Sunday, January 17, 2016

Peri-Workout BCAA + Glutamine + Citrulline Consumption Blunts Muscle & Fat Loss Compared to Powerade Placebo

"Shed the fat, keep the muscle!" That's a promise you will find not literally, but analogously in every ad for BCAAs, but do they actually do that? Help you shed fat and retain muscle? Scientific prove to support this claim is, as of yet, missing.
With BCAAs it is just as it is with 99.9% of the supplements: Ads and product labels are full of scientifically unproven claims. One of these unproven claims is that the consumption of branched-chain amino acids would protect you from losing muscle while you're dieting ... the problem with this notion is - as sound as it may seem in view of the mTOR promoting effects of leucine, there's no study which would prove that guzzling BCAAs all day will in promote fat and blunt lean mass losses when you're cutting.... or I should say "as of now, there was no study...", right? After all, there's this new study by Dudgeon et al.'s the abstract of which tells us that "BCAA supplementation in trained individuals performing resistance training while on a hypocaloric diet can maintain lean mass and preserve skeletal muscle performance while losing fat mass" (Dudgeon. 2015).
Learn more about amino acid and BCAA supplements at the SuppVersity

Glutamine Helps W/ Diabetes

Whey + C Kicks BCAA Ass

Alanyl-Glutamine is it any good?

Glutamine Insted of CHO?

GLU as Intra-Workout BV?

BCAAs deplete neurotransmitters
As we are going to see after taking a look at the design and results of Dudgeon's single-blind study in seventeen resistance-trained males (21–28 years of age) on hypocaloric diets, this is yet a potentially misleading conclusion. Not because it was wrong, but rather because it omits an observation that could be of paramount importance to dieters who have the free choice between the two treatments, the subjects of the study were randomly assigned to, namely...
  • 14g of Xtend (BCAA) before after workouts or
  • 14 g Powerade (CHO) before and after workouts
The supplements were consumed for a total study time of 8 weeks during which all subjects trained four times per week according to a standardized workout program and consumed a diet that was programmed (but not controlled) to contain roughly 35% less energy than the subjects required on workout days and approximately 10% less energy than required on off-days.
In the strict sense, this is actually no "BCAA study": Some of you may already have realized that the "BCAA supplement" the scientists used, i.e. Scivation XTend, is not really a "BCAA only" supplement. Next to only 7 grams of BCAAs per 14g of powder the subjects ingested before and after the workout, it also contains 1 g citrulline and 2.5 g glutamine and obviously a hell lot of flavorings, fillers and what not. Now, while the latter are not of any importance, both of the former have been heralded as muscle protectors, as well, with citrulline probably having the more convincing scientific data to back it up (it appears to act similar to leucine, by the way | Moinard. 2007; Faure. 2012; Ventura. 2013) outside of scenarios with extremely high glucocorticoid levels where glutamine unquestionably helps (Hickson. 1995 & 1997; Salehian. 2006). It is thus in my humble opinion at least highly imprecise to conclude that the provision of 2x7g of BCAA ameliorated the the fat to muscle loss ratio during the 8-week study.
Now you may be rightly asking yourselves why I am so vague with respect to the energy deficit. Well, everything we learn from the full text of the study is that all subjects were "provided an individualized caloric restricted diet based on individual data (body mass, body composition, resting metabolic rate, etc.)" (Dudgeon. 2015) - a diet the scientists describe as follows:
Table 1: W/ the Harris-Benedict equation you calculate the basal metabolic rate and multiply it with a factor (multiplier) that describes your activity level best to arrive at the "real" estimated energy requirements.
"The caloric-restricted diet was designed as an 8 week “cut diet” for reducing body fat, and used a modified carbohydrate-restricted diet approach (percent of total calories for workout days were 30 % carbohydrates, 35 % protein and 35 % fat and for off days were 25 % carbohydrates, 40 % protein and 35 % fat). Each individual’s daily caloric and macronutrient intake was determined using the Harris Benedict formula with an activity factor of 1.35 (lightly active individual engaging in light exercise 1–3 days/week) for workout days and 1.125 (sedentary individual) for off days" (Dudgeon. 2015).
Since the Harris-Benedict formula is only a really rough estimate of how much energy you actually need, my previous estimations of the energy deficit are as "accurate" as I can possibly be. The 1604kcal that are printed in red bold letters on top of the exemplary meal plan in Figure 2, however, suggest that the deficit on the off days was significantly larger. After all, the subjects' mean weight was >80kg and their daily energy requirements should thus be at least 2,000kcal - even on off days (and the table in which the macronutrient composition is listed actually says that the mean intake was 2046 and 2264kcal/day for the BCAA and CHO group respectively).
Table 2: Sample dietary card for a subject during an off, non-workout, day (Dudgeon. 2015).
In view of the fact that the response I got from the authors to an email in which I asked about the exact kcal deficit only referred me to the previously cited passage about the activity factors, I guess it is futile to further speculate about the energy deficit, of which I would still like to add that it was probably higher in the heavier and taller BCAA group. Why? Well, the BCAA group had plans with 2456 and 2046 kcal on workout and off days, the CHO group on the other hand were fed 2717 and 2264 kcal... Whatever, let's get to the more relevant, but not less confusing changes in body weight, lean mass and fat mass the researchers report for the BCAA and CHO groups:
Figure 1: Pre and post absolute mean body weight, body fat and lean body mass values before and after the 8-week intervention; * p < 0.05 for the difference within groups (no difference between groups | Dudgeon. 2015)
-0.1 kg and -2.3 kg of body weight, +0.4 kg and -0.9 kg of lean mass and 0.6 kg and 1.4 kg fat mass in the BCAA and CHO groups respectively - that's in line with the previously cited conclusion. The BCAA supplement blunted the small loss of lean mass in the CHO group, but if we look at the complete dataset, a somewhat different image emerges; one in which the two classic markers of body composition, namely the relative amount of body fat (aka "body fat percentage") and the lean mass as percentage of the total mass changed in a way that favors CHO over BCAA supplements:
Figure 2: Pre vs. post values for body fat % and lean mass %, the two parameters you would classically use to assess body composition (instead of absolute lean and fat mass); pre-to-post change on top of the post-bars (Dudgeon. 2015).
Now, I am not saying that the consumption of the BCAA (+citrulline + glutamine) supplement did not blunt the loss of lean mass - it obviously did. What I want you to keep in mind, though, is the fact that the consumption of 14g of BCAAs before and after workouts appears to suffocated any dieting efforts - after all, the subjects lost a practically irrelevant (and for whatever reason allegedly statistical significant) amount of 600g body fat; that's in contrast to the 1.4 kg of fat mass the subjects in the control group lost; and that's a practically relevant insight, even if this fat loss was allegedly statistically non-significant, because  it implies that BCAAs practically blunt fat loss.
Whey + Casein - A Superior Post-Workout Shake that Kicks Every Amino Acid Product's Ass | read more
So what do we make of this study? Well, first of all, I would like to come back to something fundamental: This is yet another BCCA study that did not make the practically most relevant comparison of BCAAs and cheap (whey) protein protein supplements, in which BCAAs have hitherto always failed. In my humble opinion that's a problem, after all having a carbohydrate supplement as control in a dieting study is nice, but eventually not relevant for the average trainee who is probably not really considering extra-carbs when he's dieting.  What a real trainee would have been interested in, is whether BCAAs can prevent muscle catabolism to a significantly greater degree than the cheap whey protein he's using anyway...

