Protein Wheysting?! No Significant Increase in PWO Protein Synthesis W/ 40g vs. 20g Whey, But 100% Higher Insulin, 340% More Urea & 52x Higher Oxidative Amino Acid "Loss"

No, I don't think the results would have been different, if the subjects had been young women. For older guys and gals, on the other hand, I am not 100% sure.

It has been a while since we've been taking a look at one of the two or three dozen "whey increases muscle protein synthesis" studies and, officially, we would have to wait not just for Santa, but actually until January 2014 to take a glimpse at the results Oliver C Witard, Sarah R Jackman, Leigh Breen, Kenneth Smith, Anna Selby, and Kevin D Tipton present in their soon-to-be-published paper in the journal of the American Society for Nutrition (Witard. 2014).

The intention of the researchers was (yet again) to "characterize the dose-response relation of postabsorptive rates of myofibrillar MPS to increasing amounts of whey protein at rest and after exercise in resistance-trained, young men", (Witard. 2014). This is nothing new, but still right up the average SuppVersity reader's alley, I suppose.

So what about the study design

The design of the study was simple. The 48 healthy volunteers consumed a standardized, high-protein
(0.54 g/kg body mass) breakfast. Three hours later, they all performed a standardized bout of unilateral exercise, consisting of 8x10 leg presses and leg extensions at 80% of their individual, predetermined one-repetition maximum. "Immediately" (max. 10min) after they were done with the leg workout the volunteers consumed

• 0g, 10g, 20g, or 40g whey protein isolate

as a post-workout protein shake, of which I don't have to tell you that it was likewise... standardized, right! The subjects were then hooked up with the necessary instruments and tools to measure their

• postabsorbtive rates of myofibrillar protein synthesis (MPS) , 
• whole-body rates of phenylalanine oxidation and 
• urea production 

over a 4-h period (the stopwatch started ticking the very moment the subjects had ingested the protein shake) in all four arms of this parallel research design, single-blind study with 7 subjects in each of the 0, 10, 20, and 40g whey protein isolate groups.

Change (%) in myofibrillar and sarcoplasmic protein synthesis after ingestion of 25g whey at rest (FED) and resistance exercise (FED-EX) after 3h and 5h (Moore. 2009a)

Just a reminder: You do remember that there is another muscular compartment where we can measure protein synthesis? Right? The sarcoplasma, i.e. the zone around the myofibers, where the satellite cells reside. At least for the exercised leg, in the study at hand, this may not be that important, though, because "in contrast [to protein feeding at rest], resistance exercise rapidly stimulates and sustains the synthesis of only the myofibrillar protein fraction after protein ingestion" (Moore. 2009; my emphasis). The word "only" is slightly misplaced. If you look at the figure on the left, it's obvious that "mainly" or "more significantly", would probably be more accurate.

Now that you know all the important details about the study design, it's almost time to take a look at the results. Before we finally do that, let's just briefly recapitulate the results of (Cuthbertson. 2005) who observed that 10 g EAAs at rest and (Moore. 2009b) who observed that 20 g egg protein after exercise were "optimal for the maximal stimulation of MPS in young adults". This is after all, what the researchers hypothesis that "20 g of whey protein (~10 g EAAs) would be sufficient for the maximal stimulation of myofibrillar-MPS rates at rest and after resistance exercise in trained, young men" (Witard. 2014) was based on.

Figure 1: Post-exercise serum insulin (AUC, µmol/ml x 4h) and leucine peak (mmol/ml), total phenylalanine oxidation (AUC µmol/ml x 4h x 100), urea production (AUC µmol x 4h) and plasma urea (AUC mmol/l x 4h), as well as myofibrillar protein synthesis (MPS) in the 4h after the workout (Witard. 2014).

As you can see, the actual study results confirm the scientists suspicion: The 20g of whey protein did maximized the myofibrillar protein synthetic response to a hypertophy-oriented leg training workout (see bottom line for an explanation of why I chose to underline the word "leg") in rested and exercised muscle of ~80-kg resistance-trained, young men.

We are talking about statistical significance here: I know what you are going to tell me, now. And yes, you are right. The protein synthesis was in fact higher, but that's more of a matter of how sustained the increase was and not a matter of a "faster" protein synthesis. In other words, with 20g of a fast absorbing whey protein and a whole meal with slow absorbing proteins 30-40min after you will achieve the same - if not higher muscle protein synthesis rates in the long(er) run (>2h)... ah, and by the way: The response in the untrained leg confirms: There is not additional MPS stimulus from 40g vs. 20g of whey (much contrary to the insulin spike, by the way ;-).

The side-finding that this in medical terms "high" amount of whey also lead to significant increases in urea production is - at least in my humble opinion not surprising. The increased ammonia production due to higher protein oxidation rates does after all have to be cleared from the body. Against the background that this process is facilitated by the urea cycle, anything but the observed increase in urea production would have been startling.

"Confirmed: All Wheys, Not Just Hydro Whey Boost Glucose Uptake and Liver + Muscle Glycogen Supercompensation. Plus: How Can Taurine help?" | more

The fact that this increase in urea production and plasma concentrations did occur in the first place, on the other hand, is a clear cut sign for the onset of "wastefulness" with higher protein consumption - or as Selby et al. put it:

"Indeed, in the current study, urea production rates , as well as plasma urea concentrations, were markedly raised with the ingestion of 40 g protein.

Thus, instead of incorporation into muscle protein, the metabolic fate of excess exogenous amino acids contained in the 40WP was predominantly the oxidation or excretion as an indication that a state of amino acid excess was reached." (Selby. 2014)

Whether you consider this a "waste" of valuable dietary protein or not is probably a matter of your personal concept of protein nutrition.

If you are on the "protein worshipper" side of the devide, you will probably argue that you better "burn" protein for energy than carbs or fats, because otherwise you would have to eat less protein and  more carbohydrates + fat and would "become fat". It goes without saying that this is bullshit - not to mention that anyone who is interested in performance and the sanity of his doctor. The poor guy would freak out, when he'd see the elevated AST and ALT levels the combination of "protein only" diets + intense physical exercise are going to produce.

Your doctor's mental sanity or the excited calls of his receptionist are probably not really your concern, but I would still not discard the performance and, in the long run, metabolic and psychological detriments from running on protein only. From an (bio-)energetic perspective it's the least effective of the three macronutrients and thus not exactly a suitable fuel source for high performance athletes.

