BACK TO WEB VERSION

SUMMER 2005
Combating Inactivity
by Sara LaJeunesse

Some people believe that “it’s better to look good than to feel good,” but the fact is that while exercise can improve outward appearance, it’s what it does on the inside that really counts.

Exercise not only tones muscles but also keeps blood vessels fit, which leads to a longer and healthier life. So when injury or disease prevents a person from exercising, maintaining vascular (blood-vessel) health can become a challenge.

Kevin McCully, a professor of exercise science at UGA, studies vascular health in inactive people, focusing in particular on individuals with spinal cord injuries and chronic fatigue syndrome.

“Most heart attacks and strokes are the result of unhealthy blood vessels,” McCully said. “Our goal is to identify when someone is at risk early enough to do something about it.”

McCully, UGA graduate student Lee Stoner and other UGA colleagues have studied the vascular health of people with spinal cord injuries and found that their arteries were stiffer than those of active people — that is, the sedentary group’s blood vessels didn’t expand or contract very much.

“This may mean that the heart is at greater risk,” Stoner said, “because the arteries can no longer buffer the blood pressure.”

But people with spinal cord injuries aren’t doomed to suffer the effects of unhealthy blood vessels. In a separate study, McCully, Stoner and colleagues showed that electrical stimulation of leg muscles two times a week — to mimic three sets of 10 leg lifts — can reduce vessel stiffness and improve patients’ vascular health. The researchers expect to publish findings from both studies in the journal Clinical Science later this year.

While spinal cord injuries may make movement difficult or impossible, chronic fatigue syndrome often robs people of the energy to move in the first place. Characterized by medically unexplained fatigue lasting six months or more, this disorder affects some half a million Americans at any given time. In most cases, people are too exhausted to work, much less work out.

McCully’s studies of circulation in chronic fatigue syndrome patients have not yielded clear-cut findings. He has shown that the patients display reduced oxygen delivery to muscles compared with sedentary, able-bodied people, but in a prior study he found no differences between the two groups. McCully said he believes these contradictory findings mean that people with chronic fatigue syndrome may have small but unimportant changes in blood flow.

“I don’t think that vascular health is where their problem is,” he said. “I want to focus more on why they can’t be physically active — why they can’t sustain activities.”

In one new project, he said he hopes to determine whether exhaustion in chronic fatigue syndrome patients is related to an abnormal inflammatory response associated with an overproduction of immune system proteins.

“Some of these proteins have been linked to increased tiredness,” McCully said.

McCully’s research has implications for other inactive individuals, such as the elderly and the obese. In another new project, he is investigating the relationships between obesity, physical activity and vascular health in women; this study is being done in collaboration with UGA graduate student Manning Sebatier and colleagues from the Medical College of Georgia and Georgia Prevention Institute.

“We will examine a spectrum of women who vary in terms of fitness level and amount of body fat,” Sebatier said.

For more information, contact Kevin McCully, kmccully@coe.uga.edu.