HMB has been widely publicized and has been one of the more popular supplements for over a decade. HMB is a metabolite of the branch chained amino acid leucine. With claims like increased strength, muscle size, recovery and fat oxidation, it sounds too good to be true. In fact, a publisher of a very successful magazine referred to using HMB akin to using the anabolic steroid deca durabolin. Unfortunately, the claims made about HMB don’t seem to hold up in the research.

A study published in the Journal of Strength and Conditioning, performed a met-analysis of 9 studies. The analysis was comprised of 394 subjects between the ages of 21 and 25. Some of the subjects had training experience and some didn’t.

The major findings of this meta-analysis are that HMB supplementation results in a small, beneficial increase to overall strength in untrained lifters but has a negligible effect on trained lifters. Furthermore, in untrained lifters, HMB results in a small to possibly moderate increase in lower-body strength, but it has only a negligible effect on upper-body strength. In contrast, all strength outcomes are insignificant in trained lifters. In both trained and untrained lifters, the effect of HMB supplementation on body composition is negligible.

In my view HMB is a waste of money. The only gains made were small strength gains in untrained individuals? Why would any researchers analyzing a supplement, looking for strength or lean body mass gains, use untrained individuals? They are going to make gains, especially in the first few months, just by working out. I’m amazed at how so many studies are poorly performed and yet, are still published.

A training program in the form of progressive resistance exercise builds muscular size and strength. In order for a training routine to be productive, however, it must first provide the correct stimulus to induce an adaptive response. Second, a workout that stimulates and adaptive response must provide for recovery. Third, in order for recovery and subsequent size and strength increases to occur, nutrients, which are of limited supply in our bodies, must be provided. It is clear that the most important nutrient for recovery is protein. In particular, essential amino acids contained in complete protein sources; dairy, meats, and fish. It is well documented that essential amino acids consumed before, during, and after resistance training boost strength and size gains.

HMB is a metabolite of the essential amino acid L-leucine. During many studies on protein effects, L-leucine seemed to be the single greatest contributor to muscle protein synthesis. A recent study examined the effects of an essential amino acid based product, Muscle Armor (MA); manufactured by Abbott Laboratories contains beta-hydroxy beta-methylbutyrate (HMB).

Seventeen healthy men were randomly assigned to one of two groups and performed twelve weeks of periodized heavy resistance training while supplementing with either MA or an isocaloric, isonitrogenous placebo (Control group (CG)). Every two weeks the subject?s strength and power were measured and blood was drawn. More-over the blood draws taken were performed pre, mid and post-training. Researchers found the MA group affected training induced changes in muscular size and strength to a significantly greater extent than the CG. Also found, was reduced levels of circulating muscle damage markers creatine kinase and malondealdehyde compared with the CG. In addition, the MA group experienced increases in resting and exercise-induced testosterone and resting growth hormone levels with reduced pre-exercise cortisol levels.
(Medicine & Science in Sports & Exercise. 2009;41(5):1111-1121)