The below contains some great articles relating to the nutrition requirements of the Canine Athlete
Athletic performance requires energy. Energy or calories can only be stored in the body as carbohydrates, fat, or protein. That’s it. Athletes try to maximize their body stores of these energy sources without adding unnecessary body weight that would decrease athletic performance.
Carbohydrates are stored in the form of glycogen in the muscles and liver. Muscle glycogen supplies sugar or glucose directly to the muscles during exercise. The liver glycogen is a “back-up” to deliver glucose as the muscles use up their glycogen. Unlike humans, dogs do not use large amounts of glycogen during exercise and therefore have very small stores of glycogen in their muscles and liver.
Proteins from muscle are also used for energy during exercise. This means that muscles are actually torn down during athletic events. Muscle protein is a major source of energy for dogs during exercise and athletic performance.
Fat provides the greatest amount of calories per unit of weight. But using fat for calories requires lots of oxygen. Humans can only use oxygen to burn fat at lower levels of exercise intensity. This means the faster or harder you exercise, the less fat you burn directly for energy. Human athletes can only burn large amounts of fat if they slow down to an intermediate level of exercise. Otherwise fat is burned after exercise while the body restores its glycogen and proteins.
Remarkably, dogs can burn fat at very high levels of exercise intensity. In fact, protein and fat are the major fuels for athletic performance in dogs. This is why sled dogs can pull for 10-12 hours without slowing, while a human could not perform at that intense level of exercise for that long.
The work performed by most intermediate athletes (hunting dogs, field trials, Frisbee trials, Agility, Service work, Police work, Search and rescue, livestock management and exercise with people) resembles that done by endurance athletes (sled pulling), but is of shorter duration. The muscle-fiber type profile of intermediate athletes should resemble that of an endurance athlete over that of a sprint athlete (sight hounds). In general, endurance athletes have an increased number of well-developed slow-twitch fiber muscles; athletes involved in high speed sprinting have increased numbers of fast-twitch muscles. Slow-twitch muscles have a higher capacity for aerobic metabolism, meaning that they primarily use fat in the form of free fatty acids for energy. Fast-twitch muscles can use both aerobic and anaerobic pathways in that they can use both carbohydrates in the form of glycogen and glucose for immediate energy and fat for longer term energy use.
Exercise requires transfer of chemical energy into physical work. ATP (adenosine triphosphate) is the sole source of energy for muscle contraction. ATP is formed from metabolic fuels stored in muscle (endogenous) and from other body stores (exogenous). The energy is converted to ATP using either aerobic pathways using oxygen, or anaerobic pathways that can work without oxygen. The proportion of each pathway used is determined by duration and intensity of exercise, conditioning and nutritional status of the animal.
Training and conditioning results in adaptive physiological changes that facilitate efficient delivery of oxygen and other nutrients to the working muscle. Some of these changes include increased blood volume, increased red blood cell mass, increased capillary density, increased mitochondrial volume, increased activity and total mass of metabolic enzymes.
The two primary fuels used by the body for working muscles are muscle glycogen and free fatty acids. An intermediate athlete would receive ~70-90% of their energy from fat metabolism, and only a small amount from carbohydrate metabolism. Dogs rely more heavily on free fatty acids for energy generation at all exercise levels than do people. Feeding a higher fat diet to endurance and intermediate trained athletes prepares the muscles to efficiently mobilize and use free fatty acids for energy. It also exerts a glycogen sparing effect that can help prolong glycogen use during work. By increasing dietary fat concentration you can increase the energy intake and encourage stressed dogs to increase food intake due to the increased palatability of fat in the diet. Increased dietary fat levels may also enhance free fatty acid availability.
Provided sufficient gluconeogenic precursors are available in the diet, no dietary requirements for carbohydrates exist except during gestation and neonatal development. Gluconeogenesis (formation of glucose from non-carbohydrate sources) is done by the liver and kidneys using glycerol, lactate and glucogenic amino acids. Adipose tissue supplies glycerol for glucose production (breaking down triglycerides) and fatty acids for oxidation to supply energy, whereas muscle catabolism releases glucogenic amino acids, lactic acid and pyruvate for glucose production by the liver.
Carbohydrates fed to athletes should be highly digestible to decrease fecal bulk in the colon. Excessive amounts of undigested carbohydrates reaching the colon can increase water loss through the stool, increase colonic gas production and increase overall fecal bulk and therefore add unneeded weight.
Endurance training results in increased protein needs through increased protein synthesis (anabolism-the building up of muscle) and protein degradation (catabolism-the breaking down of muscle). Catabolism is only a small portion of the overall protein needs the primary use is anabolism. Increased tissue mass associated with training must be supplied by increased protein in the diet. (2) Amino acids are used in the formation of new muscle and repair damage to muscle and connective tissue during intensive conditioning; exercise increases the animo acid catabolism.
