Russian weightlifters bring caviar to their meets. Butch Buchholz eats a cheeseburger or eggs two or three hours before his tennis matches. Muhammad Ali consumes bee pollen on a regular basis, but on fight day he wants "one of those juicy kosher steaks, well done, with all sorts of vegetables." Olympic swimming gold medalist Jim Montgomery consumes eight eggs, a pound of bacon, a loaf of bread and almost a quart of orange juice at breakfast.

The protein myth refuses to die.

Many athletic training tables still feature enormous quantities of steak, especially at the meal before a competitive event. This happens although for more than 100 years scientists have known that protein is not an immediate source of muscular energy and since the beginning of this century, they have known that carbohydrates provide fuel for muscles.

Despite all the evidence accumulated since then, Dr. Gabe Mirkin, a sports medicine authority from Silver Spring, says,"... a $70 million a year protein supplement business has aimed most of its advertising at the athlete."

Protein supplements are only one of the many special foods athletes consume in the belief they will improve performance. Just recently scientists have shown that carbohydrate loading will improve enduranoe performance, but not without some risks.

Mirkin, a runner and physician, admits it took him years to realize what nutritionists have known for decades: "Everything your body needs can be supplied by proper diet." He says he has not been immune to the promised charms of: vitamin pills by the handful, wheat germ oil, quantities of milk so large they increased his cholesterol. Yet, Mirkin says, "I was not as bad as some... I know athletes [who] have taken vitamins, iodine, magnesium, manganese, selenium, copper, zinc, calcium, potassium, sodium chloride, phosphorus, kelp, garlic, brewer's yeast, bee pollen, bone meal, lecithin, desiccated liver, ginseng, wheat germ, and pumpkin and sunflower seeds," not to mention anabolic steroids.

In "The Sportsmedicine Book" (Little, Brown, $6.95), Mirkin provides some insight into why athletes pop pills. He quotes Olympic marathon champion Frank Shorter: "I know that vitamins don't work. But after running 140 miles a week, I would hate to think another athlete might have an advantage over me just because I wasn't taking vitamins."

Robert Serfass, associate professor of physiology at the University of Minnesota said recently: "Natural preoccupation with winning and success makes athletes prime candidates for nutritional misinformation (magicwand syndrome). There is usually no more than a coincidental relationship between the champion athlete and his dietary fad."

The most respected experts in the field of sportsmedicine are unanimous in their belief, as James Fixx writes in his best seller, "The Complete Book of Running," that "there aren't [any] miracle foods."

Fixx recommends a diet based on meat, milk, fish, poultry and eggs, whole-grain cereals, legumes and nuts, leafy-green and other vegetables and fruits. He quotes Dr. Thomas Bassler, a California pathologist who recommends "avoiding highly refined foods": sugar and white flour, saturated fats and alcohol, as do some other experts.

Mirkin says: "The same rules for eating apply universally to those who exercise and those who don't." There are one, possibly two, exceptions: Those who exercise more require more calories and fluids, especially a lot of cool liquids while they are exercising. Those who are involved in endurance sports -- long distance runners, skiers, cyclers -- will probably benefit from an eating technique known as carbohydrate loading. But it is a technique which offers risks as well as benefits.

One hears about the benefits of carbohydrate loading more and more frequently in physical fitness circles. The risks, while discussed in the better sports guides, are seldom mentioned by the participants themselves.

Simply stated, carbohydrates convert to glycogen (sugar) that muscles burn during exercise. In 1967 two Swedish scientists developed the technique for carbohydrate loading: Six days prior to the event, the athlete exercises to exhaustion. Then for three days he limits his carbohydrate intake, eating mostly protein and fat. This is called the depletion phase, though not all athletes agree that the depletion phase is necessary. During the three days before the event the athlete eats a lot of small meals rich in complex carbohydrates -- pasta, bread, potatoes and fruit. Mirkin says, "This forces the muscles to bind extraordinary amounts of carbohydrates, which are then available as muscle fuel during the stress of the event."

Fixx says "loading" is a misleading term because "it doesn't mean stuffing yourself." To him it means changing the proportion of what you eat but eating the same amount.

