Acute Cardiac Effects of Ultra-Trail Running

Overview

This prospective observational study aims to investigate the acute cardiovascular effects of ultra-endurance running using comprehensive echocardiographic assessment combined with biological analyses. The main hypothesis is that participation in an ultra-trail race induces acute and transient changes in cardiac function involving both the left and right ventricles, associated with elevations in cardiac biomarkers, with physiological responses varying according to race distance and training level and showing spontaneous recovery within the days following the event. Adult amateur runners participating in ultra-trail races of 80 km or 160 km will undergo standardized clinical evaluation, electrocardiography, and transthoracic echocardiography with myocardial deformation analysis at multiple time points, including baseline, pre-effort, during the race, immediately after exercise, and during early recovery approximately one week after the event. Biological sampling will be performed before the race, immediately after exercise, and at follow-up. The primary objective is to evaluate acute changes in left ventricular systolic function assessed by global longitudinal strain. Secondary objectives include the assessment of biventricular and atrial function, cardiac and non-cardiac biomarkers, recovery patterns after ultra-endurance exercise, and the influence of race distance, training level, performance level, and sex on cardiovascular responses. This exploratory single-center study conducted in France seeks to provide an integrative characterization of cardiac adaptations to extreme endurance exercise and to generate physiological insights that may guide future research and cardiovascular monitoring strategies in endurance athletes.

Ultra-endurance running has gained increasing popularity, yet its acute cardiovascular effects remain incompletely characterized. Previous studies in endurance athletes have reported transient changes in myocardial function and elevations in cardiac biomarkers after prolonged exercise, but available data in ultra-trail settings remain limited and heterogeneous. Most prior investigations relied on pre- and post-race comparisons, small sample sizes, or incomplete assessment of right ventricular and atrial function, and rarely integrated multimodal echocardiographic imaging with standardized biological analyses. The ULTRA-ECHO study is a prospective observational physiology study designed to investigate acute and short-term cardiovascular adaptations to ultra-endurance exercise under real-life conditions. Adult runners participating in the "Trail des Échos" ultra-trail race (80 km or 160 km) will undergo standardized transthoracic echocardiography, clinical evaluation, and biological sampling at predefined time points, including baseline screening, pre-effort, during the race, immediately after exercise, and during early recovery approximately one week after the event. Echocardiographic acquisitions will be performed using standardized imaging protocols on identical ultrasound systems, with centralized offline analysis and blinded secondary review in order to ensure reproducibility and minimize operator-related bias. The primary focus of the study is the assessment of left ventricular global longitudinal strain (GLS), a sensitive marker of subclinical systolic myocardial function that may detect exercise-induced myocardial fatigue even when conventional ejection fraction remains preserved. Secondary evaluations include comprehensive structural and functional echocardiographic parameters of the left ventricle, right ventricle, and left atrium, as well as cardiac and systemic biological responses to prolonged endurance exercise. This exploratory before-after design does not include a control group, as each participant serves as their own control through repeated within-subject assessments. The study also aims to explore potential modifiers of cardiovascular responses, including race distance, finisher status, training level, performance level, and sex. By integrating sequential imaging, biomarker analysis, and early follow-up evaluation, ULTRA-ECHO seeks to improve understanding of transient cardiac adaptations and recovery dynamics associated with ultra-endurance exercise and to generate physiological insights that may inform future research and cardiovascular monitoring strategies in endurance athletes.