Can HMB Help You Get Big AND Lose Fat?

It’s the holy grail of bodybuilding: gaining muscle and losing fat at the same time. That ideal drives us to try all sorts of training routines and eating methods, and it entices us to search bodybuilding websites to buy any supplement which shows even the hint of delivering on that dual promise. Could HMB be one of those “magical” compounds?

HMB, or  beta-hydroxy-beta-methylbutyrate, first came on the scene in the mid-1990s backed by claims that it could help with all of your fitness goals, including muscle growth and fat loss.

While it never gained the popularity of creatine, HMB is still on the market, and it just might be right for you. Will it help you build muscle AND lose fat?

What the Research Says

Scientists became interested in HMB early on because they recognized it as a metabolite of the branched-chain amino acid (BCAA) leucine. Leucine has been shown to increase muscle-synthesis and reduce proteolysis, or muscle breakdown. To gain a benefit on the proteolysis side of the ledger, though, much more leucine is required than the amount needed for enhanced protein synthesis.

That led to speculation that it was a byproduct of leucine metabolism that dampened proteolysis, and subsequent research has shown that HMB in particular is very good at slowing protein breakdown. Like its “parent” leucine, HMB also enhances protein synthesis.

You might expect that a compound which helps you make new protein and preserve existing protein would be useful for building muscle, and that’s exactly what many studies have shown. A 2008 literature review from researchers at the University of Illinois, for example, reported on several independent studies in which subjects taking HMB demonstrated significantly better gains in mass when lifting intensely than a placebo group.

Typical gains were 50% or better in HMB groups when compared to the placebo-takers, with even more pronounced strength increases.

What’s maybe even more interesting is that many of these studies showed the HMB subjects lost fat during the experiment, even while they gained lean mass. Several  of the studies focused on beginners, which would help to explain those results, but many included only experienced athletes.

If you’re a serious musclehead, these returns should perk up your ears.

What the Gym Results Say

Of course, the “proof” of a supplement’s effectiveness for most guys comes in the gym and on the scale. What kinds of results are real men experiencing in the real world?

In truth, and depending on the crowd you run with, HMB seems to be something of a mixed bag. There are guys who try it for awhile and don’t notice anything in the way of improvements, and so they stop taking it.

Then, there are others who notice an almost immediate boost in training poundages and body weight. One of these responders, Derek “Beast” Charlebois wrote of his experiences with HMB on Bodybuilding.com.

Why the discrepancy?

Every aspect of human physiology is subject to something of a bell curve, with extreme cases at either end. When it comes to supplements, you have non-responders at one end and hyper-responders at the other, and those are the guys who will likely be most vocal about their results.

In the case of HMB, you really also need to consider training intensity and volume. If you are not causing much muscle damage with your workout, it seems reasonable that HMB will provide little benefit since its main job (it seems) is to limit proteolysis. If you’re tearing up the gym multiple times a week, though, HMB might give you a boost.

Will It Work for You?

There is enough positive evidence to suggest that HMB will work for a large swath of lifters who train intensely that it’s probably worth giving it a try if you can afford it and are completely healthy. Make sure you check with your doctor and get the appropriate testing done before you dive into any supplement program.

But can HMB help you build muscle and lose fat at the same time?

There are certainly some studies that support that notion, but it’s a tough combination to achieve under normal conditions. Most of us would be better off focusing on one goal or the other so we don’t frustrate either mechanism — fat loss or muscle growth. It appears that HMB could help us with either endeavor, but don’t expect it to work miracles.