More HMB Free Acid Science: Now It's Also Good For High Intensity Interval Training (HIIT) Says the Latest Sponsored Trial W/Out Calcium HMB Control in Young Men & Women

I still believe HMB is better suited for HIIT full body workouts than for cycling or running - regardless of whether it's the calcium or free acid form, by the way.

It should be obvious that it was the Journal of the International Society of Sports Nutrition, where I hit onto a very recent study by Edward H Robinson et al. (2014), a study the purpose of which it was to examine the effect of β-hydroxy-β-methylbutyric free acid (HMBFA) and cycle ergometry HIIT on maximal oxygen consumption (VO2peak), ventilatory threshold (VT), respiratory compensation point (RCP) and time to exhaustion in college-aged men and women." (Robinson. 2014).

That's not just quite a mouthful, and - this is where it becomes interesting - nothing that has not previously been studied in a comparable scenario with regular HMB (we will get back to why this is a problem in the conclusion).

You can learn more about HMB at the SuppVersity

HMB + Over- reaching = WIN

HMB, ATP, Gylcogen

HMB Pre- or Post-Workout

Does HMB Block Fat Loss?

HMB For Muscle Quality?

HMB Blocks Muscle Damage

Apropos scenario, what we are dealing with, here, is a double-blind, placebo-controlled design study, in the course of which all participants,  34 healthy men and women (Age: 22.7 ± 3.1 yrs ; VO2peak: 39.3 ± 5.0 ml/kg) who had volunteered to participate completed a series of tests prior to and following treatment (A peak oxygen consumption test was performed on a cycle ergometer to assess VO2peak, Tmax, VT, and RCP. ). 26 of the participants had been randomly assigned into either a placebo (PLA-HIIT) or 3 g per day of HMBFA (BetaTor™) (HMBFA-HIIT) group. The rest, eight participants served as sedentary controls (CTL) - well, as sedentary as college aged boys and girls usually are ;-) The participants who had been randomized to the exercise groups (PLA-HIIT and HMBFA-HIIT) completed 12 HIIT (80-120% maximal workload) exercise sessions consisting of 5–6 bouts of cycling at a work to rest ratio 2:1 - that's 2 minutes of all out cycle vs. 1 minute of total rest.

Figure 1: Changes in body composition in response to sitting around (control) and HIIT with (HMBFA-HIIT) and without (HMBFA-PLACEBO) supplementing 3g of the free acid form of HBM (Robinson. 2014)

The body composition of the participants, which was "identical" (within statistical margin) before the study, was measured with dual energy x-ray absorptiometry (DEXA) and the changes in fitness parameters were determined in a 2nd exercise test.

BetaTor™? Yes, this is the first official supplement with free acid form HMB: Being produced by Metabolic Technologies Inc (Ames, IA), it contains 1 gram of β-hydroxy-β-methylbutyrate in the free acid form, reverse osmosis water, a de-bittering agent, orange flavor, stevia extract, and potassium carbonate. At least that's what the full-text of the study at hand says. A study of which I don't have to tell you that it was obviously funded by Metabolic Technologies.

Against that background it's quite astonishing that the control group lost 10% of their total fat mass, right? Well, in view of the fact that this change was not significant, someone probably has been dieting here - not very successful, considering the absence of improvements in body fat %, by the way.

Figure 2: Time to exhaustion, respiratory compensation point (RCP) and power at respiratory compensation point (PRCP) in 34 healthy college-aged men and women after sitting around (CTL) or doing HIIT with (HMBFA-HIIT) or without the (PLA) the provision of 3g of the free acid form of β-hydroxy-β-methylbutyrate per day (Robinson. 2004)

Now you may argue that the absence of changes in body composition is awkward considering the significant improvements in time to exhaustion, the respiratory compensation point (RCP) and the power at respiratory compensation point (PRCP), which are all indicative of significant improvements in physical fitness (see Figure 2).

