Nutrition is one of the many factors that ensures optimal athletic performance. Like all athletes, swimmers require a nutritionally balanced diet containing nutrients to sustain normal daily activities as well as those associated with training and competition.
Swimming places extraordinary demands upon the respiratory, cardiovascular, and energy producing systems of the body. Calories found in food provide the energy while the remaining nutrients, particularly vitamins and minerals are used in various functions to help release the extra energy needed. Thus, a swimmer's nutritional status and dietary habits are important factors for success in both training and competition.
Swimmers are not always aware of their nutritional needs and some may consume inadequate diets. Athletes and coaches who are influenced by half-truths or misinformation may engage in expensive practices that offer no measurable advantage and can be potentially dangerous.
A nutrition knowledge questionnaire was administered to 290 elite adolescent swimmers attending United States Swimming's age group camps in the fall of 1992. 152 of the swimmers were male and 138 of the swimmers were female. Their ages ranged from 14 to 18 years of age.
Nutrition Knowledge of Swimmers
On the nutrition knowledge section of the questionnaire, the average score was 67 percent for the female swimmers and 69 percent for the males. These scores are lower than those reported in other studies in spite of the fact that 42 percent and 46 percent of the females and males had taken a previous nutrition course. Other studies with elite swimmers have shown higher scores on basic nutrition knowledge, however, when compared to athletes in other sports such as football and baseball, elite adolescent swimmers score better on nutrition knowledge.
Although the swimmers in this survey were elite for their age group, this survey showed that when it comes to food choices they are typical adolescents. Furthermore, they did not have enough nutrition knowledge to choose foods that were high in specific nutrients. For example, when asked to name a nutritious carbohydrate 62 percent chose an apple, while 38 percent chose french fries. When asked which food is a good source of protein, 36 percent chose oatmeal while 63 percent chose the correct answer of chicken. While it could be argued that the majority of swimmers picked the correct answer, it is astonishing that close to 40 percent did not. If swimmers are unable to pick the correct answer, then they are unable to choose the right foods for performance, training and health.
Vitamin and Mineral Supplementation
Like all athletes, swimmers are bombarded with information about what to eat or what not to eat, and what supplement they should or should not take. Over 50 percent of the respondents reported taking a vitamin or mineral supplement (59% female, 55% male).
This high rate of supplementation suggest that swimmers are not aware that a well balanced diet can provide adequate nutrients for most athletes and that supplementation will not improve performance unless a true deficiency exists. Vitamin C and a multiple-type vitamin was the most common supplement used by the swimmers. Iron and calcium were the most reported mineral consumed in pill form. Other swimmers said that they consistently consumed lecithin, amino acid supplements, and bee pollen. One swimmer even reported taking vast amounts of RNA and DNA.
Protein
Protein is made up of a collection of individual amino acids that form the various proteins in the body. No living tissue can be built without protein, for protein is a part of every cell. Proteins come in many forms: enzymes, antibodies, hormones, transport vehicles, tendons, muscles, ligaments, cores of bones and teeth, filaments of hair and the materials of nails. Contrary to popular belief, protein is not a primary source of energy, except when athletes are not eating enough food, especially carbohydrates.
Research suggest that swimmers need about .4-.9 grams of protein per pound of body weight everyday. However, swimmers tend to eat more protein-rich foods than their sedentary friends because they eat more foods. When swimmers were asked if they need to take a protein supplement, 39 percent of the female swimmers and 44 percent of the male swimmers said yes. These findings are consistent with other reports that males are more likely to take protein supplements than females. Other studies reported high school athletes are more likely to supplement their diet with protein than college athletes. Research shows that half of the athletes who take protein supplements are football players, although more protein supplementation is being seen in athletes other than football.
Athletes should realize that protein supplementation and/or amino acid supplements in large doses may cause amino acid imbalances and toxicities. There have not been studies conducted on human subjects of large doses of amino acid or protein supplements, and therefore no margin of safety is known. For most swimmers, amino acid or protein supplements are expensive, and unneeded supplements.
