Which type of fatigue is closely associated with muscle glycogen depletion during exercise?

The association of muscle glycogen depletion during exercise with a specific type of fatigue is best captured by peripheral fatigue. Peripheral fatigue primarily refers to fatigue that occurs at the level of the muscles themselves, impacting their ability to contract effectively. When engaging in prolonged or strenuous physical activity, especially at a high intensity, muscle glycogen stores become depleted. Glycogen serves as a key energy source during exercise, and as these stores diminish, the muscle cells are less capable of maintaining optimal performance and generating force.

Research has shown that as muscle glycogen levels drop, there is a corresponding decrease in exercise capacity, which is indicative of peripheral fatigue. This type of fatigue arises primarily from changes within the muscle, such as the accumulation of metabolic byproducts, changes in ion concentrations, and, importantly, depletion of energy substrates like glycogen.

In contrast, central fatigue involves the brain and central nervous system's ability to generate signals to the working muscles and is influenced by factors such as mental fatigue and motivation. Muscle fatigue can be a broader term that encompasses aspects of both central and peripheral fatigue, but given the specific context of glycogen depletion, peripheral fatigue is the most accurate choice. Chronic fatigue typically refers to long-term fatigue that does not improve with rest and is not