How Sled Dogs Reprogram Their Bodies

The Iditarod Trail Sled Dog Race, which takes place every March, and reunites the best dogs and breeders in the road, is a competition that shows what both the canines and the humans driving them are made of. It takes place between Anchorage and Nome, both in Alaska, and it can cover up to 1,150 miles, or 1,850 kilometers. It usually takes 12 to 16 dogs anywhere between 10 to 17 days to complete the trials, although faster and slower times were also recorded. The secret to these achievements is the dogs' ability to endure cold, and to “function” in chilly conditions, LiveScience reports.

The animals in use for such rugged challenges are not purebred Siberian Huskies, as one would expect. Rather, they are a mixture of breeds, ranging from Huskies and Pointers to the Alaskan Malamute. They are able to withstand temperatures as low as -40 degrees Fahrenheit, or -40 degrees Celsius, and can run adaptively. This means that they basically have the ability to fine-tune their bodies for the rigors of these tournaments. This comes in handy for dog crews that have about two weeks on average to travel well over 1,000 miles.

The secret here is the canines' ability to reprogram their bodies so that they do not get damaged. We, as a species, do not have this ability. The limitation is known to every athlete. In the first day of practicing a sport, cells suffer damage, caused by leaking proteins and muscle enzymes. In the case of humans, the same event happens the next time they engage in the same activity. But this doesn't hold true for sled dogs. These animals have been specifically bred not to exhibit this limitation. The end result is that they indeed show cellular leakage the first day of the race, but when they get up the next morning it's all gone.

“If you then take them out and do exactly the same exercise the following day and the day after that, and the day after that, you don't continue to get that leakage [of enzymes and proteins],” says Oklahoma State University Center for Veterinary Health Sciences expert Michael Davis, who has been studying these animals for the past 20 years. “In the course of just a day or two, they manage to adapt their system so that exercise that was injuring a muscle cell here and there on the first day is no longer injuring muscle cells,” the expert adds.

He also reveals that these animals, which weigh on average around 25 kilograms, tend to eat as much as 12,000 calories per day during the race season. This is roughly the calorie equivalent to the diet of Olympic Gold winner Michael Phelps, who ate the same amount one day before competitions. “The challenge is getting 12,000 calories into a little dog like that and it has to be very calorie-dense. While they're racing, they're eating a diet that is pushing between 60 and 70 percent fat. If you feed a diet that's very high fat to a human, a lot of humans become obese and they develop type 2 diabetes. And the dogs don't. There is no such thing as an obese Type 2 diabetic sled dog despite the fact that they're eating a diet that should produce that,” Davies concludes.