Which of the following exercises primarily uses the ATP-PC system in the process of energy production?
Correct Answer: A
The ATP-PC (adenosine triphosphate-phosphocreatine) system is the body's fastest method for regenerating ATP and is dominant during high-intensity, short-duration activities lasting about 10-15 seconds. NASM's bioenergetics section notes: "Example exercises that predominately use the ATP-PC system include short sprints, Olympic weightlifting, jumping, and plyometrics." Sprinting fits perfectly because it requires maximum muscular power output in a short time frame. Aerobics, circuit training, and marathons rely much more heavily on glycolytic or oxidative energy systems due to their longer duration and lower relative intensity. Thus, sprinting is the exercise in this list that predominantly uses the ATP-PC system.