Until now, few studies have looked at how much protein to take after a workout to achieve maximum muscle protein synthesis.
Researchers at McMaster University in Canada had six healthy young men on five different occasions perform an intense bout of leg-based resistance exercise. After exercise, they consumed either 0, 5, 10, 20 or 40 grams of whole egg protein. The researchers found that increasing protein intake stimulated increased muscle protein synthesis in a dose-dependant manner for each higher dose consumed, reaching maximum synthesis at 20 grams. The 40 gram dose showed no significant difference in synthesis. Their results suggest that there is a maximum rate at which muscle tissue can absorb amino acids after exercise and once that point is reached, there is no further muscle protein synthesis benefit.
American Journal of Clinical Nutrition; 2009, Vol. 89, No. 1, 161-168.