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.

Time Under Tension (TUT) Another Under-Appreciated Determinant of the Protein Synthetic Response to Exercise?

Image 1: Is it really time to buy some revolutionary new exercise equipment to time your time under tension? Or should you keep pumping away like there was no tomorrow?

If you have been following the SuppVersity news for some time now, you know that I am a "fan" of the research Stuart Phillips and his colleagues at the Department of Kinesiology at McMaster University in Hamilton, Ontario, are doing. Before I get to some details on their latest coup, I must yet express some concerns about Phillips' focus on immediate changes protein synthesis. Yes, amino acid ingestion and particularly leucine increase protein synthesis, yes, bolus ingestion of whey protein increases protein synthesis over sipping and yes, training with low loads (30%) and slow reps, as in the study at hand, increases protein synthesis,... but hey. Do you really give a damn about protein synthesis? No, you don't. Either you want to gain muscle or you want to get stronger and exactly here I am missing a link that would connect the short-term increases in the protein synthetic response to exercise Phillips and his colleagues are investigating in one study after the other and the long(er)-term real-world outcomes in terms of muscle size and strength gains.

Wait! Is protein synthesis really that important?

I will probably touch on this issue in tomorrow's installment of the Intermittent Thoughts, as well, so let me just say this: Muscle protein synthesis is only one out of two (maybe three processes) and probably not even the most important one, when your goals are getting really big or really strong. I mean, if increasing protein synthesis was all it would take to get as buffed as Phil Heath and as strong as Derek Poundstone, everyone would be training like a sissy (like in this study), take his BCAAs and whey protein and see amazing results... but I am once again getting off a tangent here, and as I already said, you will read more on that here at the SuppVersity in the future. So, for the time being, let's get back to the time under tension, i.e. the exact number of seconds your muscles are actually working (meaning contracting) during a given set.

Figure 1: Basic outline of the study first and second testing session (based on Burd. 2011)

For their most recent study Nicholas A. Burd et al. recruited 8 recreationally resistance-trained men (23.5 ± 1 years; 88.3 ± 5 kg; BMI=26.5 ± 1.0 kg/m²) who had performed lower body resistance exercise training with a frequency of at least 2x/week in the course of the last 2 years prior to the study [note: this certainly is a huge plus of the study, because we all know that you can have a newbie do nothing but climb stairs and he will still grow ;-] The individual one rep-max for leg-extensions was accessed once prior to the infusion trial (105kg right, 101kg left leg) and dietary intakes were recorded prior to both the resting and the exercise infusion trials, in the course of which the participants reported to the lab fasted (at 7am) before a catheter for the tracer infusion was inserted into their arm and a first (fasted) muscle biopsy was taken from their legs (3.5h after reporting to the lab).

Participants subsequently performed bouts of unilateral leg extension exercise at 30% of
their previously established concentric 1RM. Legs were randomized and balanced for dominance based on maximal strength to perform exercise at a slow lifting (SLOW) or an external work-matched control (CTL) conditions. The leg assigned to the SLOW condition performed exercise with a lifting/lowering cadence of 6 s concentric phase and a 6 s eccentric phase with no pauses until volitional fatigue (i.e. failure). Failure was defined as the point at which the participant could not lift through the full range or their technique to lift the load included motions at joints other than the knee. The CTL condition was completed with the contralateral leg and was matched to the experimental condition for contraction volume such that the leg performed an identical number of repetitions at an equivalent load, but not to failure, and was performed with a lifting cadence of 1 s concentric phase and a 1 s eccentric phase.

The participants performed a total of 3 sets with 2 minutes of rest between the sets for each condition. Lifting cadence was monitored by an instructor and by the use of a metronome. Moreover, the exact knee-joint angles were recorded by the means of a goniometer. After a subsequent 2nd blood sample was taken, all participants consumed 20g of whey protein isolate. 6h after, a 2nd bilateral biopsy was taken and the participants were fed a standard cafeteria meal. For the rest of the day they were advised to follow a diet that would mirror their previously recorded food intake, with the last meal being consumed before 22h, "to ensure a 10 h fast prior to the beginning of the 24 h post-exercise protein synthesis measurement", which took place the next morning after the consumption of another 20g of a tracer-enriched whey protein supplement.

