High Intensity Exercise and A-Fib Maturing men who regularly endure high-intensity/high volume cardiopulmonary exercise are at a higher risk for atrial fibrillation, according to N.A. Mark Estes III, M.D. At the Annual Cardiovascular Conference at Snowmass, Dr. Estes detailed this unique discovery. According to Estes, there is a trend of former college and pro athletes in their 40s-60s developing A-fib. This sparked his curiosity, causing him to delve deeper into these findings. A group of men age 40 to 60 were given thirty-day event monitors to track heart rate discrepancies in their daily routine. The results showed a series of spikes of extreme, symptomatic atrial fibrillation (AF) occurring in conjunction with high intensity exercise, and even more so immediately afterwards. While this supports Dr. Este’s theory, in depth studies in athletic heart syndromes, or electrophysiology, are few and far between. The most credible research suggests that excessive exercise is actually harmful to the body, which is a difficult concept to sell to athletes. However, Dr. Estes claims, “As you get in the high-intensity/high-endurance end of the spectrum – typically more than 5 hours per week at greater than 80% of peak heart rate – the risk of A-fib increases up to 10-fold.” So I should quit exercising? No! The risk of developing A-fib is 25% lower in men that routinely conduct moderate level exercise compared to men that engage in low levels of physical activity, according to the American Heart Association and the American College of Cardiology. What about women? For unknown reasons, this trend does not apply to women. While women who partake in moderate physical activity have a decreased risk of developing A-fib to those who do not, women who regularly engage in high-intensity exercise are not more The Takeaway? As a rule, exercise is good for your heart, and people who conduct regular, moderate exercise tend to live longer than those who lead sedentary lives. As more research and evidence becomes available about electrophysiology, the way we counsel male professional and college athletes will evolve to lower this small sub-group’s risk of A-fib.