UGA Research Magazine

Regular Exercise Better Than Stimulants at Reducing Fatigue

by Sam Fahmy



Forget so-called “energy drinks.” A new analysis by University of Georgia researchers finds overwhelming evidence that regular exercise plays a significant role in increasing energy levels and reducing fatigue.

“A lot of times when people are fatigued the last thing they want to do is exercise,” said professor Patrick O’Connor, co-director of the UGA exercise psychology laboratory. “But if you’re physically inactive and fatigued, being just a bit more active will help.”

Health professionals encourage regular exercise, but the scientific evidence on whether it increases or reduces fatigue had never been reviewed quantitatively. O’Connor, kinesiology professor Rod Dishman and lead author Tim Puetz analyzed 70 randomized, controlled trials of 6,807 subjects.

“More than 90 percent of the studies showed the same thing,” O’Connor said. “Sedentary people who completed a regular exercise program reported reduced fatigue compared to groups that did not exercise. It’s a very consistent effect.”

The study, published in the November 2006 issue of the journal Psychological Bulletin, found that the effect of exercise was stronger than treatment with stimulants such as the narcolepsy drug modafinil. Specifically, exercise increased energy and reduced fatigue by 0.37 standard deviations when compared to control groups, whereas participants in a previous study taking the narcolepsy drug modafinil had an improvement of 0.23 standard deviations.

The analysis found that nearly every group studied—from healthy adults to cancer patients to those with chronic conditions such as diabetes and heart disease—benefited from exercise.

“We live in a society where people are always looking for the next sports drink, energy bar or cup of coffee that will give them the extra edge to get through the day,” Puetz said. “But it may be that lacing up your tennis shoes and getting out and doing some physical activity every morning can provide that spark of energy that people are looking for.”

For more information contact Tim Puetz at, Patrick O’Connor at, or Ron Dishman at


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