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 ;-).

Low Testosterone ⇨ No Muscle Repair & Long-Term Gains: Testosterone's Effects on Satellite Cells & Myonuclei. Plus: Paradoxical 19% Drop in T W/ Whey + CHO Shake in Boys

Studies show that "women demonstrate significantly larger satellite cell and satellite cell nucleus areas than men" (Roth. 2000) - an effect that could be mediated by the effects of estrogen, not testosterone on satellite cells.

As a SuppVersity reader you will know that satellite cells are the "muscle reserve" that's "cooking" between the basal lamina and sarcolemma of your muscles. They are the cells your body needs to (a) repair damaged muscle cell nuclei (myonuclei) and (b) generate new myonuclei. As a SuppVersity reader you will also know that these new myonuclei are necessary to "Grow Beyond Temporary Physiological Limits" (learn more) that are imposed to your muscle by the myostatin increase that occurs, when the domain size, i.e. the volume of your muscle that's controlled by a single myonucleus, becomes too large.

To make a long story short: Without satellite cells, your muscle repair and growth will be impaired, which is why the results Thue Kvorning and Danish colleagues present in a soon-to-be-published paper in Acta Physiologica are relevant for everyone who want to gain or simply maintain maximal / optimal muscle mass.

You can learn more about satellice cells & co at the SuppVersity

Acc. Satellite Cell Growth

Training in Hypoxia

Epicatechin as a Muscle Builder

Intracrine Effects of Anabolics

NAC Impairs Sa- tellite Cell Act.

Understanding Muscle Growth

In the corresponding experiment, the Danish researchers treated 22 moderately trained young men with a GnHR analogue called goserelin that will dock to the gonadotropin receptors in the brain without stimulating the production of testosterone.

Figure 1: Graphical overview of the procedures (Kvorning. 2014)

Needless to say that the testosterone levels of the study participants were significantly reduced after 4 weeks, when the actual resistance training study began - see Figure 1 for an overview.

In obese boys whey + cho shakes lead to sign. T-reductions (Schwartz. 2014)

Speaking of ways to reduce testosterone: A recent study in obese pubertal boys showed - much to my own astonishment - that having 30 whey isolate + 30g glucose will significantly reduce the testosterone levels (19%) of the young subjects.

Don't ask me what exactly it is that causes this effect, but I suspect it may be related to the huge insulin spike (+410% - no typo!) the subjects experienced. From studies in women with polycystic ovary syndrome we know that insulin which will usually augment the release of sex hormones loses its function in vivo (Willis. 1996).

A similar temporary suppression of the pulsatile luteinizing hormone release and subsequent acute redutions in testosterone has been observed in adults in response to glucose alone (Iranmanesh. 2012). No reason to avoid carbs, though. In a study by Volek et al. the consumption of a high fat diet lead to a persistent 22% and 23% reduction in total and free testosterone (Volek. 2001).

A standardized training program which didn't look much different from what some of you may be doing at the gym (both the guys in the active and the placebo group had to perform, by the way):

"A standardized warm-up was performed before training consisting of 4 sets of squats with 20 repetitions without load and with 1 min rest between sets. Subjects from both groups trained using the same progressive strength training program. The programs were performed 3 times a week for 8 weeks and consisted of leg press, knee extension, leg curl, bench press, lat pull down, biceps curl, and elbow extension. Subjects did 4 sets of each exercise for the lower body and 3 sets of each exercise for the upper body. The strength training period consisted of 24 training sessions periodized in 3 cycles of 8 training sessions with changing training loads (6 RM – 10 RM). The goserelin group and the placebo group increased training loads to the same extent and underwent the same training volume." (Kvorning. 2014)

In contrast to the training stimulus, which was identical for both groups, the intra-muscular response to the workout differed significantly between the young men in the goserelin group (10-20x reduced testosterone levels) and their peers in the placebo group:

Figure 2: This is one of the cases, where having more is not better. Having more free satellite cells and fewer myonuclei is certainly not a good thing for someone striving to build maximal muscle mass.

