Even though marathon running is on the decline, half a million people signed up to participate in the 2020 London Marathon. It seems wild that someone would voluntarily sign up to run 26.2 miles, but those half a million people might actually be on to something. A new study published in the Journal of the American College of Cardiology found that running a marathon can help reverse signs of aging.

Researchers at Barts and University College London looked at 138 first-time marathon runners between the ages of 21 and 69. "We wanted to look at novice athletes. We didn't include people who said they ran for more than two hours a week," Dr. Charlotte Manisty, the study's senior author and cardiologist at University College London, said per CNN.