Figure 2: Fractional protein synthesis (in % per hour) - left; and relative differences in protein synthesis of slow vs. ctrl condition - right (based on Burd. 2011)

The data in figure 2 clearly shows that going to failure (and this is what I consider even more important than time under tension when training with sissy 30%1RM loads) produces profound (compare the relative increases in the smaller graph on the upper right corner) increases in fractional protein synthesis, which are, in the time-window right after the exercise bout, particularly pronounced in the mitochondrial and sarcoplasmic compartment of the muscle. In this regard, Burd et al. point out that

[w]hat we observed here was a potentiated effect, from that seen in the fasted-state, of prior exercise in enhancing the feeding-induced myofibrillar protein synthetic rates. This effect appears to be dependent on maximal fibre activation during exercise, [...] The current study is noteworthy in that an enhanced effect of protein feeding during late exercise recovery was induced by a longer time under muscle tension rather than intensity-independent contraction volume, which we have previously examined (Burd. 2010).

As far as the delay in the normally immediate increase in myofibrillar protein synthesis is concerned, the researchers speculate that both the timing of the biopsies, as well as the training status of the subjects and the specificity of their protocol about which they state that with its long loading times at relatively low intensities it must have shifted the protein (immediate) myofibrillar protein synthetic response "toward increased synthesis of proteins in the mitochondrial and sarcoplasmic pools" (cf. figure 2) - a process the underlying causes and mechanisms of which are yet unclear.

Why would you change a winning team?

Image 2: When it comes to SST and all the other training types from the alphabet soup, I alway wonder why people keep questioning what has worked well for the majority of bodybuilders and athletes, they are looking up to and whose physiques they are admiring!?

Actually this observation takes us full circle to my introductory remarks on the possible short-sightedness of measuring acute fractional protein synthesis. After all, what we are seeing here is rather the response we would expect as a consequence to a rather endurance-oriented exercise regimen. Whether the latter would entail the "size" (and strength) gains everyone currently associates with the magic words "increases in protein synthesis" remains thusly highly questionable.

This is particularly true if we take into account the results of another pretty recent study be Eonho Kim et al. (Kim. 2011), which found that an even slower (10s concentric, 10s eccentric) training protocol at 50% or the 1RM led to greater increases in flexibility but highly variable and overall lower strength gains than a traditional protocol with (4s total TUT at 80%RM) in college-aged women. This basically confirms what previous studies by Keeler et al. (+39% in traditional, only +15% in slow training; Keeler. 2001) have already established: (Super) Slow Training works, but it does not work as well classic resistance training.

And no matter whether you train slow or fast - in the end, intensity will always be determined by a matrix of loads, volume, TUT and training density and I doubt we will see a study that controls for all this variables even in the remote future (and if that happens you know that the SuppVersity is the place where you will read about it, first) - so the best thing you can do, is to rely on what worked for generations of physical culturists and that was definitely not training with 6s concentric and 6s eccentric reps ;-)

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.

80% Greater Protein Synthesis 3-5h After Workout: 20g+ PWO Protein Threshold Holds. Spiking Lower Amounts With Leucine or EAAs Will Still Yield Sub-Optimal Results

Image 1: Milk (proteins) are not just leucine or EAA - try doing that with half the amount of free-form aminos in water - the results will certainly be "suboptimal", I can vouch for that  ;-)

It has been a while since the last study from Stuart Phillips group at the McMaster University has made it to the SuppVersity news. Their latest publication does yet have the potential to pour oil on troubled waters, because the results appear to confirm that even when every other supplement appears to be failing you, you can always rely on your postworkout whey protein (Churchward-Venne. 2012). And while the study confirms that with some free form amino acid witchcraft, you can actually illicit identical post-exercise increases in protein synthesis, the previously determined threshold dosage of 20g of high quality protein is still the gold standard, for everyone whose interest is to actually build muscle which is, as you as a seasoned SuppVersity veteran know, not happening only in the first hour after a workout but within a 24h+  "window of opportunity" that has the size of barn door (cf. "Opening the 'Anabolic Barn Door' With the Key of Exercise and Nutrition Science!")!

