Describe how an oxygen debt may develope

accumulation of lactic acid in the muscles

Explanation:

The accumulation of lactic acid in the muscles would cause oxygen debt. Oxygen debt is the extra amount of oxygen required to get rid of the lactic acid that accumulates due to less supply of oxygen. The oxygen debt that occurs is paid back by the person breathing more quickly and more deeply in order to increase supply of oxygen. The rate of heart beat increases so as to transport oxygen faster to the muscle cells and lactic acid from the muscle to the liver.