The impact of excessive endurance exercise on the heartABSTRACT: Regular exercise is effective in the prevention and treatment of conditions such as hypertension, coronary artery disease, and diabetes. Studies have investigated ideal amounts or “doses” of exercise to decrease risk factors associated with disease, as well as the minimum amount of exercise required to reduce mortality. With the increase in individuals participating in ultra-endurance events, recent research has focused on the high end of the exercise dose-response range and found that chronic endurance training can cause transient myocardial changes, possibly due to repetitive transient pressure and volume overload on the thin-walled left atrium and right ventricle. Some evidence suggests that years of endurance training can lead to long-term adverse consequences, including myocardial fibrosis, atrial fibrillation, an exercise-induced acquired form of arrhythmogenic right ventricular cardiomyopathy, ventricular arrhythmias, and coronary atherosclerosis. The law of diminishing returns appears to apply as exercise extent increase, and it is likely that an upper limit exists where additional physical activity provides no further mortality benefit.
Autor / Fonte:Issue: BCMJ, Vol. 58, No. 4, May 2016, page(s) 203-209 Articles Andrea K.Y. Lee, MD, Barbara N. Morrison, BHK, Saul Isserow, MBBCh, Brett Heilbron, MB ChB, Andrew D. Krahn, MD