Effect of pyruvate and dihydroxyacetone on metabolism and aerobic endurance capacity. Med. Sci. Sports Exerc., Vol. 30, No. 6, pp. 837-843, 1998. Pyruvate and dihydroxyacetone are three carbon compounds that when infused directly into the blood or taken orally produce strong metabolic effects. When chronically fed to animals as part of their diet, pyruvate plus dihydroxyacetone reduce the rate of weight gain and body fat content during growth. These alterations in growth pattern appear to be the result of an increased loss of calories as heat at the expense of storage of lipid. Pyruvate-dihydroxyacetone supplementation has also been found to improve the insulin sensitivity of insulin resistant rats and reduce plasma cholesterol levels induced by a high cholesterol diet as well as lower blood pressure and heart rate in obese individuals. When infused in rats during prolonged treadmill running, pyruvate reduced run time to exhaustion by approximately 67%. However, when provided as an oral supplement for several days, it has enhanced aerobic endurance capacity. The mechanism of action is unclear, but available data suggest that the increase in performance following pyruvate-dihydroxyacetone supplementation may be a result of an increased reliance on blood glucose, thus sparing muscle glycogen. In summary, chronic supplementation of pyruvate-dihydroxyacetone may be beneficial from a preventive medicine prospective as well as for certain athletic endeavors.