Exercise-induced ventricular changes in recreational half-marathon runners compared with marathon/ultramarathon runners

<b>Background:</b> With the growing popularity of amateur endurance sports, including marathon running, it is crucial to recognize transient myocardial changes induced by prolonged physical exertion and to evaluate potential predictors of cardiac fatigue. <b>Methods:</b> A total of 105 runners participating in the 2023 Silesia Marathon (half-marathon, marathon, and ultramarathon) were studied. Transthoracic echocardiography was performed at baseline (1-4 days pre-race), immediately after the race, and 14 days later. Parameters of left and right ventricular function were assessed, including left ventricular ejection fraction (LVEF), left ventricular global longitudinal strain (LV GLS), right ventricular global longitudinal strain (RV GLS), right ventricular free wall strain (RV FWS), tricuspid annular plane systolic excursion (TAPSE), as well as left and right atrial strain. Regression analyses were conducted to explore demographic- and training-related predictors of exercise-induced functional changes. <b>Results:</b> Immediately post-race, LVEF decreased slightly but remained within the normal range, while LV GLS was significantly reduced in marathon and ultramarathon runners compared with baseline (p = 0.008). RV GLS and RV FWS showed smaller, non-significant declines, and TAPSE demonstrated a non-significant reduction. Atrial strain parameters were transiently decreased but normalized at follow-up. All ventricular and atrial parameters returned to baseline within two weeks, confirming the reversibility of the observed changes. Between-group comparisons revealed no significant differences in cardiac response according to race distance. Regression analyses did not identify consistent predictors of functional decline. Trends suggested that higher weekly training volume may attenuate reductions in LVEF and TAPSE, whereas older age may predispose individuals to a greater decline in TAPSE; however, these associations did not reach statistical significance. <b>Conclusion:</b> Long-distance running induces mild, transient, and reversible changes in ventricular and atrial function in amateur runners. These alterations appear largely independent of race distance and cannot be reliably predicted by simple demographic or training-related indices.