Cardiac Remodeling in Middle-Aged Endurance Athletes and Recreationally Active Individuals: Challenges in Defining the “Athlete's Heart”

Abstract

Chronic endurance exercise is known to elicit cardiac morphologic and functional adaptations collectively known as the “athlete's heart.” 1 Paterick T.E. Gordon T. Spiegel D. Echocardiography: profiling of the athlete's heart. J Am Soc Echocardiogr. 2014; 27: 940-948 Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar Yet the extent to which exercise burden and other phenotypic factors dictate the extent of cardiac remodeling remains understudied. While there are significant data in younger, elite athletes, reference values for cardiac morphology in long-standing, middle-aged endurance athletes (EAs) performing high-volume exercise, particularly when compared with recreationally active adults (RECs) who perform recommended levels of physical activity, remain limited. We therefore evaluated cardiac structure and training-related factors associated with cardiac remodeling. We hypothesized that middle-aged EAs would have greater cardiac remodeling than RECs. We further hypothesized that a higher peak rate of oxygen consumption ( V ˙ O2peak) and greater weekly exercise hours would predict a larger left ventricular (LV) volume.