Which two fuel sources are used primarily for high intensity short duration activities?

The two primary fuel sources used for high-intensity, short-duration activities are carbohydrates and phosphocreatine. Carbohydrates are quickly broken down into glucose, providing rapid energy through anaerobic glycolysis, while phosphocreatine serves as a readily available energy reservoir for immediate ATP production during short bursts of intense effort, such as sprinting or heavy lifting. Together, these fuel sources enable optimal performance in activities requiring quick, explosive energy.