Wed May 16, 2007 9:21AM EDT
By Maggie Fox, Health and Science Editor
WASHINGTON (Reuters) - Just 10 minutes of exercise a day can help even the most inactive overweight women, U.S. researchers reported on Tuesday.
Tests on overweight and obese women, many of whom had high blood pressure, showed that even small amounts of exercise improved their fitness and toned them up enough to lower their overall risk of early death.
The study is the first to reinforce using hard medical data what other studies have suggested -- that exercise does not have to be an all-or-nothing venture, Dr. Timothy Church of Louisiana State University and colleagues said.
"This information can be used to support future recommendations and should be encouraging to sedentary adults who find it difficult to find the time for 150 minutes of activity per week, let alone 60 minutes per day," the researchers wrote in their report, published in the Journal of the American Medical Association.
While virtually everybody knows that exercise is good for you, 20 percent of U.S. adults admit they do no exercise whatever and most do not get as much as is recommended.
The U.S. Centers for Disease Control and Prevention and National Institutes of Health recommend at least a half hour on most days a week of moderate exercise to reduce the risk of heart disease, stroke and cancer.
The Institute of Medicine, which advises the federal government, says people need to get themselves slightly out of breath for closer to an hour every day.
But Church and colleagues wanted to see whether women overwhelmed at the idea of that much work might be helped by something they consider a little more manageable.
They studied 427 overweight women with high or borderline-high blood pressure who had an average age of 57.
The volunteers were randomly assigned to continue their normal lives or to exercise 75 minutes a week, 135 minutes a week or 190 minutes a week. This works out to just what the NIH and CDC recommend, half as much as recommended, and 150 percent of what they recommend.
"The women in this study walked on treadmills and rode stationary cycles, but any activity of comparable energy expenditure would produce similar results," said Dr. Steven Blair of the University of South Carolina, who worked on the study.
"Any type of moderate intensity physical activity should provide comparable benefits to those seen in our study. And that's good news. This can include work around the house and yard, swimming, playing in the park with your grandchildren, or other activities that are of a similar intensity to brisk walking."
After six months, the women had not lost any weight on average and their blood pressure, as a group, had not changed.
But all the women who had exercised were fitter, as measured by oxygen intake as they exercised. And their waists were smaller.
Waist circumference is an important indicator of health risk. Women with waists bigger than 35 inches and men whose waists are bigger than 40 inches (100) have a documented higher risk of early death.
"Even a little is good; more may be better!" I-Min Lee, of the Brigham and Women's Hospital and Harvard Medical School in Boston wrote in a commentary.