In spite of the fact that in both, the placebo and goserelin groups, training lead to a signficant increase in the number of satellite cells in fast twitch type II fibers by 20 % in placebo and by 52 % in goserelin (p<0.01), the number of myonuclei, which is the one that's important with respect to future growth remained unchanged in the goserelin (p<0.05) group. In the placebo group, on the other hand, the myonuclear number increased significantly by 12 %.

In view of the resistance training focus of the workouts, it's not really surprising that on such changes were observed in the slow-twitch, endurance-type type I fibers in either group.

Can't believe estrogen is required for muscle building, check out the previous evidence in this SuppVersity article!

Bottom line: In view of preceding evidence that it's not testosterone, but estrogen that's required for proper satellite cell function (see "Estrogen, Friend or Foe of Skeletal Muscle Hypertrophy? Plus: Hey, Bro! Are You 'SERMing' Away Your Satellite Cells?" | learn more), it's a pity Kvorning et al. didn't measure the estrogen levels as well.

In view of the fact that men produce their estrogen via aromatization from testosterone, it's yet very likely that not just the T, but also the E2 levels of the men in the goserelin group were significantly suppressed. The association between estrogen and bone health and the distinctive changes in bone morphogenetic proteins signaling the researchers observed would actually support this hypothesis, which should remind you of the fallacy of abusing SERMs and / or aromatase inhibitors longer than it would be necessary to normalize your estrogen levels, guys.

And I mean, if you have enough testosterone, you'll have enough estrogen, as well, right? Comment on Facebook!

PS: I am fully aware that the necessity of satellite cell recruitment for muscle gains (and by some scientists even repair) is still debated (cf. Pallafacchina. 2013), but up to now, I still have to see the counter-evidence that is not based on mere short-term muscle protein synthesis studies. If you look at the mechanism, it should be obvious that satellite cell activity becomes important only, when the natural upper limit for functional domain sizes is reached and that was certainly not the case in any of the commonly cited rodent studies. Plus: There is evidence in favor of the important role of satellite cells in skeletal muscle hypertrophy from other studies (Appell. 1988; Schultz. 1989; Rosenblatt. 1994;  Barton-Davis. 1999; Mitchell. 2001).

References:

• Appell, H-J., S. Forsberg, and W. Hollmann. "Satellite cell activation in human skeletal muscle after training: evidence for muscle fiber neoformation." International journal of sports medicine 9.04 (1988): 297-299.
• Barton-Davis, E. R., D. I. Shoturma, and H. L. Sweeney. "Contribution of satellite cells to IGF-I induced hypertrophy of skeletal muscle." Acta physiologica scandinavica 167.4 (1999): 301-305. 
• Iranmanesh, Ali, Donna Lawson, and Johannes D. Veldhuis. "Glucose ingestion acutely lowers pulsatile LH and basal testosterone secretion in men." American Journal of Physiology-Endocrinology and Metabolism 302.6 (2012): E724-E730.
• Kvorning, Thue, et al. "The activity of satellite cells and myonuclei following 8 weeks of strength training in young men with suppressed testosterone levels." Acta Physiologica (2014). 
• Mitchell, Patrick O., and Grace K. Pavlath. "A muscle precursor cell-dependent pathway contributes to muscle growth after atrophy." American Journal of Physiology-Cell Physiology 281.5 (2001): C1706-C1715. 
• Pallafacchina, G., B. Blaauw, and S. Schiaffino. "Role of satellite cells in muscle growth and maintenance of muscle mass." Nutrition, Metabolism and Cardiovascular Diseases 23 (2013): S12-S18.
• Rosenblatt, J. David, David Yong, and David J. Parry. "Satellite cell activity is required for hypertrophy of overloaded adult rat muscle." Muscle & nerve 17.6 (1994): 608-613. 
• Schultz, E. D. W. A. R. D. "Satellite cell behavior during skeletal muscle growth and regeneration." Medicine and science in sports and exercise 21.5 Suppl (1989): S181-6.
• Schwartz et al. "Acute decrease in serum testosterone after a mixed glucose and protein beverage in obese peripubertal boys." Clinical Endocrinology (2014). Accepted Article. 
• Volek, Jeff S., et al. "Effects of a high-fat diet on postabsorptive and postprandial testosterone responses to a fat-rich meal." Metabolism 50.11 (2001): 1351-1355.
• Willis, D. E. B. B. I. E., et al. "Modulation by insulin of follicle-stimulating hormone and luteinizing hormone actions in human granulosa cells of normal and polycystic ovaries." The Journal of Clinical Endocrinology & Metabolism 81.1 (1996): 302-309.