You won't get a-whey without 20g+ of whey!

To elucidate whether the increasingly popular practice of pimping whole proteins with amino acids does make any sense in terms of being able to get away with less total protein, yet identical increases in post-workout protein synthesis Churchward-Venne et al. recruited 24 recreationally active, young adult male volunteers (22±0.6 years; 1.80±0.02m; 76.4±2.0 kg; BMI 24.3kg/m²), who had to perform a standardized 4x4 unilateral leg-workout with 3 min rest between sets consisting of

• 4x 10-12 reps of seated knee-extension and 
• 4x 10-12 reps of leg-press

at ~95% of their individual 10-rep max, which had been determined in a testing session 14 days prior.

Note: The reason Churchward-Venne et al. decided to use a unilateral exercise protocol was that this allowed them to take biopsies from both the exercised and non-exercised leg and thus determine the individual influence of exercise and supplementation.

You better make sure you get your protein, not just EAAs or leucine

Figure 1: Amino acid compositions of the test drinks (Churchward-Venne. 2012)

The study participants, who had consumed a standardized, prepackaged relatively low-protein diet (15% protein,. 55% carbohydrate, 30% fat) the day before the exercise intervention, were randomly assigned to consume one of the following drinks

• whey protein - 25 g whey protein isolate (total leucine: 3g)
• whey + leucine: 6.25 g whey protein isolate supplemented with free-form leucine (total leucine: 3g)
• whey + EAA: 6.25 g whey protein isolate supplemented with free-form EAAs (total leucine: 0.75g)

The 300ml of fluid which contained identical tracers, were consumed immediately post workout, blood and muscle biopsies were taken at regular intervals pre- and post workout and MPS, signaling through mTOR, and amino acid transporter (AAT) mRNA abundance were determined.

Figure 2: Relative expression of p-mTOR (left) and p70S6K (right) compared to baseline (Churchward-Venne. 2012)

Now what is interesting is that the "classic" markers of protein anabolism, p-akt (not shown, but exhibited significant differences between treatment), mTOR and P70S6K (figure 2 & 3) do not show a clear-cut advantage of either of the treatments. Immediately post exercise, the increase in mTOR in the exercised leg, for example, is significantly more pronounced in those subjects who consumed a whey protein shake. The "downstream" activation of p70S6K, which supposedly controls protein synthesis at the ribosome, however, is identical in all groups.

Figure 3: Pseudo (=simply weighed by the timespan) area under the curve (a.u) for mTOR and p70S6K, AUC for leucine (a.u.) and fractional protein synthesis in the exercised leg 3-5h after the workout (based on Churchward-Venne. 2012)

The same is true for the protein synthetic response measured as fractional protein synthesis in the whole post exercise period in the untrained, and up to 3h post exercise in the trained leg. Then, however, we see a markedly higher influx of protein into the trained muscle in the whey protein group, which is - and this is somewhat remarkable - not in accordance with the p70S6K levels, which would suggest that the protein influx should be maximal in the leucine and not in the whey group.

A protein pump without protein is useless

Based on the data we have, it is difficult to say whether it is the lack of an individual, a certain combination or the total amount of (non-)essential amino acids that is responsible for this affect. If you take a look at the amino acid composition of the test solutions in figure 1, it does yet appear likely to assume that it is the absence of non-essential amino acids...what? Glutamin? No, I thought so as well, but when you come to think about it, glutamine, of which we have recently seen that it does play a hitherto under-appreciated role in protein synthesis, is unlikely to exert this effect on its own. After all, Chiu et al. based their conclusions with respect to the necessity of glutamine to maximize protein synthesis on increases in mTOR expression (cf. "A New Role for Glutamine in Protein Synthesis?"). 3-5h after the workout the initially increased mTOR levels in the whey protein group had yet returned to baseline and the the leucine, BCAA and EAA levels in the blood of the subjects were identical in all groups (data not shown); and still, the influx of protein into the exercised leg musculature of the whey group was ~80% higher than that in the EAA group.

