Definition
Glycogen is the body's quick access carbohydrate store — about 400g in muscle, 100g in the liver. Hard resistance training depletes it locally in the trained muscle. Replenishing glycogen between workouts (via carbs) is what makes the next session feel strong and the muscle look full.
Real questions
Do I need carbs to build muscle?
Not strictly, but training intensity drops on very low-carb diets. Keep at least 1–1.5g/lb of carbs to fuel hard lifting.
Stack with
Put it to work
Coach Foster builds your program around glycogen and the rest of the fundamentals, shaped to your body and your week.