The regulation of glycolysis by allosteric activation or inhibition, or the phosphorylation/dephosphorylation of rate-limiting enzymes, is short- term—that is, they influence glucose consumption over periods of min- utes or hours. Superimposed on these moment-to-moment effects are slower, and often more profound, hormonal influences on the amount of enzyme protein synthesized. These effects can result in 10-fold to 20- fold increases in enzyme activity that typically occur over hours to days. Although the current focus is on glycolysis, reciprocal changes occur in the rate-limiting enzymes of gluconeogenesis, which are described in