Instead, runners have to make notes from a master map and then navigate their way through often thick undergrowth with nothing more than a compass. Oh, and there are no fixed trails to follow. Gradients are commonly steeper than 40 degrees. Runners who make it to the end will ascend and descend 120,000 feet - the equivalent of climbing up and down Mount Everest twice. What makes the Barkley so fiendishly tough is the unforgiving terrain of Frozen Head State Park in Tennessee.

There are many longer ultra-marathons, some of which take place in 40-degree heat. To complete the Barkley Marathons, you need to navigate five 20-mile loops of the course within 60 hours.

Indeed, in its 33-year history, there have only been 15 finishers in a field containing the world’s most elite ultra-marathon runners. It took place last weekend, but you will not find any list of winners: for the second successive year no-one completed it. More mean-spirited than Jose Mourinho protecting a 1-0 first-leg lead, more devious than an Eddie Jones press conference. Out There is a story of persistence, endurance and a love for the great outdoors, and the film inspires the audience to reconnect with nature themselves and to find courage for personal challenges.Billing itself as the “Race That Eats Its Young”, the Barkley Marathons is the most evil event in sport. How did setting these world records prepare Karel for a race as brutal as “the Barkley”? How did these adventures help Karel to find the necessary mindset to do well at this Spartan challenge? Out There – A journey to the Barkley Marathons is the story of Belgian ultrarunner Karel Sabbe, who holds the world records on two of the most epic trails in the world: the 4300km long Pacific Crest Trail and the 3500km long Appalachian Trail. The course is unmarked, no electronic devices are allowed and most of the race is off-trail.

Runners are to run five 20-mile loops, within a 60 hour time frame, and with more than 20.000 meters of elevation change. The race is so brutal that, since the inception of the race, only 15 people have managed to finish. The Barkley Marathons – one of the world’s toughest ultramarathons, has been held annually in the Frozen Head State Park, Tennessee, since 1987.

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