However, the Brutal Extreme Triple Triathlon makes the Kona Ironman race in Hawaii look like a school sports day. How about battling sub-zero temperatures or powering up to a mountain summit—over a course of 50 to 100 miles? Current record holders, Ryan Sandes and Ryno Griesel recently completed this grueling route in 25 days. The grueling Marathon des Sables, for example, drags runners across 149 miles of Sahara Desert sands in southern Morocco. Run over five days, many of the worlds best marathon paddlers and enthusiastic amateurs will cover 220 km on their boards. By Amanda Casanova; Looking to add something extreme to your schedule this year? While no one organization tracks such events or the …

The 934-mile Great Himalaya Trail is likely the most extreme. World’s Most Extreme Adventure Races. Most Extreme Races. In 2006, the World Triathlon Corporation rebranded its half Ironman triathlon events as 70.3 races in reference to the total swim-bike-run mileage (1.2-mile swim, 56-mile bike, 13.1-mile run). Some races take it to a whole new level. But the most extreme endurance races in the world take that to another level. The term "Half Iron" didn't quite do justice to a race that takes most between five and seven grueling hours to complete. Advertisement. These competitions test the absolute limits of … Armstrong is part of a growing group of endurance fanatics, athletes who crave impossible challenges set against some of nature’s most unforgiving backdrops. Most Extreme Races.

The reason? The Ironman is often regarded as the zenith of physical endurance challenges, testing strength, speed and sheer willpower. 12. by Nancy Yeomans Click to share on Facebook (Opens in new window) Click to share on Twitter (Opens in new window) The world's toughest, and currently longest SUP race happens annually in the Friesland canals of northern Holland. The most extreme endurance races in the world test the absolute limits of the human body and mind. Car racing used to be one of the most dangerous things a person could do, period. Hardship is part of the deal when you're a fan of extreme endurance running.

There are plenty of things that make extreme running difficult. In Pictures: World’s Most Extreme Endurance Races.

What the pros say: “The most challenging thing about UTMB is gaining over 30,000 feet of elevation.