Is Rice the New Whey to Go? Study Shows, Rice and Whey Protein Equally Support Mass & Strength Gains + Fat Loss in Resistance Trained College Aged Men

Is rice the new whey to go? Or just something for the average vegan who realizes that he cannot go without protein?

While I personally considered the study on phosphatidic acid (yesterday's news) most interesting, there were many other presentations on the ISSN conference that are worth mentioning (note: my buddy Sean Casey is about to write a summary of his stay there, I'll let you know on Facebook, when he is done). The full-text papers are however only available for one of the studies, which has likewise been conducted by Joy et el. (see PA study). The fulltext just appeared on the website of the Nutrition Journal (Joy. 2013) and is also the topic of today's SuppVersity article that revolves - once again - around the question, whether whey really is the whey (all typos intended) to go.

Is there any other way than whey?

The study was conducted with 24 college-aged, resistance trained males (21.3 ± 1.9 years, 76.08 ± 5.6 kg, 177.8 ± 12.3 cm) who had trained at least three times per week for the past 6 months. The guys were randomly and equally divided into two groups, consuming either 48 g of rice or whey protein
isolate (isocaloric and isonitrogenous) right after the workout.

Figure 1: Amino acid profile of the rice and whey protein isolate (Joy. 2013)

"The program  was designed to train all major muscle groups using mostly compound movements for the  upper and lower body. The programmed, non-linear training split was divided into  hypertrophy days consisting of 8–12 RM loads for 3 sets, with 60–120 seconds rest and  strength days consisting of 2 to 5 RM loads for 3 sets for all exercises except the leg press  and bench press which received 5 total sets. Weights were progressively increased by 2–5%  when the prescribed repetitions could be completed. All training sessions were closely monitored by the researchers to ensure effort and intensity were maximal each training session." (Joy. 2013)

The subjects s trained 3 days per week for 8 weeks as a part of a daily undulating periodized resistance-training program (see quotation. above). Ratings of perceived recovery, soreness, and readiness to train were recorded prior to and following the first training session. The changes muscle thickness was determined by ultrasonography and DEXA scans were used to assess the body composition.

Put your prejudices aside, results are the only thing that counts

Moreover bench press and leg press for upper and lower body strength were recorded during weeks 0, 4, and 8 and statistically analyzed, when the study was over.

Figure 2: Bench pres, leg press strength and peak power before, during  and after the study (Joy. 2013)

As you can see the strength increases did not differs significantly when you compare the rice to the whey protein. Against that background it is actually not very surprising to see that the same was the case for the change in body composition, I plotted in figure 3.

Figure 3: Baseline and post study body composition and muscle size (Joy. 2013)

If we take another look at the amino acid profile in figure 1, it does yet become evident that the effects could have been different, if the subjects stuck to only 50% of the amount of protein they ingested in the study at hand.

