Hydration After Exercise
The first nutritional priority after exercise is to replace any fluid lost during exercise. In general the best way to determine how much to drink (either water of a sports drink) is to:

• Weigh yourself before and after exercise and replace fluid losses.
• Drink 20-24 fl oz water for every 1 lb lost.

Eating After Exercise
It is also important to consume carbohydrate, such as fruit or juice) within 15 minutes post-exercise to help restore glycogen.

Research has shown that eating 100-200 grams of carbohydrate within two hours of endurance exercise is essential to building adequate glycogen stores for continued training. Waiting longer than two hours to eat results in 50 percent less glycogen stored in the muscle. The reason for this is that carbohydrate consumption stimulates insulin production, which aids the production of muscle glycogen. However, the effect of carbohydrate on glycogen storage reaches a plateau.

Carbohydrate Plus Protein Speeds Recovery
Research shows that combining protein with carbohydrate in the two hours after exercise nearly doubles the insulin response, which results in more stored glycogen. The optimal carbohydrate to protein ratio for this effect is 4:1 (four grams of carbohydrate for every one gram of protein). Eating more protein than that, however, has a negative impact because it slows rehydration and glycogen replenishment.

One study found that athletes who refueled with carbohydrate and protein had 100 percent greater muscle glycogen stores than those who only ate carbohydrate. Insulin was also highest in those who consumed a carbohydrate and protein drink.

Protein Needs After Exercise
Consuming protein has other important uses after exercise. Protein provides the amino acids necessary to rebuild muscle tissue that is damaged during intense, prolonged exercise. It can also increase the absorption of water from the intestines and improve muscle hydration. The amino acids in protein can also stimulate the immune system, making you more resistant to colds and other infections.

Bottom Line
If you are looking for the best way to refuel your body after long, strenuous endurance exercise, a 4:1 combo of carbohydrate and protein seems to be your best choice. While solid foods can work just as well as a sports drink, a drink may be easier to digest make it easier to get the right ratio and meet the 2-hour window.