduce your training intensity and duration, and allow more recovery between training sessions.
Prevention
Preventing exercise-induced depression involves gradual increases in exercise intensity and duration, and allowing adequate recovery. When increasing your training level, try to change only one aspect at a time. For instance, if you are increasing the intensity, you should combine it with a decrease in duration and vice versa. You should always pay attention to how your body feels during and after your workouts, and back off the intensity and/or duration if you begin feeling excessively tired or moody.
References
- "Psychosomatic Medicine"; Exercise Treatment for Major Depression: Maintenance of Therapeutic Benefit at 10 Months; Michael Babyak, Ph.D., et al.; 2000
- Exercise Science at the University of New Mexico; Overtraining: Undermining Success?; Paige Kinucan et al.
- "British Journal of Sports Medicine"; Psychological Monitoring of Overtraining and Staleness; W.P. Morgan et al.; 1987
- "Physiology of Sport and Exercise"; Jack H. Wilmore et al.; 2008
- "Overtraining Syndrome: A Clinical Perspective"; Francis G. O'Connor, M.D, M.P.H.
