Nutrition and the athlete

NUTRITION AND THE ATHLETE

For centuries, athletes have soughtfoods that would give them the winning edge. Charmis of Sparta, victor of the Olympic Games in 668 B.C., trained on a diet of dried figs. About 2,500 years later, a number of 19th century athletes purged their stomachs of "noxious matter' and then consumed large quantities of red meat and beer.

Nutritionists advise today's athletes toeat a more varied diet. In fact, athletes of the 20th century--whether they be milers on the high school track team or middle-aged joggers running for better health-- are generally counseled to follow the same dietary rules suggested for average Americans.

This means they should eat a well-balanceddiet, obtaining most of their calories from complex carbohydrates such as cereals, breads and pasta. They also should get enough fiber and avoid fatty, cholesterol-laden foods and foods high in sugar or sodium.

But some health magazines suggestthat, for the physically active, good nutrition involves more than merely eating the right foods. These publications imply that a well-balanced diet is inadequate, and that athletes must consume high-potency vitamin pills or protein supplements.

Such suggestions can bewilder athleteswho are looking for a nutritional edge in their sport. In pursuit of the promoted nutrient of the hour, they may throw away their money on pills and powders they don't even need, and end up with a poorer diet to boot.

"Clearly, it is not possible to changeaverage athletes into champions simply by altering their diet,' says nutritionist Virginia Aronson.

The most important determinant ofathletic prowess, according to the experts, is something over which we exert no control: our genes. Most rank physical training next; good nutrition comes in third.

Dr. J.R. Brotherhood, writing in thejournal Sports Medicine, puts the issue this way: "There is no magic diet that in itself enhances performance.' But, he notes, "an incorrect diet will negate much hard effort on the training field.'

For the athlete, does good nutritionmean consuming more nutrients than non-athletes? Many athletes need more of some nutrients, but the same amount of others. Much depends upon the particular sport. Marathon running, competitive swimming, or weight lifting require more calories than less demanding sports. Athletes engaged in these vigorous activities generally need more of the energy-providing nutrients, particularly carbohydrates. Because of increased fluid loss through perspiration, they also need more water and electrolytes (electrically charged chemicals within the body--See "Electrolytes: The Charge in the Body's Power System' in the July--August 1986 FDA Consumer). Yet, with few exceptions, their vitamin and mineral requirements are quite similar to those of non-athletes.

Three nutrients--carbohydrates, proteinand fat--supply energy, but carbohydrates are the major source of energy during exercise. Carbohydrates furnish the fuel for anaerobic exercise, such as sprinting, where muscles work faster than the heart and lungs can supply them with oxygen.

The body burns both carbohydratesand fat during aerobic or endurance events (cross-country skiing or running a marathon)--activities in which muscles work slowly, permitting the heart and lungs to meet immediate demands for oxygen. Initially, carbohydrates supply the bulk of this fuel, but the body obtains more of its energy from fat as aerobic activity continues.

Muscles do not perform at their bestwhen fueled solely by fat; they also require glucose (a form of sugar that circulates in the blood) and glycogen (the form of carbohydrate in which glucose is stored in muscle and the liver). If the glycogen supply runs out, an athlete's performance is encumbered.

Because the body stashes limitedquantities of glycogen--an average of 1,800 calories worth--athletes must continue to replenish their supplies by eating carbohydrates. The body harbors enough fat, on the other hand, to supply an average of 140,000 calories. But athletes don't need a high-fat diet to maintain their fat reserves; calories in excess of body needs for carbohydrates, protein and fat are all stored as body fat.

Thus, the American Dietetic Associationsuggests the same diet for athletes as for the general public--less than 35 percent of calories from fat and at least 55 percent of calories from carbohydrates. When caloric needs are high, carbohydrates, preferably starches, should supply most of the extra calories. Overweight athletes should decrease fat, not carbohydrates, in their diets.

Many athletes believe that they needvery high-protein intakes, including protein supplements. Their coaches often think so, too: A study in the Journal of the American Dietetic Association revealed that two-thirds of Texas high school coaches harbored this misconception.

Athletes in the training stages of buildingmuscle may require slightly more protein than non-athletes, particularly at the beginning of training. However, enough protein to meet these needs can be obtained from an ordinary balanced diet, especially if enough calories are consumed to take care of energy needs.