Extreme exercise found not to increase risk of cardiovascular disease, say scientists

Does extreme exercise make middle-aged male athletes more prone to heart problems? No, says sports cardiologist Dr Benjamin Levine

Published: February 7, 2019 at 9:34 am

In 2017 a scientific study found that middle-aged athletes are more at risk of calcium building up in the arteries, however that doesn't make them more prone to the heart becoming compromised and injured, a new study has found.

“The question has never been whether exercise is good for you, but whether extreme exercise is bad for you. For the past decade or so, there’s been increasing concern that high-volume, high-intensity exercise could injure the heart. We found that high volumes of exercise are safe, even when coronary calcium levels are high,” lead author sports cardiologist Dr. Benjamin Levine, who is Professor of Internal Medicine and Director of the Institute for Exercise and Environmental Medicine, collaboration between UT Southwestern Medical Center and Texas Health Presbyterian Hospital Dallas.

Using data from the Cooper Center Longitudinal Study Dr. Levine studied the stats on 21,758 generally healthy men, aged 40 to 80, without cardiovascular disease, who were followed for mortality between 1998 and 2013. The athletes, the majority of them in middle age, reported their physical activity levels and underwent regular coronary calcium scanning. Most were predominantly runners, but some were cyclists, swimmers, or rowers. There was also a subgroup of triathletes.

Coronary calcium scanning is an imaging test that helps medics classify patients without cardiac symptoms as low, intermediate, or high risk for heart attack. It represents how much calcium (and thus cholesterol deposits) has accumulated in the blood vessels that supply the heart. The scan can help physicians determine the need for medication, lifestyle modification, and other risk-reducing measures.

The majority of the high-intensity athletes in the study had low levels of coronary calcium, though their odds of having higher levels were 11% greater than men who exercised less. Most importantly, the researchers found that higher calcium scores did not raise the high-intensity athletes’ risk for cardiovascular or all-cause mortality.

"Calcium is simply to footprint of atherosclerosis; that is, a marker of the presence of the atherosclerotic process," said Dr. Levine. It is not actually the calcified plaque that we are worried about though, and calcified plaques are more stable, and less likely to rupture and cause a heart attack.

“The current study shows no increased risk of mortality in high-volume exercisers who have coronary artery calcium. Certainly, these high-volume exercisers should review their cardiovascular disease risk with their primary care doctor or cardiologists and the study results provide helpful clinical guidance.”

“The most important take-home message for the exercising public is that high volumes of exercise are safe. The benefits of exercise far outweigh the minor risk of having a little more coronary calcium.”

The study is now published in JAMA Cardiology