I don't understand anaerobic respiration and what an 'oxygen debt' is?

Respiration can be broken down into 'aerobic' and 'anaerobic' respiration. Aerobic respiration needs oxygen to be carried out, whereas anaerobic respiration takes place without oxygen. Glucose is broken down into lactic acid, which builds up in muscles and causes the 'cramping' feeling you get if you exercise intensely. Oxygen is needed to break down this lactic acid into carbon dioxide and water. This is known as the 'oxygen debt' and explains why you breathe more deeply after vigorous exercise. This is the equation for anaerobic respiration in muscle cells:glucose → lactic acidC₆H₁₂O₆ → 2C₃H₆O₃ It's important to remember that anaerobic respiration releases a lot less energy than aerobic respiration. Anaerobic respiration also occurs in yeast - producing the carbon dioxide that helps bread rise.