Final answer:
ATP is the primary fuel used during a five-second sprint, with muscle cells using stored ATP and creatine phosphate to replenish ATP rapidly.(option 4)
Step-by-step explanation:
The primary fuel for a five-second sprint is adenosine triphosphate (ATP), which acts as the energy currency for cellular activities.
While carbohydrates are the most common source of energy to fuel the body and are broken down into glucose for ATP production, during intense short bursts like a five-second sprint, muscle cells use their pre-existing ATP stores.
They also utilize creatine phosphate to quickly replenish ATP without needing oxygen, which is efficient for about 8-10 seconds.
This is essential for activities that require immediate energy, such as sprinting, before the body resorts to anaerobic glycolysis and breaks down glycogen into glucose, which then produces ATP. This process is slower and can supply energy to last about 90 seconds.