Who develops athletic heart?

Exercise that exceeds guidelines, such as exercising more than an hour most days of the week, may lead to development of athletic heart. Athletic heart commonly occurs among endurance athletes, who regularly compete in activities like marathons or other long-duration events. Many exercise several hours per day and more than 12 to 15 hours per week.

Among runners, for example, the heart remodels itself in response to having to pump a high volume of blood. As a result, the chambers of the heart enlarge to hold and pump more blood. Among weightlifters, the heart remodels itself by thickening in response to the increase in pressure applied on the heart.

Exercise is good for the body, and athletic heart results from a lifelong commitment to an activity that promotes good health. But there may be some issues that arise from an athletic heart.

First, athletes with markedly enlarged hearts may be at risk of developing atrial fibrillation, which is abnormal heart rhythms that typically occur among older adults or people with high blood pressure or heart failure. Abnormal heart rhythms are worrisome because they may lead to a stroke.

There are many potential reasons atrial fibrillation occurs in athletes. A dilated atrium – the top chamber in the heart – may become inflamed and develop scar tissue, increasing the risk of atrial fibrillation. Stress and environmental factors may also work together to increase the risk of arrhythmia.

Coronary artery calcification, or CAC, is another concern among elite athletes. Coronary artery calcification, which commonly occurs in older adults or those with risk factors for coronary artery disease, increases the risk of having a heart attack or stroke. In recent years, doctors have been using imaging tests to monitor calcium buildup in the arteries of their patients to try to determine their risk of heart attack or stroke over time.

It is not entirely clear why elite athletes develop coronary artery calcification. Fortunately, it does not appear that athletes have an increased risk of heart attack, even among those with very high levels of CAC. For example, a large study of almost 22,000 participants found that even athletes who engaged in high amounts of exercise and had elevated levels of CAC did not have an increased risk of death from cardiovascular disease over a decade of follow-up.

Some athletes are appropriately concerned about having calcium buildup in their heart arteries and may wonder whether or not they should be taking medications like aspirin or statins. But risks vary from person to person, so anyone concerned about CAC should talk to their doctor.

Putting exercise in its place

Though elite athletes may have an increased risk of developing athletic heart, exercise undoubtedly remains one of, if not the best, methods to maintain a healthy lifestyle.

For example, if someone does not exercise routinely, their heart will become stiff and not pump blood as well as it once did. Routine exercise – especially dynamic exercise like running – maintains a compliant heart and prevents stiffening. A compliant heart will expand a lot more as it fills with blood and, in turn, pump out more blood with each heartbeat. A stiff heart has difficulty filling up with blood and has difficulty pumping blood through the body.

Generally, routine exercise throughout adulthood encourages the heart to remain strong and flexible even in old age. Even if someone were only to begin regularly exercising in their 40s to 50s, it is possible to reverse some of the effects of sedentary aging.

For example, a 2018 study of 53 sedentary people mostly in their early 50s found that those who participated in a two-year exercise training program using a combination of running, cycling and elliptical exercise had hearts that became more compliant compared to the hearts of those who did not exercise.

It is never too late to start exercising. Routinely following exercise guidelines can help promote physical and mental health and help your heart stay young throughout your life.