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

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.

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

From a physiological perspective NO is not primarily there to make you look vascular and pumped, boys.

If you've read the headline and are asking yourselves "Why on earth would I even want to spend money on cosmetic pump?", you probably need a reminder of the multiple important functions nitric oxide (NO) serves in your body: (1) With their ability to relax the musculature of your blood vessels to increase the blood flow through your veins, normal NO levels are required to guarantee optimal blood flow to every body part; (2) since this includes your sexual organs, normal NO levels are also a prerequisite for normal / optimal sexual function; (3) having enough NO is also required to keep your immune defenses up, because the white blood cells need it in their fight against intruders; and if heart disease, sexual dysfunction and immune health are all things you don't care about (4) you may be interested to hear that your brain and metabolic health critically depend on normal NO levels, as well.

You can learn more about citrulline at the SuppVersity

Citrulline prevents muscle catablism more than leucine

Arginine & citrulline for blood lipid control

EAA, BCAA, or citrulline for anti-catabolism?

Glutamine not citrulline to heal the gut?

Citrulline to ignite fatty acid oxidataion?

High & low dose arginine ineffec- tive NO boosters

Now that you've got the primer on "nitric oxide beyond the pump" you may be happy to hear that a very common NO supplement, i.e. citrulline, actually delivers. But there's more: In a very recent study, scientists from the Baylor University demonstrated for KYOWA HAKKO BIO CO (so this is sponsored research) that a combined treatment with citrulline and glutathione leads to significant increases in the levels of cGMP, nitrite, and NOx (nitric oxide metabolite) in cells, rodents and humans.

Figure 1: Overview of the design of the "human part" of the study (McKinley-Barnard. 2015).

In the latter part of the study (the human part), the researchers had sixty six participants randomly assigned (in a double-blind fashion) to one of four groups (n = 15 per group) involving 7 days of the oral ingestion of four capsules containing a total daily dose of either: cellulose placebo (2.52 g/day), L-citrulline (2 g/day), GSH (1 g/day), or L-citrulline (2 g/day) + GSH (200 mg/day). Supplementation compliance was monitored by participants returning empty containers of their supplement on day 7, and also by completing a supplement compliance questionnaire.

What is glutathione and why would you combine it with citrulline? Glutathione is a low molecular weight, water-soluble tripeptide composed of the amino acids cysteine, glutamic acid, and glycine. Glutathione is an important antioxidant and plays a major role in the detoxification of endogenous metabolic products, including lipid peroxides.

Contrary to what many believe, oral GSH supplements work | more

In some cell types, GSH appears to be necessary for NO synthesis and NO has been shown to be correlated with intracellular GSH (Ghigo. 1996). GSH stimulates total L-arginine turnover and, in the presence of GSH, NOS activity is increased (Hofmann. 1995). For the authors of the study at hand this means that "GSH may play an important role in protection against oxidative reaction of NO, thus contributing to the sustained release of NO" (McKinley-Barnard. 2015) - reason enough for them to believe that "combining L-citrulline with GSH may augment the production of NO" (ibid).

Each participant ingested all four capsules containing their respective daily supplement dose each evening for six consecutive days until at Visit 3 (Day 7), participants were provided the final daily dose of their respective supplement ingested one hour prior to performing a previously familiarized biceps training program consisting of  3 sets of 15 repetitions with as much weight as they could lift per set (typically 70–75 % of 1RM | 10s rest between sets, only) on a selectorized weight machine (Body Master, Rayne, LA).

Figure 2: Nitrate concentration and change in plasma NOx in rodents (NO metabolites | McKinley-Barnard. 2015). 

Figure 2, which depicts data from the rodent study, already suggests that only citrulline or citrulline and glutathione would trigger significant increases in NO production in the 20-22 year-old healthy, well-trained (at least three resistance training sessions per week) participants, while GSH alone would trigger only a minor increases of the nitric oxide levels.

