During the fast replenishment stage, approximately how many litres of oxygen are consumed?

During the fast replenishment stage, approximately how many litres of oxygen are consumed?

• A. 1 litre
• B. 2 litres
• C. 3 litres
• D. 4 litres

Answer: (C)

After intense work, oxygen uptake remains elevated to repay the oxygen debt. The fast replenishment stage is the quick, initial portion of recovery focused on rebuilding phosphocreatine stores and resynthesizing ATP, along with restoring muscle oxygen stores (myoglobin). This rapid oxygen use happens in the first short period after exercise and amounts to roughly three litres of O2. The slow phase then handles lactate clearance and other repair processes over a longer time. So, three litres is the best approximate value.

After intense work, oxygen uptake remains elevated to repay the oxygen debt. The fast replenishment stage is the quick, initial portion of recovery focused on rebuilding phosphocreatine stores and resynthesizing ATP, along with restoring muscle oxygen stores (myoglobin). This rapid oxygen use happens in the first short period after exercise and amounts to roughly three litres of O2. The slow phase then handles lactate clearance and other repair processes over a longer time. So, three litres is the best approximate value.