Endurance exercise as a risk factor for atrial fibrillation in middle-aged male athletes: a rapid review

Hypothesis: While exercise reduces the risk of cardiovascular disease, recent research suggests that endurance training can increase the risk for atrial fibrillation in the absence of all other traditional risk factors. This rapid review aims to examine a portion of the current research available on this topic to determine whether exercise increases the risk of atrial fbrillation in middle-aged males. Methods: A search of PubMed was conducted to obtain studies from the last 15 years that examined the relationship between sports, endurance training, or lifetime accumulated hours of exercise, and atrial fibrillation. After careful selection and exclusion, six primary studies were included in this review, including case-control and cohort studies. Results: While the included articles used different study methods, atrial fibrillation risk evaluation was a common outcome measure among all six studies. Of these studies, five reported positive findings and one reported negative findings on the relationship between endurance exercise and atrial fibrillation risk. Statistically signifcant results were reported in all of the studies. Common limitations include small sample size and recall bias, thus limiting generalizability of results. Conclusion: Presently available evidence suggests that endurance exercise is a risk factor for developing atrial fibrillation in middle-aged male athletes. However, many of the studies conducted on this topic have inherent limitations, and there is little agreement on a definitive mechanism to explain this phenomenon. Further research is required to quantify the amount of exercise that is truly healthy, and the levels at which exercise may contribute to patholog