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PENS Topics : Sports Nutrition
With the exception of an increased energy intake, the nutrition recommendations for athletes are very similar to that of the general population. Today we are going to take a look at guidelines for athletes when planning meals for performance. We will also be discussing carbohydrate and fluid intakes along with the use of food supplements.
To educate university/college students on practical ways to fuel their bodies for performance.
At the end of this session participants will have learned:
Suggested Background Reading for Presenters
[Begin by handing out the quiz and allowing participants 5 minutes to complete. Discussed at certain points throughout the presentation.]
Good Nutrition for Athletes
(Overhead 2) Nutrition recommendations for athletes is very similar to that which is recommended for the general healthy population. For all people, the first rule of good nutrition is to eat a wide variety of foods in amounts aimed at maintaining a healthy body weight. Canada's Food Guide to Healthy Eating (in the US, the Food Guide Pyramid) is one tool developed to assist individuals in planning daily meals with all the servings needed for achieving a nutritious diet regardless of the type of sport. Because most athletes need more food during training, they should choose lots of high carbohydrate grains, fruits and vegetables. (Q1 - False)
It is recommended that approximately 55-60% of total energy intake be derived from carbohydrate, less than 30% of calories from fat, with the remainder (10 -15%) from protein.
A Closer Look at Carbohydrates and Fats
Carbohydrates are the body's choice fuel for physical activity. Muscles derive most of their energy from the metabolism of carbohydrates. Until fat can be mobilized, glucose is the major carbohydrate burned during the early minutes of exercise. Glucose is stored in the liver and muscles in the form of glycogen. A high carbohydrate, low-fat diet (derived from such foods as pasta, whole grain breads and cereals, vegetables, rice, potatoes) produces a large amount of stored glycogen in the exercising muscle. This in turn enhances physical endurance. A lower fat diet is necessary so that athletes can eat enough carbohydrates while still controlling their energy intake. (Q2 - True)
The body uses some carbohydrate for fuel regardless of the type of exercise. When the supply of stored carbohydrate - glycogen - is depleted, fatigue sets in. By loading the muscles with carbohydrate, the onset of fatigue can be delayed. Carbohydrate loading (maximizing muscle glycogen stores) is an advantage only in endurance events lasting more than 90 minutes or in multiple event competitions.
A Closer Look at Protein
Many people incorrectly believe that because protein helps build muscles, and muscle powers exercise, large amounts of protein must be eaten to meet the energy costs of exercise. In reality, carbohydrates should be athletes' main fuel. Protein is used as a major source of energy only when there is insufficient energy available from carbohydrate and fat. The most important role of protein is to build, maintain and repair tissue, and to produce hormones and enzymes. Muscles can utilize protein for energy, yet the body must make a greater effort to transform protein into a fuel, making it a less efficient energy source.
Excess protein (above the body's requirement) is not stored as protein, for future use. Excess protein is broken down by the liver and is either burned for energy or stored as body fat, not muscle. High protein diets are also high in fat and thus, often deprive the athlete of the most efficient fuel, carbohydrates. (Q 5 - False) Proper strength training exercises, not extra dietary protein, will stimulate muscular growth. Most moderate diets will provide sufficient protein to allow for muscle growth.
The Pre-Event and Post-Event Meal
There is no magic meal that will guarantee an athlete the competitive edge. Performance during an event is more dependent on the food consumed in the days prior to the event rather than on the immediate pre-event meal. Generally, very little energy for an event is supplied by the pre-event meal. (Q 3 - False) The goals of the pre-event meal are physical comfort and mental alertness. It is important to eat only enough to avoid hunger during the event. Drink plenty of fluids and always eat familiar foods. Athletes should avoid eating concentrated sweets prior to or during an event. Ingesting concentrated sugar can cause an insulin overshoot and lead to hypoglycemia, premature fatigue and decreased performance.
Before an event, it is recommended that you eat mainly carbohydrates with small amounts of protein and fat. Both protein and fat delay the emptying of the stomach. Neither protein nor fat contributes to the glycogen stores needed during exercise. In terms of timing, the meal should be eaten at least three hours before the event so that the stomach and upper bowel are empty at the time of the event. The pre-competition meal should be eaten several hours before the event to ensure gastric emptying and avoid discomfort. The meal should also include 2-3 cups of fluid. Suggestions are hot or cold cereal with low-fat milk and fruit, pasta with a low-fat sauce or a lean meat sandwich without mayonnaise. It is also very important to re-fuel with a high carbohydrate meal or snack as soon as possible after an activity. Although it takes at least one or two days after a hard workout to fully refill the body's carbohydrate stores, athletes should start consuming carbohydrates within 15 minutes after the activity. (Q4 - False)
What about Vitamin Supplements?
People who exercise regularly do need some vitamins such as thiamin, riboflavin and niacin in slightly greater amounts than less active people. However, the increased need for these vitamins is in direct proportion to the increased energy need caused by the increased activity. The increased need for these vitamins will be met most likely by the increased food intake. Vitamin supplements, which claim to promote an increased energy leve, are available. However, energy does not come from vitamins. Energy comes from carbohydrate, fat and protein. Although some vitamins help the body to use energy, these vitamins are easily obtained from a high carbohydrate diet that includes a variety of foods from the four food groups. (Q6 - False)
The Importance of Water
(Overhead 3) Water probably has the greatest effect on athletic performance than any other nutrient. Water is the only nutrient lost in large amounts during strenuous exercise. Some individuals may lose about two to four litres of sweat per hour (six to eight pounds of body weight) during prolonged exertion. Water loss will cause the appearance of weight loss. This quick weight loss is not due to loss of fat. Dehydration via sweat loss can impair circulatory and thermal regulatory functions, leading to cramps, nausea, fatigue, poor performance and heat exhaustion. (Q 7 - True)
It is recommended that athletes include frequent consumption of small quantities of plain, cool water every 10 to 20 minutes during exercise and ample replacement of fluids after the workout. If the water lost via sweat is not replaced, blood volume falls and body temperature rises, causing loss of coordination and confusion. Usually water is the best drink for athletes during exercise. Exceptions include prolonged exercises lasting more than one hour or during conditions of extreme sweating such as hot temperatures, humid conditions and prolonged endurance exercise. Under these conditions, an athlete may benefit more from drinking other beverages e.g., diluted fruit juices, commercial sport drinks. They supply water, additional carbohydrates and electrolytes. (Q8 - False)
[Invite students to create their own sports shakes. Have ingredients for enclosed recipes available along with an appropriate number of blenders. Encourage informal sports nutrition conversation while participants prepare their shakes.]
Canada's Guidelines for Healthy Eating
Why Wet Your Whistle
Water . . .
SPORTS NUTRITION QUIZ
(BLEND until smooth.)
(BLEND 15 seconds.)
(BLEND 15 seconds.)
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Last Modified on May 1, 2012 12:18 PM, by [DR]