The Psychology Of Fear: How Tough Mudder Designs Obstacles To Torture You

Ice, barbed wire, and electric shocks: The lead designer behind Tough Mudder talks about designing addictive torture.


“Run through a field of live wires that sure as hell don’t tickle,” Tough Mudder writes on its YouTube Channel. “Watch out for hay bales and deep sinkholes, or you will face-plant into some electrifying mud. Some Mudders℠ try to stealthily wind their way through the wires, while others barrel forward to get through as quickly as possible. Just keep your eye on the prize: this is the last obstacle you face before you cross the finish line.”


This is Electroshock Therapy–the last leg of Tough Mudder’s tortuous, mud-filled obstacle course, a 10- to 12-mile race through ice baths and barbed wire. The race has drawn 1.5 million people worldwide in the company’s financially explosive, five-year history, despite that participants have reportedly suffered heart attacks, hypothermia, and E. coli infections–in one case, a man even drowned.

This year, for its 2015 season, Tough Mudder has redesigned 10 obstacles, and introduced 10 new ones, in its most aggressive refresh since the races began–a series of updates intended to encourage more spontaneous teamwork and offer new thrills to those who’ve run the course multiple times. But as Nolan Kombol, the 28-year-old head of course design for Tough Mudder, tells Co.Design, the most important element to Tough Mudder is its psychology of fear, and the updates were largely about maximizing the mental game–to scare the newbies and keep the loyalists who shell out $100 to $200 a race coming back.

“It really is about designing the experience of the obstacles–not necessarily being a masochist, or wanting to electrocute people,” he says. “The mental challenge is much more difficult than the physical challenge. I don’t think a lot of people know that.”


Maxing The Mental Game

If Tough Mudder wanted to make the course physically harder, all the company would have to do is make it longer. Instead, Tough Mudder focuses on mental fitness, which can make the race feel emotionally taxing, without forcing attendees to train harder. The updated obstacle Electroshock Therapy makes for an apt case study. It’s what Tough Mudder classifies as a “fear of death” obstacle. It’s not like Funky Monkey’s monkey bars that, should your muscles give out, will just throw you into cold mud. Electroshock Therapy’s live wires are intended to tap into primal fear for your life.


“There are a bunch of things you could do–put people in a box with spiders and snakes on top–there are certain core fears you can tap into,” Kombol says. “Ultimately, electricity won out. Operationally, it’s something we could do. And I’m not sure there are a lot of animal lovers who wanted us to deploy 200 tarantulas per event. Electricity, while being scary, you operationally can do, and through research we found we could do [it safely].” (More on that safety aspect later.)

To increase the fear factor of Electroshock Therapy, designers added a voltage meter, visible to the participants, which increases its output as onlookers cheer louder (and get their fill of schadenfreude).

Another obstacle, Arctic Enema, has participants jump into and swim through a dumpster of water, chilled with around 75,000 pounds of ice. Then halfway though, they need to swim under a divider of barbed wire. For the Arctic Enema update, designers added a five-foot slide to heighten the fear of jumping in. “We wanted to extend that experience, so you’re sitting on the slide and then it’s too late to turn back,” Kombol explains. “The participants thought it was a lot scarier. It was easy to commit to the slide, but then you had a ‘holy shit!’ moment. What we wanted to do was elongate the ‘holy shit!’ moment and create an impact.”

Inside the ice bath, though, the barbed wire divider that forced participants to swim underwater to pass was swapped out for an island people would need to climb over instead. Why? It created a point where people needed to give one another a hand to pass, encouraging teamwork and impromptu camaraderie.



Scarier? Okay. But Is Tough Mudder Any Safer?

To some experts, Tough Mudder’s safety is up for question. Following a Philadelphia-based Tough Mudder event in June of 2013, 38 participants arrived in the ER at Lehigh Valley Hospital in Allentown, PA. The electric injuries connected to an athletic event surprised a team of doctors, who in turn published five case studies from treatments of patients injured during the race. One was a young man, 18 years old, who experienced 13 shocks that inflamed his heart as if he’d suffered a heart attack.

“I know most people wouldn’t consider electricity healthy, but running 10 miles through challenging terrain is something a lot of people could use,” Kombol contends. “It’s always inherently going to be a fairly risky event…but it’s not something we don’t think about in the design.”

Kombol’s team regularly drops accelerometers from full scale mockups of new courses, measuring impacts, and looking for the possibility of concussion were someone to land on his or her head. For Electroshock Therapy, Kombol’s design team conceptualized the experience, then consulted an internal medical team to gauge the maximum voltage that people can safely endure, and constructed the challenge within those criteria.

Medical staff maintain a presence throughout the course, and the company keeps injury reports from every obstacle at every event, Kombol says. If an injury occurs frequently–Kombol cites the hypothetical of people getting blisters when dangling from Funky Monkey’s bars–Tough Mudder will reassess the obstacle to determine if it needs to be tweaked. (Kombol would not say if any obstacles had been updated for safety in this grander redesign.)

As for the 2015 version of Electroshock Therapy, Kombol’s team tested several redesigns with volunteers–including a version that has a slide and forces participants to hop over shock wires rather than dodge through them–but ultimately, Electroshock Therapy’s classic, 40-foot long crawl (or run) through a dense cluster of relatively unavoidable live wires shocked its way into testers’ hearts. Because this frightening, miserable experience, which skill, strength, and dexterity can’t do much to avoid, is precisely the sort of PTSD-inducing event that Kombol says Tough Mudders take pride in enduring: “I sat in the focus group sessions, over and over again, where people said, ‘I hate it, and you can’t change it.'”


And what people say about the experience is remarkably important for the Tough Mudder franchise, which grew from a mere $8,000 in advertising in 2010 into a $75 million business by 2013, because the company generates 77% of its web traffic through word of mouth. Tough Mudder anticipates more than $100 million in revenue for 2014.

About the author

Mark Wilson is a senior writer at Fast Company who has written about design, technology, and culture for almost 15 years. His work has appeared at Gizmodo, Kotaku, PopMech, PopSci, Esquire, American Photo and Lucky Peach