Lingering Myths

The complex relationship between nutrition and performance continues to spawn persistent myths about what athletes should and shouldn't eat. This article dispels them.

By Leslie Bonci

Leslie Bonci, MPH, RD, is Director of the Sports Medicine Nutrition Program at the University of Pittsburgh Medical Center Health System, and a consultant to the University of Pittsburgh Department of Athletics, the Pittsburgh Steelers, Pittsburgh Ballet Theater, and several Pittsburgh-area high schools.

Training & Conditioning, 11.6, September 2001, http://www.momentummedia.com/articles/tc/tc1106/myths.htm


Many athletes have preconceived notions about the complex relationships between nutrition and sports p e r f o r m a n ce. Some of these notions are correct, but many others are myths.

Athletic trainers, strength coaches, and team physicians need to counter these myths in order to develop healthier athletes who can perform to their fullest potential. In this article, we'll take a look at some sports nutrition myths that refuse to die.

MYTH #1: Eating certain carbohydrates before exercise is a bad idea

Most athletes know that carbohydrates are an important fuel for exercise, yet many believe that it is a bad idea to consume sugar before playing or working out. They insist that doing so will result in reduced blood sugar levels and a sudden drop in energy levels during exercise.

This myth about eating sugar-containing carbohydrates may be fed by studies conducted during the 1970s that suggested athletes should avoid sugar before exercising because eating sweets stimulated the secretion of insulin. Increased insulin levels would, in turn, lower blood glucose levels and prevent the body from accessing stored fat as a fuel source.

Subsequent carbohydrate research conducted during the past two decades confirmed that pre-exercise meals will cause decreased blood glucose levels and increased insulin levels, but these later studies also made the key observation that this effect is short lived. Once exercise begins, insulin levels fall and blood glucose returns to normal.

Misunderstanding this process leads some athletes either to avoid carbohydrates or to consume nothing at all before exercising. In reality, eating pre-exercise carbohydrates, including carbohydrates from sugar-containing foods, creates additional fuel for exercise, especially for long-term physical activity. Some of these sugar-containing carbohydrates can be found in fruit, fruit juice, sports drinks, syrup, honey, and, of course, sugar.

Athletes who have morning workouts or competitive events may not wake up early enough to consume a full meal, so a sports drink, a packet of honey, or some toast with jelly can provide quick fuel to restore liver glycogen levels after an overnight fast. In cases where an athlete has a tendency to develop hypoglycemia, a pre-exercise meal of oatmeal, fruit and yogurt, or pasta may prevent some shakiness and lightheadedness.

Encourage your athletes to get beyond this carbohydrate myth and learn to eat or drink something before exercise, because exercising on an empty stomach will almost always result in diminished performance.

MYTH #2: Men do not have body image issues

Eating disorders and body image issues occur with greater frequency in females than in males, in a ratio of approximately 10:1. Despite this lopsided ratio, males dealing with unhealthy body image concerns can suffer from serious health problems, just as females do.

Young men, from the secondary school level to adulthood, are exposed to the same unrealistic body ideals as women. In certain cases, these ideals are self imposed, and in others, they are externally imposed by the expectations of teammates or coaches. For example, male athletes who participate in weight criteria sports such as wrestling, lightweight crew, bodybuilding, or gymnastics often experience seasonal eating disorders when they need to make weight. Similarly, male athletes in sports such as football, basketball, soccer, and hockey often express concern over body composition. This body composition concern ranges from a desire to increase muscle mass, to increase muscle definition, to lose "love handles," or to reduce overall body fat. The central issue linking all of these examples is an unrealistic body ideal that can be imposed externally or internally due to vanity or competitiveness.

Unrealistic body ideals can create problems such as muscle dysmorphia, which is a new classification for a distorted body image more commonly seen in bodybuilders. This disorder is characterized by an excessive preoccupation with being fit and muscular to the exclusion of all else. Muscle dysmorphic individuals express extreme dissatisfaction with their bodies and have a severely distorted body self-image. Men who suffer from muscle dysmorphia can benefit from medications and counseling. If you have an athlete who fits this description, take time to talk with this person. Let him know that you are concerned and willing to help, and don't be afraid to suggest that he get help. It is very difficult for individuals with body-image issues to change their outlook without appropriate intervention techniques. Be part of the solution in what you choose to say to your athletes. Use positive reinforcement and avoid comparing one person's body type to that of another person.

MYTH #3: Carbohydrates should be avoided for muscle building and weight management

High-protein diets are a traditional recipe for athletes who assume that large amounts of protein will result in increased muscle mass. During the 1970's and again in the 1990's, high-protein diets became a preferred method of weight loss among athletes. Much of this popularity is derived from a misunderstanding about the amount of protein a person needs and how that relates to exercise and carbohydrate intake.

