affect mTOR phosphorylation and even produces a decrease in Akt phosphorylation. Some phosphorylation of p70 S6 kinase was discovered. When BCAAs were administered following a training session, sufficient phosphorylation of p70 S6 kinase and S6 indicated activation of the signaling cascade. Role in diabetes mellitus type 2 In addition to cell signaling, the mTOR pathway also plays a role in beta cell growth leading to insulin secretion. High glucose in the blood begins the process of the mTOR signaling pathway, in which leucine plays an indirect role. The combination of glucose, leucine, and other activators cause mTOR to start signaling for the proliferation of beta cells and the secretion of insulin. Higher concentrations of leucine cause hyperactivity in the mTOR pathway, and S6 kinase is activated leading to inhibition of insulin receptor substrate through serine phosphorylation. In the cell the increased activity of mTOR complex causes eventual inability of beta cells to release insulin and the inhibitory effect of S6 kinase leads to insulin resistance in the cells, contributing to development of type 2 diabetes. Metformin is able to activate AMP kinase which phosphorylates proteins involved in the mTOR pathway, as well as leads to the progression of mTOR complex from its inactive state to its active state. It is suggested that metformin acts as a competitive inhibitor to the amino acid leucine in the mTOR pathway. Effects of BCAA supplementation on exercise BCAAs have an insulin-like effect on glucose, causing a reduction in glucose levels. BCAAs that are ingested before exercise can be oxidized by skeletal muscle and used as energy during the exercise, reducing the need for the liver to increase levels of glycogenolysis. During anaerobic exercise the pyruvate molecules that result from glucose metabolism are converted to lactic acid, the buildup of which can lead to metabolic acidosis with pH levels as low as 6.4. High levels of lactic acid cause glucose metabolism to stop in order to reduce further reduction of pH. BCAA supplementation has been shown to decrease levels of lactic acid in the muscle, allowing glucose metabolism to continue. This results in reduced rates of glycogenolysis in the liver and consequently lower plasma levels of glucose. However, studies done regarding long term effects of BCAAs on glucose levels have shown that consistent supplementation of BCAAs do not have a notable effect on blood glucose levels outside of exercise. Recent studies have also shown that