No Amount Of Running Is Too Hard On Your Heart

Ultramarathons are grueling races that typically range anywhere from 30 to 100 miles, but new research suggests that even these distances don’t tax the heart unduly.

“The good news is that while experienced runners pushed their heart limits during the ultramarathon, they did not show evidence of cardiac risk assessed through elevated biomarkers [such as cortisol levels],” said co-lead investigator Rodrigo Hohl. He’s a professor from the department of physiology at the Federal University of Juiz de Fora in Brazil.

In the study, researchers conducted blood tests on 25 participants in a 24-hour ultramarathon before and after the event.

Eleven of them were experienced ultramarathoners who’d trained a distance of more than 100 kilometers (60 miles) a week over