HMB, or β-hydroxy-β-methylbutyrate, occurs naturally in the body during the metabolism of the amino acid Leucine. Its main function resides in the synthesis of proteins, thereby causing an increase in strength, a reduction in muscle breakdown, and a shortening of recovery times.
Another of the virtues of HMB is the reduction of recovery times between workouts, helping to reduce muscle damage. The use of HMB in people who maintain a fitness lifestyle and exercise regularly are summarized in the anabolic and anti-catabolic effects.
HMB increases protein synthesis, decreasing its breakdown. This combined anti-catabolic (breakdown of anti-muscle protein) and anabolic (build-up of muscle protein) impact means more efficient lean mass development and increased power. According to some studies conducted on the performance of supplemented and unsupplemented athletes, a marked improvement in strength and endurance was noted in those supplemented with HMB.