Muscle Pump supplements are designed to promote the release of nitric oxide at a steady and constant rate throughout the day. Nitric oxide (NO) is a hormonal gas produced endogenously by a variety of mammalian cells. Its effect is most greatly seen in vascular tissues, where it causes the vasodilatation, or expanding, of the blood vessels. The increased blood flow to the muscle cells results in an overall greater amino acid and glucose uptake, enhanced muscle recovery, protein synthesis and overall muscle pump and fullness. (Fuller muscles).