Those familiar with the supplement industry are aware that most supplements are grouped into general categories, according to their supposed effects.  A few of the most popular groups are supplements intended to increase lean mass, those intended to decrease body fat, and those to increase strength.  And while many supplements concern themselves with one or maybe two of these categories, a multi-purpose supplement that targeted all three would be ideal.  According to recent research, that supplement might be HMB.

You're probably wondering - what is HMB?  Good question.  HMB stands for beta-hydroxy-beta-methylbutyrate, which is a metabolite of leucine, an essential amino acid.  While it does naturally occur in certain foods, including alfalfa and catfish, some have surmised that supplementing HMB might be beneficial (1).

The first study investigating the effects of HMB on body composition and strength in conjunction with exercise was conducted in 2000.  While the study only lasted four weeks, the benefits of HMB were clear.  Groups receiving HMB supplementation experienced two times the reduction in body fat that the placebo group experienced.   The HMB group also experienced greater lean mass gains and strength.  The researchers concluded that "regardless of gender or training status, HMB may increase upper body strength and minimize muscle damage when combined with an exercise program" (2).

A study published this month in the Journal of Strength and Conditioning Research took the prior research a step further, investigating HMB's effects throughout a nine-week exercise program.  The researchers noted that earlier research had not considered the effects on "resistance-trained" individuals, which may have accounted for the impressive results in past studies.  To counter this, the study participants were required to have at least one year of weight training experience.  The average level of experience was 3.9 years, suggesting that any growth from the study would be a direct result of the HMB, rather than so-called "noob gains" (3).

The findings of the study in regard to strength gains were curious; while one-repetition maximum in the leg extension increased by 9.1 percent on average, its effect on upper body strength was negligible.  The researchers did note, though that it was "possible that the 9-week study period was not long enough to establish the effect of HMB on gains in strength" (3)

The HMB supplementation seemed to have a greater effect in regard to body composition, though, as the HMB group members experienced a mean decrease in body fat percentage of 7 percent, while the placebo group only had a 1 percent decrease.  Additionally, the HMB group experienced greater gains in lean body mass than the placebo group (3).

So is HMB the ultimate supplement?  Not quite.  While it did boost strength it some lifts, it generated only negligible differences in others.  But it also had a positive effect on lean mass and body composition, so it may still be worth a look.  The researchers also noted that HMB seemed to be "more efficacious to individuals initiating resistance training programs and, possibly, also in less well-trained muscle groups," so more experienced lifters may not see the same benefits (3).


SOURCES:

1. HMB Supplement Review - BodyBuilding For You: http://www.bodybuildingforyou.com/supplements-reviews/hmb-supplement-review.htm

2. Panton, Lynn B., et al. Nutritional supplementation of the leucine metabolite β-hydroxy-β-methylbutyrate (hmb) during resistance training.  Nutrition, 2000; 16(9): 734-739

3. Thomson, Jasmine S., Waston, Patricia E., and Rowlands, David S. Effects of Nine Weeks of β-hydroxy-β-methylbutyrate Supplementation on Strength and Body Composition in Resistance Trained Men.  The Journal of Strength and Conditioning Research, 2009; 23(3): 827-835