"The Fallacy of Working out To Burn Calories" | learn more

On the other hand, you as student of the SuppVersity should know that intense exercise alone won't make the love-handles go away. Unless you are also "working out in the kitchen", i.e. making changes to your diet, you are only spinning your wheels; and that in spite of the fact that "The Fallacy of Working Out To "Burn Calories" comes hand in hand with the surprising ability of exercise to shut down the carb cravings | learn more.

In essence, it's thus not the fact that the subjects didn't lose weight / body fat, but rather the absence of significant effects of the shiny new free acid form β-hydroxy-β-methylbutyrate (HMBFA) supplement on the exercise induced improvements in metabolic fitness you could consider disappointing before you've had another look at the data in Figure 3.

Question? What's the mechanism, here? Answer: Nobody knows. Most scientists speculate that HMB dampens the muscle damage, reduces the need for compensation and will thus increase the degree of overcompenation, though.

Figure 3 depicts the VO2peak obtained during graded exercise test, the power at ventilatory threshold (PVT) and the amount of air the subjects were gasping at this ventilatory Threshold (VT) and here - actually somewhat to my surprise - the supplement did what I suppose the producer is soon going to promise: It resulted in greater changes inVO2 peak, PVT and VT than HIIT alone.

Figure 3: Changes (% of baseline) in VO2peak, peak power, the power at ventilatory threshold (PVT) and the amount of air the subjects were gasping at this ventilatory Threshold (VT) obtained during graded exercise test (Robinson. 2014)

What I have to say, though, is that I am still a bit disappointed that similar benefits were not observed for the peak power, for which the changes in the placebo group (PLA-HIIT) were actually more significant (p = 0.018) than those in the HMBFA-HIIT group (p = 0.04) which were "just" significant.

Overall, the beneficial effects the researchers from the Institute of Exercise Physiology & Wellness, and the Institute of Exercise Physiology & Wellness at the University of Central Florida observed in their recent trial are more flattering for the 2:1 HIIT cycling protocol than they are for the provision of 3g of the free acid from of β-hydroxy-β-methylbutyrate (HMBFA). Still, the fact that a supplement you would rather associate with strength- than endurance / fitness gains actually had beneficial effects in this high intensity interval training (HIIT) scenario is interesting. As interesting as the fact that it had these benefits in the absence of increases in peak power, which would have been what I would have expected to happen.

Unlike Wilson's recent resistance training study (learn more), neither the study protocol nor the results of the study at hand are HMB-FA specific.

Apropos interesting, as mentioned before Lamboley et al. have already examined the effect of 5 weeks on 3g of "classic" calcium-bound Ca-HMB on changes inVO2max, VT and respiratory compensation point (RCP) in physically-active college students who performed a high intensity interval spring program on a 1% inclinen treadmilll thrice per week and experienced similar increases in maximal oxygen consumption (VO2max +8.4% for PLA and +15.5% for CaHMB) and the respiratory-compensation point (+8.6% for PLA and +13.4% for Ca-HMB). Unlike the previously discussed effects of overreaching by Wilson et al. (2014 | learn more), both design and outcome of the study at hand in no way "HMBFA specific".

Against that background it appears unlikely that there wouldn't have been identical improvements in a CaHMB-HIIT group in the study at hand if Robinson et al. had decided to have a "regular HMB" control group. Practically speaking, this means: Before we don't have a study that supports the superiority of the free acid (HMBFA) over the calcium-bound form of β-hydroxy-β-methylbutyrate (CaHMB) in a HIIT scenario, you should have the price determine what form of HMB you buy if increases in VO2max are what you are looking for.

References:

• Lamboley, Cédric RH, Donald Royer, and Isabelle J. Dionne. "Effects of β-Hydroxy-β-Methylbutyrate on Aerobic-Performance Components and Body Composition in College Students." International journal of sport nutrition & exercise metabolism 17.1 (2007).
• 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) | learn more  in a previous SuppVersity article