# What marathons actually do to your heart

> A 2025 study found 176 cardiac arrests during long-distance races in the U.S., but experts say the benefits of marathon training far outweigh the risks for most people.
- Title: What marathons actually do to your heart · TIME | Shortify
- Summary: A 2025 study found 176 cardiac arrests during long-distance races in the U.S., but experts say the benefits of marathon training far outweigh the risks for…
- Keywords: marathon running, heart health, cardiac arrest, exercise physiology, cardiovascular disease, pre-participation screening, news, world, marathons, actually, heart, TIME
- Source: TIME — https://time.com/article/2026/10/30/is-running-a-marathon-good-for-your-heart
- Author: Veronique Greenwood
- Published: 2026-10-30T15:30:27+00:00
- Read time: 1 min
- Topics: marathon running, heart health, cardiac arrest, exercise physiology, cardiovascular disease, pre-participation screening, news, world
## Rare but real: cardiac deaths in marathons
A two thousand twenty-five study found one hundred seventy-six cardiac arrests during long-distance running events in the U.S. out of about twenty-nine million people who finished the races.
## Regular training is good for your heart
David Oxborough, professor of echocardiography and cardiovascular physiology at Liverpool John Moores University in the U.K., says exercise improves cardiovascular risk, reduces mortality, and has real positive benefits.

> Exercise is good for the heart.
## The race itself is a physiological shock
Daniel Muniz, senior lecturer in exercise physiology at the University of Hertfordshire in the U.K., says running a marathon is a big physiological stress with elevated markers of muscle and heart damage, at least temporarily.

> Running a marathon is a big physiological stress.
## Benefits far outweigh the risks
The consistent training required for a marathon carries positive effects for physical and mental health. Muniz says the benefits far outweigh the negatives.

> The benefits far outweigh the negatives.
## Who dies running marathons
Deaths during marathons are extremely uncommon and not random. People who die tend to be younger people with undiagnosed genetic heart problems or middle-aged men with undiagnosed heart disease.
## Screening for young and older runners
Oxborough recommends a simple twelve-lead ECG and questionnaire for people under thirty-five. For those over thirty-five or forty, he recommends seeing a GP, getting an ECG, blood tests, and possibly an exercise stress test.
## Most people can run a marathon with training
Muniz says most people with appropriate training for a number of months or perhaps a year should be able to run a marathon, starting with run-walk intervals and gradually building up distance.

> Most people with training should be able to run a marathon.
## Key takeaway

Marathon running carries rare but real cardiac risks, mainly for people with undiagnosed heart disease, but regular training for marathons improves heart health and reduces mortality for most runners.