Well, that we knew. Personally, I couldn’t run a marathon, let alone 1,100 miles over 10 to 20 days. (At this point in my life I can barely run around the block, but let’s not talk about that.) Sled dogs, however, can perform at a level far above that of even the most elite human athletes, and a 10-year study by a team at Oklahoma State University’s Center for Veterinary Health Sciences has found out why.
It seems that sled dogs have three qualities that set them apart from human athletes (the team wasn’t able to study all breeds under similar conditions, of course, so maybe this applies to all dogs – but we don’t know for sure).
First, Iditarod dogs are unusually good at adapting to exercise – even sustained, strenuous exercise. The OSU team was able to study over 5,000 dogs in various races. During the Iditarod, they measured the dogs’ biochemical profiles. Four days in, their profiles returned to normal, as if they weren’t in the middle of the most grueling race on earth. No human athlete can do that – our muscles fatigue and require recovery time.
Second, sled dogs have tremendous aerobic capacity. A fully conditioned sled dog has an aerobic capacity twice that of an untrained sled dog. Having high levels of oxygen circulating through their bodies probably prevents muscle fatigue, since oxygen depletion is a key cause of muscles giving out.
Finally, Iditarod dogs are extraordinarily efficient at converting food to energy. A roughly 55-pound sled dog can burn up to 12,000 kilocalories per day – the equivalent of 24 Big Macs. A human athlete, to sustain Iditarod-level performance for just one day, would have to eat, *and* efficiently process, the equivalent of 72 Big Macs. Sled dogs eat a commercial race diet, but it can be supplemented by anything from salmon to congealed lard (ick), all of which they’re able to convert to fuel.
How do they do it? Professor Michael Davis, the team leader, said he suspects that the dogs have very thin cell membranes within their muscle fiber, enabling them to continuously absorb nutrients from their bloodstream while they’re running. That, their quick adaptation to long-term, high-level exertion, and all the oxygen in their systems enable sled dogs to avoid the immune suppression, fatigue, muscle damage and stomach ulcers that plague human athletes.
I wish I had an extraordinary capacity to adapt to exercise and could efficiently convert huge quantities of food to fuel. Just don’t make me eat lard.
[...] A 10-year study at Oregon State University has revealed that Iditarod-competing Huskies are ridiculously well-oiled machines… “A roughly 55-pound sled dog can burn up to 12,000 kilocalories per day – the equivalent of 24 Big Macs. A human athlete, to sustain Iditarod-level performance for just one day, would have to eat, *and* efficiently process, the equivalent of 72 Big Macs.” (DogBlog.com) [...]