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Supplement Research Update: HMB-FA

Is this form of HMB the next big thing or a big bust?

Supplement Research Update: HMB-FA

Lately, I've been getting a lot of questions regarding HMB (beta-hydroxy-beta-methylbutyrate), and specifically, the new form of it: HMB-FA, which stands for "HMB free acid." For those of you who don't remember when HMB came on the scene many years ago -- also with a lot of hype -- I'll give you a brief introduction to this supplement.

What is HMB?

HMB is a metabolite of the branched chain amino acid (BCAA) leucine. Because HMB and HMB-FA are closely related, they do act in a similar manner in the body, but they also act differently. HMB was first hyped when studies done on untrained subjects showed that it increased muscle mass and strength gains better than a placebo. But follow-up studies on trained subjects showed that the effects weren't all that impressive. So, HMB fell off of everyone's radar and become another one of those supplements that looked promising in lab studies, but just did not hold up when used in the gym.

The main way that HMB is believed to work is by aiding muscle recovery following muscle damage. So, it makes sense that novice trainers experience decent gains from HMB, since their unaccustomed muscles experience the most muscle damage from weight training. When you weight train, you gain a protective mechanism within the muscle fibers that helps prevent further muscle damage. The more trained you are, the harder it is to induce further muscle damage, which is probably why HMB studies on trained lifters failed to show significant improvements in muscle mass and strength gains.

This new form of HMB, HMB-FA, is generating a lot of hype again for this supplement. HMB-FA is better taken up by the body than the standard form. The excitement over HMB-FA is due to a new study showing some impressive results, and one supplement company in particular is banking on this study to sell its new HMB-FA supplement. The question is: Does the study and HMB-FA really hold up to prove that HMB-FA is the Holy Grail?

The Study

Before I get into the study, let me state that some of the researchers are friends and colleagues of mine. The study was not flawed in terms of research. What is flawed is the way that a certain supplement company is exploiting the data to sell one of its new products. Unfortunately, the data does not really hold up in the real world, as I will explain.

In the study, which was performed at the University of Tampa, researchers had 24 weight-trained men follow a 12-week, periodized strength-training program that mainly consisted of a full-body training split. After eight weeks of training, the program utilized overreaching for two weeks. Overreaching is when you increase training intensity and/or volume and/or frequency to a point that will eventually lead to overtraining, but then you back off before you enter a state of being overtrained. (*If you are familiar with "My Six Weeks To Sick Arms" program, then you know about overreaching all too well.) During the final two weeks of the study, the subjects tapered off the training.

The first group received one gram of HMB-FA three times per day, with one dose taken 30 minutes before workouts. The second group received a placebo at the same times. The subjects had not taken any other supplements for three months prior to the study, and did not take any other supplements during the 12-week study. Remember that point, as it is an important one that I will bring up again later on.

The results that everyone is talking about are the differences in strength gains that the subjects taking HMB-FA experienced compared to the placebo group. The subjects taking the HMB-FA gained about 60 pounds more on their squat, 15 pounds more on their bench press, and about 30 pounds more on their deadlift at the end of the 12 weeks. Admittedly, those are insane results! But before you empty out your bank account and start downing HMB-FA all day, there's more information you need to know.

When the strength differences between the HMB-FA group and the placebo group were compared after the first eight weeks of training --when the subjects were following the regular periodized training program -- the only significant strength difference was for the squat, which was 15 pounds greater for the HMB-FA group than the placebo group. The difference in bench-press strength and deadlift strength between the two groups was not significant.

But how does a difference in strength gained on the squat go from a 15-pound difference after eight weeks of training, to a 60-pound difference four weeks later? The massive strength and power differences came only after the subjects were put through the overreaching protocol, which caused the placebo group to lose strength and power. So, the massive strength differences are largely due to a drop in strength in the placebo group.

A drop in strength after overreaching is to be expected for the placebo group. Remember: The subjects were not taking a pre- or post-workout protein shake, carbs, BCAAs, creatine, beta-alanine, betaine, or anything pre- or post-workout to allow them to recover properly after several grueling weeks of overreaching. In other words, they were undernourished for the training that they were doing.

In fact, three of the 12 placebo subjects (25% of the group) dropped out, two due to injury. It's no surprise that the group getting the HMB-FA would see far better gains following overreaching than a group getting nothing. HMB works by decreasing muscle breakdown from intense training; it prevents the decrease in muscle strength and muscle size that undernourished subjects experience during overreaching.

The HMB-FA group also gained significantly more muscle mass and dropped more body fat than the placebo group. The HMB-FA group gained about 15 pounds of lean mass in 12 weeks, while the placebo group gained about five pounds of lean muscle. However, after the eight-week mark, before the overreaching portion of the study, the placebo group gained almost seven pounds of muscle. The overreaching phase of the training actually caused them to lose about two pounds of muscle. Again, this is to be expected when getting no proper nutrients around workouts that involve overreaching.

