Usain Bolt Has Never Run A Mile. It Sounds Crazy, But It's Really Just Science

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Usain Bolt Has Never Run A Mile. It Sounds Crazy, But It's Really Just Science

In August of 2016, the New Yorker speculated how fast the legendary Jamaican sprinter Usain Bolt might run a mile. The nine-paragraph article included interviews with running experts and comparisons to other record holders, which might seem like a lot of work when you could just ask Bolt himself. Except you can't: Usain Bolt has never run a mile.

The Barkley Marathons Is A Race You Probably Won't Finish

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The Barkley Marathons Is A Race You Probably Won't Finish

Even for seasoned ultramarathoners, there's nothing familiar about the Barkley Marathons. First of all, registering for the race is tough: there's no website, so potential participants have to find out how to get in touch with race director Gary Cantrell (a.k.a. Lazarus Lake) directly. Cantrell is also the only one who knows when the 100-mile race will start: he blows a conch shell to wake the camping participants any time between 11 p.m. and 11 a.m. before the race, letting them know they have an hour to get to the starting line. In lieu of a starting gun, Cantrell lights a cigarette. Once the runners begin, they must complete five loops approximately 20 miles in length, each with a 12-hour time limit. This is where things get really tough: steep inclines, trails shrouded in brambles, and a complete lack of aid stations or route markers along the annually changing course leave each runner bloodied and disoriented if he or she is strong enough to complete even one loop. It's rare that a runner will complete the Barkley Marathons -- only 14 have done it in 30 years -- but many participants come back again and again to compete nonetheless.

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Key Facts to Know

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    The Barkley Marathons is a 100-mile race comprised of five 20-mile loops that you have 60 hours to complete. 0:46

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    The course is in the same park as the Brushy Mountain State Penitentiary, from which James Earl Ray, Martin Luther King Jr.'s killer, escaped. He only made it 8 miles in 54 hours. 1:44

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    Runners must find books placed along the course and rip out the page number that matches their bib to prove they completed the course. 2:32

When Humans Race Horses in a Marathon, Who Wins?

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When Humans Race Horses in a Marathon, Who Wins?

Leave it up to a couple of barflies to come up with an event as baffling as the Man v. Horse Marathon. The idea was hatched in the back bar of the Neuadd Arms Hotel in Llanwrtyd Wells, where the owner overheard his patrons' fervent discussion about whether a man could beat a horse in a distance challenge, and decided to put it to the test. The mountainous 22-24-mile event has taken place every year since 1980, and whereas you might expect the horses to beat the humans without contest, that hasn't always been the case. Human runner Huw Lobb beat the lead horse for the first time in 2004, and Florian Holzinger repeated Lobb's achievement in 2007. The reason the competition is so close comes down to evolution. Many scientists believe we evolved to be persistent hunters that chased animals across the savanna until they collapsed. Our ability to lose heat through sweat is just one adaptation that gives us a leg up on horses and other quadrupeds, who pant to expel heat but have trouble doing so at top speeds. That's likely the reason humans have been able to win: those victories took place on hot days.

Imagine Running 7 Marathons On 7 Continents In 7 Days

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Imagine Running 7 Marathons On 7 Continents In 7 Days

For most people, running even one marathon is an accomplishment -- imagine running seven. Created in 2015, the World Marathon Challenge is the world's only race that takes participants through seven marathons on seven continents in seven days. Registration fees hover around $36,000 and include business class or chartered airfare from Antarctica to Australia. Runners must finish each marathon within eight hours, or the plane will leave them behind. Temperatures throughout the course range from -4° Fahrenheit (-20° Celsius) in Union Glacier, Antarctica to 77° Fahrenheit (25° Celsius) in Sydney, Australia. To date, only 27 individuals have taken on this challenge, and all of them finished.

Sled Dogs Are The Ultimate Marathon Runners

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Sled Dogs Are The Ultimate Marathon Runners

There is no doubt that races like the Iditarod are grueling feats, but you may not fully realize just how able the furry competitors are. Sled dogs like Alaskan and Siberian huskies are made to run, and can handle long endurance races easier than you may believe. The dogs have an impressive VO2max number, which basically means the amount of oxygen their bodies can take in per kilogram of weight. In the sled dogs, the number is 230 mL per kg. For human marathon runners, that number is 85 mL per kg. In basic terms, this number represents the cardiorespiratory fitness level of the dog/human.

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Key Facts to Know

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    The majority of racing sled dogs are Siberian or Alaskan huskies. 2:40

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    Humans use glycogen and oxygen to create energy, whereas sled dogs use fat and oxygen. 3:10