Conventional wisdom would suggest that forcing your customers to endure electric shocks is probably a bad idea. But it seems to be working out for Will Dean, CEO of Tough Mudder, a $70 million company based in Brooklyn, New York. Tough Mudder hosts extreme events, in which participants work in teams to complete a 10- to 12-mile course. They jump into Dumpsters filled with ice, crawl under barbed wire through puddles of mud, and, yes, dash through live wires carrying up to 10,000 volts. In 2012, nearly 500,000 participants shelled out $95 to $200 to compete in 35 events in the U.S. and overseas. A native of Sheffield, England, Dean, 32, worked in British counterterrorism and then attended Harvard Business School. In 2010, he co-founded Tough Mudder with his friend Guy Livingstone. Now, Dean spends his days teaching Harvard case studies to employees and dreaming up new ways to leave his customers bruised, bloody, and begging for more. --As told to Issie Lapowsky

Running a growing business is a lot like playing pool. In the beginning, it's like you're playing without a cue ball. Then, you have a small team, and you need the cue ball. Suddenly, you have a lot of employees, and it's like you're hitting seven balls in a row. You have to hit that first ball very carefully to get that last one where it needs to go. That's my job now.

I get up early, typically around 4:30 a.m., and I try to get most of my work done by 10 a.m. I clear out emails and get my reading out of the way. I commission about two or three reports a week from my staff on things like what our price structure should be next year or what it costs to cancel an event.

By 10 a.m., I ride my bike about five minutes from my house in Brooklyn Heights to our offices. Tuesdays and Wednesdays are the days I'm usually in the office. Otherwise, I'm traveling. We have 110 employees, and it's probably been more than a year since we were all in the same place together. We have operations in Australia and the U.K. now, and we're opening an office in Germany this year. We're always setting up a venue somewhere. Like it or not, when your company gets to a certain size, the way you manage changes. You go from being a manager to a leader, and in my mind, there are only two things a leader should worry about: strategy and culture. Those two things take up most of my time.

Tough Mudder has a quirky culture. Once a month, we have something called Tough Mudder University, which everyone who's in New York attends. It's an 80-minute discussion of a Harvard Business School case study, based on a theme that's pertinent to Tough Mudder. For example, we did a case about Starbucks in the late '90s, when the core customer was a woman in her 30s. But by the turn of the century, it was becoming a wider national brand, and that created challenges. It's the same with us. Our early adopters were very fit 30-year-old guys. Now we have participants in their 80s, and we need to figure out how to serve those people, too. The case method is great from my perspective, because I get to interact with everyone, and it's a great assessment tool.

Every Tuesday, we have a staff meeting and give out awards. Our Kaizen Ninja Award, which is based on this Japanese concept about making constant improvements, goes to anyone who comes up with a great innovation. We also give out a Credo Award every week to someone who really embodies the values of the company. For example, Antonia Clark, our head of social media, won a Credo recently when she went above and beyond her job description and helped out the events team on many of the fall events. Tough Mudder is all about pushing your boundaries.

I spend a lot of time interviewing potential hires. We're growing so quickly that I probably do two or three interviews a day. I consider it a mental challenge to get someone to give an honest answer. I always ask, "Are you a hunter or a farmer?" It's amazing how many people take that question literally. If you take it literally, you've probably already failed. I also ask people what they would do if they had a month off. A central philosophy at Tough Mudder is that experience is the new luxury. Unlike an iPhone, which depreciates over time, memories and experiences actually appreciate over time. So, the applicants who tell me that with a month off they'd go to this festival and that festival tend to be pretty good cultural fits here. That's what we're really testing. Do you have intellectual curiosity, a natural sense of fun, an adventurous nature? Do you not take yourself too seriously?

I came up with the idea for Tough Mudder in business school. I noticed that people were bored with marathons and triathlons. Running's a bit boring. In what other sport do you have to listen to music to make it passable? I wanted to make something that was Ironman-meets-Burning Man, a test of all-around fitness, but in this fun, slightly quirky environment.

