Saturday, September 27, 2008

endurance athletes (with 4 paws and fur and a wagging tail)

so as endurance athletes we tend to develop a certain pride in our physical conditioning. we find pleasure in the abilities we've built up, revel in the capacities we've developed, marvel at the things we discover that we can do. and from that, we find ourselves with a new-found awareness of just what is possible in life and living, an assurance that it is greater than anything we can imagine, and the confidence that it is all within reach of the human soul.

but then every once in awhile something happens to remind us to reconnect with our reality, and to remember that dreams need to be made manifest before they can become real, and that manifestation is a process that involves just a little bit of work--particularly given the tools of our species: the spirit may be limitless, the mind may be free, but the body only operates in so many ways.

and this, my friends, is one of these reminders:
yes. dogs. as in: furry and 4 paws and cuddly wuddly wuvvy lovey fuzzy lick-your-face-and-wag-their-tail oh-so-cuuuuuuuuuuuuuuuuuuuuuuuuute!!!

yes. dogs. who just also happen to be capable of running us human endurance athletes into a pathetic pile of pitiable putrescent whimpering crawling mush.

yes. dogs. endurance athletes. of the kind that put the human ones to shame.

the article is from LiveScience, and if the link doesn't work i've put the full text of the article at the end of this post.

the dogs covered in the article are the ones that run the Iditarod, which for those of you who don't know is an annual sled-dog race from Anchorage to Nome, Alaska covering roughly 1,100-1,200 miles in frequently blizzard conditions with temperatures running as low as -40 degrees Celsius (yes, that cold). it honors the 1925 expedition that carried serum to combat a diphtheria outbreak in Nome. you can check out the relevant links:
the research presented by the article finds that the dogs have a unique ability to adjust to their endurance stress load. most athletes and sports scientists know that training is really a process of breaking down cells in the body, and then allowing the body to recover and repair the damage, with the end state of recovery being a body able to accommodate an increased stress load. for humans, this is a constant never-ending process, with the body always requiring a recovery phase to adapt to the training. the same thing happens in the process of a race.

dogs, however, only do this in the initial stages of increased stress. after an initial day of cell breakdown, their bodies adjust and they don't suffer the same level of breakdown again. this means that they don't need the same levels of recovery as they do at the start, and instead can maintain the same levels of stress load continuously throughout the course of training and racing. in short, they can don't need as much rest, and they can go harder farther and longer.


and that's not all. their metabolic rates are through the roof. the article states that dogs consume as much as 10,000 calories per day (!!!) on a diet with 60-70% fat (!!!!!!) with bodies weighing around 55 lbs. (!!!!!!!!!).

for perspective, the article puts this in context by comparing it to Michael Phelps' comments of eating similar amounts, but notes his radically larger body mass (and i should note, likely very different nutrition content). i prefer to refer to the caloric intake that most Ironman athletes take, which is around 6,000-8,000 calories on a long training day, and probably around 8,000-10,000 calories the day after race day--and with a nutrition content much closer to 20-30% fat.


and did i mention that dogs in the Iditarod are pulling a sled with food and supplies and a human being the entire time they're doing it?


yeah, those dogs.

looks like they're the real endurance athletes.


woof woof.

hug a dog today.

cuz they're likely to beat you on race day.

Iditarod Dogs' Endurance Secret Revealed
Jeanna Bryner
Senior Writer

Racing sled dogs could be considered the Lance Armstrongs of the canine world, for their strength and endurance. New research sheds light on how they do it.

Sled dogs are best known for "mushing" each March in the Iditarod Trail Sled Dog Race, the world's longest sled race. The canine competitors cover 1,100 miles (1,770 km) from Anchorage to Nome, Alaska, sometimes in just nine days.

The dogs often trek through heavy blizzards and endure temperatures as low as minus 40 degrees Fahrenheit (minus 40 degrees C). The chilly conditions are necessary for the dogs, which would overheat in balmier climes. That's because dogs can't sweat, except through their paws, and they generate a tremendous amount of heat purely from the burning of calories during the race.

Michael Davis of Oklahoma State University's Center for Veterinary Health Sciences has studied the sled dogs for the past 10 years. He runs check-ups on the dogs before and after races as well as during controlled experiments for which he sets up races with groups of sled dogs. The secret to the dogs' feats of day-to-day endurance lies in their ability to "reprogram" their bodies' responses to stress after just one day of competition, something humans can't do.

Davis plans to present his recent findings this week at a conference of the American Physiological Society in Hilton Head, S.C. If you were to attend a race, Davis said, you might be surprised that the dogs are not all purebred Siberian Huskies. Rather, they are mutts, with a mix of Husky, Alaskan Malamute, Pointer and other breeds.

Ultra athletes

Davis found that just like human athletes, conditioned sled dogs show body damage during their first day of exercise.

For instance, when any athlete, canine or Homo sapiens, pounds the pavement or icy ground for miles, bits of muscle enzymes and proteins leak out from their cells. Scientists say this is a sign of cell damage.

Our cells do recover in a day or so, but as soon as we go for another run, the same damage happens all over again.

For sled dogs, that's not the case. "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]," Davis told LiveScience.

He added, "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."

Davis found the sled dogs somehow reprogram their bodies after that first or second day of training with an athletic armor of sorts to prevent other bodily stresses as well.

Hungry canines

The four-legged fur-balls also have appetites rivaling any human athlete. During race season, the dogs, which weigh a mere 55 pounds (25 kg), consume 12,000 calories a day, Davis said.

For comparison, Olympic swimmer Michael Phelps reportedly eats some 10,000 to 12,000 calories a day during competitions. But Phelps boasts at least three times the weight of a race dog, Davis said.

"The challenge is getting 12,000 calories into a little dog like that and it has to be very calorie-dense," he said. "While they're racing, they're eating a diet that is pushing between 60 and 70 percent fat."

(Every gram of fat contains nine calories, compared with the 4 calories in a gram of protein or carbohydrate).

Whatever it is that allows sled dogs to chow down on so much fatty food and stay healthy could be beneficial to humans. And so results of Davis' findings have implications for humans who have become obese or developed Type 2 diabetes.

"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," Davis said. "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."

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