Aging induces whole-body aerobic glycolysis. In humans, several independent physiologic studies have shown that oxygen consumption steadily declines with aging (red line), shifting the entire body toward glycolytic metabolism, even in the presence of oxygen. As a consequence, aging and mortality are associated with aerobic glycolysis, while longevity and immortality would be associated with oxidative mitochondrial metabolism. Thus, the successful maintenance of mitochondrial “health” may be a key determinant of the life and the death of an organism.