All athletes need a diet that provides enough energy in the form of carbohydrates and fats as well as essential protein, vitamins, minerals, and fluids, especially water. Dehydration can stop even the finest athlete from playing his or her best game. This means a variety of foods are needed every day – fruits, vegetables, grains, beans, lean meats, and low fat dairy products.
While the exact percentages below may vary slightly for some athletes based on their sport or training program, these guidelines will promote health and serve as the basis for a diet that will maximize performance. Health and nutrition professionals recommend an athlete’s diet provides:
- 55 to 60 percent of the calories in your diet should come from carbohydrates – 10 to 15 percent from sugars, and the rest from starches.
- No more than 30 percent of the calories in your diet should come from fat.
- And… 10 to 15 percent of the calories in your diet should come from protein.
Carbohydrates
Carbohydrates are the preferred source of energy for your body. Carbohydrates are sugars and starches found in foods like fruits, vegetables, breads, cereals, pasta, milk, honey, syrups, and table sugar.
When you are training or competing, your muscles need energy to perform. When starches or sugars are eaten, the body changes them all to glucose, the only form of carbohydrate used directly by muscles for energy.
Whether carbohydrates are in the form of starches (in vegetables and grains), sucrose (table sugar), fructose (found in fruits and juices) or lactose (milk sugar), carbohydrates are digested and ultimately changed to glucose that your blood carries to cells to be used for energy. Your body cannot differentiate between glucose that comes from starches or sugars. Glucose from either source provides energy for working muscles.
The body uses this glucose in the blood for energy. Most glucose is stored as glycogen in the liver and muscles. During exercise glycogen is broken down in the muscles and provides energy. If you don’t consume enough carbohydrates, your glycogen stores become depleted, which can result in fatigue. Both sugars and starches are effective in replenishing glycogen stores. Usually there is enough glycogen in muscles to provide fuel for 90 to 120 minutes of exercise.
Most exercise and sport games do not use up glycogen stores so eating carbohydrates during the activity usually isn’t needed. But for some athletes, eating or drinking carbohydrates during exercise helps maintain their blood glucose and energy levels.
Most athletes need not be concerned with carbohydrate loading, the special technique of eating a lot of carbohydrates for several days before an endurance event. Instead, focus on getting enough carbohydrates everyday. The best way to ensure plenty of energy for exercise is to eat a nutritious, balanced diet that is high in carbohydrates and low in fat with lots of different foods.
Carbohydrates provide 4 calories per gram, while fat provides 9 calories per gram.
Hemoglobin, which contains iron, is the part of red blood cells that carries oxygen from the lungs to all parts of the body, including muscles. Since your muscles need oxygen to produce energy, if you have low iron levels in your blood, you may tire quickly.