Exercise and atrial fibrillation: how health turns harm, and how to turn it back.

Exercise is, together with diet, a powerful health-promoting habit. However, an association of intense physical activity with the onset of atrial and ventricular arrhythmias, and sudden death has been described. Although initially questioned, the atrial pro-arrhythmic role of endurance physical activity is now well accepted in the scientific community. Atrial fibrillation is common among endurance athletes, being a source of morbidity in otherwise healthy young and middle-aged individuals. The mechanisms for its development are still poorly understood, but likely involve some components of the athlete's heart (e.g., bradycardia, atrial enlargement) and some clearly pathological factors (e.g., atrial fibrosis). Its management must be a careful balance between exercise moderation and cessation, as extremes in exercise practice have both been related to atrial fibrillation. In this article, we review the current knowledge on exercise-induced atrial fibrillation through different perspectives, each focusing on the epidemiological evidence, the associated risk, the identification of individuals at risk, the potential approach to reduce its impact and how should these athletes be informed.