During the lactacid recovery stage, approximately how much oxygen is used?

• A. 5-10 L
• B. 1-2 L
• C. 0-1 L
• D. 20-30 L

Answer: (A)

During lactacid recovery, the body must use extra oxygen to oxidize the lactate that built up in muscles during intense, anaerobic effort. This lactate is transported to the liver and other tissues where it is converted back to pyruvate and fed into the Krebs cycle to regenerate ATP and restore pH balance. The amount of oxygen needed for this lactate oxidation is substantial but falls within a moderate range—about 5–10 liters for an average adult. This fits the idea that the total recovery oxygen debt is made up of a lactacid portion (requiring several liters) and a smaller alactacid portion that restores immediate energy stores. So, the best match is the 5–10 liters option, reflecting the typical oxygen used to clear lactate during recovery. Smaller amounts like 0–1 or 1–2 liters would be insufficient to oxidize the lactate accumulated, while a much larger figure like 20–30 liters exceeds typical recovery needs for a single bout of high-intensity work.