Understanding the body's energy systems aids in training by allowing athletes to tailor their workouts to specific performance goals. The body utilizes different energy systems—such as ATP-CP, glycolytic, and aerobic—depending on the duration and intensity of exercise. By recognizing which system is predominantly used in various activities, athletes can structure their training to target those systems effectively, optimizing performance. This knowledge also helps with recovery and nutrition, ensuring athletes fuel their bodies appropriately for each type of training session and improve overall outcomes.