What is the primary energy system used during short-duration, high-intensity activities such as sprinting?

The ATP-PCr system is the primary energy system utilized during short-duration, high-intensity activities like sprinting. This system generates energy very quickly and efficiently by using stored adenosine triphosphate (ATP) and phosphocreatine (PCr) in the muscles.

During activities that last around 0 to 10 seconds, such as a 100-meter sprint, the ATP-PCr system can provide the necessary energy almost instantaneously. ATP is readily available in muscle cells, but its storage is limited; however, the system can regenerate ATP from creatine phosphate, allowing for sustained high-power output for a brief period.

While other energy systems, such as the glycolytic system, do contribute to energy production in longer-duration, high-intensity efforts, they require more time to kick in and become the primary source of energy as the exercise duration extends beyond 10 seconds. The oxidative system, on the other hand, primarily supports longer-duration, lower-intensity activities, and fatty acid oxidation is utilized during prolonged, steady-state aerobic exercises. Therefore, the ATP-PCr system is best suited for the intense, quick surges of energy needed during activities like sprinting.