When an athlete is in training, the body's ability to gain mass is based on three factors: strength training, protein intake, and carbohydrate intake. A high-protein intake without adequate carbohydrate intake and increased training will not result in increased muscle mass. There must be a balance.

Nutritional studies indicate that the maximum amount of protein (in grams) that the body can efficiently utilize is equivalent to the body weight in pounds. In other words, a 150-pound athlete should consume a maximum of 150 grams of protein daily. If an athlete's diet exceeds that level of protein intake, there is little chance that individual will also eat enough carbohydrates. That imbalance can affect protein synthesis and energy levels during exercise, leading to earlier fatigue and suboptimal performance.

Studies also reveal that consuming a diet with a 3:1 carbohydrate-to-protein ratio soon after strength training is optimal for muscle growth. After exercising, it is better for an athlete to consume a yogurt with cereal or a scoop of protein powder mixed in a large volume of juice instead of relying on pure protein bars or protein shakes. In addition to these factors, research shows that eating a high-protein diet can lead to excess body fat, dehydration, electrolyte loss, and fatigue during exercise since protein is not an efficient energy source for activity.

Many athletes try high-protein, high-fat, low-carbohydrate diets to lose weight. Actually, weight loss with such diets occurs simply because the calorie level is low. When carbohydrates are eliminated or eaten in small quantities, there will be an initial diuresis effect, or fluid loss, which is often mistaken for a large fat loss. In reality, a high-protein diet produces no more body fat loss than a properly balanced diet.

Emphasize that your athletes eat a balanced intake of protein and carbohydrates. Let them know that a proper diet is critical to increasing muscle mass. Remind them that losing weight and maintaining that weight loss is best accomplished by a meal plan that provides a mix of nutrients, adequate calories, and appropriate energy sources to sustain activity at a high level.

MYTH #4: Vitamin-mineral supplements can replace food

Many athletes believe that using vitamin-mineral supplements gives them more energy, making them feel less tired and better able to perform. They are correct in assuming that vitamins and minerals are involved in energy metabolism; these substances enable the body to better utilize protein, carbohydrates, and fat. However, vitamin-mineral supplements do not contain calories, so they cannot be a fuel source for the body and they are definitely not a substitute for food.

Teach your athletes to do a quick eating checklist to ensure that they are consuming a varied, balanced diet before they use any supplements. Food not only provides the necessary vitamins and minerals, but fuel that the body needs for exercise as well. The truth is, an athlete who is eating a nutritious, balanced diet can perform at optimal levels without taking any supplements.

However, if an athlete's diet needs to be supplemented, here are a few key points that you can emphasize:

A poor diet with supplements is nothing more than a well-supplemented poor diet.
When used, a multivitamin-mineral supplement should contain 100 percent RDA of vitamins and a minimum of minerals.
Higher cost does not equal a better product.
Natural supplements are not always nutritionally superior.
Supplements should have a USP label and an expiration date.

MYTH #5: Water is the only drink you need

Historically, the common advice to athletes was that if one exercised for less than 90 minutes, then water was the only nutrient necessary to prevent dehydration. Recent research suggests that water alone will not support maximum performance because it does not provide other needed nutrients such as carbohydrates nor electrolytes such as sodium and potassium.

Athletes generally do not drink enough fluid during exercise. Drinking water alone during an extended workout compounds this problem. As a result, coaches and trainers need to teach their athletes not only to drink more fluids during athletic activities, but also to understand that drinking water provides only fluid.

Fluid intake is particularly important to athletes who exercise in hot, humid conditions, to athletes who have two-a-day practices and day-long competitions, or to those athletes who participate in stop-and-go sports such as football or lacrosse. All of these athletes need to consume sports drinks during activity to ensure that proper hydration and nutrient levels are maintained. Sports beverages need to be accessible to athletes, and they should be served chilled at full, undiluted strength. Additionally, athletes must learn to drink on a schedule, not just when they feel thirsty.

MYTH #6: Sports bars are nutritionally superior to food

There are several sports bars on the marketplace that are advertised as performance-enhancing, energy-boosting, fat-burning products. Some advertising campaigns may give athletes the impression that sports bars are nutritionally superior to food. That impression is false.

There is nothing magical about sports bars. They certainly can provide calories and nutrients as a snack for athletes on the go. But for athletes exercising at a high intensity on a daily basis, sports bars do not have enough calories and nutrients to meet their needs. After a day of intense training or competition, athletes need to eat a full meal to refuel. Athletes should be reminded that sports bars are just one more option in their food palette, and one that they must examine like any other food source.

Some sports bars are high in carbohydrates, others are high in protein, and their calorie levels vary dramatically. Many sports bars are fortified with vitamins, minerals, herbs, and, in some cases, potentially harmful substances such as ephedra. These bars vary widely in terms of taste and texture. If consumed during exercise, it is important to take them with fluid since many of them are quite dry.

MYTH #7: If you perform at high intensity, your diet must be OK

Many athletes consider nutrition to be low on their lists of priorities because they are feeling good and performing well. They are wrong.

