Article

[Tivers@aol.com]

Here is an article that will appear in Japan's Keiba Book. Thought you might
find it interesting.

ti
International Journal of Sport Nutrition, 9, #3

Every month, dozens of new papers cross my desk concerning the success or lack of success of certain nutrients for improving performance of various types of athlete. Of course, most of these papers have to do with human athletes, but if we wait for equine researchers to catch up, we'll be ten years behind the latest technology. So, we read the papers, extrapolate the results for application in race horses, and then test to see whether we can expect the same results as seen in humans.

The latest issue of the International Journal of Sport Nutrition includes a paper by Julia Goedecke, et al, entitled Effect of Medium-chain Triacylglycerol  Ingested with Carbohydrate on Metabolism and Exercise Performance. The conclusion: "The high carbohydrate content of the pretrial lunch increased starting plasma insulin levels, which may have promoted carbohydrate oxidation despite elevated circulating Free Fatty Acid (FFA) concentration with Medium Chain Triglyceride (MCT) ingestion."

This is an important paper because it demonstrates very clearly the way fat and carbohydrate fuels interact during exercise. MCTs are easily absorbed and easily used for energy. MCTs quickly become free fatty acids, which are immediately available as muscle fuel. Hay and other fiber also becomes free fatty acids once digested in the hind gut.

This paper states that no matter how much fat is readily available for muscles to burn, the muscles will instead choose to use glucose and glycogen instead of fat at the onset of strenuous (not necessarily maximal) exercise. This occurs because, with the presence of increased glucose in the blood, insulin takes control and moves the glucose into muscle cells as the fast-acting fuel, glycogen. Fat is left out of the exercise equation as long as there is plenty of carbohydrate/glucose/glycogen available.

Not may years ago, human athletes were supplementing with MCTs as a fast-acting fuel supply. That practice has gone out of fashion precise for the reasons explained in this paper-fat is useless if there is a sufficient supply of carbohydrate. This is true for marathoners as well as sprinters. And it's true for horses as well as humans.

The lesson: forget supplementing fat. Instead, find ways to ensure that carbohydrate intake remains high, ensuring the provision of glucose and glycogen. And remember, hay is a source of fat.

This concept is emphasized by another paper entitled The Efficacy of Carbohydrate Supplementation and Chronic High-Carbohydrate Diets for Improving Endurance Performance, by Kevin Jacobs and Michael Sherman. The authors conclude: "The available evidence would indicate that a high carbohydrate diet is the best dietary recommendation for endurance athletes."

Again, it was in the endurance athlete that scientists originally thought that fat would be the most important fuel. The logic was that fat burns more efficiently, providing a far more sustainable energy source than carbohydrate. However, when it comes to actual performance in athletes consuming high carbohydrate or high fat diets, the carbohydrate diets have proven superior, time and again. Meanwhile, equine veterinarians and researchers continue to promote the high-fat diet for racehorses as well as endurance horses. They're dead wrong.

In Carbohydrate Supplementation Improves Stroke Performance in Tennis, Vergauwen, et al conclude, " These findings indicate that carbohydrate supplementation during tennis training can affect performance and that caffeine does not provide additional effects."  Using the logic of the current regulating bodies, carbohydrate should be banned and caffeine should be allowed in equine sport.

One potential athletic fuel is lactate, a partially burned carbohydrate that can be fuel for highly oxidative muscle cells. Scientists have been experimenting with lactate supplementations, but the results so far reflect these from Bryner, et al: " The researchers concluded that adding lactate to carbohydrate drinks does not affect performance."

Exercise causes adaptation, and the rate of this adaptation is called Acquisition. Anything we can do nutritionally to increase acquisition is beneficial to the athlete during both training and competition. Kraemer, et all, investigated Hormonal Responses to Consecutive Days of Heavy-resistance Exercise With or Without Nutritional Supplementation. The results: "Protein/carbohydrate supplementation prior to and following resistance exercise can favorably affect metabolic and hormonal responses and recovery."

It is only logical that if you provide protein building blocks and the energy to enable the tissue building and repair, you're going to get an anabolic effect. But these scientists were measuring testosterone, growth hormone, insulin, insulin-like growth factor and prolactin responses to protein and carbohydrate supplementation. The mechanisms of athletic acquisition are becoming clear, and they depend a lot on carbohydrate and amino acid intake.

McNaughton, et al investigated The Effects of Creatine Supplementationon High Intensity Exercise Performance in Elite Performers, concluding, "These findings indicate that creatine supplementation can provide ergogenic benefits for elite kayakers in events of 90 to 300 seconds."

Maganaris, et al, looked at Creatine Supplementation Enhances Maximum Voluntary Isometric Force and Endurance Capacity in Resistance Trained men, concluding "The researchers concluded that muscle hypertrophy during resistance training in response to creatine supplementation may explain the observed results" (significant increases in strength).

The first creatine study used 20 grams a day for 5 days while the second used 10 grams a day for 13 days. There are dozens of recent papers concerning the benefits of supplementing this amino acid and our trials have suggested that a minimum of 2 ounces a day over a period of two weeks produces observable benefits in racehorses. The benefits are accentuated if the creatine is fed with a dose of  a carbo-loader.

Finally, this paper by DC Nieman: Influence of Carbohydrate on the Immune Response to Intensive, Prolonged Exercise, from the 10Th International Congress on Immunology, Vols 1 and 2, 1998, pp 755-758

"Many components of the immune system exhibit change after prolonged, heavy exertion, indicating that the immune system is suppressed and stressed, albeit transiently, following prolonged endurance exercise. Various attempts have been made to alter the changes in immunity following heavy exertion through nutritional or chemical means, with the most impressive results reported thus far in the carbohydrate supplementation studies."

"Overall, the hormonal and immune responses to carbohydrate compared to placebo ingestion suggest that physiologic stress is diminished, although clinical significance awaits further research."

And we await the end of our equine researchers' infatuation with fat.