Over the course of 12 miles, Tim Bergsma dunked himself into frigid water, crawled through mud underneath barbed wire and hurled himself and his teammates over 12-foot vertical walls. He saw a man with a knee injury hop through a gazebo adorned with dangling electric wires, and joined his teammates to help him to the finish line. But ask Bergsma what it was like, and he won't tell you about the pain or his muck-filled shoes. He'll tell you it was a thrill.
The former University of Michigan men's soccer captain completed a Tough Mudder, a 10- to 12-mile course featuring obstacles designed to test participants' physical and mental strength. The event is just one of many adventure- and obstacle-style races throughout the country – others include the Spartan Race and Warrior Dash – that are attracting athletes and those looking for an adrenaline-pumping way to get in shape. Tough Mudder alone saw a rise in participation from 20,000 people in 2010 to more than 460,000 in 2012, according to the event's website. That popularity, however, doesn't come without risk.
"Some of the things are, quite honestly, too extreme, and for many people are not beneficial," says Grace DeSimone, editor of the American College of Sports Medicine's "Resources for the Group Exercise Instructor" manual. "Many of [these competitions] intentionally try and provide surfaces that are challenging, whether it's mud or it's wet or it's slick in some way." Participants with known medical conditions – like those with knee or spine injuries, and especially anyone with heart conditions or chronic ailments – should be particularly cautious, she adds. For people thinking of signing up, Brett Stewart, author of more than a dozen fitness books, suggests starting to train at least three months before a Tough Mudder. Events that feature a shorter course, like the Warrior Dash, don't require the same level of training and are smart choices for beginners, he says.
The varied obstacles of these competitions, from fire jumps to climbs over cargo nets, pose their own challenges to participants, and obstacles that call for sheer physical strength aren't the only risk on the course. Temperature obstacles, like the "Arctic Enema" in Tough Mudder races – an obstacle that requires competitors to dunk themselves in a dumpster filled with water that's kept just above freezing – offer their own set of hurdles to overcome. "If you put your body into ice, it's not going to function the way you would think it would in just normal water," certified running coach Jennifer Kimbel says. In water that cold, she explains, muscles constrict and aren't as effective as they are at normal temperatures.
Bergsma's experience helping the racer with the knee injury to the finish line is just one example of the types of injuries that can happen on any course. But Stewart cautions that those aren't the norm. "Rolled ankles are the No. 1 occurrence and that happens … all the time with just trail running, and that's just on normal trail surfaces," Stewart says. "Anytime people are off their feet they're going to have to land somehow and … quite often it results in a turned ankle or a sprained knee." Aside from those, he says, bumps, bruises and scrapes occur most often, and major injuries are not common.
Most races have medical staff on hand to keep runners safe, but Stewart says participants can do a lot on their own to prevent injury. "These races are very, very exciting, but you can't get carried away. You are responsible for yourself – from the start to the finish, you've got to get yourself there in one piece," he says. And getting yourself to the end intact can be a matter of proper precaution. Something as simple as keeping your full attention on the obstacle you're clambering over or under in that moment can be the difference between reaching the finish line or the medic's tent, Stewart adds.