What is HMB
by Cory Holly, DN
HMB is beta-hydroxy-beta-methylbutyrate, a water-soluble substance produced in the body from the essential amino acid leucine. Approximately three to five percent of the leucine we consume in dietary protein is converted into HMB, which equates to about 250-1000 mg per day. Leucine is metabolized and converted into alpha-ketoisocaproate (KIC) which is then oxidized and enzymatically converted into several metabolites, including HMB. This process occurs mainly in the liver and in skeletal muscle. HMB is a natural component of breast milk and is present in small quantities in both plant and animal foods.
What does HMB do
Based on clinical evidence, HMB improves protein metabolism and nitrogen balance in favor of growth by retarding tissue breakdown and encouraging the build-up of nuclei and proteins in muscle fibers. It strengthens the immune system by enhancing white blood cell formation, protects organs, glands and functional tissue from the wasting effects of oxidative stress, decreases fat stores, lowers total and LDL cholesterol, raises HDL cholesterol, increases lean mass and strength and improves endurance.
How does HMB work
HMB decreases urinary nitrogen excretion and acts as a muscle buffer during high-intensity exercise. One theory suggests that HMB may be converted into special membrane linkage molecules called polymers. These polymers bond to the cell membrane, where they influence nitrogen chemistry and the transport of calcium. HMB also facilitates the synthesis of cholesterol inside muscle cells, which occurs as an adaptive mechanism in response to resistance tort cycles. HMB is more effective when used in conjunction with training, L-carnitine, adequate protein ingestion and possibly, creatine monohydrate.
The world's leading expert on HMB, Dr. Steve Nissen, recommends spreading out your daily dose as much as possible throughout the day. A double dose two hours before exercise will help maximize muscle and strength gains by inhibiting protein breakdown. HMB can be taken on an empty stomach or with a meal. HMB is safe and of definite value to those who want to get leaner and stronger. It is also excellent for improving immune status and guarding tissue from damage caused by stress.