AUTHOR=D’Silva Andrew, Bhuva Anish N., van Zalen Jet, Bastiaenen Rachel, Abdel-Gadir Amna, Jones Siana, Nadarajan Niromila, Menacho Medina Katia D., Ye Yang, Augusto Joao, Treibel Thomas A., Rosmini Stefania, Ramlall Manish, Scully Paul R., Torlasco Camilla, Willis James, Finocchiaro Gherardo, Papatheodorou Efstathios, Dhutia Harshil, Cole Della, Chis Ster Irina, Hughes Alun D., Sharma Rajan, Manisty Charlotte, Lloyd Guy, Moon James C., Sharma Sanjay TITLE=Cardiovascular Remodeling Experienced by Real-World, Unsupervised, Young Novice Marathon Runners JOURNAL=Frontiers in Physiology VOLUME=11 YEAR=2020 URL=https://www.frontiersin.org/articles/10.3389/fphys.2020.00232 DOI=10.3389/fphys.2020.00232 ISSN=1664-042X ABSTRACT=AimsMarathon running is a popular ambition in modern societies inclusive of non-athletes. Previous studies have highlighted concerning transient myocardial dysfunction and biomarker release immediately after the race. Whether this method of increasing physical activity is beneficial or harmful remains a matter of debate. We examine in detail the real-world cardiovascular remodeling response following competition in a first marathon.MethodsSixty-eight novice marathon runners (36 men and 32 women) aged 30 ± 3 years were investigated 6 months before and 2 weeks after the 2016 London Marathon race in a prospective observational study. Evaluation included electrocardiography, cardiopulmonary exercise testing, echocardiography, and cardiovascular magnetic resonance imaging.ResultsAfter 17 weeks unsupervised marathon training, runners revealed a symmetrical, eccentric remodeling response with 3–5% increases in left and right ventricular cavity sizes, respectively. Blood pressure (BP) fell by 4/2 mmHg (P < 0.01) with reduction in arterial stiffness, despite only 11% demonstrating a clinically meaningful improvement in peak oxygen consumption with an overall non-significant 0.4 ml/min/kg increase in peak oxygen consumption (P = 0.14).ConclusionIn the absence of supervised training, exercise-induced cardiovascular remodeling in real-world novice marathon runners is more modest than previously described and occurs even without improvement in cardiorespiratory fitness. The responses are similar in men and women, who experience a beneficial BP reduction and no evidence of myocardial fibrosis or persistent edema, when achieving average finishing times.