coordination is essential. Sprinting 100 meters requires not only good technique, but a high anaerobic power output. In distance running, cycling, or swimming, a high capacity for aerobic production of ATP is essential for success. Again, laboratory evaluation of performance requires an understanding of those factors that are important for optimal performance in a particular athletic event. Thus, a test that stresses the same energy production system required by a particular sport or athletic event is required to provide a valid assessment of physical performance.