We aspire to become a household brand name, so mapping out a long-term strategy is crucial. I speak with Cristina DeVito, our chief strategy officer, every day, and I meet with the entire five-person strategy team once a week. We just started a new business division to try to figure out what Tough Mudder will look like in five years. I imagine we'll have several types of events related to fitness. I can see us having Tough Mudder gyms and boot camps. Eventually, Tough Mudder events will be just one business unit within an overall event planning and fitness brand.

We go on retreats every quarter to a house in the Catskill Mountains. There's no phone coverage, and the Internet connection is slow. We started the retreats to get everyone thinking about the future. We always have an event coming up, but we also need to think about how we're going to run events in 2014. If you're not answering these questions now, you're just getting less and less efficient and letting things fall further away from you. We've also come up with cool obstacles for our courses during the retreats.

Right now, we prototype the obstacles at our warehouse in Brooklyn, but we're moving into a new 48,000-square-foot office this year, which will have room for a testing facility. Alex Patterson leads our obstacle innovation team. My meetings with him are always about organization. We'll discuss how many obstacles we have at different stages of development, how people are reacting to new obstacles, and what our action plan is for changing obstacles that weren't successful.

A lot of our best obstacles started in different incarnations. Take Everest, our quarter-pipe obstacle. Our original idea was that it would be a ramp, and you'd have to take a running jump to get up. The trouble was, it was just too damn steep. People would run up and go straight back down. The next time, we built it too flat, so people just walked right up. The third time, we came up with this quarter pipe. It's perfect. You get part of the way up, and then you have to jump, and your teammates pull you up.

It's one thing to test an obstacle with 50 people in our warehouse and another to test it with 10,000 people on a course. The crowd mentality takes over. With Funky Monkey, our monkey-bars obstacle, we never considered people would climb up and walk across the top of it, but at the event, for some reason, they did. Our engineers built it so that you can dangle 500 people off it, but just like cars with good braking systems, it doesn't help if the driver's drunk. Now, we've reengineered it so you can't physically get up there.

Safety is a huge concern. We invest phenomenal amounts of money on safety. We have a medical staff at each event. We probably have more lawyers on staff than some law firms do. We have a book of contingency plans that every employee reads and takes a test on. If you don't pass, you have to go through training and have a discussion with a senior manager.

We've sold more than 500,000 tickets, and somehow, we've had no deaths. Statistically, it's amazing. You take that number of people, and if they were sitting at home that day, statistically, we should have had a few heart attacks. I have to tell the team, it's coming. We have to accept that it's going to happen at some point and work to ensure it never does.

My co-founder, Guy, and I don't spend that much time in meetings one on one, but we do have dinner together at least once a week. Guy and I have been friends since high school, and I think that's the most important thing in a partnership--having someone you know really well. You know each other's strengths and weaknesses, and Guy has many strengths that I don't. He's far more patient than I am.

Usually, by late afternoon I'm wiped out. I can probably do four or five hours of meetings a day. Then my attention span's gone. I don't let anyone invite me to last-minute meetings anymore.

I normally head home around 7 p.m. My fiancée, Katie Palms, will typically be home by then. She was at Harvard Law when I was at Harvard Business, and she's now a corporate lawyer. We met at a house party. I was pretty drunk, but she begrudgingly gave me her number anyway. I called her three or four times, and she was having none of it. Eventually, she gave in, and the rest is history. Usually, we have dinner together, and if I don't have some kind of work event, I'm in bed by 10 p.m.

I always tell people I'm probably fundamentally a bit lazy. It sounds like an odd thing to say, but it's true. I frequently gravitate toward slightly easy things, but now, the only things that come to me as CEO are really damn complicated. The great thing is, on a really frequent basis, you're reminded why you're doing this. Occasionally, I'm in a situation where people don't know what I do for a living, and Tough Mudder comes up, and they're talking about how awesome it is. There's nothing like it.