There is strong evidence supporting the role of protein and amino acid supplementation in the prevention of muscle protein breakdown and augmentation of muscle protein synthesis when ingested at both pre- and post-exercise. Specifically, chronic protein and amino acid supplementation in conjunction with strength training has been linked to increased strength, power, myofribrillar protein, and myosin heavy chain I and IIa expression. 

 

Acute protein and amino acid supplementation has also been shown to attenuate muscle proteolysis caused by endurance exercise. Collectively, these data indicate that protein and amino acid supplementation may increase protein synthesis and decrease the protein degradation occurs with varying types of exercise. This evidence leads to the question of the potential effects of protein and amino acid supplementation in preserving skeletal muscle during times of injury, immobilization, and disuse.