Research Update: 5000 IU/day Vitamin D, 12g/day Citrulline Malate or Barefoot Running What's the Most Ergogenic?

Research Update: 5000 IU/day Vitamin D, 12g/day Citrulline Malate or Barefoot Running What's the Most Ergogenic?

25OHD barefoot citrulline on short notice running running economy soccer vitamin D VO2 vo2max

Who would have thought that barefoot running triggers instant improvements in running economy?

With the release of ahead of print articles for the next issue of the Journal of Strength and Conditioning Research, it is high time for yet another research update; an update with research on the effect of vitamin d supplementation on training adaptation in well trained soccer players, acute citrullin malate supplementation (10 grams 60 minutes before a workout) and high-intensity cycling performance, as well as information about the ability of barefoot running to reduce oxygen cost and improve running economy in female distance runners who have never run barefoot before.

Read more about exercise-related studies at the SuppVersity

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• The effect of vitamin d supplementation on training adaptation in well trained soccer players (Jastrzebska. 2016) - In view of the fact everybody appears to believe that the currently available evidence would imply that vitamin D supplements could enhance athletic performance, it is hardly surprising that the next issue of the Journal of Strength and Conditioning Research will contain yet another study investigating the effects of vitamin D supplements on athletic performance.
  
  What distinguishes the study at hand from the rest of the pack is that it was conducted in high-level, well trained athletes, who received either a placebo (PG) or 5000IU of vitamin D per day (SG). Both groups were subjected to the same "High Intensity Interval Training Program".
  

  

  Figure 1: Overview of he training regimen, the subjects were subjected to.

  The selection to the groups was based on peak power results attained before the experiment and position on the field. Blood samples for vitamin D level were taken from the players. In addition, total work, 5-10-20-30 m running speed, squat jump, and countermovement jump height were determined.
  
  Much to the disappointment of the average vitamin D enthusiast, there were no significant differences between SG and PG groups for any power-related characteristics at baseline. What did work, though, was the training: All power-related variables, except the 30 m sprint running time, improved significantly in response to interval training. However, the mean change scores (the differences between post- and pre-supplementation values) did not differ significantly between SG and PG groups. Thus, the authors of the study conclude that...

  

  Remember the differential effect of Vitamin D on breast cancer risk in lean vs. obese women?

  "[...] an 8-week vitamin D supplementation in highly trained football players was not beneficial in terms of response to high intensity interval training [and that, g]iven the current level of evidence, the recommendation to use vitamin D supplements in all athletes to improve performance or training gains would be premature" (Jastrzebska. 2016).

  What may make sense, however, is to avoid a seasonal decrease in 25(OH)D level or to obtain optimal vitamin D levels via higher dietary intakes and, optionally, vitamin D supplementation. Why that? Well, in vitamin D deficient athletes, there's at least some evidence that supplementing, or rather increasing the 25OHD levels help.
• Acute Citrulline-Malate supplementation and high-intensity cycling performance (Cunniffe. 2016) - Unlike the results of a previously discussed study on the effects of citrulline supplementation during an intense leg workout, in which 8g/day triggered significant performance increases, the recent double-blind, placebo-controlled, crossover study by Cunniffe et al. found no benefits of 12g of citrulline malate (in 400ml) compared to lemon sugar-free cordial (Placebo [PL]) when the 10 subjects consumed it 60 min prior to completion of two exercise trials... or, to be precise, only the heart rate differed significantly.
  

  

  Figure 2: Mean performance in the two groups; # sign. inter-group difference (p < 0.05 | Cunniffe. 2016)

