Having posted this yesterday Marathon running and heart attacks here's another NYT article saying a small minority of people have one or more risk factors rise when they have an exercise program.
A very good article; hit the link ro the whole thing.
By analyzing data from six rigorous exercise studies involving 1,687 people, the group found that about 10 percent actually got worse on at least one of the measures related to heart disease:blood pressure and levels of insulin, HDL cholesterolortriglycerides. About 7 percent got worse on at least two measures. And the researchers say they do not know why.
“There are a lot of people out there looking for any excuse not to exercise,” said William Haskell, emeritus professor of medicine at the Stanford Prevention Research Center. “This might be an excuse for them to say, ‘Oh, I must be one of those 10 percent.’ ”
But counterbalancing the 10 percent who got worse were about the same proportion who had an exaggeratedly good response on at least one measure. Others had responses ranging from little or no change up to big changes, seen in about 10 percent, where risk factor measurements improved anywhere from 20 percent to 50 percent.
“That should make folks happy,” said Dr. William E. Kraus, a co-author of the study who is a professor of medicine and director of clinical research at Duke. He was a member of the committee providing the scientific overview for the Department of Health and Human Services’ national exercise guidelines, which advise moderate exercise for at least 150 minutes a week.
The problem with studies of exercise and health, researchers point out, is that while they often measure things like blood pressure or insulin levels, they do not follow people long enough to see if improvements translate into fewer heart attacks or longer lives. Instead, researchers infer that such changes lead to better outcomes — something that may or may not be true.