high quality protein
after resistance exercise is undoubtedly one of the most important nutritional strategies for promoting an anabolic state for muscle growth.
Whether adding carbohydrate to protein offers additional benefit is less clear. Carbohydrates increase insulin, which has been shown to increase uptake of amino acids into muscle and protein synthesis. Previous work has shown however that carbohydrate alone is not a potent stimulus to increase protein synthesis. There is some evidence for an additive effect of post-exercise protein and carbohydrate, but more recent work shows that carbohydrate does not augment the response beyond protein alone. To shed additional light on this issue, Canadian researchers assessed muscle protein synthesis and breakdown at rest and after
on two separate occasions in men. During one trial subjects consumed 25 grams of whey protein and during the other trial they consumed 25 g of whey protein plus 50 g carbohydrate (maltodextrin). Compared to the protein trial, carbohydrate plus protein increased the insulin response 5-fold. Both trials resulted in a significant increase in protein synthesis and protein breakdown in the rested and exercise-stimulated condition, but there was no difference between supplements. These findings indicate that stimulating high levels of insulin by ingesting carbohydrate does not have an advantage over consuming an optimal level of protein alone on
synthesis and breakdown.
Staples AW, Burd NA, West DW, Currie KD, Atherton PJ, Moore DR, Rennie MJ, Macdonald MJ, Baker SK, Phillips SM. Carbohydrate Does Not Augment Exercise-Induced Protein Accretion versus Protein Alone. Med Sci Sports Exerc. 2010 Dec 1. [Epub ahead of print]