For a maximal effort shot put, which energy system provides energy primarily?

• A. Stored ATP
• B. ATP-PC system (phosphocreatine)
• C. Aerobic oxidative system
• D. Lactic acid system

Answer: (B)

Explosive, maximal efforts like a shot put throw demand energy very quickly and without relying on oxygen. The ATP-PC system delivers this by using stores of ATP and phosphocreatine inside the muscle to rapidly regenerate ATP as it’s used. This lets the muscle produce a high power output for a brief burst—roughly up to about 10 seconds. Stored ATP alone would run out even faster, and the aerobic system is too slow to meet the immediate energy need, while the lactic acid system would become more involved only if the effort lasted longer. So the dominant energy source for a maximal effort shot put is the ATP-PC (phosphocreatine) system.