During anaerobic training, the body works without oxygen.

• A. It uses oxygen constantly
• B. It uses oxygen during rest
• C. It works without oxygen
• D. It uses oxygen briefly after training

Answer: (C)

During very high‑intensity, short bursts, the body relies on energy systems that don’t need oxygen to produce energy. Right at the start, ATP is supplied from the phosphocreatine system for immediate power, and for slightly longer efforts energy is generated through anaerobic glycolysis, which operates without oxygen and often produces lactate. Oxygen becomes important only after the effort, when the body repays the oxygen debt during recovery. So, the statement that describes working without oxygen matches what happens in anaerobic training. The other ideas imply oxygen is used during the effort or only during recovery, which isn’t the main process during those intense bursts.