Protein, resistance exercise, and muscle protein synthesis:
Dietary amino acids increase skeletal muscle protein synthesis (MPS), an effect that is enhanced by prior resistance exercise. Factors such as the dose of dietary protein/essential amino acids (EAA) ingested, protein food source (such as whey, soy, casein), and timing of protein/EAA intake impact the magnitude (and possibly the duration) of MPS. It appears that consumption of ~ 20–25 g (corresponding to ~ 8–10 g EAA) of a rapidly absorbed protein may be optimal to stimulate MPS after resistance exercise in young healthy individuals. Whey or bovine milk appear to be the best food source to achieve this. Activity associated with intense resistance exercise results in increased rates of MPS that are sustained for ~48 h in young participants. Since resistance exercise increases MPS for up to ~48 h consumption of dietary amino acids 24 – 48 h post-exercise recovery convey the same combined effects on MPS as those that are observed when amino acids are provided immediately after resistance exercise. In conclusion, protein/EAA intake, not only immediately after, but up to ~24 h following exercise should be carefully considered as a dietary strategy to maximally stimulate exercise-induced rates of MPS. (4)