"So what would you put into a post-workout shake, Adel?" Personally, I have ~30g of whey protein and some fruit, like 1-2 bananas, a ton of water melon, or whatever else I have lying around. If no fresh fruit is available, I just grab some instant oats. And while I know that the carbs won't help with protein synthesis (Koopman. 2007), there is hardly any better timepoint to use the massive isulin spike and shuttle the glucose into the muscle than after the workout (van Loon. 2000). For me personally, the addition of carbs also prevents the brainfog, I get due to low blood sugar after an intense leg-workout and a protein shake without carbs. So, if you feel like you're not thinking straight or would have to go to bed after your shake, I would try to fix that by adding some carbs to the equation.

Bottom line: With the study at hand we (will) get further confirmation of the existence of a protein threshold of ~20g of whey protein, beyond which we won't see additional increases in acute myofibrillar protein synthesis after having a high protein breakfast and the completion of a standardized hypertrophy-oriented leg workout in young, healthy, male individuals.

If you wonder about the many underlined words in this conclusion, I may remind you of the fact that all these words describe boundary conditions that won't be fulfilled for everyone: There are more than enough people who don't have a high protein breakfast. There are people who train their whole body in a single session and would thus upregulate the protein synthesis in more than just the leg muscles. Not everyone is still young (and there is albeit inconclusive evidence that older individuals need more protein). For long-term muscle gains the sarcoplasmic protein synthesis may and the long-term (not acute) net protein balance definitely is more important than the acute increase... I could go on, but I guess you see, where this is heading: Theoretically, we'd have to do another 100 studies, but I am not sure whether Glaxosmith Kline who support Tiptons research would want to finance all of these ;-)

Reference:

• Cuthbertson, D., Smith, K., Babraj, J., Leese, G., Waddell, T., Atherton, P., ... & Rennie, M. J. (2005). Anabolic signaling deficits underlie amino acid resistance of wasting, aging muscle. The FASEB journal, 19(3), 422-424.
• Koopman, R., Beelen, M., Stellingwerff, T., Pennings, B., Saris, W. H., Kies, A. K., ... & Van Loon, L. J. (2007). Coingestion of carbohydrate with protein does not further augment postexercise muscle protein synthesis. American Journal of Physiology-Endocrinology And Metabolism, 293(3), E833-E842.
• Moore, D. R., Tang, J. E., Burd, N. A., Rerecich, T., Tarnopolsky, M. A., & Phillips, S. M. (2009a). Differential stimulation of myofibrillar and sarcoplasmic protein synthesis with protein ingestion at rest and after resistance exercise. The Journal of physiology, 587(4), 897-904.
• Moore, D. R., Robinson, M. J., Fry, J. L., Tang, J. E., Glover, E. I., Wilkinson, S. B., ... & Phillips, S. M. (2009b). Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. The American journal of clinical nutrition, 89(1), 161-168.
• van Loon, L. J., Saris, W. H., Kruijshoop, M., & Wagenmakers, A. J. (2000). Maximizing postexercise muscle glycogen synthesis: carbohydrate supplementation and the application of amino acid or protein hydrolysate mixtures. The American journal of clinical nutrition, 72(1), 106-111.

Never(!) Sip Your Whey, If You Want to Kickstart Protein Synthesis. Over 60% Reduction in 1-5h Post Workout Protein Synthesis if You "Pulse" Your PWO Shake.

Image 1: The whey isolate used in the study - I guess as a scientists you just take whatever you get sponsored ;-) All jokes aside, any other whey isolate will do just as fine.

We all know, leucine is the magic amino acid that tells your muscles to ramp up protein synthesis. We also know that whey protein, which is made from the globular proteins the manufacturers isolate from the milky by-product of cheese production, is "the whey to go" if you do not want to ingest your leucine as a free-form amino acid or as part of a BCAA or EAA free-form amino acid blend. After all, whey is not only particularly rich in leucine (~14-15%), but also highly digestible. Well, at least this is what you are told to believe by the supplement industry... but how do we know that it is really the "speed" that makes a difference? After all, in all existing studies which compare whey to "slow digesting" proteins the absorption speed is not the only independent variable. Moreover, a recent study by Reitelseder et al. on the effects of post-exercise supplementation with 0.2g/kg body weight whey vs. casein could not find significant differences in the post-exercise protein synthetic response - and that despite the fact that whey is faster digested and does contain ~5% more leucine (Reitelseder. 2011).

A cleverly designed experiment that was (how else could it be ;-) conducted by Stuart Phillips' Exercise Metabolism Research Group at the Department of Kinesiology and Neurology at McMasters University in Hamilton, Canada, could hold the answer to the question, whether the speed with which the amino acids from your post-workout protein shake hit your body actually matters (West. 2011). Instead of using caserin or another slow-digesting protein source as control, Daniel W.D. West and his colleagues effectively eliminated all other possibly interfering variables, such as the exact amino acid composition, the carbohydrate and fat or vitamin and mineral content of the control beverage, by simply comparing the protein synthetic response to strength training (8 sets of 8-10 reps at 10RM on the bilateral leg extension machine) in 8 healthy men after bolus or pulsed (10x2.5g every 20min) ingestion of 25g of whey protein.

Figure 1: Mean serum blood concentration  (nmol/ml) of essential amino acids after bolus (red) or pulsed (blue) ingestion of 25g whey protein; * significantly (p<0.05) greater than pulse, # significantly (p<0.05) greater than bolus (data adapted from West. 2011)

While, obviously, the areas under the curve were identical for both the total essential amino acid (EAA), as well as the leucine serum levels in both groups, only the bolus ingestion of 25g of whey protein caused a significant spike (+122% over baseline, +45% over pulse) of total EAA and leucine levels about 60min post ingestion (cf. figure 1, the graph for leucine looks virtually identical). Conversely, there was a transient increase (+66% over baseline, +33% over bolus ingestion) in both serum EAA and leucine content 180min at the end of the pulsed ingestion.

