Functions of Glucagon and Adrenaline During Fasting and Exercise
Glucagon: The Energy Mobilizer
Glucagon is a hormone that plays a crucial role in maintaining blood glucose levels when we're fasting or exercising. Think of it as insulin's opposite - while insulin stores energy, glucagon releases it.
During Fasting
- Stimulates breakdown of glycogen (glycogenolysis) in the liver
- Promotes gluconeogenesis (creation of new glucose from non-carbohydrate sources)
- Increases fat breakdown (lipolysis) to provide alternative energy sources
Note
Glucagon levels typically rise after about 4-6 hours without food, helping maintain stable blood glucose levels.
During Exercise
- Helps maintain blood glucose levels as muscles use up available glucose
- Increases glycogen breakdown to provide more glucose for working muscles
- Enhances fat utilization for energy conservation
Adrenaline: The Fight-or-Flight Hormone
Adrenaline (epinephrine) is our body's emergency response hormone, but it's also crucial during exercise.
During Fasting
- Promotes breakdown of glycogen stores
- Increases lipolysis (fat breakdown)
- Works synergistically with glucagon to maintain blood glucose
During Exercise
- Increases heart rate and blood flow to muscles
- Enhances glycogen breakdown in muscles and liver
