metabolism
Glycogen
The body's storage form of carbohydrate, held in the liver and muscles — the primary fuel for high-intensity exercise.
Glycogen is stored glucose. Muscle glycogen (~300–500 g) fuels the muscle it's in; liver glycogen (~80–100 g) maintains blood glucose between meals. Each gram of glycogen holds ~3 g of water, which is why low-carb diets produce a rapid initial "weight" loss — it's glycogen depletion, not fat loss.