  They consumed it 60 minutes before the workouts? Right, this happens to be the same protocol, Wax et al. used 2014 in 12 advanced resistance trained male subjects. What was different, however, is the type of exercise. While Wax et al. had their subjects squat and leg press, Cunniffe investigated the effects in a trial that consisted of ten (x 15 s) maximal cycle sprints (with 30 s rest intervals) followed by 5 min recovery before completing a cycle time-to-exhaustion test (TTE) at 100% of individual peak power (PP). I guess that explains the difference and suggest that the performance enhancing effects of citrulline are exercise dependent - obviously, this has to be investigated in future studies ;-)
• Barefoot running reduces the submaximal oxygen cost in female distance runners (Berrones. 2016) - The two most important ways to increase your running performance are (a) improving your VO2max, (b) improving your running economy aka the "O2 costs of running". That this can be achieved as easily as by dropping your shoes is thus a quite important result, Berrones et al. observed in during three 5-minute submaximal running trials representing 65, 75, and 85% of VO2max in fourteen recreationally active, trained distance female runners (age = 27.6 +/- 1.6 yrs; height = 163.3 +/- 1.7 cm; weight = 57.8 +/- 1.9 kg) who were completely inexperienced with unshod running.
  
  Following initial testing, each subject was randomized to either unshod or shod for days 2 and 3. Berrones et al. analyzed the data with a 2-way (condition by intensity) repeated measures ANOVA. The results of this analysis shows that the runners' submaximal oxygen consumption was significantly reduced at 85% of VO2max (P = 0.018), but not during the 65% or 75% trials (P > 0.05, both).
  

  

  The improvement in VO2 consumption during barefoot running was sign. only for 85% VO2max (Berrones. 2016).

  No other dependent measure, i.e. respiratory exchange ratio (RER), lactate, heart rate (HR), and ratings of perceived exertion (RPE), was different between unshod and shod conditions; and still, the scientists' conclusion that "training or competing while barefoot may be a useful strategy to improve endurance performance" (Berrones. 2016) may be useful for recreational or competitive distance runners.

You want more short exercise news? Well, this is not exactly a short one, but still: "GYM-Science Update: Bands Aid W/ Deadlifts? 16x1 or 4x4 for HIIT? Kettlebell HIIT Workout Better Than HIIT-Cycling?" | more

Bottom line? Well, I guess I should answer the question in the headline even if it is obvious, right? The answer is: "barefoot running". What we should not forget, though is the fact that previous research suggests that having normal (not extra-high) vitamin D levels is as important for athletes as 8g of citrulline are useful for strength trainees.

Against that background I wouldn't be surprised if the next SuppVersity Research Update featured studies showing beneficial effects of vitamin D and citrulline malate supplements and no or even ill effects of barefoot running... but hey, the results of the Berrones study are still impressive, right? Don't forget: the subjects had never run barefoot before | Comment on Facebook!

References:

• Berrones, Adam J.; Kurti, Stephanie; Kilsdonk, Korey; Cortez, Delonyx; Melo, Flavia; Whitehurst, Michael. "Barefoot running reduces the submaximal oxygen cost in female distance runners." Journal of Strength & Conditioning Research: Post Acceptance: January 19, 2016. doi: 10.1519/JSC.0000000000001330. 
• Cunniffe, Brian; Papageorgiou, Maria; O’Brien, Barbara; Davies, Nathan A; Grimble, George K; Cardinale, Marco. "Acute Citrulline-Malate supplementation and high-intensity cycling performance." Journal of Strength & Conditioning Research: Post Acceptance: January 19, 2016. doi: 10.1519/JSC.0000000000001338.
• Jastrzebska, Maria; Kaczmarczyk, Mariusz; Jastrzebski, Zbigniew. "The effect of vitamin d supplementation on training adaptation in well trained soccer players." Journal of Strength & Conditioning Research: Post Acceptance: January 20, 2016. doi: 10.1519/JSC.0000000000001337
• Wax, Benjamin, et al. "Effects of Supplemental Citrulline Malate Ingestion During Repeated Bouts of Lower-body Exercise in Advanced Weight Lifters." The Journal of Strength & Conditioning Research (2014).

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

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

anti-catabolic BCAA catabolism citrulline glutamine lean mass lose fat peri-workout post-workout pre-workout supplementation supplements XTend

"Shed the fat, keep the muscle!" That's a promise you will find not literally, but analogously in every ad for BCAAs, but do they actually do that? Help you shed fat and retain muscle? Scientific prove to support this claim is, as of yet, missing.

