HMB - wplyw (niemal zerowy!) na kompozycje ciała

A na jak licznych grupach były prowadzone badania ujęte w tej metaanalizie...?

działa w duzych ilościach

Widziałem jakieś nowsze analizy - działa!

To poprosimy o nie Sławku.

Szkoda czasu. Zarobiony jestem...

No to musimy pozostać przy tym co wiemy. HMB działa tylko w badaniach producenta. Na ludziach "działa" tak jak w tym artykule.

Breakthrough HMB Research: Additional(!) 10% Reduction in Body Fat, 5% Higher Lean Mass + 2x Higher Strength Gains After 12W of Heavy Lifting in Trained Individuals

First, it was "as potent as oxandrolone", then it was "disappointing", "dysfunctional" and "tasted like crap"... you know what I am talking about? Well, then you've been around in the bodybuilding and fitness community for some time. And since you are here, at the SuppVersity, your goto source for the latest information from the realms of nutrition, exercise and supplementation science, you will probably be aware, that HMB, the molecule, I have obviously been referring to in the first sentences of this article, is about to make a comback - in liquid form and without the calcium bond in calcium β-hydroxy-β-methylbutyrate the studies that were presented at the last ISSN conference (read previous article) caused quite sensation in the fitness community.

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.

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

- three training phases -- with Phase 1 (Table 1, top) consisting of a daily undulating periodized
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%"

I know the above is more than some of you want to process; so if you don't want to read it just keep in mind that we are dealing with a highly anabolic exercise protocol, which is - if anything - too intense to be considered "what the average fitness enthusiast will do in the gym". This does not change, though, that the results I plotted in Figure 1 are more representative of what the majority of you could achieve on a corresponding regimen (exercise + supplementation), than the albeit impressive results of the myriad of classic HMB studies in elderly patients (Wilson. 2008).



Apropos, "impressive" - I should say that this attribute applies to the results Wilson et al. present in their recent paper, as well; and that's true for both, the supplement and placebo group!

"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 feel to induce changes, as Jacob and his colleagues observed in the study at hand.

Reference:

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, Gabrial 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)

Zmieniony przez - bodanis w dniu 2015-01-20 20:32:56