BROOKLYN – They slid through fire into a pool of mud, climbed mounds of dirt and withstood electrical jolts that sent them face-first into cloudy puddles.

They ran 11.7 miles, scrambling through more than a dozen obstacles, and in the end, standing in their soiled clothes, gripping beers and wearing grins, they were sore, filthy – and proud.

"Crazy. Challenging. Fun. Stupid," Rich Allen, 38, of Okemos said shortly after he finished the Tough Mudder endurance competition Saturday, Sept. 20, at Michigan International Speedway.

He was among about 10,000 people from Michigan and elsewhere who opted to do for enjoyment what some might consider a strange, voluntary form of corporal punishment.

To set up the course, organizers used 450,000 gallons of mud and 100,000 pounds of ice for its "artic enema," which requires men and women to submerge themselves in freezing water. Maybe most notoriously, participants also must move through a field of electrically charged wires dangling above muddy puddles crisscrossed with bales of straw. The inevitable shocks kept few on their feet.

One might have the same experience walking into North Korea, carrying a bible, joked Thomas Saunders, 22, an Air Force staff sergeant stationed at Wright-Patterson Air Force Base in Ohio.

A participant in past events in Pennsylvania and Ohio, he completed his fourth Tough Mudder on Saturday, taking along fellow soldier Matt Rainwater, 27, and civilian intelligence analyst Bill Bates, 53, of Fairborn, Ohio.

None of the three had heard about the Norovirus that sickened hundreds of 2013 participants, and no one approached Saturday expressed concern about potential illness.

Organizers this year took extra precautions, setting up wash stations and messaging competitors about proper hygiene, said event director Barry Shaw, a Tough Mudder operations manager.

Shaw reported no serious injuries and said the challenge, staffed by a "robust" team of safety or medical professionals, went smoothly.

"Anyone weird enough to do this doesn't care about possible flu-like symptoms," Saunders said.

Mark Hamilton, 27, of Ludington, a former Marine, twice went to Afghanistan. "We've done worse," he said when asked about last year's virus.

He and six others wore red T-shirts with "Sgt. Chuck Strong" printed across their backs.

Strong, a member of the Marine Corps' elite special operations command, was killed in Afghanistan this week, according to USA Today. The 28-year-old from Suffolk, Va., served with Hamilton while they were in Afghanistan in 2011. Hamilton was a truck driver and Strong, "the definition of a Marine," was the vehicle commander.

The Tough Mudder group tried to honor Strong as best as they could, Hamilton said.

The seven, joined by a few others, locked arms as they walked through the "electroshock therapy" obstacle.

"It was awesome. It's all about camaraderie," said Cliff Bannon, 46, also of Ludington, said of the Tough Mudder.

Friends, family and strangers work together, helping each other, participants said. Parts of the course cannot be done alone.

Unlike other mud runs, the Tough Mudder is not about time or competition. It's about "doing something strong and uplifting with people you love," Shaw said.

Finishers raved about the race. Many had fun with it, wearing silly costumes.

There were men in kilts. Allen and his friends, all cat haters, donned silly feline T-shirts and coined the event the "Tough meow-dder," a phrase scrawled in pink fabric paint across the bottom of Allen's shirt.

One person wore a T-shirt that read "I wish my wife was this dirty" and a man in checkered spandex chanted "We are mudders, mighty, mighty mudders."

It was the culmination of months of hard work, said Brandy Goolsby, 37, of Southfield who came to Brooklyn with a group that had been training since January. "You just never know how tough you are..."

Despite their aching muscles, several said they would do it again.

Will it return to the speedway? "That's always the plan," Shaw said.