That's what the latest study reports.
Could exercise actually be bad for some healthy people? A well-known group of researchers, including one who helped write the scientific paper justifying national guidelines that promote exercise for all, say the answer may be a qualified yes.
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 measure related to heart disease: blood pressure and levels of insulin, HDL cholesterol or triglycerides. About 7 percent got worse on at least two measures. And the researchers say they do not know why.
“It is bizarre,” said Claude Bouchard, lead author of the paper, published on Wednesday in PLoS One, and a professor of genetics and nutrition at the Pennington Biomedical Research Center, part of the Louisian State University system.
Dr. Michael Lauer, director of the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute, the lead federal research institute on heart disease and strokes, was among the experts not involved in the provocative study who applauded it. “It is an interesting and well done study,” he said. (continue reading at Well Blog NYT)
The conclusion? You guessed it -- there is a need for more study to know more about what exercise actually does.
Over the years we have been told that coffee is bad, then it's good. Same thing for wine, same thing for butter, same thing on and on and on.
All things in moderation. Do what you like. Enjoy life.