Exercise Could Be, Er, Bad for Your Heart, Study Says

Exercise could affect your risk of heart problems. Photo credit: Ed Yourdon

The background

Claude Bouchard, professor of genetics and nutrition at the Pennington Biomedical Research Centre, and his group of researchers have published a paper in the journal PLoS One which reveals that for about 10 percent of people studied, exercise created an increased risk of heart disease.

What do these results mean for the public? The Periscope Post finds out.

What do the results show?

The New York Times reported on the findings and flagged up that out of six separate exercise studies which examined 1687 people, around 10% of people got worse in at least one measure that is related to heart disease risk, such as blood pressure, insulin levels, and HDL cholesterolortriglycerides. Furthermore, around 7 percent got worse on at least two measures. The New York Times said “the researchers said they don’t know why” this happened.

The idea of exercise being bad for some people’s hearts is also backed up by Dr Mark Wiley on his blog. He quoted a study from the New York University Medial Centre, which found that men who exercised hard enough to break a sweat five-to-seven days a week increased their risk of atrial fibrillation by 20%. Those who didn’t exercise did not increase their risk.

Were there any good results?

Yes: to counterbalance the 10 percent whose heart risk got worse, there was about the same proportion of people who had an “exaggeratedly good response” to exercise, with some people improving by between 20 percent and 50 percent. Yet the results may not concretely mean that there will be more or fewer heart attacks or strokes: this is because exercise trails do not follow the participants afterwards, but rather predict their likeliness of having such illnesses. The New York Times described this type of exercise study as hypothesis-generating rather than proof.

What can be done to reduce the risk?

The New York Times said that some doctors are worried that this will give some people an excuse not to exercise. The doctors polled advised people who do exercise to continue to exercise as before: and it may be that researchers need to figure out how to tailor exercise plans to individual needs. There should also be more research into the actual effects of exercise, which at the moment is under-studied.