During extended exercise, the body primarily uses fats for energy as glycogen stores become depleted. While carbohydrates serve as the main energy source during high-intensity activities, fats become increasingly important in longer, lower-intensity exercise. Fat oxidation provides a more sustained energy supply, supporting endurance activities. Additionally, proper fat utilization is essential for long-distance athletes to maintain energy levels. Therefore, adapting nutrition, including healthy fat sources, is vital for maximizing endurance performance.