Steps taken before a race can go a long way to ensuring a safe finish, and doing some research to determine what will be required of you is a muddy step in the right direction, DeSimone says. "If people want to learn more about it, go and watch one. Be an observer first," she says, explaining that seeing obstacles beforehand helps potential participants determine which are too extreme for their personal fitness level.
Experts say physical preparation is key – and that means a whole lot more than just going for a jog. Exercises that build upper body strength are essential, along with those that use participants' own weight for resistance. "[For participants], a lot of it is taking themselves regularly out of their comfort zone and preparing for the extra [exertion]," DeSimone says. She recommends interval exercises – short periods of extreme exertion – to prepare for the physical and mental exhaustion competitors face.
Stewart has similar recommendations, suggesting that participants engage in plyometric training – motions meant to stretch and shorten a muscle quickly – to prepare for obstacles that focus on more than just "lungs and legs." He recommends jumping and bounding actions to mimic obstacles that require dynamic movement. And simple exercises can fit the training bill, Kimbel adds. Exercises that use a person's body weight as leverage – such as push-ups, pull-ups and lunges – prepare participants for the rigors of the course and don't require a gym or trainer.
Obstacles like those littered throughout Tough Mudder and Spartan Race courses demand far more of participants than cardiovascular endurance. Vertical walls require competitors to hoist themselves up and over and often mean pushing and pulling teammates. Lugging large rocks and logs across various distances combines upper and lower body strength with endurance, and slim beams or unstable platforms over water and mud call for precision balance – and maybe some swimming ability.
All these maneuvers demand a level of fitness that requires the seemingly simple act of getting started, which highlights a major health benefit: "Anything that encourages people to work for the event, to get up in the morning and get out of bed and go strength train and run, I think that's a great thing," Kimbel says. "When people are motivated to finish races like this, it gets them out running, it gets them out training for it and that's a good thing."
And while some may find more traditional road races intimidating, the fact that just finishing an obstacle course can be counted as a success makes them somewhat more beginner-friendly, Stewart says. "The majority are the people that get off the couch and do something that's out of their comfort zone, make the decisions to eat better, even to train just a little bit better," he says. "The bottom line is they make a difference in their life and these races provide the goals."
[Read: 7 Mind-Blowing Benefits of Exercise.]
As tough as these courses are, Stewart says participants have the opportunity to learn from failure. "The best thing about obstacle races is they're challenging, but in the end they're forgiving," he says. "This is not life or death: This is a challenge, this is a race, this is still fun and the idea is to push yourself as far as you can and once you've gotten there, well, you've learned something. And the next time you show up you can work on getting a little better."