During prolonged physical activity, the body utilizes carbohydrates as a primary energy source. As glycogen stores deplete, the body continues to break down carbohydrates to maintain energy levels. This process supports endurance performance, especially in aerobic activities. Consuming carbohydrates during extended exercise can prolong stamina and enhance output. Once glycogen stores are low, the body shifts towards fat utilization, but this process is slower, making carbohydrates crucial for peak performance in endurance sports.