The definition: A person who actually pays to crawl through, be encrusted in and sometimes flip into mud. A tough mudder is a person who does it over 12-and-a-half miles of muddy track, through wire electrified to 10,000 volts and what seem like medieval torture devices with names like "Arctic Enema."
Welcome to the Tough Mudder. Don't call it a race, "it's a challenge," admonish the organizers, who are bringing their British-special-forces-designed (read painful) courses with their 29 obstacles (walls, 15-foot planks, ice baths, nightmare monkey bars, greased halfpipes, electrified army crawls, etc.).
I attended one of 35 tough mudder events being held this year. It's one of the fastest growing businesses in America, going from 50,000 participants in 2010 to a projected half million in 2012.
It's competitive, to an extent. The goal, said a wise-cracking emcee psyching up the crowd of 6,000 before our start time, is to do your best, but also to help your fellow mudder.
"If you find someone face down in the dirt, they are no longer enjoying the course -- help them," he said.
It was among those hundreds milling around, stretching in their compression shorts, head bands -- many were bare-chested -- that I found perhaps the toughest mudder about to start the race.
A former Marine, Ben Lunak was standing with a group of wounded warriors at the aptly named Mesa Proving Grounds in Mesa, Ariz., where 6,000 pain-craving lunatics gathered for the Tough Mudder.
Lunak's Humvee was blown up near Ramadi, Iraq, in 2005. When he went to in Germany a few days later he looked down, surprised that his leg was still attached. And then he asked for it to be amputated.
"If they left it," he told me, "it would just be a bum leg and I would be walking around with a cane, and that's pretty much worthless. I just wanted to get out of the hospital, and I said, 'Why wouldn't you amputate it? What are we waiting for?'"
Lunak nearly ascended Mount Kilimanjaro last year, and now he was attempting this -- something the organizers have proudly branded, "probably the toughest race on the planet."
I asked another wounded warrior what attracts them to something like this. One would think it's just more pain for people who've been through so much already.
His answer: "It is! It's great pain! There's only a few wounded warriors here and we've been through this before and we'll do it time and time again, and we're just gluttons for pain. ... Gluttons for pain, we love it."
These were the people I'd be running with. It was going to be a long day.
Every tough mudder begins with a preemptive pledge to suck it up. I do not whine. Kids whine. I help my fellow mudders complete the course, and I overcome all my fears.
The race began. It seemed easy enough, a few mud crawls beneath barbed wire, a couple of obstacles like hay bales and giant ruts. And then came the official Tough Mudder reminder that this was no jog in the park: the Arctic Enema.
"It's a dumpster filled with ice water, it's absolutely freezing. It's the mother of all ice cream headaches," said Alex Paternson, the Mudder's marketing chief.
He's one of the people who devises names like Arctic Enema, Devils's Beard, Shocks on the Rocks and Funky Monkey.
He's also a Harvard graduate with a law degree. Ergo, the other part of his job: ensuring that the sadistic, surprisingly legal obstacles don't get the fledgling company sued.
The man who founded the company, an Englishman named Will Dean, came up with the idea at Harvard Business School. Yes, a lot of smart people are involved with this.
Dean was quickly told it wouldn't fly. But with an $8,000 marketing budget and lots of word of mouth over Facebook, the first Tough Mudder took place in May 2010. It was a hit.
After the first year, 50,000 people had participated in the events. This year, a projected 500,000 are expected to get mudder. In fact, according to the Outdoor Industry Association, participation in extreme races spiked about 85 percent from 2006 through 2010. The rise is exponential.
So post-Arctic Enema, as I huffed beside Patterson (who's done five of these), I asked why anyone would want to this.
"You know, people want to prove something to themselves," he said. "Everybody has their own reason. Some have said they're bored with conventional fitness, some are they're just sitting in their office job and nothing has actually scared them since they were 9 years old and other people."
They also donate part of the proceeds to the Wounded Warrior Project, which is how Lunak was there. He blew through the first eight miles of the 12.5 mile course.
"Dude I keep getting shocked!" he croaked as we crawled beneath electrified wire in the mud.
I'd been so convinced the electrified wire was just a mind game that I didn't pay attention until I, too, got shocked.
Lunak was quickly becoming an inspiration to the other runners, nimbly crossing a wobbly two-by-four where at least half of the runners fell. It took him a while, but when he finished, a roar surged through the crowd -- a powerful moment. And the feat was extraordinary when you consider he was doing it on a single functional leg.
But by that point, Lunak's prosthesis began to fill with water and mud. He could no longer run. His stump was swelling.
But it got worse. We Walk the Plank (jump off a 15-foot platform into frigid water) climb Everest (quarter pipe slicked with mud) and scale a mud hill, which was the hardest obstacle, requiring extraordinary teamwork. We actually stood on each other shoulders, about 10 of us!
All this seems serious business -- except no one seemed to take themselves too seriously. Some were dressed in tuxedos, another group of people wore tutus and one person carried a giant inflatable monkey throughout the course (I briefly carried him). Yet others wore kilts (bad idea). Some wore homemade super-hero costumes. And throughout, the runners upheld the challenge's main motto: "Help your fellow mudder."
Just before the final obstacle, Patterson asked me if ABC News has a good health plan. I laughed ... but in a few seconds I'd take it seriously.
With 28 obstacles down, we approached Electric Shock Therapy, the final obstacle.
Lunak went through first, Wounded Warrior flag in hand.
We saw him stumble and collapse seemingly lifeless, face-first into the mud.
Patterson yelled, "Get the flag!" I didn't care about the flag, but worried that Lunak had been seriously hurt and sprinted in.
Just as I reached him -- ZING!
I got zapped in the head. Lights out.
I came to face-first in the muddy water -- eyes wide open, totally disoriented. It felt as if I'd been clubbed in the back of the head.
At that point, everybody was screaming, "Get up!"
I tried, and I saw Lunak stumbling forward, and, ZAP! Again, hammered by the 10,000-volt charge in the head, I collapsed into the water.
Finally, we all crawled out, stumbled to our muddy feet and somebody yelled: "The Wounded Warriors Project -- everyone give it up for them."
The Wounded Warriors, Patterson and I are crowned with bright orange headbands and are handed beers.
Muddy beyond recognition, exhausted, cut up and disoriented, we all grinned stupidly
Another bunch of hypothermic, beat up and shockingly satisfied customers.