Question

Repaying the oxygen debt requires replacing oxygen that was ________.

1) consumed during exercise
2) produced during exercise
3) stored in the muscles
4) exhaled during exercise

Answer 1

Repaying the oxygen debt requires replacing oxygen that was **consumed during exercise**. During intense exercise, the body may rely on anaerobic metabolism, producing lactic acid and creating an oxygen debt. After exercise, the body needs to consume additional oxygen to convert accumulated lactic acid back into energy, ultimately repaying the oxygen debt.

Answer 2

Repaying the oxygen debt involves replacing the oxygen consumed during exercise to normalize the body's levels of ATP, creatine phosphate, and lactic acid.

Step-by-step explanation:

Repaying the oxygen debt requires replacing oxygen that was consumed during exercise. This concept refers to the amount of oxygen needed to restore the body to its pre-exercise state. During intense muscle activity, ATP is produced anaerobically, leading to an accumulation of lactic acid. Oxygen debt occurs because of the need to convert this lactic acid back to pyruvic acid and ultimately to glucose or glycogen, a process that requires oxygen. It is also necessary to replenish the ATP and creatine phosphate levels which were utilized during the exercise without the presence of oxygen.

An increase in breathing rate after physical activity is a clear indicator of the body working to repay the oxygen debt. This increased demand for oxygen continues until the levels of ATP, creatine phosphate, and lactic acid in the body are normalized to pre-exercise conditions.