Image 2 (dormtainment.com): Subjects from the EAA, the leucine and the whey group (from left to right) after ingestion of the respective fluids - just kiddin' *rofl*

But let's be honest, in the end, these results only what common sense should have told us all along: You can push the gas pedal as much as you want (leucine group) and still won't get very far if your protein tank is half empty. Similarly, you can ingest as much leucine as you want and it will still have little effect on total protein synthesis, regardless of whether you train or not. For the practitioner, any further speculations about the minimal amount of leucine, a given persons in a given age-group would need to maximally stimulate protein synthesis, as the authors make them in their discussion of the results are non-significant compared to the following straight forward take home messages:

1. 20-25g of whey protein are still the go to post-workout protein source
2. building a better post workout protein from free form EAAs is not feasible
3. the importance of the non-essential amino acids in "real" protein is probably under-appreciated
4. the importance or I should say potency of leucine is probably much over-estimated
5. muscle protein synthesis and thus skeletal muscle hypertrophy is not a 2h post workout game

In essence, it would suffice to remember just (1) and (5) and to follow the simple yet effective maxime to get 20g+ of quality protein (not 20g leucine ;-) with every meal to get big and muscular and, as all of you who read yesterday's news or one of the many previous posts in which I envoked the findings of Loenneke et al. which show just that: People with a frequent intake of quality protein have the lowest body fat levels (Loenneke. 2012).

References:

1. Chiu M, Tardito S, Barilli A, Bianchi MG, Dall'asta V, Bussolati O. Glutamine stimulates mTORC1 independent of the cell content of essential amino acids. Amino Acids. 2012 May 8. [Epub ahead of print]
2. Churchward-Venne TA, Burd NA, Mitchell CJ, West DW, Philp A, Marcotte GR, Baker SK, Baar K, Phillips SM. 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. 2012 Mar 25.
3. Loenneke JP, Wilson JM, Manninen AH, Wray ME, Barnes JT, Pujol TJ. Quality protein intake is inversely related with abdominal fat. Nutr Metab (Lond). 2012 Jan 27;9(1):5.
4. Moore DR, Robinson MJ, Fry JL, Tang JE, Glover EI, Wilkinson SB, Prior T, Tarnopolsky MA, Phillips SM. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr. 2009 Jan;89(1):161-8.

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.

You can learn more about protein intake at the SuppVersity

Are You Protein Wheysting?

Cod protein for recovery

Protein requ. of athletes

High EAA protein for fat loss

Fast vs. slow protein

5x More Than FDA Allows

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.

Whey or Casein? Pre- or Post Workout Protein? Insights into Peri-Workout Nutrition from Small Scale Study in Elderly People Bring Milk Back onto the Radar

You already read it in the title of this post: The following data comes from a small scale study (Dideriksen. 2011) in elderly people. Those, who listened to my dissertation on how reliable science is (aired on Carl Lenore's Super Human Radio on Wednesday, 20 April 2011), will know that a small number of participants from what one may call a "special population", in this case 15 elderly men and nine elderly women (age 68 ± 1 years, range 61–80 years), dictates caution in view of the overall significance and reliability of the data. The results which are soon to be published in the Scandinavian Journal of Medicine & Science in Sports are nonetheless, worth to be taken note of.

Diderisken et al. had their subjects (again: 15 elderly men and 9 elderly women; age 68 ± 1 years, range 61–80 years) perform 5 sets of eight repetitions at 80% of 1 RM in both unilateral knee-extension and bilateral leg-press with 3 min of rest between sets and measured muscle myofibrillar and collagen fractional synthesis rates (FSR) by a primed continuous infusion of l-[1-¹³C]leucine using labeled proteins during a 6-h recovery period. Other than the researchers had expected the fractional protein synthesis rates did not depend on form or timing of the 0.45 g/kg LBM supplemental protein their subjects consumed.