Figure 2: Relative increases in mTOR phosphorylation (left) and myofibrillar fractional muscle protein synthesis rates (right) over fasted baseline after bolus or pulsed ingestion of 25g of whey protein (data adapted from West. 2011)

As the relative increases in myofibrillar fractional muscle protein synthesis rates (FSR over fasted baseline) in figure 2 (right) go to show, the spike and not the total amount of EAA/leucine over a given time period (as measured by the area under the curve) is what kicks the muscle protein synthetic machinery into gear. Even with the lower serum EAA levels at the ~3h (=180min) mark, both protein synthesis as well as mTOR-phosphorylation (figure 2, left) were still higher in the group who consumed their 25g of whey in a single bolus. So, even if your whey tastes so good that you feel like it would be a sheer waste to gulp it down all at once, you better ignore those moral objections if you want to make the most of your post-workout nutrition ;-)

Exercise the one and only "nutrient partitioner"

These results are obviously important, in that they substantiate the current practice of "getting your fast digested protein in right after exercise", what I personally did yet find even more revealing is the following remark that can be found in the extensive discussion of the results:

An intriguing and important divergence between our findings and reports in which aminoacidemia resulted in only a transient rise in MPS with infusion of amino acids or with amino acid consumption is that our results were postexercise. It appears that a unique aspect of resistance exercise is to selectively sustain elevated synthetic rates of myofibrillar proteins after protein consumption. In contrast to the effects of protein consumption alone at rest, the current results and our earlier work showed that the highest rates of MPS were observed at 3–5 h postexercise when aminoacidemia had subsided.

So, what am I preaching in each and every post? There is only one "nutrient repartitioner" which works: EXERCISE. Now, get your ass to the gym and save the money the supp companies want you to spent on dubious supplements which - even if they worked - don't give you any advantage over what you can accomplish with exercise alone for a container full of tasty whey protein isolate (which ought to be ingested in bolus portions of 25g, of course ;-).

Pre Workout Protein Supplementation 101: Slow or Fast, Bolus or Pulse? Protein Synthetic Response is Identical!

Should she drink her protein shake all at once or in 33ml gulps every 15min, if she has it before her workout? And wait, wouldn't it be better to have the shake afterwards, anyway? A recent study provides some answers.

I don't know if you notices, but it has been a while since the last study from the Exercise Metabolism Research Group at the Department of Kinesiology of the McMaster University in Hamilton, Ontario, Canada, hit the SuppVersity news. Allegedly, I mentioned Stuart Phillips only a couple of days ago, when I referenced the West study on "Associations of exercise-induced hormone profiles and gains in strength" (West. 2012), in the context of the questionable significance of post-exercise increases in testosterone levels, as far as muscle and strength gains are concerned - for those who missed that, it was  in the "Anabolic Workouts Revisited" post from last Monday. That was however about it as far as the news of the last weeks are concerned. So I was already wondering, when the first of you would be showing initial signs of "acute protein synthesis in response to protein ingestion study withdrawal symptoms", when I hit onto the latest study Phillips' group at McMasters participated in. The lead author of the study is however Louise M. Burke who's currently working at the Australian Institute of Sport in Canberra, Australia.

What happens if you ingest your post-workout protein before the workout ;-) ?

The aim of the study, of which the authors explicitly state that it is a quasi-followup to previous results which have conclusively identified fast acting protein sources (mostly whey, in some instances EAAs) as superior triggers, or I should say, promoters of post-exercise protein synthesis, was

"[...] to investigate the effects of manipulating patterns of aminoacidemia from protein sources consumed before a bout of resistance exercise bout." (Burke. 2012)

To this end, Burke et al. simulated the ingestion of slow or fast protein sources by bolus vs. pulse feeding of a leucine-enriched (+5g) whey protein drink (Nestec by Nestlé, sponsor of the study; the reason for the enrichment was to make sure that there would be a decent amount of leucine in each pulse serving).

• Bolus (B) - 1 x 500ml w/ 25g whey + 5g leucine drink, 14 x 33ml placebo every 15 min
• Pulse (P) - 1 x 500ml placebo drink,  14 x 33ml w/ 1.79g whey + 0.36g leucine each
• Placebo - 1 x 500ml placebo drink, 14 x 33ml placebo drink

The subjects, 12 resistance-trained men (age: 27y; body mass: 94.3kg; 1 RM single leg ext.: 42.8kg) with greater than 2 yr of experience of regular (at least twice per week) strength training, who had followed a standardized diet before each of the testing sessions (energy content of 80kcal/kg BM; 45%/34%/21% of the energy from carbs/fats/protein), started consuming their large 500ml beverage and the subsequent 14 small 33ml servings (every 15 min) 45min before they performed a standardized leg training session:

"This bout consisted of a  standardized warm-up, followed by 10 sets of 8–10 repetitions of leg extension at a workload equivalent to 80% of the specific leg 1 RM with 2-min recovery between sets. The leg that performed exercise was alternated for each trial. The duration of the resistance bout was approximately 45 min." (Burke. 2012)

Before during and after the exercise bout blood samples were collected. Muscle biopsies from the vastus lateralis of the exercised leg were taken 45min before, as well as after 1 h and 5 h of recovery.

Figure 1: Serum leucine and insulin levels after bolus and pulse ingestion, expressed relative to placebo group (left) and fractional protein synthesis rate (in %/h) during the 5h following the rest period after the workout (right; based on Burke. 2012)

As you can see in figure 1 the results basically confirmed the scientists expectation that the provision of protein before a workout would work just as well, because - more than anything else - it is the availability (or should I say abundance?) of amino acids in the blood stream that is the main determined of post the actual fractional protein synthesis rate (FSR) after moderate  volume workout like the one the participants conducted in the study at hand. In addition it did, at least as far as the protein synthetic response goes, neither make a significant difference, whether the subjects had all their protion at once before the workout or consumed it in 15min intervals before and during the workout.

Bolus or pulse = fast or slow? Pulsed whey does not equal casein (imho)

What I am personally not happy with, though, is the way Burke et al. equate the "pulse" protocol to the ingestion of a "slow" protein source, such as a micellar casein protein, for example. While they put that into perspective in the discussion of the results (see below) and despite the fact that do see the rationale of Burke et al. not to use a real slow digesting protein like casein in order to have absolutely identical amino acid compositions and to exclude other confounding factors, it is at least in my humble opinion somewhat confusing for the "average" reader. And while it is likely that the results for a "real" slow digesting protein would be similar, this would warrant direct experimental evidence. A fact the authors only hint at indirectly towards the end of the discussion of their results, when they state:

"[...] A specific issue in interpreting the finding of these previous studies and in increasing the utility of the concept of ‘‘fast’’ and ‘‘slow’’ dietary proteins is the difficulty of determining the individual and interactive contributions of the different AA composition of protein-rich foods and the digestibility of proteins or protein-rich meals to the pattern of delivery of these AAs. Our protocol, in which the same (fast) protein was consumed to achieve its traditional AA profile or as a series of small divided feed-ings to replicate the plasma leucine response associated with a slow protein, provides an opportunity to differ-entiate these effects." (Burke. 2012)

But hey, who knows, maybe that's going to be the research question of the next paper... and in the mean time it will spare you to buy two or even more different protein powders ;-)

"So what's better Dr. Andro? Pre- or post-workout protein supplementation?"

