|Substrate Utilization and Oxidative Stress during Sustained Strenuous Exercise|
Sustained strenuous exercise (40-50% VO2max continuously for consecutive days) is possible through aggressive fat supplementation, however human athletes undergo depletion of body glycogen stores and the potential for impaired provision of glucose to glucose-dependent tissues.
Strenuous exercise, also, often leads to global oxidative stress, resulting in tissue damage and organ dysfunction. Our laboratory has developed a canine model of strenuous sustained exercise utilizing elite Alaskan sled dogs. The dogs participating in these studies are competing at the highest levels of sled dog sports (ie. The Iditarod Trail Sled Dog Race). These amazing athletes are capable of exercising at approximately 50 % VO2 max for up to 14 days (with very few adverse effects) covering some of the harshest terrain and enduring the most severe weather conditions on Earth as they traverse the Alaskan interior and Pacific coastline in the 1100 mile Iditarod. Our studies of Alaskan sled dogs are directed at uncovering methods by which these dogs utilize glucose-independent processes which are supported during sustained strenuous exercise, and their unique methods for alleviating or preventing oxidative damage.