Where in the body is glycogen primarily stored?

Glycogen is primarily stored in the liver and muscle tissues due to the specific roles these organs play in glucose metabolism and energy storage. In the liver, glycogen serves as a readily available source of glucose that can be released into the bloodstream to maintain blood sugar levels, particularly during periods of fasting or increased energy demands. Muscle tissue, on the other hand, stores glycogen to fuel its own energy needs during physical activity. This localized storage allows muscles to efficiently access glucose for rapid energy production, especially during exercise.

The liver has a higher capacity for glycogen storage compared to other tissues, and it can mobilize this stored glycogen to maintain blood glucose levels for the entire body. Muscle glycogen is utilized primarily by the muscles themselves and is critical for exercise and physical performance. Hence, the combination of these two tissue types makes them the primary sites for glycogen storage in the body.