I guess most of you won't care anyways, as there is another question that's now preying on your minds... but to be honest, I can't provide you with a definite answer to it (see headline). What I can do, however is compare the study by West et al. (West. 2011) which used 25g of whey protein post workout to the one at hand (Burke. 2012).

Figure 2: Fractional protein synthesis (FSR in %/h) after the workout with post workout protein ingestion (West. 2011) and pre workout protein ingestion (Burke. 2012) on the left; relative increase in FSR in the two trials (compared to fasted for West. 2011 vs. Placebo for Burke. 2012) on the right (please mind that this is by no means a scientifically valid comparison, it's more of a "food for thought illustration"!)

I've done just that for you in figure 2, and what this comparison tells you is that it does not make a difference, whether you ingest all your protein as a bolus after a workout or start "pulse ingesting" (mind my words in the previous paragraph wrt to "slow != pulse") your protein 45min before the workout - at least, if you take the relative increase in fractional protein synthesis as a measure (figure 2, right). 

Unfortunately, both the composition of the protein supplement (25g whey in West. 2011 vs. 25g whey + 5g leucine in Burke. 2012), as well as the exact outcome variables that were measured (1-3h and 3-5h FSR in West. 2011 vs. 5h post workout FSR in Burke. 2012) were different, so that the comparison of the relative increases in protein synthesis I plotted on the right hand side of figure 2 is actually not 100% valid.

Moreover, and this is something I know a couple of you will now be thinking of, this comparison does by no means allow for any quantitative predictions with respect to the question of ...

What would happen, when you do both: Pulse ingest before and bolus ingest afterwards?

If  you don't remember or - even worse ! - have not read the previous SuppVersity post "Protein Synthesis Beyond the '20g Limit': Study Shows Exercise Facilitates 32% Greater Increases in Fractional Protein Synthesis With 40g Instead of 20g of Whey PWO" click on the image and (re-)read it ;-)

In view of the fact that the existence of a "threshold level" of protein intake, where the addition of even more protein won't yield any further benefits appears to be self-evident, the exact amount of this limit has yet still to be determined. At least after a workout, it seems that this threshold would be higher than the 25g and 20g of protein the subjects ingested in the Burke and West studies, respectively (please read my previous post "Protein Synthesis Beyond the 20g Limit" for a more detailed discussion of this topic).

That being said, it is reasonable to assume, but would likewise warrant experimental verification, that the combination of both protocols could increase the fractional protein synthesis even further. Yet while I am 100% sure that they won't simply add up, I would hesitate to bet money that the difference would actually reach statistical significant... at least with a low volume leg extension workout as it was used in the studies at hand.

References:

• Burke LM, Hawley JA, Ross ML, Moore DR, Phillips SM, Slater GR, Stellingwerff T, Tipton KD, Garnham AP, Coffey VG. Preexercise aminoacidemia and muscle protein synthesis after resistance exercise. Med Sci Sports Exerc. 2012 Oct;44(10):1968-77.
• West DW, Burd NA, Coffey VG, et al. Rapid aminoacidemia enhances protein synthesis and anabolic intramuscular signal-ling responses after resistance exercise. Am J Clin Nutr. 2011; 94:795–803. 
• West DW, Phillips SM. Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training. Eur J Appl Physiol. 2012 Jul;112(7):2693-702.  

Maximal Protein Synthesis in the Elderly: How Much Protein Does it Take? Another Study to Suggest More is Better!

Maximal protein synthesis requires protein, but how much exactly you need will depend on your age - the older you are the more PWO protein you'll need.

Scientists from the University of Auckland were fed up with the lack of information about the differential response in protein synthesis in response to the ingestion of various amounts of protein. Accordingly, Randall F. D’Souza et al. conducted a study to characterize the changes in intramuscular levels of EAAs and BCAAs and the expression of the "protein pump" p70S6K at Thr389, a marker of protein synthesis, in response to resistance exercise and graded ingestion of whey protein in older men.

As a regular SuppVersity reader you will probably already think: "Where is the actual measurement of the fractional protein synthesis?" The unfortunate answer: It's not there.

You can learn more about protein intake at the SuppVersity

Are You Protein Wheysting?

5x More Than the FDA Allows!

Protein requ. of athletes

High EAA protein for fat loss

Fast vs. slow protein

Less Fat, More Muscle!

Previous research had show that the ingestion of graded amounts of high-quality protein such as whey after resistance will maximize with "only" 20g of egg protein (Moore. 2009) or whey (Witard. 2014) in young men. Multiple studies in older adults (>60 years), on the other hand, suggest that they exhibit a lower anabolic signaling and MPS response to protein feeding, resistance exercise, and the combination of feeding and exercise when compared to young men (Cuthbertson. 2005; Fry. 2011; Burd. 2013). Scientists call this phenomenon age-related "anabolic resistance" (Yang. 2012b).

Figure 1: In contrast to the fractional protein synthesis in the elderly, which increases with increasing amounts of protein, the FSR of young men shows a ceiling effect at 20g+ whey protein (Yang. 2012a; Moore. 2009)

As you can see in Figure 1 from a 2012 study by Yang, the same 20g of extra-whey (total dose 40g) that was useless in young men, lead to a significant increase in protein anabolism in elderly men. Compared to young men, the MPS response to feeding 40 g of protein was yet still slightly lower in older vs. count men (Yang. 2012a; Churchward Venne. 2013b).

What is particularly relevant for the study at hand, and the previously criticized absence of actual MPS measurements is the fact that deficits in feeding induced p70S6K phosphorylation may at least partially underpin anabolic resistance in aged skeletal muscle (Cuthbertson. 2005), which is why measuring the p70S6K phosphorylation in older human subjects (mean age 71 years) in response to the graded ingestion of whey protein after a leg workout consisting of three sets of 8–10 repetitions of bilateral barbell smith rack squat, 45°leg press, and seated knee extensions at 80% of the subjects' predetermined 1R is not as irrelevant at it may initially have seemed.

