The obstacle course races are meant to appeal to a broad swath of the population — April's Tough Mudder event in West Virginia drew 14,000 people — who want a fun, muddy day off the couch.

Baltimore Ravens head coach John Harbaugh and team staffers were among those who braved the Tough Mudder course in April. The Ravens posted a video of the group on the team website; at one point, Harbaugh is shown crawling military-style through mud. He looks at the camera and says, "This is awesome! This is really fun!"

Tim Milan, a Baltimore resident who ran in that event, said it was "a blast" until the last obstacle, "Electroshock Therapy," where participants dash through live electrical wires. He said he touched one of the wires and was thrown into the mud. "That was the only part that I didn't really appreciate."

Still, Milan, 38, noted that participants had to sign a liability waiver and generally knew what they faced. Organizers "do a great job of trying to scare you out of doing it to begin with," he said.

For Jeff Fink, 31, a 2011 Warrior Dash was a jumpstart to getting back in shape. He was a big man — 6-foot-5, 250 pounds — who had a lot of friends and traveled the country to watch baseball games.

He collapsed during the event, held on a weekend when high humidity pushed the heat index in Kansas City to above 100 degrees, according to news reports. His core temperature when he was brought to a hospital was 108.3 F, father Randy Fink says, and he died from multiple organ failure after spending 10 days in the hospital.

Another man, Jeremiah Morris, 28, also died from apparent heatstroke in a hospital a day after that event; his family could not be reached for comment.

Randy Fink traveled last year from his Iowa farm to Warrior Dash's obstacle course, accompanied by a race organizer and a cousin who had run with his son, to see if new safety precautions had been added. The cousin pointed out places where there were more emergency technicians and more water at the stations. Still, Fink wishes race organizers would promise to cancel events when the heat index was in the danger category.

"I could see [organizers] were trying, so I kind of let it go a little bit," said Fink. "But it still kind of bothers me."

Alley, the spokeswoman for Warrior Dash's parent company, declined to answer questions about specific incidents at Warrior Dash races, but said participant safety is the company's top priority.

Fink feels race companies could do much more to improve safety at events, but notes that participants may overlook the danger posed by the obstacles.

"I get the feeling that a lot of the young people that run these races — and I was that way too — is that they feel they're invincible," he said.

The obstacles and aura of danger are part of the attraction of these races, said Scott Roberts, who teaches psychology at the University of Maryland, College Park and researches persuasion and social influence.

"They can appeal both to people that are into the fitness challenge and training, as well as your average Joe who wants to have fun. ... A lot of them are marketed in a way that seems like a fun physical challenge, but not one that you couldn't complete," he said, adding that the social aspect is also appealing.

But marketing messages that emphasize a challenging, fun-filled afternoon may belie the courses' difficulty, he cautioned. "Some of them, I think, are pretty obviously grueling. But others may make you seem like you're playing in the mud, and people may not realize how strenuous they may be."

Still, he added, "for at least some people, they're attracted to the badge of courage."

Waivers and lawsuits

Water obstacles have led to problems at several events.

Robert A. Fecteau II says he was paralyzed after diving head-first into a muddy pool at the 2010 Richmond Filthy 5K Mud Run in Virginia. He sued organizers, claiming that the pool was shallower than it appeared and that there were no warnings about its depth — even though participants were encouraged to "dive."

Race organizers have contested the lawsuit, which is scheduled for trial in July. Stanley P. Wellman, an attorney for organizers, said Fecteau was not registered for the race and used someone else's bib. Fecteau navigated two other mud pits safely, and no one affiliated with the race encouraged participants to dive into the pits, Wellman added.