With BCAAs it is just as it is with 99.9% of the supplements: Ads and product labels are full of scientifically unproven claims. One of these unproven claims is that the consumption of branched-chain amino acids would protect you from losing muscle while you're dieting ... the problem with this notion is - as sound as it may seem in view of the mTOR promoting effects of leucine, there's no study which would prove that guzzling BCAAs all day will in promote fat and blunt lean mass losses when you're cutting.... or I should say "as of now, there was no study...", right? After all, there's this new study by Dudgeon et al.'s the abstract of which tells us that "BCAA supplementation in trained individuals performing resistance training while on a hypocaloric diet can maintain lean mass and preserve skeletal muscle performance while losing fat mass" (Dudgeon. 2015).

Learn more about amino acid and BCAA supplements at the SuppVersity

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As we are going to see after taking a look at the design and results of Dudgeon's single-blind study in seventeen resistance-trained males (21–28 years of age) on hypocaloric diets, this is yet a potentially misleading conclusion. Not because it was wrong, but rather because it omits an observation that could be of paramount importance to dieters who have the free choice between the two treatments, the subjects of the study were randomly assigned to, namely...

• 14g of Xtend (BCAA) before after workouts or
• 14 g Powerade (CHO) before and after workouts

The supplements were consumed for a total study time of 8 weeks during which all subjects trained four times per week according to a standardized workout program and consumed a diet that was programmed (but not controlled) to contain roughly 35% less energy than the subjects required on workout days and approximately 10% less energy than required on off-days.

In the strict sense, this is actually no "BCAA study": Some of you may already have realized that the "BCAA supplement" the scientists used, i.e. Scivation XTend, is not really a "BCAA only" supplement. Next to only 7 grams of BCAAs per 14g of powder the subjects ingested before and after the workout, it also contains 1 g citrulline and 2.5 g glutamine and obviously a hell lot of flavorings, fillers and what not. Now, while the latter are not of any importance, both of the former have been heralded as muscle protectors, as well, with citrulline probably having the more convincing scientific data to back it up (it appears to act similar to leucine, by the way | Moinard. 2007; Faure. 2012; Ventura. 2013) outside of scenarios with extremely high glucocorticoid levels where glutamine unquestionably helps (Hickson. 1995 & 1997; Salehian. 2006). It is thus in my humble opinion at least highly imprecise to conclude that the provision of 2x7g of BCAA ameliorated the the fat to muscle loss ratio during the 8-week study.

Now you may be rightly asking yourselves why I am so vague with respect to the energy deficit. Well, everything we learn from the full text of the study is that all subjects were "provided an individualized caloric restricted diet based on individual data (body mass, body composition, resting metabolic rate, etc.)" (Dudgeon. 2015) - a diet the scientists describe as follows:

Table 1: W/ the Harris-Benedict equation you calculate the basal metabolic rate and multiply it with a factor (multiplier) that describes your activity level best to arrive at the "real" estimated energy requirements.

"The caloric-restricted diet was designed as an 8 week “cut diet” for reducing body fat, and used a modified carbohydrate-restricted diet approach (percent of total calories for workout days were 30 % carbohydrates, 35 % protein and 35 % fat and for off days were 25 % carbohydrates, 40 % protein and 35 % fat). Each individual’s daily caloric and macronutrient intake was determined using the Harris Benedict formula with an activity factor of 1.35 (lightly active individual engaging in light exercise 1–3 days/week) for workout days and 1.125 (sedentary individual) for off days" (Dudgeon. 2015).

Since the Harris-Benedict formula is only a really rough estimate of how much energy you actually need, my previous estimations of the energy deficit are as "accurate" as I can possibly be. The 1604kcal that are printed in red bold letters on top of the exemplary meal plan in Figure 2, however, suggest that the deficit on the off days was significantly larger. After all, the subjects' mean weight was >80kg and their daily energy requirements should thus be at least 2,000kcal - even on off days (and the table in which the macronutrient composition is listed actually says that the mean intake was 2046 and 2264kcal/day for the BCAA and CHO group respectively).

Table 2: Sample dietary card for a subject during an off, non-workout, day (Dudgeon. 2015).

