Coenzymes are substances that facilitate the activities of enzymes. Evidence shows that Coenzyme Q-10 plays a very important role in the production of energy throughout the body. It also has been found to have powerful antioxidant effects, destroying free radicals in the body. Improved energy production is of particular importance to athletes and bodybuilders. Coenzyme Q-10 helps the body convert food into energy in the form of ATP. Nearly every cell in the body contains at least some Coenzyme Q-10, with mitochondria, the energy powerhouses of cells, containing the most. The heart and liver, due to their high content of mitochondria, contain the most Coenzyme Q-10.