What are the disadvantages of anaerobic respiration?

One disadvantage is that it is much less efficient than aerobic respiration regarding ATP production. It produces much less energy from the same amount of substrate and only makes 2 ATP per glucose molecule. Another disadvantage is that it produces lactic acid as a byproduct. The excess lactic acid can lead to muscle cramps and a decrease in blood pH. This is because following heavy exercise, the muscles and the liver must convert the lactic acid back to pyruvic acid.