In view of the fact that the response I got from the authors to an email in which I asked about the exact kcal deficit only referred me to the previously cited passage about the activity factors, I guess it is futile to further speculate about the energy deficit, of which I would still like to add that it was probably higher in the heavier and taller BCAA group. Why? Well, the BCAA group had plans with 2456 and 2046 kcal on workout and off days, the CHO group on the other hand were fed 2717 and 2264 kcal... Whatever, let's get to the more relevant, but not less confusing changes in body weight, lean mass and fat mass the researchers report for the BCAA and CHO groups:

Figure 1: Pre and post absolute mean body weight, body fat and lean body mass values before and after the 8-week intervention; * p < 0.05 for the difference within groups (no difference between groups | Dudgeon. 2015)

-0.1 kg and -2.3 kg of body weight, +0.4 kg and -0.9 kg of lean mass and 0.6 kg and 1.4 kg fat mass in the BCAA and CHO groups respectively - that's in line with the previously cited conclusion. The BCAA supplement blunted the small loss of lean mass in the CHO group, but if we look at the complete dataset, a somewhat different image emerges; one in which the two classic markers of body composition, namely the relative amount of body fat (aka "body fat percentage") and the lean mass as percentage of the total mass changed in a way that favors CHO over BCAA supplements:

Figure 2: Pre vs. post values for body fat % and lean mass %, the two parameters you would classically use to assess body composition (instead of absolute lean and fat mass); pre-to-post change on top of the post-bars (Dudgeon. 2015).

Now, I am not saying that the consumption of the BCAA (+citrulline + glutamine) supplement did not blunt the loss of lean mass - it obviously did. What I want you to keep in mind, though, is the fact that the consumption of 14g of BCAAs before and after workouts appears to suffocated any dieting efforts - after all, the subjects lost a practically irrelevant (and for whatever reason allegedly statistical significant) amount of 600g body fat; that's in contrast to the 1.4 kg of fat mass the subjects in the control group lost; and that's a practically relevant insight, even if this fat loss was allegedly statistically non-significant, because  it implies that BCAAs practically blunt fat loss.

Whey + Casein - A Superior Post-Workout Shake that Kicks Every Amino Acid Product's Ass | read more

So what do we make of this study? Well, first of all, I would like to come back to something fundamental: This is yet another BCCA study that did not make the practically most relevant comparison of BCAAs and cheap (whey) protein protein supplements, in which BCAAs have hitherto always failed. In my humble opinion that's a problem, after all having a carbohydrate supplement as control in a dieting study is nice, but eventually not relevant for the average trainee who is probably not really considering extra-carbs when he's dieting.  What a real trainee would have been interested in, is whether BCAAs can prevent muscle catabolism to a significantly greater degree than the cheap whey protein he's using anyway...

... and maybe, whether the latter has a similar negative effect on fat loss as the BCAAs in the study at hand - which leads me to the actual take home message of the study, which is, as usually, not as straight forward as the conclusion of the abstract suggested. When all is said and done, the study at hand does after all suggest that someone who is approaching the single-digit body-fat zone, where every gram of muscle that is not lost counts, could benefit from the apparent lean mass protective effects of BCAA the scientists observed in the study at hand. It does yet also indicate that someone who's "making weight" for a competition should take a second look at the data in Figure 1 + 2 and acknowledge that taking a BCAA supplement may be the reason he will fail to achieve his weight loss goal. You don't believe that? Well, let's do some scientifically not exactly kosher extrapolations: If you manage to lose 10 kg in 10 weeks without BCAAs, for example, the data from the study at hand suggests that your weight loss "on BCAAs" over the course of those 10 weeks would be as meager as 434 grams ... whether that's in fact the case (I doubt it ;-) will have to be studied in future studies, just like the effect of BCAAs, citrulline and glutamine, alone and whether using your regular whey protein before and after the workout wouldn't have the exact same, or even better effects | Comment on Facebook!

