If you're a novice, she said, it might make sense to read through the list of obstacles and avoid those that don't have any recommended training.
"Clearly you can get dirty, take a few risks and not get hurt," she said.
Risk-taking, however, may not look the same to everyone. Kircher points to research that certain personality types, even different brain chemistry, crave risk.
"Granted, it can't be too dangerous for the culture to accept it, but it has to be tough," Kircher said of Tough Mudder-style races. "And when you talk about really risky things people are doing of their own volition, it's really not a question about their safety per se, but the costs to society as a whole...We can't tell other people they can't take risks unless they're hurting the culture as a whole."
Other research has proposed a theory of "risk homeostasis," suggesting that people are going to take a certain amount of risks no matter what. A race car driver, for example, may counteract their aggressive behavior on the race course by driving in the slow lane on the highway.
"If that's true, it seems like this race could be where people are really putting themselves out there," Kircher said. "They're not hurting anybody else, and they're doing it willingly. Maybe then you feel like you don't have to do drugs."