Research Advancement of the Effects of the Co-ingestion of Carbohydrate and Protein on Muscle Glycogen Synthesis after Exercise

Muscle glycogen is the major energy source in human body,it can provide the energy for muscle contraction rapidly.A large amount of muscle glycogen will be depleted after long term and high intensity exercise,and it will affect the exercise performance also.The rapid synthesis of muscle glycogen is an important part for the post-exercise recovery,many studies have reported that the process of muscle glycogen synthesis can be accelerated by the supplementation of carbohydrate after exercise.On the other hand,some recent studies found that the muscle glycogen synthesis can be further promoted by the co-ingestion of carbohydrate and protein after exercise.However,some other studies were not observed positive results.Based on the summarization and analysis of the published scientific papers,this paper found out that the ingestion rate of carbohydrate and protein was the major reason for the inconsistent findings among different studies.If the ingestion rate of carbohydrate was slower than 1.0~1.2g/kg/h,the co-ingestion of protein at a rate of 0.2~0.4g/kg/h will promote the muscle glycogen synthesis rate significantly.The higher insulin level after the ingestion of protein will enhance the transportation of glucose,and protein supplementation can also strengthen the activity of glycogen synthetase,the both reasons may resulted in the greater synthesis rate of muscle glycogen after protein ingestion.However,the suitable forms and types of the supplied proteins,and also the potential mechanisms behind the findings have not been investigated clearly so far.Further studies can focus on the abovementioned questions and provide evidences for making scientific nutrition supplementation programmes which can promote the muscle glycogen synthesis rate after exercise.