References:

• Dudgeon, WD; Page Kelly, E; Scheett TP. "In a single-blind, matched group design: branched-chain amino acid supplementation and resistance training maintains lean body mass during a caloric restricted diet." Journal of the International Society of Sports Nutrition  (2016) 13:1.
• Faure, Cécile, et al. "Leucine and citrulline modulate muscle function in malnourished aged rats." Amino acids 42.4 (2012): 1425-1433.
• Moinard, Christophe, and Luc Cynober. "Citrulline: a new player in the control of nitrogen homeostasis." The Journal of nutrition 137.6 (2007): 1621S-1625S.
• Hickson, R. C., S. M. Czerwinski, and L. E. Wegrzyn. "Glutamine prevents downregulation of myosin heavy chain synthesis and muscle atrophy from glucocorticoids." American Journal of Physiology-Endocrinology and Metabolism 268.4 (1995): E730-E734.
• Hickson, Robert C., et al. "Protective effect of glutamine from glucocorticoid-induced muscle atrophy occurs without alterations in circulating insulin-like growth factor (IGF)-I and IGF-binding protein levels." Experimental Biology and Medicine 216.1 (1997): 65-71.
• Salehian, Behrouz, et al. "The effect of glutamine on prevention of glucocorticoid-induced skeletal muscle atrophy is associated with myostatin suppression." Metabolism 55.9 (2006): 1239-1247.
• Ventura, G., et al. "Effect of citrulline on muscle functions during moderate dietary restriction in healthy adult rats." Amino acids 45.5 (2013): 1123-1131.

Synephrine More Ergogenic, Than Thermogenic? Pump Supps Revisited - L-Arginine, L-Citrulline and Respective Whey-Peptides & -Nitrates | ISSN Research Review '15 #2

Synephrine More Ergogenic, Than Thermogenic? Pump Supps Revisited - L-Arginine, L-Citrulline and Respective Whey-Peptides & -Nitrates | ISSN Research Review '15 #2

arginine arginine nitrate citrulline ISSN15 ISSN2015 l-arginine l-citrulline nitrate nitrates performance pump pump supplements supplements vasolidation whey peptides

Synephrine, arginine, citrulline - Which pre-workout ensures that you're "on fire"?

As I pointed out previously, my initial idea to cherry pick only the most interesting study results that were presented in form of of poster presentations at the Twelfth International Society of Sports Nutrition (ISSN) Conference and Expo in 2015 didn't work out. The number of interesting studies is is simply too much for a single SuppVersity article to discuss them all.

Accordingly, I am now posting the 2nd serving of what is going to be a multi-part series of articles with brief discussions of the most significant results of the >20 studies and short references to those that didn't make the SuppVersity cut in this, previous and future installments of this series for one reason or another.

Read more about ISSN and other studies at the SuppVersity

Vitargo, Red Bull, Creatine & More | ISSN'15 #1

Pump Supps & Synephrine & X | ISSN'15 #2

High Protein, Body Comp & X | ISSN'15 #3

Keto Diet Re- search Update | ISSN'15 #4

The Misquantified Self & More | ISSN'15 #5

BCAA, Cholos-trum, Probiotics & Co | ISSN'15 #6

• Synephrine More Ergogenic Than Thermogenic? There was not just one, but two poster presentations and a full paper that has been published only days ago on synephrine containing supplements at the ISSN meeting and on the ISSN website, respectively. Synephrine? Yes, that's the supplemental non-starter, ah... I mean allegedly powerful fat burner from orange peels. The one with promising fat loss results in rodents, but discouraging results in practice.
  
  Luckily, the studies that were presented in form of posters by scientists from the Texas A&M University (Jung. 2015 & Dalton. 2015) at the ISSN meeting did not deal with synephrine as fat burner. Rather than that, Jung et al. and Dalton et al. took a look at the short- and long-term safety of synephrine as a pre-workout. A pre-workout that contained either 3g beta alanine, 2g creatine nitrate, 2g arginine AKG, 300mg N-acetyl tyrosine, 270mg caffeine, and 15mg Mucuna pruriens, alone (PLA) or the same baseline ingredients and synephrine.
  