No differences were observed in muscle myofibrillar and collagen FSR with Whey [administered post workout] compared with CasPost [casein post workout], and it did not differ between CasPre [casein pre workout] and CasPost.

This being said, secondary data on the leucine concentration does support the well-established advice to prefer whey over casein in the (non-existent) "post workout window":

The plasma leucine concentrations were increased during the entire post-exercise periods in CasPre, CasPost, and Whey compared with the basal levels. The leucine concentrations reached a peak of 227 ± 11, 282 ± 17, and 490 ± 32 μmol/L in CasPre, CasPost, and Whey, respectively. [...] The total leucine response expressed as the AUC in the time period 15–390 min after the resistance exercise bout was significantly higher in Whey compared with all the other groups (P<0.05), higher in CasPost compared with CasPre (P<0.05), and lower in Control than in the other groups (P<0.01).

This very ability of whey protein to "spike" leucine levels post workout go hand in hand with findings from previous studies (in rodents, as well as human subjects) that suggest a slight yet significant advantage of whey over casein in view of the nutritional amelioration of exercise induced muscle anabolic responses. It is yet worth mentioning that both additional casein pre-ingestion and casein (co-)ingestion post-workout could be valuable strategies to prolong the increase in total (TAA) and essential (EAA) amino acids. This hypothesis is supported by the following findings:

[...] plasma TAA concentrations were increased in CasPre (15–150 min), CasPost (30–60 min), and Whey (30–60 min) compared with the basal levels. The plasma EAA concentrations were increased in CasPre (30 min), CasPost (30–270 min), and Whey (30–60 min) compared with the basal levels.

Figure 1: Nature already invented
the perfect peri-workout drink: Milk!
(photo (cc) Chedid, Janine. 2004)

In essence the combination of a slow acting casein before workout and a mixture of fast acting whey and slow acting casein protein after workouts would maximize both total, as well as, essential amino acid levels over a time period from 15-60 and 30-270 minutes, respectively - with a whey-induced "anabolic" leucine spike in the immediate vicinity of the workout.

Well, that being said, guess who has already developed such a pre/post/peri-all-in-one-workout formula for you? Nature! The name? Milk! Milk is roughly 80% casein and 20% whey, has some additional carbs in it that will get you through your workout and is full of healthy minerals and vitamins that will help you recover even faster. Make it raw unpasteurized milk from the happy grass-fed cows of a local farmer and there will be little room for further improvements ;-)

"20g or 40g of Whey?" That's the Wrong Question, When 4-5x 20-25g from Different Sources Would be the Answer!

Image 1: There could be a reason that your favorite protein powder comes with a scoop and a suggested serving size of 25-30g protein (max.)

If you could just pick one dietary supplement to take to desert island, what would it be? Creatine? Unquestionably a good choice. Yet even if the local fauna provided you with unlimited amounts of eggs, meats and fish, a whey protein powder, or I should say a leucine-rich complete protein source would probably be a better choice. Despite the fact that I am still skeptical as far as the real world significance of supplementally augmented post-exercise increases in fractional protein synthesis as the main, let alone exclusive determinant of skeletal muscle hypertrophy is concerned, it is undebatable that the delicate balance between protein breakdown and synthesis is at least the most obvious and, in the short term, probably in fact the most influential contributor to muscle growth.

"Only 1.2 - 1.6 protein per kg/day!?" - Calm down! The total amount is not all that counts

According to the latest installment of the "A to Z of Nutritional Supplements" series in the British Journal of Sports Medicine (the part on protein was - you may already have guessed it - co-authored by no one else but Stuart Phillips) the "current scientific evidence" suggests that

1. daily intakes higher than the RDA, to be precise, 1.2-1.6g/kg body weight,
2. an emphasis on leucine-rich protein sources (I suggest dairy, alternatively pea protein),
3. multiple servings of 20-25g of protein / protein-rich foods spread equally across the day,
4. an additional protein shake immediately after your workout

"should be very effective at allowing repair, remodelling and adaptation, and gains in lean mass in athletes" (Phillips. 2012).

