How does Exercise Improve Mental Health?

We know that exercise has positive effects on the brain. Researchers at Duke University demonstrated several years ago that exercise can be an effective antidepressant. Other research has shown that exercise can improve the brain functioning of the elderly, and may even protect against dementia. How does exercise improve mental health?

One theory for some of the benefits of exercise included the fact that exercise triggers the production of endorphins. These natural opiates are chemically similar to morphine. They may be produced as natural pain-relievers in response to the shock that the body receives in exercise. Researchers are beginning to question whether these substances improve mood. Studies show that endorphins do not cross the blood-brain barrier easily. Their ability to relieve pain probably occurs at the level of the spinal cord, leaving some other mechanism responsible for the mental health effects of exercise.

Recent studies have found that exercise boosts activity in the brain's frontal lobes and the hippocampus. We don't really know how or why this occurs. Animal studies have found that exercise increases levels of serotonin, dopamine and norepinephrine. These neurotransmitters have been associated with elevated mood, and it is thought that antidepressant medications like Prozac also work by boosting these chemicals.

Exercise has also been found to increase levels of "brain-derived neurotrophic factor" (BDNF). This substance is thought to improve mood, and it may play a role in the beneficial effects of exercise. BDNF's primary role seems to be to help brain cells survive longer; so this may also explain some of the beneficial effects of exercise on dementia.

The bottom line is that most of us feel good after exercise, and it's probably not from endorphins. Physical exercise is good for our mental health and for our brains. Someday we will understand it all better - but we can start exercising today.

Last updated 4/27/06

Sources - About.com, John Briley "Feel Good After a Workout? Well, Good for You." The Washington Post Tuesday, April 25, 2006; James A. Blumenthal, et.al. "Effects of Exercise Training on Older Patients With Major Depression". Archives of Internal Medicine, October 25, 1999; Michael Babyak, et.al. Exercise Treatment for Major Depression: Maintenance of Therapeutic Benefit at 10 Months. Psychosomatic Medicine, September/October 2000.