Diet plays an important role in the endurance potential of canine athletes. The Alaskan sled dog might be considered the ultimate canine athlete, sometimes pulling a sled more than 1,000 miles in subzero temperatures. Providing a well-balanced diet is essential to meet the special needs of dogs in such nutritional-stress situations. Not only should the diet fed to these dogs be high in protein, but it also should be high in fat, which serves as the major energy source for exercising muscles.
High Nutrient Demands
Dietary Effects on Performance
A high-fat diet can help muscles burn fat more efficiently. During sustained exercise, fatty-acid oxidation is the primary source of energy for the muscles. Increasing the efficiency of fat metabolism spares the body’s use of carbohydrates, and because most dogs have in excess of 10 to 50 times more energy stored in fat than in muscle glycogen (carbohydrate), this might boost the animal's exercise performance.
IAMS™ studies1 have shown that in trained sled dogs as in ordinary dogs, exercise performance was enhanced by switching from a low-fat to a high-fat diet (from 25 to 65% of calories from fat), as indicated by increased:
- Mitochondrial volume—Increasing the volume of the muscle cell's 'power houses' increased the capacity for fatty-acid oxidation.
- Aerobic capacity—Muscles were better equipped to utilize fatty acids for fuel because of increased ability to utilize oxygen.
- Fatty-acid oxidation—By increasing fatty-acid utilization during exercise, more energy was released for the muscles to use.
When dogs were switched back to a low-fat diet, all of these criteria decreased to their previous values.
These results indicated that by increasing the availability of fat stores and capacity to metabolize fat for energy, a high-fat diet promotes exercise endurance in canine athletes.
1 Reynolds AJ, et al. “The effect of diet on sled dog performance, oxidative capacity, skeletal muscle microstructure, and muscle glycogen metabolism.” Recent Advances in Canine and Feline Nutritional Research: Proceedings of the 1996 IAMS International Nutrition Symposium. Carey DP, Norton SA, Bolser SM, eds. Wilmington, OH. 1996. 181–198.