Figure 3: Changes in NO metabolites (NOx) and cGMP levels (McKinley-Barnard. 2015) in the human study.

The data in Figure 3 (left) which tells you that the increase in stable NO metabolites (NOx) in the blood of the subjects in the citrulline + GSH group was the highest. What may surprise you, though, is that the increase in nitric oxide that is obviously partly mediated by an increase in c-GMP (Figure 3, right) levels was not only maintained after the workout, the levels even kept increasing.
This is in contrast to your regular "pump" formula (using only citrulline), where the levels drop back to baseline ( and potentially even lower - after all only 30 min were monitored) after the workout.

Why is that important? Well, if you look back at the "nitric oxide beyond the pump" list from the introductory paragraph, you will notice that almost all of these "beyond the pump" effects are health-relevant during, but also and even more so after the workout.

8g/day Citrulline Increase Leg Workout Performance - More Reps on Leg Press, Hack Squat & Leg Ext. in Exp. Gymrats (more). Whether CIT + GSH can do more, remains to be seen!

Bottom line: We still need more, non-sponsored research to figure out how practically significant the results of the study at hand actually are. Important questions, like "Which one, citrulline alone or citrulline + GSH is the better performance booster?", "Does the effect last or will your body get used to it?", "Is chronic ingestion of the supplement necessary or does it suffice to take it pre-workout?", or "Does the lasting increase in stable nitric oxide metabolites McKinley-Barnard and her colleagues observed in the CIT + GSH group actually have meaningful health-effects?" still have to be addressed, before one can wholeheartedly recommend taking (probably pretty expensive) citrulline + GSH supplements | Comment on Facebook!

References:

• Ghigo, D., et al. "Correlation between nitric oxide synthase activity and reduced glutathione level in human and murine endothelial cells." Amino acids 10.3 (1996): 277-281.
• Hofmann, Heinrich, and Harald HHW Schmidt. "Thiol dependence of nitric oxide synthase." Biochemistry 34.41 (1995): 13443-13452. 
• McKinley-Barnard, Sarah, et al. "Combined L-citrulline and glutathione supplementation increases the concentration of markers indicative of nitric oxide synthesis." Journal of the International Society of Sports Nutrition 12.1 (2015): 27.

Low vs. High Load Resistance Training - Yes, You Can Gain Muscle W/ "Low" Loads - Non-Significantly More Even!

It turns out, the biceps may even benefit from higher rep, lower weight training.

You probably remember my Facebook post about Brad Schoenfeld's then unpublished study which proves that you can gain muscle using low(er) weights, as well. Now, that the study has eventually been published, it would appear to be about time to take a closer look at the procedure and results in order to determine how relevant, the finding Schoenfeld, Peterson, Ogborn, Contreras and Sommez present in their not yet printed, but peer-reviewed and accepted paper in the Journal of Strength and Conditioning Research.

The purpose of the study, and that should be obvious considering what I already gave away, was to compare the effect of low- versus high-load resistance training (RT) on muscular adaptations in well-trained subjects.

According to the results of this study you better periodize to benefit from high & low loads!

30% More on the Big Three: Squat, DL, BP!

Block Periodization Done Right

Linear vs. Undulating Periodizationt

12% Body Fat in 12 Weeks W/ Periodizatoin

Detraining + Periodization - How to?

Tapering 101 - Learn How It's Done!

Schoenfeld et al. recruited eighteen young men who were - important fact! - "experienced in RT". More specifically, ...

"[s]ubjects were between the ages of 18-35, did not have any existing musculoskeletal disorders, were free from consumption of anabolic steroids or any other illegal agents known to increase muscle size for the previous year, and were experienced lifters (i.e., defined as consistently lifting weights at least 3 times per week for a minimum of 1 year, and regularly performing the bench press and squat). The range of lifting experience for all subjects was between 1.5 and 9 years of consistent training" (Schoenfeld. 2015).