Workout + supplements, that's the "whey to go" ;-)

The exercises were performed in a circuit manner with 1 min rest between each exercise and 3 min rest between subsequent sets, the exercise protocol took approximately 20 min to complete. Following completion of the exercise protocol, subjects were immediately provided with a fixed-volume (350 mL) beverage, containing a flavored noncaloric placebo, or oneof the four doses of whey protein concentrate (10 g, 20 g, 30 g, or 40 g).

Figure 2: Intramuscular amino acids. This figure is a heat map which shows groups means fold changes from the resting fasted condition. Green represents a decrease in amino acid content, white represents no change, and red represents an increase in amino acid content (D’Souza. 2014)

Subjects were instructed to ingest the beverage within 2 min and were required to ingest the total volume provided. Following consumption of the supplements, subjects rested in a supine position throughout the 4 h of post-exercise recovery with additional muscle biopsy samples collected at 2 and 4 h post exercise.

Figure 3: Higher protein intake = higher increase in p70S6K phosphorylation (left graph). This increase is linearly associated with intramuscular leucine levels (right graph | both from D’Souza. 2014)

As you can see in Figure 3, there was a similar dose-dependent increase in p70S6K as it was observed previously for MPS in skeletal muscle of elderly subjects by Yang et al. (2012b). In fact, the fold change in the phosphorylation of p70S6K (Thr389) at 2 h post exercise was correlated with the dose of whey protein consumed (r =0.51,P<001) and was found to be significantly correlated with intramuscular leucine content (r =0.32,P=0.026).

Moreover, the intramuscular BCAAs, and leucine in particular, appear to be important regulators of anabolic signaling in aged human muscle during post-exercise recovery via reversal of exercise-induced declines in intramuscular BCAAs.

Suggested Read: "Protein Timing Does Matter! Yet Only in Trained Men. More Than 2x Higher Relative Protein Retention W/ Immediate vs. 6h Post Whey Consumption in Bodybuilders vs. Rookies" | read more.

Bottom line: In the absence of a young control group and actual muscle protein synthesis (MPS) measurement, the study at hand cannot finally answer the question, whether older men require higher amounts of protein than young ones to achieve maximal increases in post-workout protein synthesis, but it is at least another piece of evidence that "more helps more" - at least in the elderly.

As mentioned in other recent posts, there are yet still many confounding variables that would have to be controlled and modified as well to answer the important (?) question: "How much protein does it take to achieve maximal post-workout protein synthesis?" Which confounding factors that would be? Well, what about the training experience? The baseline muscle mass? The protein content of the diet? And so on and so forth || Comment on Facebook!

References:

• Burd, N. A., S. H. Gorissen, and L. J. van Loon. 2013.  Anabolic resistance of muscle protein synthesis with aging. Exerc. Sport Sci. Rev. 41:169–173.
• Churchward-Venne, T. A., N. A. Burd, C. J. Mitchell, D. W. West, A. Philp, G. R. Marcotte, et al. 2012. Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men. J. Physiol. 590:2751–2765.
• D'Souza, Randall F., et al. 2014. Dose‐dependent increases in p70S6K phosphorylation and intramuscular branched‐chain amino acids in older men following resistance exercise and protein intake. Physiological Reports 2.8: e12112.
• Churchward-Venne, T. A., L. Breen, and S. M. Phillips. 2013a. Alterations in human muscle protein metabolism with aging: protein and exercise as countermeasures to offset sarcopenia. BioFactors 40:199–205.
• Churchward-Venne, T. A., C. H. Murphy, T. M. Longland, and S. M. Phillips. 2013b. Role of protein and amino acids in promoting lean mass accretion with resistance exercise
  and attenuating lean mass loss during energy deficit in humans. Amino Acids 45:231–240.
• Churchward-Venne, T. A., L. Breen, D. M. Di Donato, A. J. Hector, C. J. Mitchell, D. R. Moore, et al. 2014. Leucine supplementation of a low-protein mixed macronutrient beverage enhances myofibrillar protein synthesis in young men: a double-blind, randomized trial.
  Am. J. Clin. Nutr. 99:276–286.
• Cuthbertson, D., K. Smith, J. Babraj, G. Leese, T. Waddell, P. Atherton, et al. 2005. Anabolic signaling deficits underlie amino acid resistance of wasting, aging muscle. FASEB J. 19:422–424.
• Moore, D. R., M. J. Robinson, J. L. Fry, J. E. Tang, E. I. Glover, S. B. Wilkinson, et al. 2009. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am. J. Clin. Nutr. 89:161–168.
• West, D. W., and K. Baar. 2013. May the Force move you: TSC-ing the mechanical activation of mTOR. J. Physiol. 591:4369–4370.
• West, D. W., N. A. Burd, J. E. Tang, D. R. Moore, A. W. Staples, A. M. Holwerda, et al. 2009a. Elevations in ostensibly anabolic hormones with resistance exercise enhance neither training-induced muscle hypertrophy nor strength of the elbow flexors. J. Appl. Physiol. 108:60–67 .
• West, D. W., G. W. Kujbida, D. R. Moore, P. Atherton, N. A. Burd, J. P. Padzik, et al. 2009b. Resistance exercise-induced increases in putative anabolic hormones do not enhance muscle protein synthesis or intracellular signalling in young men. J. Physiol. 587:5239–5247.
• Witard, O. C., S. R. Jackman, L. Breen, K. Smith, A. Selby, and K. D. Tipton. 2014. Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. Am. J. Clin. Nutr. 99:86–95
• Yang, Y., L. Breen, N. A. Burd, A. J. Hector, T. A. Churchward-Venne, A. R. Josse, et al. 2012a. Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men. Br. J. Nutr. 108:1780–1788.
• Yang, Y., T. A. Churchward-Venne, N. A. Burd, L. Breen, M. A. Tarnopolsky, and S. M. Phillips. 2012b. Myofibrillar protein synthesis following ingestion of soy protein isolate at rest and after resistance exercise in elderly men. Nutr. Metab. 9:57.

23g of Dairy Protein + 5g of Leucine Turn Cardio Sessions Into Muscle Building Workouts - More Protein + Extra Leucine = Higher mTOR, But Minimally Improved FSR

No matter how much you supplement, running will probably never be the "most anabolic" sport of all. On the other hand, it's certainly less catabolic than broscienctific horror stories of muscle loss and weakness would tell.

Researchers from the Massey University Wellington claim: "Ingesting 23 g of protein with 5 g added leucine achieved near-maximal FSR after endurance exercise." (Rowlands. 2014; my emphasis). If you think "near-maximal" fractional protein synthesis after endurance exercises sounds incredible, I would like to invite you to join me and take a look at the design and results of this recent study from the School of Sport and Exercise.

