Although a daily routine of physical activity confers remarkable benefits for quality and quantity of life, prolonged continuous high-intensity exercise can cause adverse structural remodeling of the heart and large arteries. An evolving body of data indicates that chronically training for and participating in extreme endurance competitions (marathons, ultra-marathons, Iron-man distance triathlons, etc.) can cause acute volume overload of the atria and right ventricle, with transient reductions in right ventricular function and elevations of cardiac biomarkers, all of which generally return to normal within 7 to 10 days.
In veteran extreme endurance athletes, this recurrent myocardial injury and repair may eventually result in patchy myocardial fibrosis, particularly in the atria, and right ventricle, creating a substrate for atrial and ventricular arrhythmias.
Furthermore, chronic, extreme endurance exercise may be associated with accelerated aging in the heart and coronary arteries. This presentation will discuss the cardiac pathophysiology of extreme endurance exercise, and make suggestions about better fitness patterns for conferring optimal health and longevity.