... and maybe, whether the latter has a similar negative effect on fat loss as the BCAAs in the study at hand - which leads me to the actual take home message of the study, which is, as usually, not as straight forward as the conclusion of the abstract suggested. When all is said and done, the study at hand does after all suggest that someone who is approaching the single-digit body-fat zone, where every gram of muscle that is not lost counts, could benefit from the apparent lean mass protective effects of BCAA the scientists observed in the study at hand. It does yet also indicate that someone who's "making weight" for a competition should take a second look at the data in Figure 1 + 2 and acknowledge that taking a BCAA supplement may be the reason he will fail to achieve his weight loss goal. You don't believe that? Well, let's do some scientifically not exactly kosher extrapolations: If you manage to lose 10 kg in 10 weeks without BCAAs, for example, the data from the study at hand suggests that your weight loss "on BCAAs" over the course of those 10 weeks would be as meager as 434 grams ... whether that's in fact the case (I doubt it ;-) will have to be studied in future studies, just like the effect of BCAAs, citrulline and glutamine, alone and whether using your regular whey protein before and after the workout wouldn't have the exact same, or even better effects | Comment on Facebook!
References:
  • Dudgeon, WD; Page Kelly, E; Scheett TP. "In a single-blind, matched group design: branched-chain amino acid supplementation and resistance training maintains lean body mass during a caloric restricted diet." Journal of the International Society of Sports Nutrition  (2016) 13:1.
  • Faure, C├ęcile, et al. "Leucine and citrulline modulate muscle function in malnourished aged rats." Amino acids 42.4 (2012): 1425-1433.
  • Moinard, Christophe, and Luc Cynober. "Citrulline: a new player in the control of nitrogen homeostasis." The Journal of nutrition 137.6 (2007): 1621S-1625S.
  • Hickson, R. C., S. M. Czerwinski, and L. E. Wegrzyn. "Glutamine prevents downregulation of myosin heavy chain synthesis and muscle atrophy from glucocorticoids." American Journal of Physiology-Endocrinology and Metabolism 268.4 (1995): E730-E734.
  • Hickson, Robert C., et al. "Protective effect of glutamine from glucocorticoid-induced muscle atrophy occurs without alterations in circulating insulin-like growth factor (IGF)-I and IGF-binding protein levels." Experimental Biology and Medicine 216.1 (1997): 65-71.
  • Salehian, Behrouz, et al. "The effect of glutamine on prevention of glucocorticoid-induced skeletal muscle atrophy is associated with myostatin suppression." Metabolism 55.9 (2006): 1239-1247.
  • Ventura, G., et al. "Effect of citrulline on muscle functions during moderate dietary restriction in healthy adult rats." Amino acids 45.5 (2013): 1123-1131.