Carbohydrate loading benefits endurance athletes by optimizing glycogen stores prior to prolonged exercise events. By increasing carbohydrate intake a few days before an event, athletes can augment their muscle and liver glycogen levels, enhancing their ability to sustain high-intensity performance. This strategy improves endurance and delays the onset of fatigue. It is particularly effective in competitive sports like marathons and long-distance cycling, where sustained energy levels are critical for achieving peak performance.