Proper nutrition before and after competition or workouts can improve performance and results and in recovery. Many people today are putting too much emphasis on protein. Your muscles need carbohydrates for fuel and after a hard workout, they need to replace depleted glycogen - glycogen is the energy source that your muscles use and it most readily comes from carbohydrates.
PRE EXERCISE Eating before exercise can be tricky and very individual, you want to make sure that you can tolerate different foods at different times. Don't try new things the day of a big race or competition, and be aware of your body's signs. In general, you want to start with an empty stomach but plenty of energy flowing in your blood and stored in your muscles. Some people prefer a light snack within the hour before exercise, some prefer a larger snack about 2-3 hours before, others perform better with a large meal. It is also important to have enough fluids, and avoid greasy foods that can upset the stomach. Here are some guidelines:
1 hour before: fruits, fruit/vegetable juices, energy gels
2-3 hours before: fruits, fruit/vegetable juices PLUS low-fat yogurt and/or bread or bagel
3-4 hours before: fruits, fruit/vegetable juices plus low-fat yogurt, bread or bagel, PLUS a meal that is high in carbs, moderate in protein and low in fat (ie, pasta w/sauce, whole wheat bread w/chees/peanut butter/lean meat, cereal, baked potato), energy bar
POST EXERCISE Most important, replace lost fluids, about 20 oz per pound of weight lost during the exercise session.
Within 15-30 minutes, replace carbohydrates with a drink or light snack.
Within about 2 hours, have a meal that is high in carbohydrates, about 100-200 grams, together with some lean protein. That's about 3 cups of pasta or mashed potatoes.
For an excellent article called "Training Diet" from the Iowa State University, click here.