The research builds on what is already known about the benefits of exercise and fills in some gaps by addressing the effects of fitness in blacks.
"A little bit of exercise goes a long way," said Peter Kokkinos, lead author of the study. "Thirty minutes a day, five days a week of brisk walking is likely to reduce the risk of mortality by 50 percent if not more."
With 15,660 participants, the researchers said the study is the largest to look at the link between fitness and mortality. The study also sets itself apart by looking at how exercise affects blacks, whose death rates are higher than whites. About 43 percent of the veterans in the study were black.
The findings were published Tuesday online in the American Heart Association journal Circulation.
A treadmill test was used to determine the fitness level of the veterans at facilities in Washington, D.C., and Palo Alto, Calif. The men
-- who had an average age of 60 -- were then put into four categories ranging from "low fit" to "very highly fit." Researchers followed up for an average of eight years to see who was still alive.
The study showed that as fitness levels went up, the risk of death dropped for both blacks and whites. When researchers looked at blacks and whites with heart disease, results were similar.
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In the least fit group, 44 percent died; for moderately fit, 30 percent; highly fit, 15 percent; and very highly fit, 8 percent.
"Exercise is just as beneficial to African-Americans, in fact in some cases it might be more," said Kokkinos, director of Exercise Testing and Research Lab in the cardiology department at the Veterans Affairs Medical Center in Washington.
Experts say that the study's strengths include its size and that all participants had the same access to health care since they were VA patients. The researchers, however, didn't know the cause of death or how physically active the veterans were.
Kokkinos said the veterans took the exercise treadmill tests for various reasons, including everything from annual checkups to complaints of chest pain. He said they excluded anyone with serious problems.
Dr. Tracy Stevens, a cardiologist with Saint Luke's Mid America Heart Institute in Kansas City, Mo., said that the study reinforces the need for doctors to talk with their patients about exercise.
"This is more evidence that exercise is one of the best medicines that we have," said Dr. Randal Thomas, director of the Cardiovascular Health Clinic at the Mayo Clinic.
On the Net:
American Heart Association, http://www.americanheart.org/
Press; By JAMIE STENGLE]
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