http://www.nytimes.com/2008/06/05/health/nutrition/05Best.html
Here is what is known about proteins, carbohydrates and performance.
During exercise, muscles stop the biochemical reactions used to maintain themselves such as replacing and resynthesizing the proteins needed for day to day activities. It’s not that exercise is damaging your muscles; it’s that they halt the maintenance process until exercise is over.
To do this maintenance, muscles must make protein, and to do so they need to absorb amino acids, the constituent parts of proteins, from the blood. Just after exercise, perhaps for a period no longer than a couple of hours, the protein-building processes of muscle cells are especially receptive to amino acids. That means that if you consume protein, your muscles will use it to quickly replenish proteins that were not made during exercise.
But muscles don’t need much protein, researchers say. Twenty grams is as much as a 176-pound man’s muscles can take. Women, who are smaller and have smaller muscles even compared to their body sizes, need less.
