And when that happens, eventually we're going to run out of oxygen. So when the rate of glycolysis is much higher than the rate of oxidative asphylation that takes place in the mitochondria of our cells, in that case, we're going to begin the process of lactic acid fermentation. And so these skeleton muscle cells produce lactic acid, which dissociates into H plus ions and lactate. And that's where we obtain the lactate from. Now, eventually, that lactate enters our blood plasma and makes its way into our liver cells. And the liver cells transform that lactate into pyruvate by the action of an enzyme we call lactate dehydrogenase.