Which energy system is most associated with very short, explosive efforts like a sprint in the 100-meter dash?

• A. Aerobic respiration.
• B. Creatine phosphate system.
• C. Anaerobic glycolysis.
• D. Oxidative phosphorylation.

Answer: (B)

The energy system powering very short, explosive efforts relies on the phosphagen (creatine phosphate) system. Muscles store creatine phosphate that donates a phosphate to ADP to quickly regenerate ATP, fueling maximal contractions in a matter of seconds. This system operates without oxygen, so it’s ideal for immediate, high-intensity bursts and has a very rapid, but limited, energy supply—roughly enough to sustain near-max effort for about 8–12 seconds. In a 100-meter dash, the initial part of the race is dominated by this rapid ATP production, with some contribution from anaerobic glycolysis as the sprint continues and fatigue begins to set in. In contrast, aerobic pathways (oxidative phosphorylation) are slower and support longer, endurance-type efforts, not short, explosive bursts.