The subjects were matched according to baseline strength, and then randomly assigned to 1 of 2
experimental groups:

• a low-load + high rep resistance training routine (LL) where 25-35 repetitions were performed per set per exercise (n = 9), or
• a high-load RT + normal rep routine (HL) where 8-12 repetitions were performed per set per exercise (n = 9). 

During each session, subjects in both groups performed 3 sets of 7 different exercises representing all major muscles. Training was carried out 3 times per week on non-consecutive days, for 8 total weeks (not other high intensity exercise was allowed during the study period;; dietary intake was monitored and didn't show sign. inter-group differences). The exercises performed were: flat barbell press, barbell military press, wide grip lat pulldown, seated cable row, barbell back squat, machine leg press, and machine leg extension. As Schoenfeld et al. point out, the "exercises were chosen based on their common inclusion in bodybuilding- and strength-type RT programs" (Schoenfeld. 2015).

The results of the study at hand put a question mark behind some, but not all of the recommendations in Kramer's paper. The ones on exercise order and workout structure (see above) are still valuable (Kramer. 2004)

So how can low load training build muscle? While it has long been shown that low(er) reps and higher weight are superior when it comes to building maximal strength and despite the fact that strength is an important prerequisite to induce the overload that's required to trigger adaptational changes in the form of skeletal muscle growth in response to resistance training, it is by no means clear that the latter, i.e. the induction of continuous progressive overload to trigger muscle growth wouldn't be possible with low reps - irrespective of the fact that Kraemer & Ratamess claim in their often cited paper about the "Fundamentals of resistance training: progression and exercise prescription" (Kraemer. 2004) that the high load was necessary, because it was required to recruit all motor units and thus fully activate the muscle and its growth potential.

Since even light load exercises can recruit a maximum amount of motor units if they are performed to failure, this argument is yet only relevant if we are talking about light load  + no-failure training. It is thus not surprising that previous studies comparing the muscular adaptations in low- versus high-load training programs yielded conflicting results. Results that were mostly generated in untrained subjects and are thus, much in contrast to the study at hand, pretty irrelevant for most of you.

"To facilitate recovery", the researchers provided the subjects with a supplement on training days containing 24g protein and 1g carbohydrate (Iso100 Hydrolyzed Whey Protein Isolate, Dymatize Nutrition, Farmers Branch, TX) which was consumed within one hour post-exercise, as this time frame has been purported to help potentiate increases in muscle protein synthesis after the workouts (cf. Aragon. 2013).

Figure 1: Overview of all relevant study results. Only the changes in squat strength and strength endurance as measure by 50% bench presses were statistical significant, there was a trend for greater increases in 1RM BP (Schoenfeld. 2015) 

As the data in Figure 1  tells you, both resistance training protocols yielded significant increases in biceps and triceps size. For biceps, the high rep training had a measurable, but non-significant edge producing 8.6% vs. 5.3% increases in biceps size (remember how people train their biceps, that's often ballistic, i.e. they are throwing high weights around, so maybe the benefits are simply a result of improved form).

For the triceps, the quadriceps (9.5% vs. 9.3%) and the biceps' antagonist, the triceps (5.2% vs. 6.0%) the differences were marginal and likewise non-significant. Now, it would be revealing, but boring if the results of high rep + low load and low rep + high load training were identical, right? Well, luckily, Schoenfeld et al. did find differences, as well. More specifically, they observed that the

"[i]mprovements in back squat strength were significantly greater for HL compared to LL (19.6 vs. 8.8%, respectively) and there was a trend for greater increases in 1RM bench press (6.5 vs. 2.0%, respectively)" (Schoenfeld. 2015).

In addition, and not much to your surprise, I guess, the upper body muscle endurance (assessed by the bench press at 50% 1RM to failure) improved to a greater extent in the low load (LL) compared to high load (HL) group (16.6% vs. -1.2%, respectively).

If there was a novelty effect that skews the results, this would only mean that you must periodize appropriately..

