Chocolat Milk's and Endurance Exercise Recovery
Chocolate milk – the new post-exercise recovery drink of champions!
The process of glycogen synthesis is called glycogenesis (Figure 1 Panel A) and glycogen degradation is called glycogenolysis (Figure 1 Panel B).
Glycogenesis is the process by which the body stores excess glucose that is not required for ATP production through the production of branched glycogen. When we consume chocolate milk, we are in part consuming glucose, and glycogenesis may consequentially occur. Initially, glucose is phosphorylated by ATP to produce glucose-6-phosphate (G6P). This G6P molecule is then converted to glucose-1-phosphate (G1P) by phosphoglucomutase. Then, G1P is added to UTP by UDP-glucose pyrophosphorylase which is the carrier for G1P. UDP-glucosyltransferase adds the 1st glucose unit to glycogenin which autocatalyzes further glucose units to create a sort of “primer” (of about 8 glucose residues) that is used for the following steps. Glycogen synthase elongates the glycogen chain using the aforementioned primer and then finally, branching occurs.
Glycogenolysis is the removal of glucose residues from the non-reducing ends of glycogen. Three enzymes associate with a glycogen molecule and work in tandem for glycogenolysis. First, glycogen phosphorylase phosphorolyzes alpha (1, 4) linkages, which causes the release of G1P from one of the glycogen branches. The remaining three glucose units are transferred to form a longer chain by glucotransferase which also hydrolyzes the alpha (1, 6) link to produce free glucose. Finally, phosphoglucomutase converts the free G1P to G6P. Free glucose and G6P can enter glycolysis in both the liver and muscle cells but in liver cells, free glucose can be transported into the bloodstream. Glucose-6-phosphotase, an enzyme not found in muscle cells, is needed to hydrolyze G6P into free glucose for transportation in the bloodstream.
In the context of this report, after we
The process of glycogen synthesis is called glycogenesis (Figure 1 Panel A) and glycogen degradation is called glycogenolysis (Figure 1 Panel B).
Glycogenesis is the process by which the body stores excess glucose that is not required for ATP production through the production of branched glycogen. When we consume chocolate milk, we are in part consuming glucose, and glycogenesis may consequentially occur. Initially, glucose is phosphorylated by ATP to produce glucose-6-phosphate (G6P). This G6P molecule is then converted to glucose-1-phosphate (G1P) by phosphoglucomutase. Then, G1P is added to UTP by UDP-glucose pyrophosphorylase which is the carrier for G1P. UDP-glucosyltransferase adds the 1st glucose unit to glycogenin which autocatalyzes further glucose units to create a sort of “primer” (of about 8 glucose residues) that is used for the following steps. Glycogen synthase elongates the glycogen chain using the aforementioned primer and then finally, branching occurs.
Glycogenolysis is the removal of glucose residues from the non-reducing ends of glycogen. Three enzymes associate with a glycogen molecule and work in tandem for glycogenolysis. First, glycogen phosphorylase phosphorolyzes alpha (1, 4) linkages, which causes the release of G1P from one of the glycogen branches. The remaining three glucose units are transferred to form a longer chain by glucotransferase which also hydrolyzes the alpha (1, 6) link to produce free glucose. Finally, phosphoglucomutase converts the free G1P to G6P. Free glucose and G6P can enter glycolysis in both the liver and muscle cells but in liver cells, free glucose can be transported into the bloodstream. Glucose-6-phosphotase, an enzyme not found in muscle cells, is needed to hydrolyze G6P into free glucose for transportation in the bloodstream.
In the context of this report, after we
References: (1) Burke, L.M., Kiens, B. and Ivy, J.L. (2004) Carbohydrates and fat for training and recovery. J.Sports Sci. 22, 15-30 (2) Karfonta, K., Lunn, W., Colletto, M., Anderson, J. and Rodriguez, N. (2010) Chocolate Milk And Glycogen Replenishment After Endurance Exercise In Moderately Trained Males: 862: June 4 9: 45 AM-10: 00 AM.Medicine & Science in Sports & Exercise. 42, 86 (3) Lunn, W.R., Pasiakos, S.M., Colletto, M.R., Karfonta, K.E., Carbone, J.W., Anderson, J.M. and Rodriguez, N.R. (2012) Chocolate milk and endurance exercise recovery: protein balance, glycogen, and performance.Med.Sci.Sports Exerc. 44, 682-691 (4) Parkin, J., Carey, M.F., Martin, I., Stojanovska, L. and Febbraio, M.A. (1997) Muscle glycogen storage following prolonged exercise: effect of timing of ingestion of high glycemic index food. Med.Sci.Sports Exerc. 29,220-224 (5) Saunders, M.J. (2011) Carbohydrate-protein intake and recovery from endurance exercise: is chocolate milk the answer? Current sports medicine reports. 10, 203-210