Glycogen is essential for athletic performance as it serves as the primary storage form of carbohydrates in the body. During physical activity, glycogen is converted into glucose, providing the necessary energy for muscle contraction and endurance. The availability of glycogen directly affects performance, particularly during intense or prolonged exercise. Adequate glycogen reserves can delay fatigue and enhance an athlete's capability, making it crucial to maintain a diet rich in complex carbohydrates prior to events to optimize performance.