By Jimmy Downs

Saturday Nov 17, 2012 (foodconsumer.org) -- Japanese researchers have early demonstrated that taking whey protein hydrolysate can help replenish muscle glycogen after exercise more effectively than consuming when protein or branched chain amino acids, valine, leucine and isoleucine.

The current study led by A. Kanda of Meiji Company Limited  in Odawara, Kanagawa and colleagues conducted the simple study and found again that whey protein hydrolysate (WPH) was more effective than whey amino acids and casein.

In the study, ddY mice were fed diets with whey protein hydrolysate or a mixture of whey amino acids or casein for five weeks and then gastrocnemius muscle glycogen and total glycogen synthase (GS) were measured.

The researchers found at the end of the dietary intervention, gastrocnemius muscle glycogen levels were significantly higher, 4.35 mg/g in mice on the diet with whey protein hydrolysate, compared to 3.15 mg/g in mice on the diet with whey amino acids or 2.51 mg/g in those on the diet with casein. 

Similarly, total glycogen synthase levels were significantly higher in the whey protein hydrolysate suplemented mice than those on the whey amino acids supplemented diet or controls, 153% compared to 89.2%.  Also phosphorylated glycogen synthase levels were decreased by 49% in mice eating whey protein hydrolysate.

The researchers concluded "These results indicate that dietary WPH may increase the muscle glycogen content through increased GS activity."