BCAA have the ability to act as an anti-catabolism during fasting, because they are insulinogenic amino acids, and insulin is a hormone that strongly inhibits muscle catabolism.
Therefore, when you take BCAA, even if plasma insulin increases slightly, it is possible to suppress gluconeogenesis in the liver by reducing the proteolysis of muscles and other tissues.
Therefore, BCAA supplementation can prevent skeletal muscles from using amino acids as energy sources during long-term fasting periods (such as 8 hours of sleep). In addition, when the body has the necessary nutrients, insulin is a hormone with high synthetic properties.
Insulin can increase muscle protein synthesis by obtaining essential amino acids directly from the amino acid pool between cells. This is why when insulin levels increase, increasing the amount of BCAA in the body can speed up the synthesis of muscle protein.