How long can resting muscles store enough ATP to perform work without oxygen?

Resting muscles can store enough adenosine triphosphate (ATP) to perform work for a very short duration, typically about 2 to 4 seconds. This immediate ATP supply is essential for rapid, high-intensity activities where quick bursts of energy are necessary, such as sprinting or lifting heavy weights.

During this brief period, the energy stored in ATP is utilized almost instantly, as it is easily accessible for muscle contractions. Once this small reserve of ATP is depleted, muscles must rely on other energy systems, such as creatine phosphate breakdown and anaerobic glycolysis, to generate ATP for sustained activity. These processes, however, take a little longer to ramp up and can sustain muscle activity for longer durations but not as rapidly as the readily available ATP.

The other choices indicate longer timeframes than resting muscles can actually store usable ATP without oxygen, highlighting the need for energy systems to transition after this initial period of work has been performed.