How is glycogen primarily stored in the body?

Glycogen is primarily stored in the body in the liver and muscle tissues. This storage is crucial for maintaining energy levels during physical activity and ensuring a stable blood glucose level.

In the liver, glycogen serves as a reserve of glucose that can be released into the bloodstream when blood glucose levels drop, thereby playing a vital role in glucose homeostasis. The liver can store approximately 100 grams of glycogen, which can be mobilized rapidly to meet energy demands, especially in times of fasting or intense exercise.

Muscle glycogen, on the other hand, is primarily used as a direct energy source for muscle contractions during exercise. Muscle cells store about 400 grams of glycogen, and this stored glycogen can be broken down into glucose for use by the muscles without affecting blood glucose levels directly.

This dual storage mechanism allows the body to effectively manage energy demands during various states of activity while also ensuring enough glucose is available for other critical functions throughout the body.