Well, because as lactic acid takes place, or as lactic acid fermentation takes place, it produces lactic acid. And the lactic acid basically dissociates into H plus ions and lactate ions. And what that means is those H plus ions, as they build up, they will increase the acidity of that environment found within and outside of these cells. And that will basically or that can cause damage and harm to the cells of our body. And so what happens is the buildup of the H plus ions essentially inhibits the activity of the third enzyme, phosphor Fructacion age, which essentially catalyzes the most important step, the commitment step of glycolysis. And if this enzyme is inhibited, that causes the inhibition of hexokinase and that essentially causes the process of glycolysis to stop.