|This is Ernestine Shepherd; and while Ernestine is not one of the study subjects she would qualify. After all, she is 74. And she is also something else: An example of the anti-aging effects of life-long exercise and sensible nutrition.|
In a randomized controlled study, the Jeffrey R. Strout and his colleages from the University of Central, the University of North Carolina, the Georgia Southern University, the United States Sports Acadamy, and the University of Tampa, observed that the 3g of "good old" calcium-β-hydroxy-β-methylbutyrate (CaHMB) works just fine to increase leg strength and muscle quality in >65yr old subjects.
To be able to evaluate the effects of HMB alone and in combination with strength training, the scientists divided the study into two main phases:
- Phase I consisted of two non-exercise (NE) groups: (a) ad libitum diet plus placebo (NEPLA) and (b) ad libitum diet plus CaHMB (NEHMB).
- Phase II consisted of two resistance exercise (RE) groups: (a) ad libitum diet plus placebo and resistance exercise (REPLA) and (b) ad libitum diet plus CaHMB and resistance exercise (REHMB).
2x1.5g + 4g carbs did the trick
Muscle quality (MQ) - what is that? "Muscle quality (MQ) was calculated as muscle strength relative to muscle mass. MQ has been used and described previously as an indicaor of muscle function (Lynch et al., 1999; Tracy et al., 1999)." (Strout. 2013) Being a measure of strength relative to muscle mass, MQ is considered a predictor of health status, mortality and a better indicator of muscle function than strength alone (spec. the hilarious grip strength measures you see in many studies in geriatric journals).The supplement had to be consumed with a non-alcoholic drink at least 2x per day. In addition to the HMB or placebo powder it contained an additional 4g of carbs (I am mentioning this, because it cannot be excluded that this had a minimal effect on the absorption or metabolism of HMB). The resistance training sessions (RE) in the 2nd phase of the study were performed three times per week. The volume of the training sessions (number of sets per exercise per week) was as follows (quoting directly from Strout. 2013):
- week 1 was pre-testing only,
- weeks 2 and 3 included one set per exercise,
- week 4 was two sets,
- weeks 5–10 were three sets,
- week 11 was one or two sets,
- week 12 was mid-testing only,
- weeks 13 and 14 were one set,
- week 15 was two sets,
- weeks 16–22 were three sets,
- week 23 was one or two sets, and week 24 was post-testing, only.
Exercises included the bench press, lat pulldown, bilateral leg press, hack squat, and bilateral leg extension. The subjects rested for 2-5min between the exercises and used a classic linear progression (+2-4kg), whenever they felt comfortable performing their exercises with 12 reps at their previous training weight.
|Figure 1: Changes in body composition in response to phase 1 (no exercise) and phase 2 (resistance training) of the 2x 12 week intervention study (Strout. 2013)|
What I consider particularly interesting, here, is the statistically significant increase in fat loss, which is certainly not the first thing you may be thinking about, when it comes to HMB supplementation. In a way this reminds me of the astonishing effects Zemel et al. observed in their recently published Leucine + B6 study (see corresponding SuppVersity article from August 31) and would support the notion that leucine and/or its metabolite HMB increase the oxidative capacity of skeletal muscle - at least in situations of increased cellular stress (obesity in the Zemel study or training in the study at hand; see as well "Leucine + Resveratrol - Synergistic Sirtuin Boosters: +118% Fatty Acid Oxidation, 60% Increase In Muscular Glucose Uptake, -30% Visceral Fat & More - To Good to be True? | read more"). In this context, Strout et al. write:
"Phase I of the current study demonstrated that prolonged supplementation with CaHMB [alone] improved total lean mass (LM), strength, function and MQ without resistance exercise.
The fat loss certainly reminds me of the recent leucine + B6 study
In addition, the progressive, high-intensity resistance training protocol used in Phase II resulted in increased LM, strength, and MQ, with or without CaHMB.
Moreover, the CaHMB intervention in Phase II resulted in a significant decreased total fat mass along with the increased total lean mass and arm MQ from the training."
"One interesting finding regarding the CaHMB treatment in the present study was its effect on fat mass, which was consistent with Vukovich et al. (2001). CaHMB alone did not cause fat loss. However, resistance training with or without CaHMB resulted in a significant loss of fat mass at week 12, whereas only the CaHMB group was able to further the reduction in fat mass at week 24." (Strout. 2013)They then make a questionable statement about how "resistance exercise is not thought to be a potent stimulus for total body fat loss", but get back on track when they add:
"[...] recent evidence suggested that CaHMB supplementation improved fatty acid oxidation, adenosine monophosphate kinase (AMPK), and Sirt1 and Sirt3 activity in adipocytes and in muscle cells (Bruckbauer. 2012). Collectively, these proteins act to improve mitochondrial biogenesis, fat oxidation, and energy metabolism." (Strout. 2013)This would support my own hypothesis that the fat loss is mainly a function of mitrochondrial activity / increases in mitochondrial capacity. And while it has to be determined whether similar effects can be observed in non-muscle cells, even he local improvement of mitochondrial biogenesis would have beneficial downstream effects on whole body metabolism - including the brain!
|If you want to learn more about the usefulness of HMB, I suggest take (another) look at my article about the results of a 2012 dissertation (read more)! And a previous report in the short news about the difference between leucine & HMB (read more)|
- Will these effects occur in individuals on "high" (=2xRDA) protein diets, as well?
- Will they add to the beneficial effects a regular whey protein has to offer?
- Is age critical to benefit or are we going to see the same, improved or smaller effects in younger individuals, as well?
A note on protein requirements in the elderly: Did you know that the current recommended protein intake for the elderly is 0.6g/kg body mass and that Campbell et al. were able to show that at least 1.0g/kg is needed simply to maintain a normal nitrogen balance ? No, well now that you know the 1.1g/kg baseline protein intake in the study at hand tell you what kind of scenario we are talking about - one of protein adequacy, at best!In my humble opinion the latter is specifically true with respect to questions (1) and (2) as corresponding data is hitherto simply non-existent. So we are hard pressed to tell whether you can achieve identical or at least similar body recompositioning effects by simply adding a whey protein shake or protein bar that is not 80% sugar to the diets of our unfortunately protein-underfed "best agers".
On the other hand, previous studies in trained athletes, as well as the user feedback due to which HMB more or less disappeared from the market would suggest that this definitely is the case for younger folks, meaning the usefulness of regular, slow digested calcium HMB in the context of an already highly optimized training and nutritional regimen in people who do not have to fight the age-induced continuant catabolism is more than questionable.
- Bruckbauer A, Zemel MB, Thorpe T, Akula MR, Stuckey AC, Osborne D, Martin EB, Kennel S, Wall JS. Synergistic effects of leucine and resveratrol on insulin sensitivity and fat metabolism in adipocytes and mice. Nutr Metab (Lond). 2012 Aug 22;9(1):77.
- Stout JR, Smith-Ryan AE, Fukuda DH, Kendall KL, Moon JR, Hoffman JR, Wilson JM, Oliver JS, Mustad VA. Effect of calcium β-hydroxy-β-methylbutyrate (CaHMB) with and without resistance training in men and women 65+yrs: A randomized, double-blind pilot trial. Exp Gerontol. 2013 Aug 24.
- Vukovich MD, Stubbs NB, Bohlken RM. Body composition in 70-year-old adults responds to dietary beta-hydroxy-beta-methylbutyrate similarly to that of young adults. J Nutr. 2001 Jul;131(7):2049-52.