Figure 4: Theoretical model for protein dose and the anabolic response (adapted from Joy. 2013)

"In the present study, the combined muscle thickness of the VI and VL increased in both the rice protein (0.2 cm) and whey protein (0.5 cm) conditions. Lean body mass increased in the rice protein condition by 2.5 kg, and it also increased in the whey protein condition by 3.2 kg. Combined bench press and leg press 1-RM strength increased in the rice protein condition by 76.4 kg and in the whey protein condition by 89.5 kg. However, no significant differences were observed between the two conditions for any measure. The collective findings of our study and others suggests that as the amount of protein consumed increases, the importance of the relative leucine content of the protein diminishes" (see figure 4; Joy. 2013).

Overall, the study at hand does therefore provide reliable evidence that people with dairy intolerance fair pretty well with a rice protein - as long as they make up for the 30% lower leucine content.

---

Rice protein can be a valuable replacement for whey. Just remember, you cannot live on rice alone, because you would be running the risk of not getting adequate lysine, which would heavily compromise the nitrogen balance increase anxiety, impaired catecholamine release, etc. (cf. Albanese. 1941; Smriga. 2000, 2002, 2003). As part of a regular diet, rice proteins do yet in fact appear to be a viable (yet higher to dose) alternative to whey protein, which has be the way been shown to help with blood lipid management, only recently (Yang. 2013).

References:

• Albanese, Holt LE, Brum-Back JE, Hayes M, Kajdi C, Wangerin DM. Nitrogen Balance in Experimental Lysine Deficiency in Man. Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, NY). Royal Society of Medicine. 1941; 48(3): 728-730. 
• Joy JM, Lowery RP, Wilson JM, Purpura M, De Souza EO, Wilson SM, Kalman DS, Dudeck JE, Jäger R. The effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance. Nutr J. 2013 Jun 20;12(1):86.
• Smriga M, Mori M, Torii K. Circadian release of hypothalamic norepinephrine in rats in vivo is depressed during early L-lysine deficiency. J Nutr. 2000 Jun;130(6):1641-3. 
• Smriga M, Kameishi M, Uneyama H, Torii K. Dietary L-lysine deficiency increases stress-induced anxiety and fecal excretion in rats. J Nutr. 2002 Dec;132(12):3744-6.
• Smriga M, Torii K. L-Lysine acts like a partial serotonin receptor 4 antagonist and inhibits serotonin-mediated intestinal pathologies and anxiety in rats. Proc Natl Acad Sci U S A. 2003 Dec 23;100(26):15370-5.
• Yang L, Han G, Liu QH, Wu Q, He HJ, Cheng CZ, Duan YJ. Rice protein exerts a hypocholesterolemic effect through regulating cholesterol metabolism-related gene expression and enzyme activity in adult rats fed a cholesterol-enriched diet. Int J Food Sci Nutr. 2013 Jun 14.
   

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.

Want to Stay Lean on a High-Fat Diet? Consume Whey Protein Everyday.

Listeners of Carl Lenore's Super Human Radio already know: Dr. Paul Arciero of Skidmore College is going to publish a study the results of which confirm that obese individuals can lose weight and improve markers of metabolic health by just adding a 20g shake of whey protein 3x a day.

While you still have to wait for the detailed results of this study to be published, another group of scientists (Shertzer. 2011) derived similar results from a study on mice. Despite being on a high fat diet, mice who received 100mg of whey protein isolate (WPI) per liter of their drinking water (WPI group) ...

had lower rates of body weight gain and percent body fat and greater lean body mass, although energy consumption was unchanged. These results were consistent with WPI mice having higher basal metabolic rates, respiratory quotients, and hepatic mitochondrial respiration. [...] Livers from WPI mice had significantly fewer hepatic lipid droplet numbers and less deposition of nonpolar lipids. Furthermore, WPI improved glucose tolerance and insulin sensitivity.

While you are waiting for the human study to be published (the SuppVersity will have it first ;-), get yourself some tasty whey protein and listen to Dr Arciero on Super Human Radio!