During a 25-second maximal sprint, which energy system predominates and why?

During a 25-second maximal sprint, which energy system predominates and why?

• A. Glycolytic (anaerobic glycolysis) system; phosphagen stores are depleted within roughly 10 seconds, so glycolysis provides the majority of ATP.
• B. Phosphagen (ATP-PCr) system; stores are sufficient for the entire 25 seconds.
• C. Oxidative (aerobic) system; oxygen supply supports high-intensity sprint.
• D. Aerobic glycolysis; lactate is cleared quickly to maintain power.

Answer: (A)

During a 25-second maximal sprint, the body uses primarily anaerobic glycolysis because the phosphagen stores (ATP-PCr) are limited and can power maximal effort for only about 10 seconds. Once those stores are depleted, glycolysis provides the majority of ATP to sustain the high power needed for the remainder of the sprint. The oxidative (aerobic) system can contribute, but its rate of ATP production is too slow to maintain peak sprint speed at that intensity. Lactate production increases as glycolysis proceeds, reflecting the dominant energy source rather than rapid clearance. So, glycolysis supplies the bulk of the energy for a 25-second maximal sprint.

During a 25-second maximal sprint, the body uses primarily anaerobic glycolysis because the phosphagen stores (ATP-PCr) are limited and can power maximal effort for only about 10 seconds. Once those stores are depleted, glycolysis provides the majority of ATP to sustain the high power needed for the remainder of the sprint. The oxidative (aerobic) system can contribute, but its rate of ATP production is too slow to maintain peak sprint speed at that intensity. Lactate production increases as glycolysis proceeds, reflecting the dominant energy source rather than rapid clearance. So, glycolysis supplies the bulk of the energy for a 25-second maximal sprint.