HMB is a category of products containing this substance, also known as β-hydroxy-β-methylbutyrate. It is an active metabolite of the amino acid leucine, which, together with valine and isoleucine, belongs to BCAAs. HMB is sought after by athletes in order to reduce the time required for regeneration. This effect is attributed to it because it appears to have a positive effect on reducing the myofibrillar damage caused by power training. It also boasts anti-catabolic effect and belongs to the basic workout supplements.