As interest and participation in recreational endurance exercise has steadily increased, the number of masters level recreational endurance athletes also has increased. While the benefits of regular and moderate physical activity on cardiovascular health are well established, recent data have raised concern that long-term endurance exercise participation is associated with adverse cardiovascular outcomes. In this review, we discuss the supporting evidence and limitations of prior research focused on these recent controversies. Specifically, we address the association between extreme levels of endurance exercise and longevity, risk of atrial fibrillation, accelerated coronary artery atherosclerosis, and arrythmogenic cardiac remodeling. We aim to provide sports medicine practitioners with knowledge of these contemporary controversies in sports cardiology and will highlight the importance of shared decision making in situations of clinical uncertainty.