Muscle glycogen storage is crucial for athletes, particularly in endurance sports. Glycogen is the stored form of carbohydrates in muscles and the liver, serving as a key energy source during prolonged exercise. Adequate glycogen levels help maintain performance and delay fatigue, allowing athletes to sustain energy output. Conversely, depleted glycogen stores can lead to diminished endurance and increased fatigue. By managing carbohydrate intake effectively, endurance athletes can optimize their glycogen stores for improved performance during competitions.