Athletes are always seeking a "winning combination," and this often includes eating a certain way in hopes of gaining a competitive edge. This has led to some bizarre and even dangerous training regimens.
Not long ago, for example, a university swimming team was instructed to avoid fluids lest they become "waterlogged." A ski team was told not to eat cereal-based products. Runners consumed massive amounts of wheat germ oil. And a football team was fed huge slabs of rare steak, an extremely high-fat diet than most people believes is "high protein."
While such odd dietary practises may have historical precedents, few, if any, have a scientific foundation. There have been some extensive performance, however, and almost all suggest that because athletes are so physically active, they need more food and liquids than sedentary people. But being active does not mean you need extra protein, vitamins or minerals.
The number of calories needed by an athlete depends upon the type of exercise. Sprinlers or football players, for example, may require far fewer calories than long-distance runners. In general, football players need about 3,600 to 4,200 calories a day during training, while a long distance runner may require 6,000 a day when preparing for a marathon (and he still will lose weight unless he takes a day off now and then).
The need for fluids also varies, especially when the weather is warm. Extra salt is indicated only when heat is extreme or sudden. And when salt is needed, it should be added to food, rather than taken as tablets, which may produce cramps or vomiting.
Studies also indicate that the exact proportions of fat, protein and carbohydrate make little difference for short-term events, whereas high-carbohydrate diest appear to have a definite advantage for long-distance events. This is borne out by the work of Swedish scientiest. P.O. Astrand, who developed a technique called glycogen-or carbohydrate loading about 10 years ago.
The limiting factor in the performance of a long-distance athlete is the body's capacity to deliver oxygen to the muscles and other tissues. More oxygen is produced in burning carbohydrates than in burning fat; thus the more carbohydrate that can be stored in the body, the longer the athlete can keep going.
We store carbohydate in the form of glycogen - also known as "animal starch" - in the muscles and in the liver. Liver glycogen is a readily available source of energy, but the amount stored in the liver is only enough to last from, say, supper to breakfast. As a result, the primary source of energy to the muscles is the glycogen that is stored in the muscles.
Dr. Astrand found that if athletes depleted their stores of muscle glycogen through strenuous exercise, and then ate diets very high in carbohydrates while they relaxed for several days, they could increase muscle glycogen stores enough to substantially lenghten their endurance time. In effect, it's as if the muscle hoards glycogen against the time when enourmous demands are made on it.
To store muscle glycogen, an athlete exercises almost to the point of exhaustion about a week before the event to deplete his glycogen stores. A runner, for example, might run hard for six minutes, followed by six to 10 400 meters dashes. For the next three days, he almost exclusively eats foods high in protein and fat, thereby keeping the carbohydrate stores low. Then he adds large quantities of carbohydrates - up to 60 per cent of the total calories - to every meal.
Most athletes reach their peak of muscle glycogen storage after about three days, but some take longer. The Swedish test showed that this loading technique can almost double the reserve capacity in some trained athletes.
But you can't win a race by simply gorging on high carbohydrate foods. Nor will eating a lot of carbohydrate right before the competition help because muscle glycogen is replenished. Moreover, since liver glycogen is replenished automatically with every meal, the eating of honey, sugar or some other so-called "quick-energy" foods right before competitive events will not be helpful, either.
It is a common misconception that exercise uses up protein. The facts are that muscles burn carbohydrates and fats during exercise; protein is only used a s fuel when carbohydrates and fats are no longer available in the body. To be sure, an athlete needs high-quality protein, but he requires no more than his more sedentary counterpart.
In short, there is no great mystery in athletic nutrition, despite what some athletes and trainers would like you to believe. With the exception of glycogen-loading, there appears to be no way to manipulate a diet to gain a competitive edge.