Now, that's not exactly true, and we'll talk more about that in just a moment, but basically, gluconeogenesis is actually the process by which we take the pyruvate and turn it back into glucose. Now, what about lactate? Well, we know if we're exercising vigorously, our skeleton muscles will begin to produce ATP to actually contract our skeletal muscle. 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.