Overall, there's little to add to the authors' conclusion that their "findings indicate that both HL and LL [low load, high rep] training to failure can elicit significant increases in muscle hypertrophy among well-trained young men; however, HL training is superior for maximizing strength adaptations" (Schoenfeld. 2015); and while the latter is hardly news, the study is of particular significance in view of the ongoing debate about "go heavy or go home" as it proves a significant gain in muscle size can be achieved with both "going heavy" or "going light", as long as you don't go home, but train to failure.

What remains to be seen, though, is whether the high rep, low load training had the bonus of a novelty effect. After all, it can be expected that none of the subjects trained in a 25-35 rep range before they participated in the study. If that's the case and there is a novelty effect that bolstered the size gains, this wouldn't mean, though, that high rep training was useless. What it would mean, however, is that you'd have another reason to periodize your training properly - don't you think so? | Tell me about your experience and give me your thoughts. Comment on Facebook!

References:

• Aragon, Alan Albert, and Brad Jon Schoenfeld. "Nutrient timing revisited: is there a post-exercise anabolic window." J Int Soc Sports Nutr 10.1 (2013): 5.
• Kraemer, William J., and Nicholas A. Ratamess. "Fundamentals of resistance training: progression and exercise prescription." Medicine and science in sports and exercise 36.4 (2004): 674-688.
• Schoenfeld, et al. "Effects of Low- Versus High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men." Journal of Strength and Conditioning Research Publish Ahead of Print. DOI: 10.1519/JSC.0000000000000958

Does Your Pre Workout Inhibit Fat Loss? Study Shows Nitrate Supplements Decrease Metabolic Rate By 4.2%

If you want other to see your pump, you got to be ripped. If not, why care about reductions in BMR?

If you remember my posts about the first generation, arginine-based pre-workout products you will be aware that the only pump they produced was the word "pump" in their name or product description. The reason was and still is simple. The mere provision of l-arginine, which is a precursor to nitric oxide does not lead to an increase in nitric oxide production. Why? Well, think of a building a house: Just buying some concrete won't make you a proud home owner, either ;-)

The bad thing: Arginine didn't work. The good thing: This means it didn't decrease your BMR, either

Against that background it's quite astonishing that arginine and citrulline based pre-workout products have dominated the top-seller lists of the big supplement vendors for decades. A fact that's probably partly due to other potential benefits of these amino acids, of which one - you as a SuppVersity reader know that - could be fat loss | learn more about the potential fat loss effects.

On a side note:  I am pretty sure the fact that the other potential benefit is an increase in sexual stamina didn't hamper the sales either (Neuzillet, 2013; Hotta. 2014 ;-)

With more and more people openly declaring that they would no longer waste money on "good tasting, but expensive and disfunctional products", they industry was yet pressed to develop alternatives. Luckily, our body has two options it can chose from, when producing nitric oxide.

Fortunately, the industry has developed better alternatives...?

You know option #1, the arginine ➲ nitric oxide pathway, and - with all the hype and hyperbole that surrounded the introduction of the first nitrate supplements - I am pretty sure, you know the other one as well, the nitrate-nitrite ➲ nitric oxide pathway

Figure 1: The Arginine- and the Nitrate-Nitrite - NO pathway are the yin and yan of nitric oxide production (Lundberg. 2008).

As the illustration (Figure 1) I have "borrowed" from a comment by Jon. O. Lundberg et al. (2008) illustrates quite nicely, the arginine and nitrite nitric oxide pathway are the yin and yan of NO production.

With the "yan", i.e. the nitrate-nitrite ➲ nitric oxide pathway being a relatively "new kid on the NO block", that recycles (=reduces) inorganic anions nitrate and nitrite to form bioactive NO in blood and tissues during physiological hypoxia.

