Who Rules the Endurance World?

The Iditarod Trail Race sled dogs may be the fittest animal athletes on the planet.

Who Rules the Endurance World? Dean Karnazes asks in his Runner's World Blog. He has found the answer in Alaska:

Racehorses have an extremely high VO2 max of 180, primarily because their hearts are as big as basketballs and can pump huge amounts of oxygen-rich blood throughout their system. Cheetahs, on the other hand, are sprinters designed for short bursts, so their VO2 max levels are lower than elite human endurance athletes.

So just who is it that rules the world when it comes to stamina? You might actually have one in your household. Dogs have tremendously high VO2 max scores. In fact, the Iditarod Trail Race sled dogs may be the fittest animal athletes on the planet, some recording VO2 max levels over 200!