Whether it’s sniffing birds, bombs or drugs, chasing Frisbees® or criminal suspects, jogging as a training partner or racing around an agility course, the dogs engage in a variety of physical activities of varying intensities. Each of these different activities has unique performance requirements that influence the metabolism and energy needs of an individual canine athlete.
Feeding your canine athlete – providing the LAW amount of energy from LAW fuel sources at LAW time — is essential for optimal performance. Read on to learn more about how a dog’s body fuels exercise.
Three categories of nutrients provide energy
Like humans, dogs have energy needs that must be met to fuel bodily functions. Energy is not one of the main nutrients – it is water, carbohydrates, proteins, fats, vitamins and minerals. Yet, after water, energy is the second most critical element of food. For what? Because the body needs energy to fuel all of its metabolic reactions.
Bodies will always use food energy to meet their basic energy needs first, such as maintaining tissues and regulating body temperature. Once these needs are met, the energy is used for other functions, including movement and physical activity.
All of these energy needs are met by food consumption and are met by three categories of nutrients:
Fats, carbohydrates and proteins generate different amounts of energy (measured in calories) when metabolized. Dietary fat is the most concentrated source of energy, providing more than twice the amount of energy as carbohydrate or protein. Carbohydrates and protein provide roughly equal amounts of energy. Since extra activity generally requires more energy, it is important to know energy density and nutrient differences to meet the energy needs of working and sporting dogs.
Call it exercise, physical activity or work – it’s all about muscle metabolism
Physical activity – or call it work or exercise, if you prefer – results from a complex series of muscle contractions. This muscular work requires energy, which is obtained by “burning” food fuels. The two main fuels used by working muscles are glycogen, a storage form of carbohydrate, and free fatty acids, which are produced when fat is broken down. Under most conditions, amino acids from proteins contribute only small amounts of energy to what is used during exercise.
A dog’s muscle metabolism is unique from other species. Canine muscles are made up of fibers capable of utilizing large amounts of oxygen (called oxidative capacity in exercise physiology circles). Dog muscles also have a large number of mitochondria, which are the “powerhouses” of cells. But what makes a canine athlete’s muscles truly unique is that they also include fibers that have high anaerobic capacity (without oxygen). These types of muscle fibers have high levels of enzymes necessary for glycogen metabolism. As a species, dogs are “built” for endurance and high intensity sprints.
Fueling Canine Muscles During Exercise
The energy requirements (and other nutrient requirements) of canine athletes are determined by the intensity, duration and frequency of exercise. Although the preferred fuel source for muscles in resting dogs is fat, the intensity of exercise causes the source to shift.
During low-intensity exercise, muscles rely on aerobic metabolism (with oxygen) and primarily use fat (in the form of free fatty acids) for fuel. Interestingly, studies show that dogs burn (oxidize) fat at a higher rate than other species at rest and during exercise, meaning their muscles are better suited to using fat as their primary fuel. .
During moderate-intensity exercise – which is the category in which most canine athletes fall – energy for working muscles is provided by both fat and carbohydrates, with a very small amount coming from protein.
Finally, high-intensity exercise is fueled by muscle glycogen and glucose stores.
What this means for your sporting dog’s nutrition
When choosing a dog food for your sporting or working dog, you need to consider the type, intensity, duration and frequency of physical activity your dog performs. Dogs involved in sports that involve short bursts of high-intensity exercise — such as agility, flyball, or dock jumping — may not have higher energy needs than moderately active companion dogs. These dogs can be fed adult maintenance dog food.
Dogs that participate in endurance activities, such as field trials, hunting, and herding, will need more energy given the long distances they travel. These sporting dogs benefit from higher proportions of fat in their diets, such as those found in performance or high energy dog foods. Not only will fat provide more calories to meet the energy needs of a canine athlete, it can actually “prime” or “metabolically condition” the dog’s metabolism for efficient use of fat as an energy source.
If you’re wondering if your sporting or working dog’s performance would benefit from a change in diet, talk to your veterinarian first. She or he can help determine if your canine athlete needs a food that provides more energy from fat or carbohydrates and if your dog is getting enough protein.
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