> People aged 35 or older who exercise intensively for years run a higher risk of specific cardiovascular diseases. This is the conclusion of new international research in which Radboudumc participated. Cardiovascular diseases are often not considered in relation to athletes, says researcher Thijs Eijsvogels. This is unjustified, it now appears. Heart rhythm disorders and calcification of the coronary arteries actually occur more frequently among very dedicated athletes. However, this concerns very intensive exercise, says Eijsvogels. "Exercise where your heart rate and breathing rise significantly, to the point where you can no longer hold a decent conversation." Nor does it concern a one-off intensive workout, but at least five to ten years. "Exercising is healthy in principle," emphasizes Eijsvogels. "It lowers the risk of premature death and numerous chronic diseases." The greatest health benefits can be achieved if someone who does not exercise becomes active. The Health Council's recommendation is to engage in at least 150 minutes of moderate-intensity physical activity per week. "If you exercise between three and five hours a week, you have reached your maximum health benefits," says Eijsvogels. "Above that, it doesn't yield much more." Therefore, beyond a certain amount and intensity of exercise, additional risks actually arise, says the researcher. "But we don't yet know exactly where that tipping point lies." It is also not yet known why avid athletes suffer more frequently from cardiac arrhythmias and calcification of the coronary arteries. However, it is clear that cardiovascular disease manifests differently in avid athletes than in people who have exercised normally or not at all. They may notice this through a sudden loss of performance during exercise, says Eijsvogels. "For example, if you can no longer cycle at the pace you were doing before and see on your sports watch that this coincides with a temporary disruption of the heart rhythm."