New study debunks myth that endurance athletes risk heart damage

Endurance athletes have debated the issue for years. Is training for marathons actually causing damage to our hearts?

A new long-term follow-up study, published in JAMA Cardiology, investigated how variable heart rates at finish lines leads to future damage.

Researchers tracked 152 male recreational marathon runners (mean age 43) and measured heart function and biomarkers before the race, immediately after, at one day and three days, and again at 10 years.

Right after the marathon, the right-ventricular ejection fraction (RVEF) dropped— the finding that has raised medical concerns. The median value went from 52.4 per cent pre-race to 47.6 per cent immediately after finishing. By the next day, it had improved to 50.7 per cent, and by day three it was essentially back (51.3 per cent). Ten years later, it was still stable at 51.9 per cent. The dip showed up, it resolved within days, and it didn’t drift downward across a decade.

Left ventricular measures shifted slightly in ways that were statistically significant, but the values stayed within normal physiological ranges. It’s a reminder that “changed” doesn’t necessarily mean “damaged.”

 In this group of recreational marathoners, the heart’s post-race changes were temporary and didn’t translate into progressive ventricular dysfunction over a decade of continued running. Read more about the study at https://jamanetwork.com/journals/jamacardiology/article-abstract/2842747?resultClick=24