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  • Cheetahs are the fastest land animal in the world.

  • But did you know that humans can leave them in the dust?

  • At least in the long run.

  • That's right, when it comes to endurance.

  • We can outrun wolves, cheetahs, and even horses.

  • Now in the beginning, humans fall short because we're lousy sprinters.

  • Case in point, Usain Bolt couldn't outrun a cheetah in the 100-meter dash if he wanted to. And he tried.

  • But marathons and ultra-marathons are a whole other ball game.

  • Each year, a small town in Wales holds the Man Versus Horse Marathon.

  • It's a 22-mile race between riders on horseback and runners.

  • And while horses often win, humans will sometimes prevail.

  • So what makes humans such endurance running superstars?

  • The secret weapon is our sweat.

  • We have two to four million sweat glands all over our body, which means we can run and cool ourselves at the same time.

  • Having no fur is also a huge plus.

  • In contrast, dogs rely on panting to cool down.

  • And other animals, like horses and camels, also sweat, but less effectively.

  • As a result, they overheat faster and must slow down sooner.

  • The mechanics of our running stride also makes us particularly well-suited for endurance running.

  • A human's running gait has two main phases.

  • Aerial, when both feet are off the ground.

  • And stance, when at least one foot touches the ground.

  • While in the air, gravity pulls us down, which generates a lot of kinetic energy.

  • However, the second we hit the ground, we instantly decelerate, losing that kinetic energy in the process.

  • Some of it goes into vibrations and sound as we strike the ground.

  • But most of it actually goes straight to our tendons.

  • Here's where our special adaptations come in.

  • The tendons and muscles in our legs are very springy.

  • They act like a pogo stick.

  • Converting kinetic energy from the aerial phase into elastic potential energy, which we can use later.

  • In fact, our IT Band can store 15 to 20 times more elastic energy than a chimpanzee's similar body part: the fascia lata.

  • When it comes time to step off, those springy tendons can turn 50% of that elastic pogo stick energy back into kinetic, making it easier to propel forward.

  • Without that extra energy, we'd have to exert that much more effort just to take a step.

  • So how did humans get to be such great endurance runners?

  • Some anthropologists believe this became important around two to three million years ago, when we started hunting and scavenging.

  • Because we couldn't chase down a gazelle like a cheetah, early humans learned persistence hunting.

  • Where they would track prey over long distances until the prey either overheated, or was driven into a trap.

  • In fact, persistence hunting remained in use until 2014, such as with the San people of the Kalahari Desert.

  • But distance running can still help you, even if you're not interested in running down your next meal.

  • Studies show running can lower body weight, body fat, and cholesterol levels.

  • And the longer you train, the greater the health benefits.

  • Just one year of training has been shown to reduce body weight by about seven pounds, lower body fat by 2.7%, and decrease resting heart rate by 2.7%.

  • It may seem really hard, or maybe even impossible to run a mile or a marathon.

  • But in fact, you were born to go on that run.

  • We all were.

  • (upbeat music)

Cheetahs are the fastest land animal in the world.

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B2 US endurance kinetic energy running kinetic energy elastic

How Humans Evolved to Become the Best Runners on the Planet

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    Liang Chen posted on 2019/01/28
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