As the authors point out, "the purpose of this study was to determine if a reduced dose of protein and leucine ingested following endurance exercise resulted in a similar anabolic signal impulse for the stimulation of skeletal muscle myofibrillar protein FSR, relative to the higher protein-leucine dose associated previously with improved recovery of performance." (Rowlands. 2014)

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In addition Rowlands and colleagues examined the phosphorylation (as a surrogate marker of activity)of signaling proteins within the mammalian target of rapamycin complex 1 (mTORC1) pathway to study the associations between plasma amino acids, translational signaling and myofibrillar FSR. The scientists' hypothesis was that the lower ingested quantity of protein (23 g) plus leucine (5g) would be sufficient to stimulate myofibrillar FSR to an equivalent magnitude to a 3-fold higher amount.

If the latter was possible, Rowland et al. assumed that the mTORC1 pathway phosphorylation between the two protein-leucine would be identical, as well.
The subjects were 12 endurance-trained male cyclists with mean age 30 y, stature 179 cm, and weight 78.1 kg (7.8) completed the study. Mean VO 2 max was 60.4 mL/kg /min with a corresponding Wmax of 323 W.

Figure 1: Graphical overview of the experimental procedure (Rowlands. 2014)

"The research design was a randomized single-blind triple crossover. Details of one of the three 7-d experimental blocks and the experimental testing protocol are provided in Figure 1. Two weeks prior to the first experimental block, participants completed a standard test on a Velotron ergometer (Racer Mate, Seattle, USA) to determine VO2 max and Wmax. The next day participants completed a familiarization of the testing procedure (100-min cycle, see below) (Figure 1A).

Physical activity and diet were standardized for 4.5-d prior to a 2-d period of control prior toeach experimental testing day. Standardization was prescribed by way of verbal and writing instructions and record in training and dietary recall diaries; participants were asked to replicate on days -6 to -2 (outcomes not recorded). Control of exercise on protocol day -2 (Figure 1A) comprised a 90-min ride with a warm up of 10 min at 30% (Wmax), 8 min at 40%, 2 min at 50%, then intervals (4 x 5 min at 70%) interspersed with three blocks of 3 x 2-min intervals at 85%, 80%, and 75%, respectively, interspersed with 2-min periods at 50%, followed by 5 min at 40%."

Following this ride and for the remainder of day and day following (Figure 1B), participants performed no training and were provided with a preweighed diet providing sufficient energy to balanceindividual caloric requirements based on the Harris-Benedict equation for activity factor of 1.6.

Don't be fooled by the amino acid additions: While there is plenty of evidence that "optimized amino acid blends" or "enhancements" are great for supplement producers to justify why they're selling you cheap whey protein / bullshit amino acid products at a crazy price, there is no evidence that they are superior to plain whey protein (see "Are You Still Wasting Money on Amino Acid Products?" | read more)... What? Oh, you want to know why Rowlands et al. do it in the study at hand? Well, because they work for Nestec Ltd. aka Nestlé - I guess that's also why there was no 30g of pure whey isolate control ;-)

The 100 min of cycling comprised a warm-up (as above), intervals (%Wmax) of 8 x 2-min (90%), 2 x 5 min (70%), 2 x 2 min (80%) and 3 x 1 min (100%), interspersed with recovery 2-min (50%); and 8 min cool-down (40%). During exercise, participants consumed 800 ml /h of artificially sweetened electrolyte solution to maintain hydration and were fan cooled.

The supplementation regimen

Following exercise, participants showered, and then ingested the first nutrition serving 10-min after cessation of exercise and subsequently every 30 min over the first 90 min of the 240-min assessed recovery (Figure 1B).

Figure 2: Nutrient composition of the test drinks, which contained a whey + milk mixture that was enriched with leucine and spiked with maltodextrine, fructose and canola oil (Rowlands. 2014)

"The experimental beverages consisted of milk-based drinks containing milk protein concentrat and whey protein isolate (2:1 w/w), L-leucine, maltodextrin and fructose (1:1 w/w), and freeze dried canola oil. Four equal servings of 300 ml of the beverages were consumed during the recovery period for a total volume of 1200 ml.[...] The 15LEU supplement was compared to one-third of the protein-leucine quantity (23.3/5/180/30 g, 5LEU) - an intake hypothesised to yield a bioequivalent similar myofibrillar FSR, and to a nonnitrogenous, isocaloric control (0/0/274/30 g, CON). All beverages also contained 1.4 g NaCl, 14.4 g vanilla essence, and 3.6 g of emulsifier (Paalsgard 0096, Paalsgard A/S, Denmark) per 1200 mL."

As the data in Figure 3 shows, even the "small" shake was potent enough to achieve (almost) maximal fractional 0.95%/h protein synthesis rates.

Figure 3: mTOR (C1+C2) response to protein ingestion (left) corresponding mean fractional protein synthesis (%/h; right) in the 12 healthy male subjects (Rowlands. 2014)

Although the 15LEU = high protein drink achieved minimally higher protein synthesis rates, the discrepancy between the extremely elevated mTOR levels early post ingestion and the effective differences in FSR clearly suggest that we are approaching a physiological maximum with at FSR rates of 0.11% /h... or as Rowland et al. put it:

"The current myofibrillar FSR appeared to be limited by an undefined intramuscular mechanism since only a small and bioequivalent increase in FSR occurred with 15LEU despite sustained 1.4- to 1.9-fold higher plasma leucine and amino-acid concentrations and higher p70S6K-rpS6 phosphorylation." (Rowlands. 2014)

With reference to previous research by Atherton et al., Rowlands et. al. speculate that they may have encountered a "muscle full" effect (Atherton. 2010) to explain the discordance between human muscle protein synthesis and mtorc1 signaling.

Figure 4: Fractional protein synthesis in response to resistance training + whey protein ingestion (Tang. 2009)

Bottom line: Whether we are seeing a "muscle full" effect is something that's difficult to tell. What appears to be certain, though, is that resistance training allows for a greater uptake of protein synthesis (Tang. 2009; 0.15% /h in response to resistance training + whey protein). Although the supplements were somewhat different, I am thus inclined to believe that the absence of resistance training and the corresponding mTOR-C2 activation in response to aerobic ( (mTORC1 by supplementation, only) vs. resistance training (mTORC1 by supplementation, mTORC2 by contraction) is the limiting factor, here (Drummond. 2009).

