• Image about Tedd Mitchell

New research is proving that what’s good for the body is good for the mind too.

Still postponing that fitness routine? Now you have even more reason to shift into gear. Exercise, long touted for shedding those pounds, can also lighten your mind’s load, according to an accumulating body of research.

For years, well into the 1990s, those pleasurable chemicals called endorphins reaped the credit for that burst of energy and optimism you got after a workout, says Tedd Mitchell, MD, president and CEO of the Dallas-based Cooper Clinic. “But the benefit of physical activity is probably multifactorial — it’s not just the old endorphin high people used to talk about.”

Exercise appears to influence the circulation of mood-linked neurotransmitters, such as serotonin and dopamine, he says. Plus, as anyone who runs can attest, a few miles can jettison some anxiety-producing adrenaline. “It’s like taking a dose of a tranquilizer,” Dr. Mitchell quips.

And that payoff can persist long after cooling off, according to University of Vermont research presented at last year’s American College of Sports Medicine meeting. The study, which tracked mood for 24 hours after a workout, found that participants were more upbeat as many as 12 hours later.

What’s exciting exercise enthusiasts like Dr. Mitchell, though, is that animal studies are starting to provide further insights intobrain-related hypotheses “that indeed you are changing the brain structure itself,” he says.

Researchers at the University of Colorado at Boulder, for example, have found indications of a protective effect. Through a series of studies, they’ve learned that active rats react less to a stressful event compared with their sedentary counterparts. Their brains also exhibit less serotonin activity. Better understanding that psychological buffer is important, research associate Benjamin Greenwood explains, “because stress can increase depression and anxiety.”

Sustained exercise — for the rats, it meant running on a wheel for a set amount of time each day for six weeks — appears to be necessary. The lower stress response was identified in the rats after six weeks of running but not at three weeks.

In fact, regular exercise may mirror an antidepressant’s benefits in people with mild or moderate depression, according to onestudy involving Cooper researchers that focused on women. After three months of aerobic exercise, participants said their symptoms declined by 47 percent, which was similar to a pill’s effectiveness, Dr. Mitchell says.

But those results require time — at least 30 minutes several times a week — and physical exertion, says Mitchell, a coauthor of Move Yourself. You should be breathing hard and only able to talk in clipped sentences, which is roughly equivalent to a four-miles-per-hour walking pace, he says. “You can’t just stroll around the yard and make yourself feel better.”

The emotional lift should kick in quickly, a week or two after launching an exercise regimen, Dr. Mitchell says. If it doesn’t, he says, seek out a doctor’s help.

For most of us, there’s likely room for improvement.

According to federal statistics, only one-fourth of Americans exercise vigorously, breaking a sweat at least three times each week. A fitness regimen may be just the mood boost many people need.