Tara Wetzel was crawling on her hands and knees through mud and under sprinklers when she was zapped with one electrical shock after another — up to 10,000 volts at a time.

“You learn as a kid that water and electricity don’t mix,” said Wetzel, 27, a licensed cosmetologist. “It was kind of terrifying.”

But the stinging “Electroshock Therapy” wasn’t the worst part of the 10-mile Tough Mudder obstacle course Wetzel paid $180 to experience last December on a ranch near Sarasota. No, the worst part, she said, was jumping into the “Arctic Enema,” a pool of green-colored ice water.

“They literally had an 18-wheeler there full of fresh ice,” Wetzel said.

All she got for finishing was a tacky orange headband and a beer. But, the grueling experience was so exhilarating that Wetzel was planning to do it all again — along with about 4,200 other gluttons for punishment and fitness adrenaline junkies — at South Florida’s first Tough Mudder, which is taking place this weekend at Homestead Miami Speedway.

Tough Mudder is a leader in the growing obstacle course racing craze, spreading around the nation and the world.

“It’s probably the fastest growing outdoor sport in the country, and Florida is the epicenter due to the weather,” said Garfield Griffiths, a Fort Lauderdale-based Brit who founded Mud Mingle for singles and The Challenge, a five-mile test of brains, brawn and endurance.

Last weekend, about 10,000 participants slogged 9.3 miles of rugged terrain in mud-caked sneakers that felt more like cement blocks. They climbed towering walls, crawled under barbed wire in thick mud and negotiated some 20 other military-grade obstacles in the Florida Super Spartan at Oleta River State Park in North Miami.

Participants never know what to expect, but the Super Spartan was especially surprising. A natural forest fire broke out in the park, causing the fire department to reroute racers after the elite men category had started, according to the race organizers.

“Some of the elite guys were told to go the wrong way and we ended up carrying a 50-pound brick about 600 meters, instead of the 200 meters we were supposed to,” said Allan Ajoy, who proudly admits to being an obstacle course racing addict.

He had never heard of a mud race until June 2010, when he saw a handbill for one called Tarzan’s Cup in Miami. “I went there with no expectation,” he said.

Now, rarely a weekend goes by that Ajoy — a regional manager for the Lincoln Road clothing store French Connection — isn’t covered with mud somewhere. He has done the Superhero Scramble, Hog Wild, Beach Beast, the Savage Race and Run for Your Lives, a 5K obstacle course infested with zombies.

Oh, and he’s also done Muddy Buddy, the Gorilla Gauntlet Games, Sqwish Sqwash, the Warrior Dash, American Mud Race, the Merrell Down & Dirty and the Jungle Cup

“For me, it’s my getaway,” said Ajoy, 36. “Monday through Friday I’m all about fashion. On Saturday and Sunday, I’m a superhero.”

Saturday, Ajoy he participated in the Homestead Tough Mudder as a member of the 800-strong Mudfunrun team.

Tough Mudder was conceived about five years ago as Will Dean’s entry in the Business Plan Contest at Harvard Business School. In 2009, Dean — who had worked in financial counterterrorism at the British Foreign and Commonwealth Office — launched the company with a childhood friend on a shoestring budget of $20,000. The next year, Tough Mudder held three events. Today, it’s a global brand that has made a reported $75 million. Its 2013 calendar boasts up to 52 events, including 15 in Europe, Australia and Canada.