Sports Medicine

, Volume 37, Issue 4, pp 444–447

Cardiovascular Adaptations to Marathon Running

The Marathoner’s Heart
Conference Paper

DOI: 10.2165/00007256-200737040-00045

Cite this article as:
Thompson, P.D. Sports Med (2007) 37: 444. doi:10.2165/00007256-200737040-00045


Endurance exercise training produces a series of cardiac adaptations including resting bradycardia, first and second degree atrioventricular block, increased intolerance to orthostatic stress, and enlargement of the left ventricular walls and of all cardiac chambers. Cardiac dimensions may be increased beyond the upper limits of normal and some endurance athletes demonstrate mild reductions in estimated left ventricular ejection fraction. Among athletes, such adaptations occur primarily in well trained endurance athletes. Clinicians should be aware of the cardiac changes accompanying endurance training to avoid unnecessary evaluation of physiological changes. On the other hand, the presence of conduction abnormalities or cardiac enlargement in low level or recreational athletes should prompt a search for pathological causes. Many of these findings were presented in the 1977 report on the marathon and have simply been better defined with subsequent studies.

Copyright information

© Adis Data Information BV 2007

Authors and Affiliations

  1. 1.Division of CardiologyUniversity of Connecticut, Hartford HospitalHartfordUSA