Glycogen is large, branching carbohydrates constructed of glucose molecules. It is found within the muscles and the liver. It is the primary energy source during prolonged exercise.
During long-time activity, muscle glycogen is broken down to glucose to continue producing ATP. When glycogen is depleted, it leads to bonking or hitting the wall. Athletes maximize glycogen stores by loading carbohydrates prior to big events and maintain the stores during activity with gels, beverages, or bars. Proper management of glycogen—through a balance of what you consume and the intensity of training—is crucial for optimal endurance performance and putting off fatigue.
