Are adventure races like Tough Mudder and Spartan worth the risk?

Thrill seekers may be getting more than they bargained for when they sign up for adventure races like Tough Mudder, Warrior Dash and Spartan Race.

Every summer thousands of people gather in cities across North America to test their toughness with a series of obstacle-based races that have you diving into ice pools, jumping through fire and enduring electric shock. Seriously.

The goal? To prove you’re not only fit but—more importantly—badass.

Dustin W. Ballard, an emergency physician at Kaiser Permanente Medical Center in California explains, “The Tough Mudder participant who conquers his or her fears along with the event also may garner confidence and optimism to face challenges elsewhere in life.”

While most people cross the finish line with little more than a mouthful of mud, others aren’t so lucky.

The Spartan rash

In the summer of 2013, reports of the “Spartan Rash” began circulating when a number of participants from the Spartan Race in Marseilles, Illinois took to social media complaining about a series of itchy, red bumps.

The Spartan Race claims to be the “World’s Best Obstacle Race.” Established in Vermont, the race now takes place in 15 countries across the globe with participants running upwards of 20 kilometres, crawling through dirt under barbed wire, jumping over fire and wading through ditches filled with mud.

NBC spoke to a number of affected participants whose sought out medical help for the condition and were told that the cause could be anything from poison ivy to swimmer's itch. The Illinois Department of Public Health backed up that claim stating an, “environmental survey suggested that many poison ivy plants were likely crushed when some obstacles were constructed, which would have released urushiol, the oil of poison ivy, into the mud.”

Since the Marseilles race, a Facebook group dedicated to the rash has gathered more than 400 followers sharing itchy, post-race war stories—and pictures. Though the Spartan organizers acknowledged the outbreak, one participant was told to toughen up under the justification that “the original Spartans wouldn’t have complained about a poison ivy rash.”

Infections

Last fall during an obstacle run in Nevada, the U.S. Centers of Disease Control and Prevention reported that 22 participants had picked up Campylobacter coli infections, which causes cramping and diarrhea. The source of the infection turned out to be surface water from mud pits on the course, which participants accidentally drank during an obstacle that had them jump through ditches filled with the contaminated water.

Heart attacks

At a Spartan Race in Vail Lake last year, at least two heart attacks were reported among the nearly 5,000 participants along with a series of broken bones. An emergency doctor at the Temecula Valley Hospital told The Press Enterprise, "It's the most patients we've seen from one event." Another heart attack was reported at a Tough Mudder race in Allentown, Pennsylvania the same year.

In Temecula, the extreme heat was a major factor in the increasing number of injuries as it was a shocking 100 degrees Fahrenheit (approximately 38 degrees Celsius).

Dr. Alex Diamond, a sports medicine expert at Vanderbilt University in Nashville, Tennessee told ABC News, “They’re literally jumping over fire, into rock pits, diving head-first into ponds. Some of these obstacles really are just inherently dangerous.”

Drowning

Since 2011, there have been at least four obstacle race-related deaths reported according to the Baltimore Sun. The most recent occured in 2013 in West Virginia during the popular Walk-the-Plank obstacle at Tough Mudder, which involves a 15-foot high jump into a deep pool of cold, muddy water. The combined fear of heights and swimming created a back up on the course causing participants to ignore safety regulations and over crowd the pool.

Though deaths are still minimal in comparison to the number of participants, injuries including heat exhaustion, dehydration, rolled ankles, cuts, bruises, dislocated shoulders and splinters are common.

However, in January, the Associated Press reported that a new obstacle involving tear gas would be added to the Tough Mudder course. Will Dean, Tough Mudder CEO was quoted as saying, “it definitely will make your eyes sting while you’re in the smoke, but ultimately it’s safe.” All obstacles for Tough Mudder have their roots in military training drills and the new one is meant to provide participants with a sense of chemical warfare. “The idea of doing something that sounds painful, disorientating, is definitely something that’s a little scary,” Dean explains. “The reason we have it is because it’s intimidating.”

Like any race, there are inherent risks involved in competing but with organizers upping the ante each year, there’s a concern of knowing when enough will be enough. In order to stay safe out there is to, “challenge yourself but do so with calculated risk,” says Ballard. “The smartest ‘mudder’ is the one who pushes through obstacles until the point that his body tells him to stop.”

[Correction: 07/21/15 - An earlier version of this story mentioned all four deaths occured at Tough Mudder. Tough Mudder has clarified to Yahoo Canada that there has only been one death at Tough Mudder, specifically.]

[Tough Mudder responded to the article stating Tough Mudder has hosted over 150 events hosted in past 5 years, with more than 2 million Mudders safely earning their headbands. 98% of Tough Mudder participants complete the event without need of any medical assistance, and the most common medical issues addressed on site are dehydration, heat exhaustion, and hypothermia. These issues are by far the most regular, but others injuries treated include minor abrasions, contusions, and lower-body sprains. The majority of injuries do not occur at obstacles, but are sustained while running along the course.]