What Happens to Your Body During an Ultramarathon

Your Body at the Finish Line

As you hit the homestretch, you may be ready to finish, but your body is still working overtime.

- The Heart is Affected: Many scientists believe that ultra distances can be problematic for the heart. "Ninety-six percent of the finishers developed a significant increase in cardiac Troponin I, which can be an indicator of heart muscle damage—and 12 percent showed signs suggestive of significant cardiac damage," according John Somuroo, professor at the Countess of Chester Hospital and author of a 2009 ultra-endurance study. However, damage isn't always severe enough to cause lasting effects.  

- Weight Loss: In the same study, runners who completed 50 miles in 15 hours lost an average of 4.4 pounds; 100-mile runners who finished within 36 hours lost an average of 6.6 pounds. However, some believe this could be a loss of water weight, which is why it's important to hydrate from start to finish. "Some people drink sports drinks as well as chicken broth [in addition to water] because of the high sodium content of the broth," says Gill.

No matter what, everyone feels different at the end of a race, says Gill. "It all depends on training, preparation, and what you do during the race. With that said, you can have the best training and prepare yourself 100 percent before the race, and still feel horrible at the end."

Between exhaustion, weather changes, injuries and more, running an ultramarathon ends up pitting you against yourself, rather than the finish line. Despite all that, reaching the end is an accomplishment unmatched by any other distance.

More: Nutrition Guide for Your First Ultra

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