Intense training and the heart: sport is good for you, but after the age of 35 personalised check-ups are needed

Regular physical activity is one of the main tools for cardiovascular prevention and contributes to greater longevity. But what happens when training becomes very intense, continues for decades and reaches volumes similar to those of professional athletes?

A recent narrative review, Does too much exercise damage the heart? A narrative review of the long-term cardiovascular effects of intense training,, published in the European Journal of Preventive Cardiology and coordinated by Alessandro Zorzi, lecturer in the Department of Cardiac, Thoracic, Vascular Sciences and Public Health at the University of Padua, answers this question. The work analysed the most recent scientific literature, with particular attention to studies published since 2020 and research on large populations.

The analysis mainly concerns endurance sports, such as running and cycling, practised for many hours a week and for many years, with particular attention to master athletes, that is, sportswomen and sportsmen aged 35 and over. There is, however, no training threshold beyond which exercise automatically becomes harmful for everyone.

The data indicate that, in a small proportion of athletes, intense and prolonged activity may be associated with electrical and structural changes in the heart. In men with a long history of endurance sport, in fact, a higher frequency of some disorders linked to a slowing of the heartbeat has been observed, in rare cases to the point of requiring a pacemaker. The strongest association concerns atrial fibrillation, which is more common in middle-aged or older men who have undertaken intense training for many years.

Some studies have also identified small areas of scarring in the heart muscle and a greater presence of plaques in the coronary arteries, especially in selected groups of men. It has not, however, been shown that these alterations are directly caused by exercise or that they necessarily lead to an increase in cardiovascular events.

Troponin can also rise after prolonged endurance events. This is a generally transient phenomenon: in most cases values return to normal within 24–72 hours, and the increase does not automatically equate to a heart attack or permanent damage. Dilation of the aorta, on the other hand, is rare in young people and, in older athletes, tends to progress slowly.

“The message we want to convey is not, of course, that sport is bad for the heart,” stresses Zorzi. “Physical activity remains one of the most powerful forms of prevention” and, at population level, the benefits far outweigh the possible risks. The alterations mainly affect “a minority of highly exposed athletes who are probably predisposed”.

For this reason, according to Flavio D’Ascenzi, lecturer in Sports Cardiology at the University of Siena and co-author of the review, “in some rare cases, after years of intense and prolonged activity, alterations may appear that warrant attention”. Athletes who follow this type of training could therefore benefit from “more personalised assessments and check-ups”.

The review also highlights possible differences between men and women: the alterations have mainly been observed in men, while in women cardiac remodelling appears less marked. Studies on female athletes remain limited, however, as do those conducted on non-white and non-Western populations.

The conclusion is therefore reassuring: for the vast majority of people sport is safe and associated with better health and survival. In a small proportion of predisposed individuals, however, decades of high-volume training may be accompanied by changes that warrant clinical attention. Sports cardiology can thus help athletes continue to train safely, adapting checks and follow-up to age and individual characteristics.