Question

Answer the following in detail: During exercise (and also starvation), what energy substrate or fuel mobilisation processes are carried out in the body to sustain plasma glucose levels? Include in your answer any hormones that would facilitate these processes.       

Answer 1

Blood glucose levels are tightly regulated by several hormones.
During the starvation of exercise, blood glucose levels are reduced.
Glucagon is a peptide hormone secreted by the alpha-cells of the pancreas. It is a catabolic hormone. It promotes gluconeogenesis and glycogenolysis.
Gluconeogenesis = Synthesis of glucose from non-carbohydrate sources
Glycogenolysis = Breakdown of glycogen to release glucose

Epinephrine is a steroid hormone secreted by adrenal glands. It also stimulates glycogenolysis in the liver.

Once glycogen reserves are deprived, the lipid reserves are mobilized (Lipolysis).
Once lipid reserves are also deprived due to extended starvation, proteins also enter the catabolic pathways to provide energy (Muscle degradation).