During physical activity, the body primarily utilizes adenosine triphosphate (ATP) for energy. ATP is produced through three main pathways: the phosphagen system, glycolysis, and aerobic metabolism. The choice of energy pathway depends on the duration and intensity of the activity. For shorter, high-intensity efforts, the phosphagen system is dominant, while for prolonged lower-intensity exercises, aerobic metabolism becomes more prominent. Additionally, the body utilizes stored glycogen and fat for energy, particularly as exercise duration increases. Effective fueling strategies before, during, and after exercise can significantly enhance performance and recovery.