|HMB-FA could be for ladies, too - or don't you want to look good naked, girls?|
Now, more than 6 months later, I got a message from Jacob Wilson that he and his colleagues have "just published the first long term periodized HARDCORE training study using HMB-Free acid." It's, as Jacob says, and I can confirm, the "most controlled study to date" (Wilson, 2014 - Facebook).
No, soccer mums! HMB is not going to kill your kid: I am nor sure why, but whenever supplements work (best example creatine), it won't take long until the first rumors of potentially hazardous side effects appear (Fuller. 2014). First on the Internet, then on TV (see the WPXI News Item Jose Antonio posted recently on the ISSN Facebook site). Against that background it's good to know that the no-observed-adverse-event-level (NOAEL) for HMB is 2.48 and 2.83 g/kg BW d−1 in male and female rats, respectively. For a human being this would translate to ~70-100g/per day and thus certainly more than you'll be able to afford, when the free acid form of HMB will hit the market.And after a brief with Jacob about the study design that revealed that the authors omitted the (imho critically important) information that the subjects received both HMB and a whey protein supplement (the latter is not mentioned in the methodology section), I would even agree that Jacob's conclusion that "his" study shows that HMB "clealy works in trained athletes" (Wilson, J. Facebook Conversation. 2014) is accurate as well.
Let's first take a look at what Wilson et al. did
Before we go on with the results, of which I know that they are what intrigues you most, let's briefly take a look at the pretty unique design of the combined exercise training + supplementation regimen the scientists from the University of Tampa, the IMG Acadamy, the University of Central Florida, and the Iowa State University came up with for this experiment:
- 12 weeks is the study length we are looking at -- plenty of time for muscle growth, you would say, but if you want to use trained athletes, this is probably as short as it may be to make sure that you get measureable results
Table 1: Overview of Phase 1-3 (Wilson. 2014)
resistance-training program 3 days per week during, Phase 2 (Table 1, middle) 2-week
overreaching cycle during weeks 9 and 10, and Phase 3 (Table 1, bottom) tapering (volume) for weeks 11 and 12 - needless to say that this is an intense protocol which will, even without HMB, produce serious gains
- 20 is the number of resistance trained men who participated in the study -- with 9 guys in the placebo and 11 guys in the HMB group enough to detect statistically significant differences, if those are actually physiologically relevant (in other words: a single outlier, maybe a "non-responder" - if there was such a thing - won't ruin the whole data set)
- standardized baseline tests for strength & body comp, as well as blood draws and analyses -- this is so basic that I actually thought about even mentioning it
- 3g of per day that's the dosage of HMB in a free acid form (HMB-FA) -- the free form of HMB has been shown by Fuller et al. in 2011, already, to have a superior bioavailability
There is more than just a superior bioavailability to HMB-FA! What's in fact more important than the increased relative amount of HMB that makes it into your blood stream, is the speed at which this process takes place. Improved absorption kinetics, ie. faster absorption ➲ greater anabolism - if we apply what we've learned about the difference between 30g of whey protein and a quarter-pounder, this would mean that cannot expect to see the same results with 3g and probably not even with 9g of calcium bound "regular" HMB - even if the total amount of HMB that hits your blood stream would be higher!"
- 30g of whey protein isolate (Dymatize ISO100, chocolate) that's the dosage of additional whey protein all subjects received -- this information is unfortunately missing from the original paper - a mishap that had me question the value of the data, initially; and if I had not been able to acquire it from Jacob directly, I would probably have torn the study apart, pointing to the possibility that HMB (FA or not) would produce similar non-existent results as the 3g+ of leucine people add to their whey protein shakes, falsely hoping this would increase the protein synthesis "beyond 100%"
|Figure 1: Changes in strength and body composition over the course of the 12-week study (Wilson. 2014))|
"HMB-FA resulted in increased total strength (bench press, squat, and deadlift combined) over the 12-week training (77.1 ± 18.4 vs. 25.3 ± 22.0 kg, p < 0.001); a greater increase in vertical jump power (991 ± 168 vs. 630 ± 167 W, p < 0.001); and increased lean body mass gain (7.4 ± 4.2 vs. 2.1 ± 6.1 kg, p < 0.001) in HMB-FA- and placebo-supplemented groups, respectively." (Wilson. 2014)Whether or, the more appropriate question probably is, to which degree the superior lean and strength gains in the HMB group are a result of the blunted increase in creatine kinase (−6 ± 91 vs. 277 ± 229 IU/l, p < 0.001), an (imho) very unreliable marker of muscle damage and cortisol (−0.2 ± 2.9 vs. 4.5 ± 1.7 μg/dl, p < 0.003), a suspected catabolic, the role of which in the orchestrate of muscle growth does yet remain highly elusive (learn more in "All About Cortisol" | read more), in the HMB-FA group during the overreaching cycle is questionable and imho of corelative, not causal nature.
Previously, HMB turned out to be particularly useful in scenarios where muscle loss was an issue (the previously mentioned studies in elderly individuals). You also know from a previous article of mine that Wilkinson et al. were able to show that HMB - contrary to leucine, by the way - an excellent inhibitor of protein breakdown. In am overreaching scenario, of which you can see based on the significant strength decreases in the placebo group at the end of the overreaching phase (see Figure 1, left), it is thus possible that the added anti-catabolic effects of HMB are what actually made the difference. In turn, this would yet mean: If you don't train like a maniac, even high amounts of additional HMB may fail to induce changes, as Jacob and his colleagues observed in the study at hand.
- Fuller Jr, John C., et al. "Subchronic toxicity study of β-hydroxy-β-methylbutyric free acid in Sprague-Dawley rats." Food and Chemical Toxicology (2014).
- Rathemacher, John, et al. "Improved method of administering beta-hydroxy-beta-methylbutyrate (hmb)" WO 2011075741 A1. 2011
- Wilson, Gabriel J., Jacob M. Wilson, and Anssi H. Manninen. "Effects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A review." Nutr Metab (Lond) 5 (2008): 1.
- Wilson, Gabriel J., 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." European Journal of Applied Physiology (2014)