By Diana Gerstacker

A single man with a microphone stands among hundreds of jittery competitors with the Start sign looming overhead. They form a tight circle around him and fall silent awaiting final instruction.

"Tough Mudder is not a race, but a challenge. You will put teamwork and camaraderie before your course time,” the speakers boom. “You will help your fellow mudders complete the course."

A collective "Hoo-rah" comes from the anxious crowd.

"You will overcome all fears.”

Tough Mudder is a 10-12 mile obstacle race and arguably the most popular competition of its kind. A typical mudder event draws between 10,000 and 20,000 competitors and after more than 100 events; they've had 1.3 million participants to date. Mudder pride runs so deep that more than 4,000 competitors have chosen to have a permanent reminder of race day tattooed on them at the finish line and competitors come back time and time again.

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Extreme races and physically punishing competitions have become increasingly popular in recent years. The allure seems to come in stages, teamwork and struggle then triumph and bragging rights.

Challenges in the mainstream races range from a running or crawling through field of hanging live electric wires to mind games like memorization and then punishment for failure. Facing your fears and proving your resilience are what these challenges are all about and most people finish races like Tough Mudder with nothing more than a few scratches and bruises -- and a renewed sense of self confidence.

There are other races, though, that push the limits of what the human body and mind are actually capable of. These races are in most cases exclusive; reserved for the lunatics and not for the faint of heart. The chances of finishing these races are slim, but the odds of injury are astronomically high. Occasionally there are deaths, yet each year more competitors sign up for these torture fests.

Fitness Challenges That Could Kill You Slideshow


Everest Marathon

The Everest marathon is the highest marathon in the world according to the Guinness Book of World Records. If you thought your local marathon was hard, try breathing normally at 17,000 feet and negotiating your way over rock and dirt on the side of a mountain for 26.2 miles. The Everest Marathon requires a medical exam two days before the race by their team of professionals and they will also supervise each runner’s adjustment to the altitude, this is not negotiable. The organizers also insist on competitors getting to know one another, as they may need to help each other on the mountain.


H.U.R.T. 100-mile Endurance Run

One hundred miles, 25,000 feet of elevation and dense Hawaiian forest put the H.U.R.T. 100 on our list. This trail running competition is among the toughest in the world. Running on unpacked dirt, rocks and over massive tree roots, you have 36 hours to complete the race. Supposedly even the fastest finisher of all time took more than 20 hours.


Barkley Marathons

This no-frills Tennessee backwoods torture course was inspired by the story of an assassin's escape from prison and begins with the lighting of a cigarette. 100 miles and almost 60,000 feet of vertical climb seems an impossible feat with a 60-hour cutoff for qualifying finishes. Only 14 people have ever officially finished in the races nearly 30 year history. Add rapidly changing weather conditions, a scarcely marked "trail" and plenty of thorns and brush to slow you down -- this race might actually be worse than prison.


6633 Ultra

The 6633 ultra is a race over a distance of either 120 miles or 350 miles, because 26.2 miles simply isn't challenging enough at the Arctic Circle in sub-zero temperatures. Adding strain to pure insanity, each runner is required to carry all supplies with them and then cook their own food. The only thing guaranteed at rest areas? Shelter and hot water, so if you make it to a checkpoint you can die with a roof over your head.


Badwater UltraMarathon

This Ultra hell run came about in an attempt to link the lowest point in the continental U.S. to the highest point, and tackle this feat on foot. Considered one of the toughest races on the planet, the most direct route is 146 miles long with 19,000 feet of total elevation gain. But since the U.S. Forest service has banned competitive races in the John Muir Wilderness, the official race has been scaled back to a mere 135 miles long. Some competitors continue on unofficially in an attempt to complete the original challenge. As if 135 (or 146) miles up hill could get any worse, the event takes place in the killer heat of California's summer. Temperatures in past races have reportedly reached 130 degrees.


The Marathon des Sables

The Sahara desert will make California heat feel like a cool breeze and you’ll wish you were only racing 135 miles. In this marathon, spend a total of six days trekking 151 miles across the world's hottest desert and even the camels will think you're crazy.


Talisker Whisky Atlantic Challenge

According to the Talisker website, more people have been into space or climbed Everest than have rowed the Atlantic. They say this is the toughest race on earth, and we might have to agree. The race alone can take up to 90 days to complete, starting in the Canary Islands and ending in the West Indies. The total trek is nearly 3,000 miles long over choppy shark-infested waters. If blisters, a “near starvation diet” and sleep deprivation sound like a good time, this challenge is for you.

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