Athlete’s Heart

Athlete’s heart is the collection of physiological structural, functional, and electrical adaptations that can develop in response to sustained exercise training. It reflects exercise-induced cardiac remodeling in response to repeated increases in circulatory demand rather than a specific heart disease. The extent and pattern of remodeling vary considerably with training volume and type as well as factors such as body size, sex, age, and ethnicity .^1,2

Structural adaptations can include increased left ventricular mass, modest thickening of the ventricular walls, and enlargement of the left and right ventricular cavities and atria. These changes can increase the heart’s capacity to fill with and eject blood during exercise. In well-trained endurance athletes, larger ventricular chambers can support a greater stroke volume, allowing more blood to be pumped with each heartbeat .^1,2

Athlete’s heart is broader than physiological cardiac hypertrophy. Physiological hypertrophy specifically describes adaptive growth of cardiac muscle, whereas athlete’s heart also encompasses changes in chamber dimensions, cardiac function, and electrical activity. The remodeling is generally accompanied by preserved cardiac function, although individual features can sometimes extend beyond conventional reference ranges for the general population .^1,2

This overlap makes athlete’s heart important to distinguish from conditions such as hypertrophic, dilated, and arrhythmogenic cardiomyopathies. Similarities in ventricular size or wall thickness can occur, but pathological cardiomyopathies arise from disease processes rather than normal adaptation to training. No single structural feature by itself necessarily establishes that cardiac enlargement in an athlete is physiological .^1,2