Skeletal muscle glycogen stores yield about how many kilocalories?

• A. 800 kcal
• B. 1000 kcal
• C. 1560 kcal
• D. 2100 kcal

Answer: (C)

Skeletal muscle glycogen serves as the major readily available energy reserve for short, high-intensity activity. Carbohydrate provides about 4 kcal per gram, so the total energy stored in muscle glycogen equals the amount of glycogen in the muscles times 4. In a typical adult, skeletal muscle glycogen is roughly 350–450 g, with a common estimate near 400 g. That yields about 1,600 kcal of energy from muscle glycogen. So, an estimate around 1,560 kcal fits well with the usual figure for this storage pool. (Liver glycogen adds a smaller reserve, around 100 g or ~400 kcal, but it’s separate from the skeletal muscle store.)