What is the predominant energy system utilized by a structural firefighter performing a forcible entry?

The ATP-PCr energy system, also known as the phosphagen system, is primarily utilized during activities that require short bursts of intense effort, typically lasting from 0 to about 10 seconds. Structural firefighting often involves high-intensity tasks, such as forcible entry, which require quick, powerful movements to break through barriers.

During these short-duration, high-intensity efforts, the body relies on stored adenosine triphosphate (ATP) and phosphocreatine (PCr) to rapidly regenerate ATP, allowing the firefighter to exert maximal force with minimal delay. This system is vital in scenarios where immediate strength and power are crucial, as seen when a firefighter needs to quickly break down a door or perform other demanding tasks.

While other energy systems like the glycolytic system or the aerobic system play a role during longer or sustained efforts, they are not predominant in the initial phase of rapidly executed, high-intensity actions typical during firefighting tasks. Thus, the ATP-PCr system is the most critical energy source for these quick, explosive efforts.