Anerobic glycolysis is the transformation of glucose to lactate when limited amounts of oxygen (O2) are available. This is only an effective means of energy during short, intense exercise, providing energy for 30 seconds to 2 minutes. It replenishes very quickly over this period and produces 2 ATP per glucose for about 5% of glucose's energy potential(38 ATP molecules). The speed at which ATP is produced is about 100 times that of oxidative phosphorylation. Lactate being acidic, the pH quickly drops when it accumulates in the muscle eventually inhibiting enzymes involved in glycolysis. It is the liver that gets rid of this excess lactate by transforming it back into an important glycolysis intermediate called pyruvate.See aerobic glycolysis for longer, low intensity energy.