Oxygen is the most critical nutrient needed by the human body. It is the only nutrient that we cannot be without for more than just a few minutes-not water, not food, not vitamins-only oxygen. Oxygen is required in our mitochondria to oxidize our fuels (foods like sugars, fats and proteins) to create the all-important ATP. ATP or adenosine triphosphate is the high-energy molecule that powers essentially all the processes in the body requiring energy. Almost all chronic illness is associated with an inability of the mitochondria to utilize oxygen normally also called mitochondrial dysfunction. This explains why chronic illness is so often associated with fatigue, exercise intolerance and inability to lose weight.