Tough Mudder injuries are on the rise.
Competitors "Walk The Plank" and then jump into the muddy waters during a Tough Mudder event held at the Seneca Hunt Club on May 18, 2013.
Credit: Stan Grossfeld / The Boston Globe / Getty Images

Tough Mudder injuries are on the rise.

Obstacle races like Tough Mudder, and its cousins Warrior Dash and Spartan Race, offer challenges and, yes, bragging rights beyond the typical road race. They may also differ in another, less enticing way, a new study suggests: the number and kind of race-related injuries that send competitors to emergency rooms.

Doctors at Lehigh Valley Hospital cataloged the injuries that came to their emergency room from the Tough Mudder race on June 1 and June 2 in Allentown, Pennsylvania, (the same place the race started back in 2010). They attended to a total of 38 patients from the race.

Only some of the cases were the sort of dehydration or sprained ankle you'd expect to see in a typical race. Others were different types of orthopedic injuries, such as damaged shoulders and busted knees, which happened as a result of the obstacles. Several people fell from fairly high heights, from 8 to 15 feet, during the course of the race. And a number of patients were admitted after getting electric shocks, an obstacle only found in Tough Mudder races, with symptoms including burns, head injuries, and heart inflammation.

Dr. Marna Greenberg, director of emergency medicine research at the Lehigh Valley Hospital and Health Network, had initially wondered if many of the injuries might be in middle-aged couch potatoes who took on a Tough Mudder before they were up to the challenge. But injuries happened in people of all ages, she found, including in those who were physically fit.

So how can you avoid getting injured. Well, there is some prep you can do to boost stamina and build the functional strength you'll need to get yourself over, under, and through the obstacles, but it won't protect you against everything. "You can train for endurance, but there's no training you can do for many of these obstacles," Dr. Greenberg says. "Imagine how impossible it might be that you could train to be shocked."

This year is shaping up to be Tough Mudder's most popular yet, with 1.5 million people entering its U.S. events. We get the race's grueling, gritty appeal – just make sure you keep the risks in mind, too.