How long does the phosphagen system supply energy for during exercise?

The phosphagen system, also known as the ATP-CP system, is the body’s primary source of energy during short bursts of intense physical activity. This system relies on stored adenosine triphosphate (ATP) and creatine phosphate (CP) for energy production. It is capable of supplying energy very quickly but is limited in duration.

When engaging in high-intensity activities, such as sprinting or heavy lifting, the phosphagen system can provide energy for approximately 8-10 seconds. This is due to the finite amount of ATP and CP available in muscle cells. After this time frame, the stores of these substances become depleted, and the body must rely on other energy systems (like anaerobic and aerobic metabolism) for sustained energy.

In contrast, the other options extend beyond the typical energy supply window of the phosphagen system. The duration of energy supplied by the phosphagen system is critical, as understanding this allows athletes and trainers to design effective training programs and manage workload during high-intensity efforts.