According to a study done at UT Southwestern Medical Center, supposedly exercise alone can help reduce symptoms of mild to moderate depression. The researchers in this study surveyed adults aged 20 to 45, and found that their depressive symptoms were reduced almost 50 % in those people who participated in 30-minute aerobic exercise sessions 3-5 times per week.

The results of this study were published in the January 2005 issue of the American Journal of Preventive Medicine, and are comparable to results from other studies where patients who had mild to moderate depression were treated with Antidepressants or cognitive therapy.

According to Dr. Trivedi, one of the authors of the study, 'The effect you find using aerobic exercise alone in treating clinical depression is similar to what you find with antidepressant medications. The key is the intensity of the exercise and continuing it for 30 to 35 minutes per day.'

The study included 80 people who were placed randomly into five groups. Two of the groups participated in moderately intense aerobics which were consistent with public health recommendations (one of those groups exercised three days per week, with the other exercising for five days).

Two other groups in the study participated in lower-intensity aerobics for 3 days and 5 days a week. A fifth group in the study did flexibility/stretching exercises 15 to 20 minutes, 3 days a week.

People that participated in the moderately intense aerobics did experience a decline in their depressive symptoms by an average of 47 % after 12 weeks. Those people in the low-intensity exercise groups showed a 30 % reduction in their symptoms. And those in the last group averaged a 29 % decline.

Most people do not think of exercise as a treatment for depression; however, this study does suggest that it can have that effect. As many as 19 million people in the United States are thought to suffer from depressive disorders1. Exercising on a regular basis can help many of these people lift the symptoms of their depression. Reference: American Journal of Preventive Medicine, January, 2005

1National Institute of Mental Health (NIMH)