What is the role of muscle glycogen during high-intensity exercise?

Muscle glycogen plays a crucial role during high-intensity exercise as it serves as a key energy source for sustained efforts. When engaging in activities that require significant power output, such as sprinting or heavy lifting, the body relies heavily on glycogen stored in the muscles. Glycogen is a form of carbohydrate that can be rapidly mobilized to provide glucose during periods of high energy demand, ensuring that muscle contraction can continue effectively.

In high-intensity settings, the rate at which glycogen can be broken down and converted into glucose is much faster compared to using fat as a fuel source. While fat is utilized during lower-intensity activities, it cannot supply energy quickly enough for the immediate and intense energy demands of high-intensity exercise. Therefore, muscle glycogen becomes the preferred and essential fuel source, allowing for optimal performance in these high-energy activities.