Though there's no definitive research showing exercise by itself can cure depression (search), many mental health experts agree that it has positive mental benefits and can be a useful tool in overall therapy.
Life changed for Reed Steele five years ago when a series of injuries kept him from competing for his college cross country and track teams.
Unable to run, he got depressed. He turned to drugs and alcohol, hoping they could provide the escape that running had. Before long, his depression deepened until he was hospitalized and suicidal.
Today the 25-year-old feels better, thanks to a combination of antidepressants (search), therapy — and exercise, a combination of swimming, cycling and moderate running.
"Exercise is extremely important for mental health," said Steele, of Roseville, a Twin Cities suburb. "When I was really depressed I wasn't exercising ... I didn't have any desire to do anything."
Depression is a serious illness thought to be related to chemical imbalances in the brain, much more severe than an occasional case of "the blues." Depression affects the whole body: energy level, appetite and concentration.
"What we're really finding is that people that are depressed are quite inactive, both in kind of expending energy and in getting things done, working toward goals, taking care of personal business," said Matt Kushner, a clinical psychologist and associate professor of psychology at the University of Minnesota.
He recommends exercise for his patients as part of therapy that emphasizes routines, habits and goals. In addition, he said, patients who start exercising find they feel better and are less inclined to overeat or abuse drugs and alcohol.
"If I could pick one activity from a long list ... exercise would always be the one I would go to," he said. "Exercise is sort of a gift that keeps on giving."
Dr. Douglas G. Jacobs, associate clinical professor of psychiatry at Harvard Medical School, said it's important to understand that exercise alone doesn't cure depression.
"The general evidence is that the best treatment for depression is a combination of medication and psychotherapy," he said. "I haven't seen anything that says exercise as a sole treatment for depression is effective."
However, he said people with depression should try to exercise, because it improves their overall health.
Sue Masemer, an exercise physiologist at the Flagship Athletic Club in Eden Prairie, said there's no definitive research explaining exactly how exercise affects one's mood, but evidence shows a link between exercise and neurotransmitters in the brain. And, she said, there's no doubt there's a connection between the physical body and the mental psyche.
"There are those pieces that are almost somewhat intangible," Masemer said. "As (people) get in better shape, they have more energy, accomplish more ... people are amazed at what they are able to accomplish, physically and emotionally."
Diane Strand, a 41-year-old mother of two who was diagnosed with depression about two years ago, said she started running about 10 years ago as a way to get rid of stress after going through a divorce. Running helps her "think things through" and let off steam.
"When I feel stressed I go for a run and when I come home I feel like a whole new person," said Strand, of Cedar Rapids, Iowa.
She said she began running 10K races and half-marathons, and eventually a full marathon, and she found that each one built her self-confidence. "It is more mental than it is physical," she said. She also lost 25 pounds when she first started running — a big boost to her self-esteem.
"I think when I can be on a steady exercise program, like when I'm training, that's when I find that I really don't need my medications," said Strand, who started her own brokerage insurance company and is engaged to be married. "I definitely can tell a big difference."
Steele, the former competitive runner, now is studying psychology at the University of Minnesota. He no longer uses drugs or alcohol, he says. He exercises about five times a week, though not nearly at the intensity of his competitive career.
"I think I still get down, but it's not nearly to the level where I was," Steele said. "Now it's more just what a lot of people go through."