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

The primary energy system utilized during high-intensity, short-duration activities such as sprinting is the phosphagen (ATP-PC) system. This system is responsible for providing immediate energy through the breakdown of stored ATP and phosphocreatine in the muscles.

During activities that last from about 0 to 10 seconds, like a sprint, the demand for energy is very high, and the body relies on this fast-acting system because it can regenerate ATP quickly without the need for oxygen. The phosphagen system allows for explosive movements, as it kicks in almost instantaneously and supports activities that require rapid bursts of energy.

In contrast, other energy systems are not as efficient for such brief, intense efforts. The oxidative system primarily supports endurance activities and takes longer to activate, making it unsuitable for short, high-intensity efforts. Aerobic metabolism also involves oxygen and is more suited for longer-duration, lower-intensity activities. While the lactic acid system does contribute to energy production for performances lasting slightly longer than what the phosphagen system can support, it does so at a slower rate and is more closely associated with moderate activities that exceed about 10 seconds.