Final answer:
During prolonged exercise or starvation, increased gluconeogenesis and sustained fatty acid oxidation are the most likely occurrences.
Step-by-step explanation:
During prolonged exercise or starvation, the most likely occurrence is increased gluconeogenesis. Gluconeogenesis is the process by which the body produces glucose from non-carbohydrate sources, such as amino acids and glycerol. As the body needs more glucose for energy, it will convert proteins and fats into glucose through gluconeogenesis.
Furthermore, sustained fatty acid oxidation is also likely to occur during prolonged exercise or starvation. Fatty acid oxidation is the process of breaking down fatty acids into acetyl CoA, which can then enter the Krebs cycle to produce ATP.
The activation of the pentose phosphate shunt and the occurrence of the Cori cycle are not typically associated with prolonged exercise or starvation.