Many studies performed over the last 10 years illustrate that exercise lifts mood and can relieve various mental disorders.
One recent major study, published in the January issue of American Journal of Preventive Medicine, showed that adults aged 20 to 45 with mild to moderate depression who participated in 30-minute aerobic exercise sessions three to five times a week reduced their symptoms by almost 50 percent.
Texas Southwestern Medical Center in Dallas, performed the study involving 80 people divided into five groups. One group performed moderately intense aerobic exercise five days a week, and another group did the same workout three days a week. Two other groups mimicked that schedule but did lower-intensity aerobic activity. The fifth group did 15 to 20 minutes of stretching exercises three days per week.
Participants in both moderately intense groups experienced a decline in depressive symptoms by an average of 47 percent after 12 weeks. Those in the lower-intensity groups showed a 30 percent drop in symptoms, and those in the stretching group averaged a 29 percent decline.
James Blumenthal conducted oft-cited studies, published in Archives of Internal Medicine in 1999 and 2000, that treated older adults suffering from a major depressive disorder with 30 minutes of exercise three times a week or the antidepressant Zoloft, or both.
The exercise group showed better improvement in symptoms than the other two groups. Blumenthal said he was not shocked that exercise outperformed Zoloft alone, but was somewhat surprised to see that those who only worked out did better than those who exercised and took Zoloft.
"I don't really know" what might explain that, he said. "Maybe [the exercise-only] people are gaining a sense of self-mastery" without any help from a drug, he said. "I can't help but think that's a part of it."
With exercise, one begins to see improvements in depression markers after a few weeks, John Ratey (an associate clinical professor of psychiatry at Harvard Medical School and a specialist in mood disorders) noted, about as long as it takes antidepressant drugs to begin working in many people. "And we are talking about seriously ill people here -- the clinically depressed. They are responding to exercise."
(Article from John Briley -Washington Post).