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=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2020.00232

DOI=10.3389/fphys.2020.00232

ISSN=1664-042X

ABSTRACT=Aims
Marathon 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 cardiovascular remodelling response following competition in a first marathon.
Methods 
Sixty-eight novice marathon runners 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. 
Results
After 17 weeks unsupervised marathon training, runners revealed a symmetrical, eccentric remodelling response with 3-5% increases in left and right ventricular cavity sizes, respectively. Blood pressure fell by 4/2 mmHg with reduction in arterial stiffness, despite only 11% demonstrating a clinically meaningful improvement in peak oxygen consumption.
Conclusion
In the absence of supervised training, exercise-induced cardiovascular remodelling 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 blood pressure reduction and no evidence of myocardial fibrosis or persistent oedema, when achieving average finishing times.