Fluids and Hydration
Training in a hot, humid environment can lead to dehydration. Swimmers are vulnerable to dehydration, especially during the hot summer months. Performance can suffer when a swimmer loses as little as 2 percent of body weight as sweat. To prevent dehydration, swimmers must drink plenty of fluids before, during and after a workout or competition. Thirst is not an accurate indicator of how much fluid a swimmer needs. One of the major concerns of this survey is the belief of young adolescent swimmers that thirst is an adequate measure of hydration status. This misconception was more prevalent in the female swimmers than in the male swimmers (49 percent females and 24 percent males). To maintain hydration levels, swimmers need to keep a fluid bottle by the side of the pool when working out and drink as often as possible. To minimize poor performance due to dehydration swimmers should:
• Drink two cups of fluid for each pound lost in workouts/competition.
• Drink one to two cups of fluid prior to working out or competing.
• Drink 4-10 ounces of fluid every 15-20 minutes during training.
• Dark urine indicates dehydration and the need to replenish fluids.
• Sports drinks formulated with 6-7% carbohydrate and sodium, replace fluids faster than water, improve performance and help optimal rehydration.
Pre-event Nutrition
The type of food swimmers eat prior to competition influences how well they perform in the water. Over 50 percent of the respondents reported eating before an event with the majority eating 60 to 90 minutes prior to the start of their event. Of concern is the fairly large percent (28% female, 42% male) who do not eat anything before an event. Swimmers need to consume carbohydrates before competition and training. How much carbohydrate should the swimmer consume in the pre-exercise meal? The general rule of thumb is .5 to 2 grams of carbohydrate per pound of body weight consumed 1 to 4 hours before the start of exercise. To avoid potential gastrointestinal distress, the carbohydrate content of the meal should be reduced as the time to exercise decreases. For example, a carbohydrate feeding of .5 grams of carbohydrate per pound within one hour before exercise, where as 2 grams of carbohydrate per pound can be consumed safely four hours before exercise. The best pre-event meal should contain primarily carbohydrates. Fatty food such as potato chips, donuts, french fries, and pastries, take longer to digest and provide little energy during racing. Protein foods that are likely to contain high amounts of fat (peanut butter, cheese and high-fat meats like salami, bologna and bacon) are also more slowly digested. Eating foods high in fat and protein before competition can actually diminish swimming performance. For this reason, it is recommended that swimmers eat high carbohydrate foods like pasta, cereals, bagels, fruits and vegetables.
Body Weight
When elite adolescent swimmers were presented with the question of "Are you happy with your current weight, 56 percent of the females and 62 percent of the males said yes. Of those who said that they were unhappy with their present weight, 74 percent wanted to lose weight while 26 percent wanted to gain weight. For the swimmer who wishes to change his or her body weight, a well-planned and supervised weight control or weight gain program should be emphasized.
Nutrition Information
There are many individuals and organizations that can provide a swimmer with nutrition information. However, most swimmers do not know if the information they are receiving is fact or fallacy. The swimmers in this survey were asked where they obtain their nutrition information. Forty percent of the females and 53 percent of the males reported that their nutrition information comes from their coach followed by parents (32% females and 18% males). Dietitians (13% females, 6% males), physicians (14% females, 10% males), and teachers (2% females, 3% males) were less frequent providers of nutrition information. These results emphasize the importance of disseminating accurate dietary information to coaches and parents so athletes have access to sound nutritional guidance.
Summary
When swimmers make poor food choices, due to a lack of nutrition knowledge, then they are not providing adequate fuel or nutrients for optimal training or performance. Since many swimmers are unaware of what nutrients they eat, how much they eat, and what nutrients are required for optimal performance, a credible nutrition education program seems warranted. Areas that have been identified are:
• Ninety percent of the swimmers surveyed want credible materials about nutrition and performance.
• Many swimmers are taking supplements, probably out of misbelief.
• Weight control issues are prevalent. Therefore, providing safe and sound information about how to achieve desired weight goals are crucial.
• Swimmers need to be taught how to hydrate before, during and after training and competition to maximize their athletic ability.
• Many swimmers don't eat before a workout and may not be achieving their maximal performance levels.
For More Information
U.S. Swimming and the Gatorade Company have developed an eighteen page brochure providing the swimming community with practical, up-to-date information on sports nutrition.
To request up to 100 free brochures for use in school based or club swimming programs, send the number of brochures requested, your name and shipping address to:
The Swimmers Diet
847 West Jackson, 5th floor
Chicago, IL 60607
"The type of food swimmers eat prior to competition influences how well they perform in the water. Over 50 percent of the respondents reported eating before an event with the majority eating 61-90 minutes prior to the start of their event. Of concern is the large percent who do not eat anything before an event."
Eating Before an Event