Amino acids provide ~5-15% of the energy used during exercise; most of this energy comes from the branched-chain amino acids (leucine, isoleucine and valine). All of these are essential amino acids and cannot be synthesized from other amino acids; they must be included in the diet. The "biologic value" of a protein is an indicator of the amount of essential amino acids found in that product. Muscle and organ meat based proteins have the highest level of essential amino acids, and are also the most digestible and most bioavailable.
Excessive protein intake may predispose an athlete to increased amino acid catabolism. Amino acids are not stored as proteins in the body but are deaminated (broken down) to ketoacids. These ketoacids are either oxidized for energy or converted to fatty acids and/or glucose and stored as adipose tissue (fat) or glycogen. The diet fed should supply adequate calories as fat and carbohydrate so that the protein fed can be used primarily for tissue synthesis and not for energy.
Recommended Caloric distribution for Canine Athletes
Calories from protein: 30-35% ME Calories from fat: 50-65% ME Calories from carbohydrate: 10-15% ME
First, let’s take a look at the most important nutrients that are absolutely vital to athletic dogs and must always be present in sufficient amounts in your performance dog diet.
Phosphocreatine is a molecule that’s utilized well in work that requires short, explosive bursts of power from the dog’s body. It is present in muscle tissue.
Although phosphocreatine is not an energy source in itself, what it does is converts adenosine diphosphate (ADP) into adenosine triphosphate (ATP) which allows it to be used for muscle contraction by your canine.
Studies in exercising dogs have observed how this anaerobic process provides maximum power for up to 10 seconds, making it essential for intense, short lasting work such as weight pulling or sprints by your dog.
Pet owners of “regular” dogs are usually not big fans of grains and carbohydrates in general. But for athletic dogs, carbohydrates can be very useful in several ways.
Glycogen is a carbohydrate stored in the muscle in the dog’s body, and used in the initial moments of muscle activity. The break down time is half of that derived from phosphocreatine, and it lasts up to 30 seconds. The depletion is rapid though, and can quickly lead to muscle fatigue and weakness.
High amount of protein is what most dog owners are after, and rightfully so. Protein promotes the increase of muscle tissue and facilitates the formation of new muscle, while having a restorative effect on damaged muscle and connective tissue in athletic dogs.
Amino acids that come from consuming protein are an essential part of the canine diet, making up 5-15% of the energy used by the athlete during physical exertion. The types of amino acids vary, but most important ones are leucine, isoleucine and valine.
These three amino acids must be provided in your athletic dog’s diet to boost performance and decrease recovery time. Ideal sources of high quality, nutrient-dense protein and amino acids are muscle and organ meats, which provide excellent bio-availability and are highly digestible. This reduces fecal bulk and maximizes canine performance.
In specific groups of working dogs, studies have shown that lower carbohydrate and higher protein diet are more beneficial due to better glycemic control.
This makes it an essential component in any canine’s diet but even more so in the diet for athletic dogs, especially when taking into account the importance of minimizing injury.
It is important to note that protein should be used as a source of tissue support, rather than energy, while carbohydrates and fats provide the majority of fuel for the muscles. Over-feeding of protein is not good and it may cause excessive amino acid catabolism.
Canines differ from humans in the sense that they rely on free fatty acids for muscle fuel at all exercise levels, which is why very low carbohydrate diets work for most dogs.
In endurance and intermediate athletic dogs, a high fat diet allows the muscles to mobilize and use free fatty acids for energy while the glycogen sparing effect of fat also helps to prolong the use of glycogen during physical activity.
Some studies suggest that 66% of energy from dietary fat in the athletic canine’s diet is superior to lower 44% of energy from dietary fat. Other studies suggest that the numbers are slightly different. However, the conclusion is that fats are essential for athletic dogs.
Examples of intermediate canine athletes include search and rescue dogs, many types of working dogs and guide dogs.
In fact, most canine athletes are considered intermediate athletes. The intensity can be low to moderate and may last a few hours with these athletic or working dogs.
The intermediate athletes like service and working dogs perform best on a high fat diet, according to studies, with 70-90% of their energy being sourced from fat metabolism. These canines use both fast and slow-twitch muscles.
Fast twitch muscles are able to metabolize using both aerobic and anaerobic pathways, utilizing glycogen and glucose for immediate, short bursts of energy and fat for longer, sustained energy. Slow-twitch fiber muscles utilize fat for energy due to their increased capacity for aerobic metabolism.
Endurance canine athletes work at a moderate to high-intensity level for an extended time period.
These athletic dogs require very high levels of dietary fat to serve as the primary source of fuel for exhaustive forms of exercise that require long-lasting energy. The above mentioned studies as well as further research indicates that a high fat diet increases endurance capacity and maximizes energy production in athletic dogs.
When fed high fat diets (53-67% of energy) these dogs were able to run for 20 miles before reaching exhaustion, compared for 15 miles when fed moderate amount of dietary fat (29% of energy) diet.
