Glycogen is degraded by the sequential action of three enzymes:
Glycogen synthesis in the liver and muscle - Tuscany Diet
Addition of glucose-1-P to the 4' carbon of a glycogen chain is not favored thermodinamically, since the phosphate transfer potential of C-O-P bonds is quite low. Glucose-1-P will therefore be activated,i.e., transformed into a species with high phosphate transfer potential. accomplished by reaction with uridine triphosphate(UTP, an analog of ATP, with uridine replacing adenine).
Glycogen Synthesis and Metabolism
Glycogenin, which I mentioned previously, primes glycogen synthesis. The amount of glycogenin will influence how much glycogen a cell can store . Thus the production of active glycogenin primer in the cell has the potential to be the overall rate limiting process in glycogen formation. A company called markets glycogenin but not for human consumption. I don't believe that the FDA has approved synthetic glycogenin for human consumption. Another component of glycogen metabolism has been discovered which may even have greater influence on total glycogen stores than does glycogenin. This is the low molecular mass form of glycogen called proglycogen . If proglycogen could be converted into macroglycogen , muscle glycogen levels may increase significantly. I believe that this will be the next big step in glycogen resynthesis advancements.