HMB (beta-hydroxy beta-methylbutyrate) is a natural compound made in the body from the branched chain amino acid leucine. HMB capsule can prevent the breakdown of body protein， so HMB is ideal for use by all athletes wanting to gain lean muscle size and strength, including bodybuilders, rugby players, sprinters and other strength athletes. HMB is also used widely by endurance athletes, such as runners, cyclists and tri-athletes, as it reduces muscle damage following long periods of exercise, and can speed up recovery between training sessions.