High fat diets also allow nitrogen excretion to be reduced, minimizing fecal volume and water loss, and reducing the heat of digestion compared to that of carb breakdown. This allows for lower temperature regulation and dog comfort when working in the heat.
Fat adaptation was shown to be an effective strategy in improving performance in these canine athletes. Providing adequate nutrition for athletic dogs is key in supporting them to reach optimal performance and maintain physical health.
If you are competitive canine sports enthusiast and you are trying gain a competitive edge over your competition you will be particularly interested in the following advice. Feed your pet a homemade meat based diet using a professionally balanced recipe. The diet should consist of at least 40% meat protein, fresh colorful veggies, and very limited grain. Adding digestive enzyme, omega fatty acids, and trace mineral, and probiotic supplements will enhance nutrient absorption, reduce inflammation, prevent leaky gut syndrome, and properly alkalinize the body. Glucosamine, chondroitin, dimethyl glycine and MSM are nutraceuticals which help to prevent injury by strengthening and repairing connective tissue structures such as joint cartilage, ligaments, and tendons.
Creatine is an important supplement to consider if you want to help build your dog’s muscle mass. The addition of L carnitine, alpha lipoic acid, arginine and coenzyme Q10 will help enhance cellular energy production and consequently strength and endurance… Dimethylglycine and Megahydrate are nutraceuticals that help to oxygenate, hydrate and detoxify muscle cells. Homeopathic such as Traumeel, Spascupreel, and Thalmus can be placed in the pet’s drinking water and will reduce pain, inflammation and muscle spasm after strenuous competition. Post competition systemic enzymes, will reduce inflammation and prevent tendonitis, myositis, and ligamentitis.
A new study published in the British Journal of Sports Medicine suggests that arginine supplementation may indeed enhance endurance performance. The study was designed by Mayur Ranchordas of Sheffield Hallam University in Sheffield, England. Six competitive cyclists participated in the study. They were randomly assigned to blindly consume either a drink containing 6 grams of arginine or a placebo drink daily for three days. At the end of the supplementation period all of the subjects completed an incremental cycling test to exhaustion (to measure VO2max) followed by a simulated 20 km time trial on stationary bikes. After a washout period the experiment was repeated, but this time those who received arginine the first time got the placebo and those who started with the placebo got the supplement.
Performance in the incremental cycling test to exhaustion was unchanged between the placebo and supplementation conditions. Arginine had no effect on VO2max. However, arginine did improve time trial performance. On average, it took the subjects 32 minutes and 48 seconds to complete the time trial in the placebo condition. After three days of arginine supplementation, their average time dropped to 32:04. That’s a statistically significant 1.7 percent improvement.
How was this effect achieved? It appears that arginine supplementation reduced the oxygen cost of cycling. Oxygen consumption was 6 percent lower in the time trial undertaken after arginine supplementation, even though average power output was slightly greater. Arginine also reduced blood pressure at rest and increased peak power in the VO2max test (from 385 watts to 395 watts) without increasing oxygen consumption at peak power. All of these data taken together suggest that arginine supplementation improved cycling performance by enabling the subjects to generate more power with the same energy (or the same power with less energy).
These findings build on the results of a similar study conducted by researchers at the University of Exeter and published in 2010. In that study, the oxygen cost of moderate-intensity cycling was found to be reduced by arginine supplementation and time to exhaustion at a very high intensity was significantly increased.
l-Carnitine supplementation can stimulate erythropoiesis, reduce exercise-induced plasma lactate concentrations and decrease post-exercise muscle damage. Canine athletes perform short-duration, very high-intensity exercise that has the potential to incur substantial muscle damage.
We tested the novel hypotheses that l-carnitine supplementation in Canine athletes would: (1) elevate haematocrit at rest and immediately post-exercise; (2) reduce peak post-exercise plasma lactate; and (3) reduce indices of muscle damage (plasma creatine phosphokinase, CPK and aspartate aminotransferase, AST). Six conditioned Canine athletes (30.1 ± 1.6 kg) underwent a randomized placebo-controlled crossover study to determine the effects of 6 weeks of l-carnitine supplementation (100 mg kg− 1 of body weight/day) at rest and following a workout.
In accordance with our hypotheses, l-carnitine elevated resting and immediately post- exercise haematocrit (control, 60.1 ± 1.7, l-carnitine, 63.6 ± 1.7; P < 0.05) and reduced peak post- exercise plasma CPK and AST concentrations (both P < 0.05). Those dogs with the highest peak post-exercise plasma CPK concentrations under placebo conditions evidenced the greatest reduction with l-carnitine supplementation (r = 0.99, P < 0.01). However, contrary to our hypotheses, l-carnitine did not change peak post-exercise plasma lactate concentrations (control, 27.0 ± 2.1, l-carnitine, 27.7 ± 1.3; P>0.05).
We conclude that l-carnitine supplementation increases the potential for oxygen transport and reduces plasma indicators of muscle damage, CPK and AST in Canine athletes.
Source: Cambridge Journal