Quality, Consistency and frequency over gluttony

For an 80kg athlete this would translate into a total protein intake of 96-128g of protein per day. Sounds pretty sparse, right? Well, if we just count proteins from meats, eggs, fish, dairy and dietary supplements and discard the protein from other sources, this would leave our 80kg athlete with max. 4-5 meals at which he would easily achieve the "threshold" limit of 25g; five opportunities to monetize on the dietary induced increase in protein synthesis; and five potentially protein anabolic spikes in plasma amino acid concentrations.

Remember: In the slowly abating hoopla around leucine people tend to overlook that despite its ability to set the protein synthetic machinery into gear, leucine needs the other EAAs and conditionally essential amino acids to get its muscle building job done.

And though the actual data does not provide any revolutionary new insights into the "ideal" amount of protein, a recently published study from Kevin D. Tiptons group at the University of Birmingham provides further evidence that everyone who strives to maximize skeletal muscle protein synthesis should be primarily concerned about the consistent and frequent (3) ingestion of quality (2) protein (Jackman. 2012).

Figure 1: Urea production (µmol/h/kg * 4h) and fractional myofibrillar protein synthesis (per hour) in the 4-hour recovery period after an intense leg workout and supplementation with either 20g or 40g of whey protein (data based on Jackman. 2012)

Despite the fact that there was a greater increase in fractional myofibrillar protein synthesis after the ingestion of 40g vs. 20g of whey protein after the 8 sets of 10 repetitions of leg presses and leg extensions the 30 previously resistance trained male subjects in the Jackman study had to perform, the +10% difference (+51% increase in MPS in the WP40, +41% in the WP20 group; increase expressed vs. placebo), the latter did not reach statistical significance over the 4h post workout period.

Diminishing returns with large vs. multiple bolus ingestions

Contrary to previous studies investigating the differential response to different amounts of dietary protein in the vicinity of a strength workout (cf. "Protein Synthesis Beyond the 20g Limit"), in which the subjects often trained in a fasted state, the Jackman study also confirms that the profound beneficial effects of immediate protein supplementation are retained, even if the last "protein rich meal" was consumed "only" 3h before the workout.

Figure 2: Experimental protocol of the Jackman study (based on Jackman. 2012)

This beneficial effect of repeated protein ingestion / protein timing stands in line with with the observation that Jackman et al. observed peak amino acid concentrations in the WP20 and WP40 arm of their study 15-30min and 45-60min after the ingestion of the respective amount of whey protein. From the fact that the latter went hand in hand with a statistically significant increase in insulin concentrations and +25% greater urea production in the WP40 trial, we can assume that a non-significant amount of the additional 20g of protein of the 40g whey protein shake was "abused" for gluconeogenesis instead of getting stored within the muscle tissue.

Image 2: The results Adelfo saw from the consistent intake of a perfectly timed mixture of fast and slow digesting proteins speak for themselves - intermittent fasting or not, consistency and frequency are key!

So, even if you don't care about "wasting" dietary protein, you better make sure to distribute your protein intake evenly within your "feeding window", with 20-25g of fast-digesting protein like whey every 2-3h, or a combination of fast digesting and slow digesting proteins (like whey + casein, or whey alone followed by a complete meal) every 3-4h to maintain a decently high and thusly "pro anabolic" level of amino acids in your blood stream while avoiding the hyperinsulinemic effects of larger boluses of whey protein. And if you don't think that this will work, or would be incompatible with the Intermittent Fasting protocol you have taken up as of late, I suggest you go through Adelfo Cerame's contest prep diet again, because with the lions share of his protein intake coming from very slow digesting "real food" protein sources (specifically meats and casein from cottage cheese and raw milk, cf. "3.2kg of Lean Mass With 40g of Casein Pre-Bed"), he strategically spiked with whey protein in the vicinity of his workouts - Adelfo achieved just that: a decent level of hyperaminoacidemia (=elevated serum amino acids) to make optimal use of the "24h Barn Door of Opportunity".