Well, what will happen is the cells will basically experience Hypoxia. And Hypoxia is defined as the state of our cells in which we don't have enough oxygen to actually go around all the cells. And so we have oxygen deficiency. Now, if the cells don't have enough oxygen, they basically cannot regenerate those energy plus molecules in the citric acid cycle. And that's why they switch to an anaerobic cycle we call lactic acid fermentation. And lactic acid fermentation is actually able to produce those NAD plus molecules.