Nutrition and Athletic Performance

Alternate Names : Sports Nutrition

Nutrition, also called healthy eating, plays a key role in athletic performance.

Information
Healthy nutrition should be a part of every athlete’s training program. Whether an athlete enjoys sports for fun or competition, he or she needs healthy nutrition. The body needs calories and nutrients to run a race or to take a walk.

Generally, sports can be divided into 2 categories.

  • short duration/high intensity, as in sprinting or weight lifting
  • long duration/lower intensity, as in sustained running or jogging

In reality, most sports alternate between the two.

Athletes need healthy amounts of calories, protein, and water. Minerals, electrolytes and antioxidants, which are substances that fight the effects of free radicals that can damage the body, are important, too.

Calories from carbohydrates are the quickest source of body fuel. Carbohydrates are easily broken down to sugar, also called glucose. Glucose circulates in blood and is taken up by cells that need energy. For active people, a steady intake of carbohydrates fuels the muscle cells. Carbohydrates also fuel the heart, nerves, and brain cells.

Glucose can be stored in the muscles and liver. This form of glucose is called glycogen (glie-kah-jen). When blood glucose levels start to fall, glycogen is changed to glucose, raising blood glucose levels. Well trained athletes who eat a high-carbohydrate diet can improve glycogen stores. This means more fuel for longer workouts. Commonly called “carbohydrate loading,” this type of diet works by building glycogen stores.

Before a strenuous event, a high carbohydrate meal such as pasta, potatoes, or rice is recommended. Tomato sauce on the pasta and toppings on potatoes are OK. Just make sure that 70% to 80% of the calories for the meal should come from carbohydrates.

Strenuous workouts should be followed by a snack or meal of 100 to 200 grams of carbohydrates to replace the glycogen stores. For example, 1 cup of white rice and a few pieces of fruit add up to 100 grams of carbohydrate. In general, endurance athletes should build a diet based on the bottom of the Food Guide Pyramid. These are foods high in carbohydrates and include grains, breads, starchy vegetables, fruits, yogurt, and milk.

People involved in short-duration, high-intensity activities need carbohydrates, too. People in sports such as weight lifting tend to focus on protein. Protein helps with muscle growth, but carbohydrates fuel the body. Carbohydrates should make up about 55% to 65% of the total calories eaten.

Some athletes want to build muscle mass. To do so, protein intake should be between 1 to 2 grams per kilogram of body weight. For example, a 154-pound (70-kilogram) person can eat 70 to 114 grams of protein per day. Eating more protein than that taxes the kidneys and can be harmful. People who eat a lot of protein should also drink a lot of water. Water will help flush out the waste products from the breakdown of protein in the body, which helps to avoid any harmful effects.

Water is a key factor in ensuring an athlete’s health. In addition to the 8 glasses a day that all healthy people need, athletes should drink 1 to 2 cups before working out or competing in an event. Endurance athletes need to drink 4 to 10 ounces every 15 to 20 minutes during training or competition. Water or sports beverages are OK. Drinks that contain caffeine or alcohol are not. This is because they are both diuretics that can lead to dehydration, which is a loss of body fluid.

Sports beverages are a good source of the electrolyte minerals potassium, sodium, and chloride. These drinks can help replace those key minerals in athletes who sweat a lot. However, simply eating a balanced diet will also provide plenty of electrolytes.

Iron is another key mineral for athletes. It helps carry oxygen in the blood. Female and/or vegetarian athletes should have their iron levels checked to screen for iron deficiency anemia.

Exercise causes oxidative stress, a type of stress caused by exposure to oxygen. Athletes may have a higher need for antioxidant nutrients. Athletes should make sure they get the recommended daily allowance for vitamins A, C , and E, as well as the mineral selenium.

Provided by ArmMed Media
Revision date: June 22, 2011
Last revised: by Sebastian Scheller, MD, ScD