Navigation Links
Lessons from the Iditarod
Date:9/24/2008

HILTON HEAD, SCDogs are often called "man's best friend," and rightly so. Consider, for example, that they never interrupt us when we talk, are always happy to see us when we arrive home, and provide comfort when we are lovesick. Since dogs became domesticated 15,000 years ago, they have worked with and lived next to humans, which some say may account for the special bond. Each of the 400 breeds and varieties are unique, but only one stands out as the ultra-athlete canine: the racing sled dogs.

Racing sled dogs are best known for their "mushing" each March during the Iditarod Trail Sled Dog Race, the world's longest sled race. They are the premier ultra-endurance competitors, covering 1,100 miles from Anchorage to Nome, Alaska, sometimes in just nine days. It is unclear how they can keep running, despite heavy blizzards, temperatures as low as 󈞔F, and winds up to 60 mph. No other animal has been found to come close to the physiological attributes these dogs display.

Dr. Michael Davis has focused on the mysteries of this breed for work for more than a decade. The professor at the Oklahoma State University's Center for Veterinary Health Sciences will discuss his recent findings entitled, "Metabolic Strategies for Sustained Endurance Exercise: Lessons from the Iditarod." His presentation is part of the American Physiological Society's (APS) (www.The-APS.org) conference, The Integrative Biology of Exercise V, being held September 24-27, 2008 in Hilton Head, SC.

How Do They Do It? The Exercise Physiology of Sled Dogs

The physiological understandings that Davis and his colleagues have uncovered thus far are extensive. Among their findings is:

  • Rapid Adaptation to Exercise and EnduranceThe most striking feature of these canines is their ability to rapidly adapt to sustained strenuous exercise in 24-48 hours. Conditioned dogs display most of the metabolic changes that are found in human endurance athletes during their first day of exercise, including depletion of muscle energy reserves, increases in stress hormones, evidence of cellular injury (such as to proteins, lipids and DNA), and oxidative stress. However, with subsequent consecutive days of exercise at the same intensity, these changes are reversed. Within four days after exercise begins, the metabolic profile of the dogs returns to where it was before the race began, despite their sustained, strenuous exercise. When human ultra-athletes become fatigued, they stay that way until a period of recovery that may take a full day.

  • Enormous Aerobic CapacityRacing sled dogs have enormous aerobic capacity. While the untrained sled dogs have an average aerobic capacity of 175 ml/kg/min VO2 max (ratio of volume of oxygen to body weight per minute), the aerobic capacity of the fully conditioned sled dogs is estimated to be about twice that (300 ml/kg/min).

  • Using A High-Fat Diet to Fuel ExerciseDuring periods of racing, sled dogs can burn up to 12,000 kilocalories per day (kcal/day). This means that a 55-pound sled dog will consume the equivalent of 24 McDonald's Big Macs to fuel their run on any given day. Some of the running dog's high-fat diet is converted to energy in the liver, and used as fuel in the initial stages of exercise. Preliminary data suggests that this process is a desirable trait intended to efficiently support exercise in the racers. It is worth noting that humans would need 72 Big Macs to fuel the power they need to make a day's run, assuming their body could absorb and process all the fat contained in the beef.

Next Steps

The mechanisms that make these four-legged athletes premiere in performance is still unknown. Dr. Davis theorizes that it may involve the regulation of extremely thin membranes in the muscle fibers and changes in the cells that are responsible for the body's energy production. "These are one-of-a-kind athletes. What we learn from them will undoubtedly tell us a lot about human performance as well."


'/>"/>

Contact: Donna Krupa
DKrupa@The-APS.org
703-967-2751
American Physiological Society
Source:Eurekalert

Related biology news :

1. Lessons from evolution applied to national security and other threats
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/9/2016)... Elevay is currently known as ... for high net worth professionals seeking travel for work ... world, there is still no substitute for a face-to-face ... your deal with a firm handshake. This is why ... of citizenship via investment programs like those offered by ...
(Date:4/28/2016)... April 28, 2016 First quarter 2016:   ... 966% compared with the first quarter of 2015 The ... 589.1 M (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) ... guidance is unchanged, SEK 7,000-8,500 M. The operating margin ...
(Date:4/19/2016)... 20, 2016 The new GEZE ... compact web-based "all-in-one" system solution for all door components. ... or the door interface with integration authorization management system, ... systems. The minimal dimensions of the access control and ... building installations offer considerable freedom of design with regard ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... 23, 2016 , ... Charm Sciences, Inc. is pleased to ... AOAC Research Institute approval 061601. , “This is another AOAC-RI approval of the ... Vice President of Regulatory and Industrial Affairs. “The Peel Plate methods perform comparably ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... announced the launch of the Supplyframe Design Lab . Located in Pasadena, ... explore the future of how hardware projects are designed, built and brought to ...
(Date:6/23/2016)... BEACH, Calif. , June 23, 2016  Blueprint ... new biological discoveries to the medical community, has closed ... co-founder Matthew Nunez . "We have ... us with the capital we need to meet our ... will essentially provide us the runway to complete validation ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... quality, regulatory and technical consulting, provides a free webinar on Performing ... July 13, 2016 at 12pm CT at no charge. , Incomplete investigations are ...
Breaking Biology Technology: