I hear it often: A friend swears that her running practice staves off bouts of low spirits. Another says going to the gym before work keeps him mentally steady.
Perhaps you’ve heard similar stories; perhaps you believe it for yourself.
Those anecdotes prompt some questions. Is there evidence to support the idea that exercise can have an effect on depression? And if so, how much exercise? A number of research studies have been done to answer those questions and others.
One study assigned participants, 202 depressed adults at least 40 years old, to one of four groups. One group attended supervised group exercise sessions three times per week, where they monitored their heart rate as they walked or jogged on a treadmill for 30 minutes. A second group received similar instructions but were left to work out on their own at home. Groups three and four took pills: either the antidepressant medication sertraline or a placebo.
After 16 weeks, researchers rescreened participants for depression and found 45 percent of the people in the supervised exercise group no longer met the criteria for major depression. In the other groups, 40 percent of home exercisers, 47 percent of medicine takers and 31 percent of placebo pill takers were no longer depressed.
That’s right, the supervised exercisers did as well as the people who took an antidepressant. As promising as these results were, however, it was a small study.