Improved endurance is a function of three critical processes: 1) the speed in which carbohydrate is absorbed in the stomach, 2) how fast the blood delivers carbohydrate from the GI tract to muscles, and 3) the speed at which carbohydrate is transported from the blood into the muscle cell where it can metabolized into energy. The amino acid, arginine, plays an important role in two of these processes.
Studies have shown that arginine improves nutrient and oxygen delivery because it is a precursor for nitrous oxide, an essential compound shown to increase blood flow. Arginine also stimulates specific agents responsible for the transport of carbohydrate from the blood into the muscle cell. Finally, arginine is a potent stimulator of insulin release.
Confirmation of arginine’s role in improving muscle performance has been shown in a recent study conducted by Australian researchers. The researchers found that arginine increased glucose uptake into muscles when administered during exercise. What this study suggests is that consuming a protein that contains a higher percentage of arginine will improve exercise performance. Because pea protein contains almost four times the arginine levels of whey protein, combining pea and whey protein may product a positive synergistic effect on exercise performance.