Not everyone thinks carbohydrate loading improves athletic performance and more than a few think the hazards ought to be spelled out. "Even for endurance athletes in top physical shape, carbohydrate packing can be fraught with potential problems," Mirkin says. "It can possibly cause death," and he warns that the unbalanced diet can cause kidney problems, prostatitis, potassium deficiency.

Mirkin warns: "Because all long-term effects of repeated super-compensation are not known [the] method should not be attempted more than two or three times a year."

"The Complete Marathoner," a collection of articles on the sport, edited by Runner's World magazine, says: "Super-compensation is potentially hazardous... the person using these procedures may be trading future health shock for improved performance now." Moderation is what "marathoner" recommends. While the experts suggest a benefit-risk assessment be made about carbohydrate loading, they generally agree about other popular practices among athletes: salt tablets are worse than useless; quick energy sources don't really work; water is better than "sports drinks," but fluid during competition is essential..

Says Mirkin: "Never take salt tablets! Let your taste buds tell you when to salt your food.

"If you get too much salt in your system, you may develop high blood pressure, clots in your blood stream, or heat exhaustion." Mirkin says several football players have died in the heat after taking salt tablets, but despite this many big-name teams give out thousands of salt tablets each year.

Mirkin says it's ridiculous to believe that "an acclimatized athlete" loses much salt in hot weather. On the other hand, he says, potassium, found in fruits and vegetables, should be replaced after exercising.

Mirkin and his fellow experts criticize reliance on sugar, too. Instead of satisfying you, sugar makes you hungry, and tires you more quickly because the glycogen is used up at a faster rate, he says. It has little nutritional value and when you exercise strenuously you need increased amounts of nutrients. In addition, Mirkins says, a large concentration of sugar in solution, just prior to or during an endurance event, can cause stomach cramps because the sugar draws water into the stomach. Honey, molasses, corn syrup and maple syrup, he says, act just like sugar.

Fixx and others confirm the cramping effects of sugar and its ability to lower blood sugar levels. He says even if sugar increases your energy during a long run, "there's no point in trying to eat anything else in the middle of a race; you won't be able to digest it."

"The Complete Marathoner" says: "There seems to be no reason for eating dextrose tablets, honey, etc., as fatigue sets in during the race. The material remains in the stomach too long to be of any practical value in supplying immediate energy."

On the other hard, "Nutrition for Athletes," a booklet put out by the American Alliance for Health, Physical Education, and Recreation, says "quick energy" foods don't help athletic performance of short duration. "The extra energy needed for shortterm performance is already available within the body."

For endurance events, the booklet recommends small amounts of sugars in fluid during the event. This is where products such as Gatorade, Body Punch and ERG come in. These are sold as mineral-replacement drinks for athletes, but Mirkin says they are not beneficial during competition. He claims they "contain too much sugar."

According to "The Complete Marathoner": "Various commercially available drinks claim to have everything you need to take during an endurance run. Unfortunately there is little hard data to back up these claims.

"All in all, the research studies on the effects of drinking a carbohydrate solution during an endurance event on the body's energy-producing mechanisms are contradictory."

The manufacturer of Gatorade disagrees. According to V.K. Babayan, vice-president of science and technology for Stokely-Van Camp, "We have a physiologically sound formulation which supplies a balance of both water and electrolytes."

Serfass is more critical about the sports drink. "You don't need it. Water is the surest way for replacing fluids and it does a much better job. If it's cool water it's more quickly absorbed than warm."

Babayan says, "If Gatorade is a pleasant tasting fluid that not only supplies water but the electrolytes, then it is a much more acceptable medium for the athletes than just trying to sip water."

About the importance of high fluid intake there is little debate. You should drink as much as you can, preferably cool liquid. Mirkin says he doesn't know of one athlete who ever developed stomach cramps from cold drinks.

Day-to-day nutrition for athletes, then, is quite similar to dietary recommendations for non-athletes.

Serfass recommends hard work and a well-balanced diet for athletes, instead of "... the vain and fanatical search for the mystical substance which will transform one's mundane, unresponsive body into a virtual citadel of orthomolecular power, capable of unlimited Mercurial and Herculean accomplishments." CAPTION: Illustration 1, Copyright (c) 1978, The Complete Marathoner, World Publications, from Runner's World Magazine; Illustration 2, Copyright (c) 1978, The Complete Marathoner, World Publications, from Runner's World Magazine