. . .A study published in the current edition of Missouri Medicine found that 50 men who had run at least one marathon a year for 25 years had higher levels of coronary-artery plaque than a control group of sedentary men. A British Medical Journal study published this year compared the carotid arteries of 42 Boston Marathon qualifiers with their much-less active spouses. “We hypothesized that the runners would have a more favourable atherosclerotic risk profile,” says the article. As it turned out, that hypothesis was wrong.
A small body of research suggests that heart problems may arise not in spite of extreme-endurance exercise but because of it. That has led some cardiologists to theorize that, beyond a certain point, exercise stops preventing and starts causing heart disease.
“Studies support a potential increased risk of coronary artery disease, myocardial fibrosis and sudden cardiac death in marathoners,” Peter McCullough, a Baylor University cardiologist, wrote as lead author of an editorial in the current Missouri Medicine. . .