  

  Figure 1: Number of reps on sets 1-3 & 4-6 in the control and treatment conditions (Ratamess. 2015)

  Now, the fact that some synephrine in your preworkout won't kill you is not really exciting. I have to admit that. What is exciting... at least sort of, though is the fact that the questionable thermogenic turned out to be an effective ergogenic in the already published and thematically related study by Ratamess and colleagues (Ratamess. 2015). A study that shows that p-synephrine of which previous studies indicate that it is a potent, but highly selective β-3 adrenoreceptor may nor be the best fat burner (the good old ephedrine was a pan-receptor activator and clenbuterol & co target the β-3 receptor, maybe that's also why the fat loss results are rather disappointing) , but at least an underestimated ergogenic.

Is p-synephrine different from synephrine? That's a good question without a clear question. Most supplements that list synephrine on the label actually contain P-hydroxy-α-{methylaminomethyl}-benzylalcohol aka p-synephrine, a protoalkaloid compound that differs from m-synephrine and o-synephrine structurally and comes in form of to stereoisomers in most supplements - the l-enantiomer and the d-enantiomer as the racemate d,l-synephrine. While the latter have been shown to be present in bitter orange, other forms, like the m,s-isomer may are suspected to be adulterations from synthetic phenylephrine supplement producers use to "spike" (Allison. 2005) their products (I assume this was not the case with the samples the researchers in the study at hand used, but the chaos wrt to the types of synephrine puts a huge "?" behind the assumption that you'll see the same effects from any given synephrine or synephrine + caffeine supplement. 

• As the data in Figure 1 goes to show you, the p-synephrine supplement, which was administered to twelve healthy, college-aged men at a dosage of 100mg either alone (S) or in conjunction with 100 mg caffeine (SCF) for three days. On the day on which the subjects participated in a standardized resistance exercise protocol consisting of 6 sets of squats for up to 10 repetitions per set using 80 % of their one repetition-maximum (1RM) with 2 min of rest in between sets, the supplement was ingested 45 minutes before the workout. In comparison to the placebo treatment synephrine alone triggered a significant increase in total repetitions and volume load. When synephrine was combined with 200 mg of caffeine, it also increased the mean power and velocity of squat performance. What did not change in response to either synephrine alone or caffeine and synephrine, though, were the blood lactate levels or the rate of perceived (RPE) exertion the subjects reported on the usual visual analogue scales.
  
  For me personally, that's a surprising result. For the scientists it "indicate[s that] supplementation with S and SCF can enhance local muscle endurance during resistance exercise" (Ratamess. 2015); and I have to admit: They are right. One thing you should keep in mind, though, is that unlike caffeine, where you often see reductions in RPE and thus an effect you will feel, synephrine will - even if it works - do its purported "magic" more subtly.
• The Latest on "Pump Supplements" - Creatine, Arginine, Citrulline, Nitrates -- To make sure that this series is not turning into a 12-part article, I will address the results of Moon's, Suzuki's and Vogel's results in one item (since Moon's paper basically summarizes the results of studies by Falcone and Joy, I won't discuss those separately) .
  
  

  

  Figure 2: Increases in blood flow volume (BFV) 33 minutes after the ingestion of 1.87g of RC, 3.67g of CP (citrulline content 1.87g), 1.87g of RA, or 3.07g of AP (arginine content 1.87g) before 3 sets of 15 arm curls (Moon. 2015).

  Moon et al.'s comparison of citrulline's and arginine's ability to increase the exercise-induced vasodilation and blood flow yielded unsurprising results that confirm that citrulline-based ingredients are more effective than arginine-based ingredients for modulating vasodilation and blood flow. Now that alone wouldn't be news-worthy if the scientists had not tested the effects of both, rawe L-citrulline (RC) and raw L-arginine (RA) and, citrulline and arginine bound to a whey peptide (CP and AP, respectively).
  
  I guess I am not going to surprise you, when I tell you that regular arginine was the worst vasodilator in this quartet. What is more surprising, though, is the extent to which the peptide bonding increased the vasodilating effects of regular citrulline and even arginine. With the the former producing 2x higher increases in vessel diameter and 9% higher increases in blood glow volume than regular citrulline (let's not even mention regular arginine | see Figure 2) the effects are pronounced enough to be potentially "feelable" and "visible" during a workout.
  
