Adaptive Changes in Endurance Athletes: A Review of Molecular, Echocardiographic and Electrocardiographic Findings

Regular physical activity has a beneficial impact on the cardiovascular system. However, the intense and prolonged exertion typical of professional athletes and amateur marathon runners can lead to adaptive changes in the heart. These changes encompass both structural and functional modifications, which may have positive or negative effects on cardiac function and contribute to the development of so-called "athlete's heart." Prolonged exercise induces adaptations at the molecular and cellular levels, including altered gene expression and remodeling of myocardial proteins. It may also cause transient elevations in biomarkers such as N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity troponin. Some athletes experience cardiac arrhythmias, including atrial fibrillation. Morphological changes, such as myocardial hypertrophy or chamber dilation, can be assessed using echocardiography. Studies have reported potentially benign valvular abnormalities, as well as cases of myocardial fibrosis and arrhythmias. Early diagnosis of cardiac conditions in marathon runners is essential for effective prevention and health monitoring. This article reviews the current data on cardiac changes in endurance athletes, based on the literature from the past decade.