Healthy nutrition is very important for sports training
One to two hours before your workout, you should eat a light meal, or protein bar or drink.
Pre-workout drink (immediately before workouts)
The latest research data indicates that a small pre-workout meal supplement containing at least 10g of protein or about 6g of essential amino acids will minimize muscle protein breakdown during intense physical exercise. Whey protein isolate is the preferred choice since it digests fast.
Post-workout drink (0-45 minutes after workouts)
This is a critical time for proper recovery. You need to rush nutrients into your body preferably within 30 minutes of your workout. A delay of an hour or two can make a significant difference in your recovery, muscle protein synthesis and glycogen replenishment.
The post-workout formula should contain at least 15g of whey protein (which is fast-digesting) and about 45g of high-glycemic carbohydrates. Don’t mix this formula in milk since it will slow down digestion.
Try packing a shaker bottle in your gym bag containing the dry protein powder formula. As soon as you’re done working out or practice ends, add water at the drinking fountain, shake it up and drink it on the way home. Or eat a high-carb protein bar. Avoid fat in this meal (under 6g is fine).
Post-workout meal (2-3 hours after workouts)
After about two hours your body is primed to stimulate further muscle protein synthesis and recovery. Eat about 20-40g of protein along with low-glycemic carbs. Lean meats and steamed vegetables are a good choice. Stay away from refined carbs like breads, pastas, rice and cereal to minimize insulin stimulation unless you are trying to gain weight. Once the metabolic window to build muscle has passed, excess carbs and insulin will only make you fat.
This information is from Nutrition Express in an article called “Strength and Muscle Building Plan For High School Athletes”