To the Editor We read the epidemiological work by Boraita et al1 with great interest. The article aims “to determine AF [atrial fibrillation] incidence in a large cohort of elite athletes” and concludes that “the incidence of AF is low among young elite athletes.”1 However, the authors do not present any incidence data to answer the research question or support their conclusion. In fact, the authors present prevalence estimates of AF in elite Spanish athletes referred for cardiological screening; they observed that 21 of 6813 athletes (0.3%) had a diagnosis of AF during their final examination.