The latter would imply that the results are not applicable to resistance training directly. Even if corresponding studies clearly suggest that there is a limit to the benefits of "evermore" protein with resistance training, as well, the "limit" may be higher than "just" 23g of mixed dairy protein + 5g of leucine.

Reference:

• Atherton, Philip J., et al. "Muscle full effect after oral protein: time-dependent concordance and discordance between human muscle protein synthesis and mTORC1 signaling." The American journal of clinical nutrition 92.5 (2010): 1080-1088.
• Drummond, Micah J., et al. "Rapamycin administration in humans blocks the contraction-induced increase in skeletal muscle protein synthesis." The Journal of physiology 587.7 (2009): 1535-1546.
• Rowlands, David S., et al. "Protein-Leucine Fed Dose Effects on Muscle Protein Synthesis After Endurance Exercise." Medicine & Science in Sports & Exercise (2014).
• Tang, Jason E., et al. "Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men." Journal of Applied Physiology 107.3 (2009): 987-992.

Eccentric Exercise "Superior Driver of Acute Anabolic Signalling That May not be Mirrored in the Rate of Muscle Protein Synthesis", 12 Week Human Study Suggests

Concentration curls are one of the few exercises, where eccentrics make sense. They are safe and you can even do them if you don't have a training partner.

The title of today's SuppVersity article is actually an almost literal quote from the abstract of a recent paper from the Aarhus University that's about to be published in an upcoming issue of the peer-reviewed scientific journal Amino Acids, where it says: "In conclusion, maximal eccentric contraction mode may constitute a superior driver of acute anabolic signalling that may not be mirrored in the muscle protein synthesis rate."

Quite an intriguing conclusion that puts yet another huge questionmark behind the usefulness of the three dozen of studies that measure exclusively (acute) protein synthesis to assess the efficacy of certain exercise and/or supplementation regimen.

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Before we get caught up in discussing the implications of the study at hand (as we are going to see later, we would be jumping to conclusions, anyways), it would yet be wise to take a closer look at the data that's at the heart of the previously cited conclusion.

Rahbek and her colleagues from the University of Aarhus and the University of Copenhagen set out to confirm the following hypothesis (Rahbek. 2014):

1. 

   Don't waste money on amino acid blends | learn why

   In the exercise-habituated state, single-bout  eccentric contractions would augment muscle protein synthesis and mTOR signalling compared to concentric contractions
2. The effects would be amplified if the subjects consume whey protein hydrolysate and carbohydrates after the workout compared to carbohydrates, alone.
3. Compared to the concentric training, the eccentric training would provide a stronger hypertrophy response and a more sustained increase in proteins involved in the mTOR protein synthetic cascade.

Luckily the Danish researchers did not content themselves with measuring the acute response to a single exercise, but used the funds they received from Arla Foods Ingredients group wisely and recruited twenty-four young healthy recreationally active men (height, 1.82  ±  0.015  m; weight, 78.1  ±  1.8  kg; age, 23.9 ± 0.8 years; fat %, 16 ± 0.9 %) as their study subjects for a 12-week study with (1) a short period of exercise habituation, (2) a single-bout resistance exercise trial to investigate the acute phase exercise responses, and (3) a 12-week training period to investigate accumulated resistance exercise responses.

"All participants per formed eccentric work (ecc) with one leg and concentric work (cOnc) with the other leg. eccentric exercise was randomly ascribed to either the dominant (preferred kick ing leg) or the nondominant leg to exclude any potential pre-training differences between the legs." (Rahbek. 2014)

In addition, the effects of a WPH +cHO supplementation versus isocaloric cHO supplementation were investigated in the single bout trial and the training period. The participants were randomly divided into one of the two supplement groups and supplements were provided in a double blinded fashion. this within-participant design with regard to contrac tion mode was used to minimize the potential differences in the training response that are inherent with group designs because of differences in initial training, nutritional and hormonal status. Accordingly, the following four inter ventions were compared: (I) eccentric training with WPH + CHO; (II) eccentric training with CHO only; (III) conencentric training with WPH + CHO, and; (IV) concentric training with CHO.

Injury warning - eccentric squats are not save ;-) Aside from the ease of execution and the high standardization the mere fact that you can do safely do eccentric leg extensions was probably the main reason for the Danish researchers to pick the leg extension as their exercise of choice. I can only warn you, not to do squats or a similar multi-joint full-body exercise "eccentrically" - with or without spotter!

Throughout the study period, the participants were instructed to maintain their normal habitual physical activity level and dietary intake. Three days prior to the start of the study, the participants were asked to refrain from physical exercise. One basal muscle biopsy was then sampled from a randomly chosen leg. The biopsy was repeated twice: Three days after the 7-day habituation phase, and 3-6 days after the last training session 12 weeks later.

"Each participant completed 2–3 exercise sessions per week over a 12-week period to a total of 33 training sessions. All exercise sessions were initiated with 5 min light bicycling warm-up. Eccentric load was aimed at 120 % relative to concentric loading, with a training supervisor assisting to allow isolated exercise modality of the two legs. the load difference is parallel to the approximate strength difference between slow ecc[entric] and con[centric] contractions during isokinetic strength testing." (Rahbek. 2014)

Unfortunately, the resistance training program consisted of isotonic knee extensions, only (understandable from a science perspective, but disappointing for all of us who would have preferred a more realistic training scenario). The latter were performed with the following set × repetitions:

Figure 1: Sustained elevations in anabolic signalling were observed only in the eccentric training group.

• 6 × 10– 15 rM (sessions 1–4),

• 8 × 10–15 rM (sessions 5–10),

• 10 × 10–15 rM (sessions 11–20), 

• 12 × 6–10 rM (sessions 21–28), and 

• 8 × 6–10 rM (sessions 29–33) 

The participants were instructed to perform the exercise with picture perfect form and at a tempo of 2 seconds on both the concentric and the eccentric phase of the exercise. Two minutes of recovery were interspaced between sets and all training sessions were closely supervised and monitored by qualified training instructors to ensure proper execution and loading.

Figure 2: Changes (%) in quadriceps CSA over the 12-week training period (Rahbek. 2014)

In spite of its minimalist nature, the training program elicited measurable increases in muscle size, which were significantly more pronounced, when the subjects consumed 0.30g/kg whey protein hydrolysate and 0.30g/kg carbohydrates, instead of 0.60 g/kg carbohydrates (CHO trial) after the workout (see Figure 2).

