Life Lines

Wishing it were cold outside…

i-a78b88103dfe53a0c58a52449bfeb3d3-Screen shot 2010-10-06 at 9.00.28 PM.pngAs the heat drags on in the southwestern United States, I cannot stop dreaming about sledding through the snow. So I checked out the trusty American Physiological Society press releases to see what the animals might be doing in cold environments that I can only dream about these days.

In my search I watched a really neat video of Dr. Michael Davis (Center for Veterinary Health Sciences at Oklahoma State University) who works on perhaps one of the “coolest” animals (pun completely intended): sled dogs! Oh, how I envy these animals. Racing sled dogs are incredible athletes as they traverse the world’s longest Iditarod Trail Sled Dog Race every March. The trek is daunting as they run from Anchorage to Nome, Alaska in only 9 days. In case you are wondering, that is 1,100 miles! Considering the blizzards, low temperatures (lows of -40°F), and high winds up to 60 mph, this feat is nothing short of amazing. I, of course, have no ambitions of being that amazing, I just long to make snow angels and watch them race.

Here is what Dr. Davis has discovered about these athletes:

-These sled racing dogs have an incredible ability to quickly adapt to sustained endurance exercised in as little as 24-48 hours. These conditioned dogs develop depleted energy reserves, cellular injury and oxidative stress expected with strenuous exercise. However, unlike humans, if they keep training for four days, their metabolic profile returns to what is was before training. I suddenly feel really lazy.

-These dogs roughly double their aerobic capacities when fully conditioned to support the exercise.

-During races, these sled dogs burn A LOT of calories (up to 12,000 kilocalories per day (kcal/day)). The press release equates that to “a 55-pound sled dog will consume the equivalent of 24 McDonald’s Big Macs to fuel their run on any given day.” To sustain this, they ingest high fat diets which are converted to energy by their livers.

The video of Dr. Davis can be viewed here.

Visit The American Physiological Society to read the full Press Release.

Comments

  1. #1 Robert S.
    October 14, 2010

    I wish I could switch over that quickly as well. It’s truly amazing the amount of power these dogs can convert day in and day out.

    Oh, and I’m commenting to the future! Time travel or blog bug? You decide.

  2. #2 Birger Johansson
    October 15, 2010

    Yes, canids are very capable long-distance runners (felines favor ambush predation and short spurts of energy).
    As I look out at the snow that fell yesterday and still has failed to melt, I see why predators are so few and scarce; there is not very much energy in the system now that photosynthesis has stopped. The accumulated fat reserves of herbivores (and what little plant matter they can find during the winter) is supposed to last and provide body heat for a very long time, for both herbivores and their predators (taking a walk in the cold wind really brings the lesson home).
    It is amazing that there are any non-hibernating animals at all in the boreal zone. And since wolves use up so much energy running, you need a whole county to feed a flock during winter.

  3. #3 natural cynic
    October 15, 2010

    Humans can do this kind of endurance – the RAAM or [bicycle] Race Across America. This year’s route covered 3005 miles from Oceanside CA to Annapolis MD. The race is done as a solo rider or in relay teams composed of 2, 4, or 8 team members.
    The event is timed continuously from start to finish and the solo riders rest short periods each day [much shorter periods than the dogs in the Iditarod]. Roughly half of the solo starters completed the route.
    Selected Results:
    men’s solo [age<50] Jure Robic 9days 46min
    men’s solo [50-59] T. Woudenburg 10days 23hr 14min
    women’s solo Barbara Buatios 11days 19hr 48min
    4 man Bandwidth.com 6days 2hr 39min
    8 man Team Type 1* 5days 10hr 48min
    * all team members are Type 1 diabetics
    RAAM website

  4. #4 natural cynic
    October 18, 2010

    The overall winner of the solo event was Jure Robic with a time of 9days 0hours 46min

    somehow it was eaten by the ether