Fit but Foul

Why running outside may be better for your brain--even if it's hard on your knees.

By PT Staff, published on May 01, 1995 - last reviewed on August 30, 2004

If you're shooting for a runner's high, you're not likely to find it on a treadmill.

The psychic benefits of running are all in the setting, says Georg Eifert, Ph.D., a University of West Virginia psychologist.

Eifert recorded hormonal and mood changes in 10 avid runners after they jogged in three different terrains: the first around a college campus, then twice inside on a treadmill. During the first indoor run, the athletes listened to a tape recording of the sounds in a botanical garden. The second was to the tune of their own heartbeat, recorded and amplified as they ran.

Heart rates were accelerated after every run, but cardiovascular benefits are not all there is to exercising. Eifert found that after the outdoor run, the athletes felt more invigorated, refreshed, and happy than before they started. And their bodies showed it: Levels of adrenaline and noradrenaline, hormones associated with positive mood, were up. Levels of the stress hormone cortisol were down.

Running indoors to the beat of their own hearts, runners felt more fatigued and depressed after than before. Their physiology matched their foul mood: Adrenaline levels dropped, cortisol climbed. The run with the botanical recording begat no mood changes, and negligible hormonal changes.

Even though your heart doesn't care where you run, your head does. If your mood sours after a treadmill run, you aren't likely to continue to exercise at all.

So pack the treadmill into the hall closet--where all good exercise equipment goes to die--and take to the streets.