Mud runs, essentially military-style obstacle races in muck, might appall the neat freak but for some people mud is the medium for a challenging test of true grit and fitness.
Neal Pire, owner of Inspire Training Systems, in Ridgewood, New Jersey, has trained several people for mud runs, which come in varying lengths and levels of difficulty and appeal to people who enjoy performing and withstanding the elements.
"Most of the people I've seen do it are the extreme fitness enthusiasts," said Pire, an expert with the American College of Sports Medicine. "The oldest was in her late 40s. It's not a lifetime affair."
"Spartan run, Mud Run, Tough Mudder -- each have their own flavor," he said, naming a few mud runs which are organized by organizations, companies and charities. "They all have obstacles, like water, climbing and crawling under barbed wire."
Roni Noone, 36-year-old wife and mother who has sloshed through at least two mud runs so far, said there is something motivating and inspiring about climbing a wall and jumping into a lake.
"The mud is just there and there's something very primal about it," said Noone, who is based in Baltimore, Maryland.
A runner and blogger, Noone was seeking a fresh challenge when she started doing obstacle-based runs. This year she completed a five km (3.1-mile) mud race called Rebel Run and the Tough Mudder, an approximately 12.5-mile (20-km) obstacle course trek, climb and swim through fire, mud and ice water designed by British Special Forces.
"Tough Mudder is a notch up from the typical mud run," said Noone, who trained for 12 weeks to prepare.
She said teamwork and camaraderie make mud runs less lonely than long-distance running.
"They're challenging, fun and very team oriented," she explained. "You're not supposed to go through it without someone helping you."
Matt Sauerhoff plans to run his first Tough Mudder in October.
Sauerhoff, who manages personal trainers at a New York Health and Racquet Club in New York City, will be joined by his work colleagues.
"It's great for team building, to bring us all close together."
The Tough Mudder is an extreme event, he added.
"You're running and diving in the mud, climbing over logs and up cargo nets," said Sauerhoff, who hopes to come out of the messy adventure with some ideas he can pass on to his fitness clients.
"Some people don't like to be pushed to the point of exhaustion," he said. "I don't need to lift a car off of my chest. What's important to me is high endurance."
To prepare his clients Pire runs a type of boot camp that features a lot of change of direction, crawling and performance-based drills.
"These are essentially simple things: climbing, crawling, running," he said, but very demanding physically and mentally.
"If you're not used to that stress, you're not going to feel so good. Not to mention the blood from the barbed wire," he added.
But he added that mud runs are very social affairs.
"I don't know anybody who's done this without a friend," he said. "The social aspect drives people. Lots of husbands and wives, boyfriends and girlfriends and friends. Then they party afterwards."
Christine Bohle, a senior industry marketing manager at Eventbrite, an online self-registration and ticketing company that includes mud runs, said they tend to attract people of all fitness levels.
"It's about having fun and getting through it," Bohle said.