Sub-par eating habits do not produce maximum athletic performance. Athletes who ignore nutrition would be surprised how much their performance could be boosted simply by eating regular, balanced meals. For most athletes, the difference between a suboptimal and optimal eating plan can translate to a 10- to 15 percent improvement in performance.

This is not an issue of good foods versus bad foods, but of eating enough food, eating a mix of foods, and eating before, during, and after exercise. I always encourage my athletes to experiment by changing one thing about eating and noting what happens during exercise, including the strength, speed, stamina, and recovery perspectives. There is no such thing as the perfect diet, nor is a perfect diet necessary, but a little attention to detail can have a significant, positive impact on performance.

MYTH #8: Calorie and nutrient intake should remain level all year

Many athletes keep a fairly consistent eating schedule all year, and do not vary it greatly whether they are in training or not. Nutrient needs during training are always greater than during competition, and athletes should take this into account. Athletes who do not increase their intake during training may find that their performance diminishes in response to inadequate nutrition. As the number of hours of training increases, so do carbohydrate requirements.

To better understand this concept, let's look at how the number of hours of strength training affects the recommended intake of carbohydrate per pound of body weight: An athlete exercising for one hour requires 2.7 to 3.0 grams of carbohydrate. When that athlete exercises for two hours, the carbohydrate requirement climbs to 3.6 grams. Three hours of exercise require 4.5 grams and four hours of exercise require 5.4 to 5.9 grams of carbohydrate. These figures underscore the need to adjust one's diet to changes in athletic activity. Protein needs are also greater in the initial stages of strength training, and they decrease as the body acclimates to the increased levels of exercise.

Just as caloric needs increase during training, athletes also need to adjust calorie intake during times of decreased activity. All too often, I see athletes reporting for training camp several pounds above their playing weights because their food intake has remained level while exercise decreased.

Emphasize to your athletes that nutritional needs do not stay the same from in-season to off-season. Intake should increase with a more demanding training schedule, and it should decrease as training tapers off. Athletes must learn to maintain that fine balance between energy intake and output for maximal performance.

MYTH #9: The body knows best when it comes to refueling

Many athletes believe that they should eat only when they are hungry and drink only when they are thirsty. Neither of these assumptions is correct.

Exercise can diminish sensations of thirst and hunger. By the time an athlete feels hungry or thirsty, nutrient levels are down and the process of dehydration has already commenced. Similarly, an athlete who is afraid to eat before a competition due to a nervous stomach may fatigue more quickly due to a lack of fuel.

As coaches and athletic trainers, we need to teach athletes to eat and drink on a schedule rather than doing so only when the urge strikes them. For example, if an athlete is not hungry after intense exercise, try recommending a post-exercise snack of concentrated carbohydrate beverage or juice. For an athlete who only drinks to satisfy thirst, encourage that he or she drink fluids regularly and consume an additional three or four sips when drinking. If one of your athletes has a nervous stomach, suggest a handful of dry cereal, part of a cereal bar, or a cup of sports drink before exercising. Being in tune with one's body is a good trait to possess, but sometimes we need to let the mind intervene and do what is best for the body to refuel, replace, and recover.

MYTH #10: Calories Matter Most For Weight Loss

Many people believe that losing weight is simply a matter of consuming fewer calories than one expends, no matter where the calories come from. That statement is only partially true. For an individual who exercises regularly, cutting too many calories out of a diet can result in decreased performance. Since carbohydrate and fat are the main fuels for exercise, the athlete who wants to lose weight must maintain a diet that contains adequate amounts of carbohydrate and fat, but in smaller quantities than before.

Here is a good rule of thumb to calculate an athlete's daily energy requirements: For male athletes, multiply body weight (in pounds) by 23 to calculate the number of daily calories required for weight maintenance. For female athletes, multiply body weight (in pounds) by 20 to calculate the number of daily calories required for weight maintenance. When calculating weight loss in men and women, subtract 250 calories per day from the calculated calories for weight maintenance. Losing weight can be aided by subtly changing eating habits:

Choosing low-calorie beverages or water instead of juice;
Watching and reducing the fat added to foods such as mayonnaise and salad dressing;
Eating two or three fewer bites at every meal;
Being conscious of proper portions of food. Reading the nutrition label on many foods can be helpful in determining serving sizes.

Athletes are constantly bombarded with conflicting advice and misinformation regarding the best and quickest way to lose weight. As a result of this misinformation, many athletes experience a very temporary weight loss along with a diminished exercise capacity. Ask your athletes to record what they eat for three or four days and then suggest two or three things that they could do to cut the calories. One can have one's cake and eat it too, just make sure it's a smaller piece!

Coaches and athletic trainers can boost their athletes' performance while helping to maintain their athletes' health simply by correcting many of the nutritional myths surrounding sports. That definitely is a win-win situation.