Figure 3: the myofibrillar protein FSR for WPH + CHO and CHO supplement groups ± eccentic versus concentric resistance exercise contraction mode exercise, are shown as mean ± standard deviations during time intervals 1–3 h and 3–5 h, respectively (Rahbek. 2014)

Anabolic advantage practically irrelevant? What we don't see in Figure 1 is a significant advantage for the eccentric over the concentric trial. Despite significantly more pronounced expressions of mTOR and p70S6K (see Figure 1) in hours 3-5 after the workout - how come?

Well, the fact that the increase in muscle size in the non-protein supplemented eccentric training group is lower that the one in the concentric group, while the gains in the WPH + CHO group are superior already suggests that this may be a question of protein availability and breakdown. While the former is low on the CHO only trial, the latter is just as high as it was in the eccentrically trained WPH + CHO group. This could explain the differences and the disappointing net "advantage" of pro-anabolic eccentric training the researchers observed in the study at hand.

Which brings me back to my premature conclusion that the study at hand would support the uselessness of acute measures of protein synthesis! I mean, take a look at Figure 3  - what results would you predict based on the acute fractional protein synthesis rates? Yes, exactly the result we got after 12 weeks of resistance training - astonishing! And would more protein or another shake 3 hours later have made a difference? I don't think so. Look at the FSR rates in Figure 3 again. Doesn't it look as if 0.1% was simply all you could expect? It would still be worth a study... unfortunately, I am not sure if Arla is going to pay another one, because the one thing they were interested, i.e. the usefulness of whey is the only unambiguous result of the study at hand.

References:

• Aagaard, Per, et al. "Neural inhibition during maximal eccentric and concentric quadriceps contraction: effects of resistance training." Journal of Applied Physiology 89.6 (2000): 2249-2257.
• Rahbek et al. "Divergent resistance exercise contraction mode and dietary supplementation type on anabolic signalling." Amino Acids (2014). Ahead of print.

Protein Blends, Not Isolates Promote Maximal Skeletal Muscle Protein Retention(!) - It's Not About How Much You Pump into the Muscle, It's About How Much You Retain

Scientific evidence suggests: There is not one optimal protein to build muscle - it's the mix of fast to slow proteins that's key.

For someone like yourself, who's making sure to get his daily dose of SuppVersity Science News, the results Reidy et al. present in their latest paper in the Journal of Applied Physiology can hardly be surprising. I have, after all, written about the superiority of whey + casein blends as potential muscle builders only recently ("When Whey & Casein Unite in the Spirit of True Physique Improvements, BCAAs & Glutamine Better Shut the F*** Up"  | (re-)read the article). It was thus only to be expected that a study in which the scientists from the University of Texas Medical Branch compared the effects of the prolonged hyperaminoacidemia that's associated with the ingestion of a blend of plant (25% soy) and dairy (50% casein, 25% whey) proteins (with varying digestion rates) to that of a pure rapidly digested whey would yield a definite points win for the "time-released" formula.

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The reasons why it's still well worth taking a closer look at the study results are (a) the fact that the f**** up supplement industry is still trying to tell you that protein blends would be inferior to overpriced isolates and (b) the educative value of the post-workout + post-supplementation serum amino acid profiles Reidy et al. observed the 16 healthy, young subjects (age range: 19 –30 yr) who participated in their double-blind, randomized clinical trial (with body fat levels of >24% those were certainly no physical culturists, though ;-)

Figure 1: Graphical overview of the study design (Reidy. 2014)

As you can see in Figure 1 the study protocol involved a standardized resistance training session in the course of which the subjects who had been kept on a diet containing 20% protein, 60% carbohydrate, and 20% fat at 12 kcal/kg for 72h, performed leg extensions on a Cybex-VR2 (Medway, MA), i.e. 8 sets of 10 repetitions at 55% (set 1), 60% (set 2), 65% (set 3), and 70% (sets 4 – 8) of the participants previously determined 1 RM with 3-min rest between sets, before they consumed the protein beverages (Whey or Blend) exactly 1 h postexercise.

Figure 2: Net phenylalanine enrichment (left) and inward and outward transport (right)

The ingestion of the beverages of which the blend and the whey protein contained of 20.1 g total protein (providing 1.9 g leucine, 1.0 g phenylalanine, 1.3 g valine, and 9.0 g EAA; 50% protein from sodium caseinate, 25% protein from whey protein isolate, and 25% protein from soy protein isolate) and 17.3 g of protein (providing 1.9 g leucine, 0.6 g phenylalanine, 1.1 g valine, and 8.7 g EAA; 100% whey protein isolate), respectively, lead to significant increases in amino acid transporter activity (2/SLC38A2, proton-assisted amino acid transporter 1/SLC36A1, cationic amino acid transporter 1/SLC7A1).

"However, the ingestion of the protein blend resulted in a prolonged and positive net phenylalanine balance during postexercise recovery compared with whey protein (P 0.05)." (Reidy)

In view of identical postexercise myofibrillar protein synthesis in both groups this difference may appear negligible. If you've been following my articles about the often oversimplified protein synthesis and increases in skeletal muscle mass, you should be aware that net retention and not fractional synthesis is the term you have to look for, when you're analyzing corresponding studies.

Bolus ingestion could be a superior alternative: In view of the fact that the advantage of protein blends is directly related to their ability to trigger sustained increases of the level of amino acids in the blood, the same can be achieved by the ingestion of whey protein at regular intervals - e.g. at least every 2 hours. Needless to say that this is not just more expensive, but also less practical than the 20-40g of a protein blend many of you are probably already consuming right after their workouts.

Bottom line: I am still very hesitant to suggest buying a blend with significant amounts of soy in it, when egg proteins should do a similarly beneficial job as a "filler" that keeps the amino acids (AA) levels elevated when the influx of AAs from whey is beginning to seize and the slow digesting casein protein (in the study at hand, we had regular sodium caseinate, which is actually faster digesting than micellar casein) are not yet fully digested.

In general, however, the study at hand clearly supports the notion that protein blends that are designed to provide a sustained elevation of all essential amino acids in the blood (not just BCAAs, learn why) will induce a superior growth response. Whether the same is true if we compare the ingestion of a single protein blend shake to the repeated (ev. 2h) ingestion of 20g of whey protein, will yet have to be elucidated in future studies.

Reference: 

• Reidy, Paul T., et al. "Soy-dairy protein blend and whey protein ingestion after resistance exercise increases amino acid transport and transporter expression in human skeletal muscle." Journal of Applied Physiology 116.11 (2014): 1353-1364.