The HMB-FA group also lost more than 10 pounds of body fat over the 12 weeks, while the placebo group lost about four pounds of body fat. HMB has been shown in previous studies to aid fat loss, so these results are expected.

Metabolic Technologies, Inc. funded this study and supplied it with the HMB-FA, known as BetaTOR, which is also in the supplement that is banking on the results. In addition, three of the study's authors are employees of Metabolic Technologies, Inc. I don't want to claim that foul play was involved, since I'm not sure that any data massaging would be needed. Taking HMB-FA during an overreaching training protocol will produce better results than taking nothing -- that's pretty simple.

One could argue that designing a study that involved overreaching and provided one group nothing as far as workout nutrition and the other group with HMB-FA, was meant to guarantee better results for the HMB-FA group. But I know that many of you will find the results far less credible when the study was not only funded by the company that has a financial interest in the supplement being tested, but also co-authored by members of that company. I am providing you with that information for full disclosure purposes, so you can make your own conclusion about any potential outside influences on the study results or design.

Jim's take-home points

I'll start with the question that you want me to answer: Do I think that HMB-FA is a supplement that will produce significant results for you? My short answer is "no." But let me explain in more detail.

Do I think that if you were dumb enough to follow an overreaching training program (or any training program), and didn't bother to take pre-workout and post-workout protein, carbs, BCAAs, creatine, beta-alanine, or betaine, that taking HMB-FA would provide better benefits than nothing? Absolutely!

Do I think that if you were following proper workout nutrition and taking pre-workout and post-workout protein, carbs, BCAAs, creatine, beta-alanine, and betaine and added HMB-FA to your supplement regimen that you would see a big difference? Absolutely not.

However, if, after you have your proper workout nutrition covered with pre-workout and post-workout protein, carbs, BCAAs, creatine, beta-alanine, and betaine, and you have the money to spend on HMB-FA, then go ahead and try it. I will warn you that the only HMB-FA product available on the market today costs about $70 for a 28-day supply. Speaking from experience, I can guarantee you that it won't provide $70 worth of benefits in 28 days.

The problem with research studies like this one is that to truly see if a supplement is beneficial, you have to remove all other variables, meaning all other supplements. It's one of the limitations with the results we find in the lab and how they carry over to the real world.

No one who takes their training seriously would follow a training program and not have their pre-workout and post-workout nutrition and supplementation perfected; at least, no one who follows my advice. So, the results of the study don't really apply to those who follow proper pre-workout and post-workout nutrition. Adding HMB-FA would have little added benefit to a solid supplement regimen and considering the cost of HMB-FA, it's not really worth the minimal benefits.

I would predict that if you did a similar study, but with four different groups: 1) an HMB-FA group, 2) a placebo group, 3) a pre-workout and post-workout protein, carbs, BCAAs, creatine, beta-alanine, and betaine group, and 4) an HMB-FA plus pre-workout and post-workout protein, carbs, BCAAs, creatine, beta-alanine, and betaine group, the results would be as follows: Group 1 would produce better gains in muscle size and strength than Group 2. Both Groups 3 and 4 would produce better gains in muscle size and strength than Group 1 and Group 2. Group 4 would have no additional benefits beyond what Group 3 experienced.

Many other supplements before HMB-FA also arrived on the scene with a lot of hype, thanks to research studies showing impressive results compared to taking a placebo. But in the real world, these supplements failed to produce any true benefits. Supplements like GAKIC, phosphatidic acid, colostrum, GPLC, and the original HMB all come to mind.

The problem with the hype generated from a study like this one is that everyone is looking for that magic bullet. But I have some bad news for you. That magic bullet does not exist. A single ingredient like HMB-FA is not going to deliver crazy results.

The key to getting impressive results with supplements is using a combination of ingredients that are true nutrients that work in synergy with one another, and when taken with a solid diet, provide real, long-term benefits in strength and power, endurance, muscle growth and fat loss. That's the key to taking a whey/casein protein powder blend, BCAAs, creatine, beta-alanine, and betaine, to name a few, before and after every workout. These are nutrients with a long track record in the lab and the gym that have been proven to work well together.

So, stop looking for the magic bullet in one ingredient and focus on combining the proper nutrients and proper timing of those nutrients for the best long-term and continuous results. That's what sports nutrition is really about. Once you educate yourself on nutrient combinations and timing, then you truly have found the Holy Grail.


Wilson, J. M., et al. The effects of 12 weeks of beta-hydroxy-beta-methylbutyrate free acid supplementation on muscle mass, strength, and power in resistance-trained individuals: a randomized, double-blind, placebo-controlled study. Eur J Appl Physiol. 114(6):1217-1227, 2014.

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