Final answer:
Anaerobic respiration during intense exercise results in the production of lactic acid. This leads to the accumulation of an oxygen debt, which is the amount of oxygen needed to restore ATP levels and convert lactic acid to pyruvic acid and glucose or glycogen.
Step-by-step explanation:
Anaerobic exercise is intense exercise that breaks down glucose without using oxygen. The process of anaerobic respiration, called glycolysis, produces lactic acid as a byproduct. The buildup of lactic acid during anaerobic exercise contributes to the development of an oxygen debt, which is the amount of oxygen needed to restore ATP levels, convert lactic acid to pyruvic acid, and convert lactic acid into glucose or glycogen.