  

  

  Citrulline & Glutathione - GSH Amplifies & Prolongs CIT's NO Boosting Effects During + After Biceps Workout | learn more.

  Against that background I would be curious to see, whether the likewise recently reported performance enhancing effects of citrulline Suzuki et al.'s observed in twenty two well-trained young men who consumed 2.4 g / day of L-citrulline or placebo for 7 days and they took 2.4 g of L-citrulline or placebo 1 hour before 4 km cycling time trial on day 8 would be enhanced by bonding citrulline to whey peptides.
  
  I mean, if citrulline-whey-peptides appear to offer the same effects citrulline does, but at a higher efficacy, their beneficial effect on cycling time trial performance of which the Suzuki et al. argue that it was mediated by an up-regulation of plasma NO availability should be superior to that of raw citrulline, as well, right?
  
  And now that we are already talking about what really matters, i.e. performance enhancements, not increases in blood flow, it would also be interesting to see a follow up on the last "pump supplement" study to be mentioned in this installment of the ISSN Research Review: A study by Vogel et al.'s on the vasolidating effects of an arginine-nitrate based pre-workout supplements that shows significant increases in brachial artery diameter. Increases that are quantitatively similar to those Moon et al. observed for citrulline-whey-peptides in the previously discussed study. That does not mean, though that they are equally effective, though. To be able to say that we would need a study in which both agents are compared head-to-head. Unless this study is done and a follow up on Vogel's study proves that the increases in blood flow will actually produce significant performance gains, the only thing I can say about arginine nitrate is: It's interesting, but with respect to its ergogenic effects more studies have to be done.

You don't believe citrulline can do anything for you? Check this out: 8g/day Citrulline Increase Leg Workout Performance - More Reps on Leg Press, Hack Squat & Leg Ext. in Exp. Gymrats (more)! It is thus by no means useful for "cosmetic pumps", only 

Studies that didn't make the cut in this issue are Brooke Bouza et al.'s study on the exercise and calorie information on menus (Bouza. 2015) as well as O'Conner et al.'s tart-cherry study (O'Connor. 2015). That's not because there were methodological issues or something. It's much simpler: The notion that "exercise and calorie information on menus is not enough to improve food choices in Hispanic adults" (Bouza. 2015) is about as unsurprising as the word "potentially" (O'Connor. 2015) in the conclusion of O'Connor's study is daunting. And by the way, now that you know that tart cherry "potentially increases running performance and attenuates post-race markers of inflammation" you actually know the most relevant finding of O'Connor's study, right? | Comment on Facebook!

References:

• Allison, D. B., et al. "Exactly which synephrine alkaloids does Citrus aurantium (bitter orange) contain?." International journal of obesity 29.4 (2005): 443-446.
• Bouza, Brooke, et al. "Exercise and calorie information on menus is not enough to improve food choices in Hispanic adults." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P3.
• Dalton, R., et al. "Safety and efficacy of a pre-wrkout dietary supplement with and without synephrine." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P5.
• Falcone, Paul H., et al. "Acute hemodynamic effects of L-arginine, arginine nitrate, and arginine peptide on exercise-induced vasodilation and blood flow in healthy men." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P10.
• Joy, Jordan M., et al. "A comparison of raw citrulline and citrulline peptide for increasing exercise-induced vasodilation and blood flow." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P18.
• Jung, Y. P., et al. "Effects of 8 weeks pre-workout dietary supplement ingestion with and without synephrine on blood chemistry panel." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P4.
• Moon, Jordan R., et al. "A comparison of citrulline and arginine for increasing exercise-induced vasolidation and blood flow." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P6.
• O'Connor, A., et al. "Short-term powdered tart cherry supplementation encircling an acute endurance challenge potentially increases running performance and attenuates post-race markers of inflammation." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P7.
• Suzuki, Takashi, et al. "Oral L-citrulline supplementation enhances cycling time trial performance in healthy well-trained males." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P52.
• Vogel, Roxanne M., et al. "Acute hemodynamic effects of a multi-ingredient performance supplement on brachial artery vasodilation and blood flow volume following elbow flexion exercise in healthy young men." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P28.