It goes without saying that there is a bottle neck to this process as well, but the rate limiting availablility of oxygen which hampers the argine-based NO generation by NOS becomes limited as oxygen levels fall is actually a signal for the nitrate–nitrite ➲ nitric oxide to really kick in.

There is more yin and yan, here

If you take a closer look at the results of a study in the America Journal of Clinical Nutrition (Figure 2), you will yet have to realize that there is "more yin and yan", here than you'd probably hope for. According to the data scientists from the venerable Karolinska Institutet in Stockholm, Sweden, present in their paper, "[d]ietary inorganic nitrate reduces the RMR." (Larsen. 2014)

Figure 2: VO2 consumption (marker of fatty acid oxidation) and basal metabolic rate (BMR) relative to means (left), thyroid hormone (T3, T4) levels after 3-d dietary intervention with sodium nitrate (Larsen. 2014)

Whut? Yes, you read Larsen et al. right: In their randomized, double-blind, crossover study, in the course of which the Swedish scientists measured the resting metabolic rate (RMR) of 13 perfectly healthy 18–49 y olds (17 women) via indirect calorimetry after a 3-d dietary intervention with sodium nitrate (NaNO3 @ 0.1mmol/kg body weight) or a placebo (NaCl), Larsen, Schiffer, Ekblom et al. observed a statistically and (probably) physiologically significant reduction BMR reduction of 4.2% which correlated strongly to the degree of nitrate accumulation in saliva (r²= 0.71) and fits in nicely with the reduced O2 consumption of which Bailey et al. were the first to observe it in response to nitrate supplementation during exercise (Bailey. 2009).

Interestingly, these effects were not - as you may have been speculated - brought about by changes in thyroid hormone status. And the subjects insulin sensitivity, glucose uptake, plasma concentration of isoprostanes, as well as their total antioxidant capacity were unaffected, as well.

Suppversity Suggested Read: " The Beat Your Personal Bests W/ Beets 101: How Much? 8.4 mmol Nitrate ~400-1300g Beets! When? 2.5h Pre Workout!" | read more

Bottom line: If the 0.1mmol/kg were not equivalent to only 200–300 g spinach, beetroot, lettuce, or other vegetable that was rich in nitrate, I would probably say: Here you have it! Another supplement that's not just useless, but actually detrimental to your goals.

The way things are, I will refrain from ranting and rather suggest you simply skip the supps and consume the spinach, beetroot, lettuce and other high nitrate veggies right away. Most of the human studies which support the ergogenic potential of nitrates have been conducted with beetroot juice instead of capped sodium-nitrate.

And let's be honest, the weight loss advantage of having green and not so green nitrate containing vegetables in your is eventually beyond doubt. So, if there was a similar reduction in RMR from your daily serving of spinach, you can be more or less certain that it was compensated by the beneficial weight loss effects of the whole spectrum of nutrients that's present in this edible flowering plant in the family of Amaranthacea.

Reference:

• Bailey, Stephen J., et al. "Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans." Journal of Applied Physiology 107.4 (2009): 1144-1155.
• Hotta, Yuji, et al. "Oral l‐citrulline supplementation improves erectile function and penile structure in castrated rats." International Journal of Urology (2014).
• Larsen, Filip J., et al. "Dietary inorganic nitrate improves mitochondrial efficiency in humans." Cell metabolism 13.2 (2011): 149-159.
• Lundberg, Jon O., Eddie Weitzberg, and Mark T. Gladwin. "The nitrate–nitrite–nitric oxide pathway in physiology and therapeutics." Nature Reviews Drug Discovery 7.2 (2008): 156-167.
• Neuzillet, Y., et al. "A randomized, double‐blind, crossover, placebo‐controlled comparative clinical trial of arginine aspartate plus adenosine monophosphate for the intermittent treatment of male erectile dysfunction." Andrology 1.2 (2013): 223-228.

Cell Swelling Keeps Muscles "Pumped" For More Than 52h. Size Increases of Up to 16% After a Single Leg Workout! Plus: Changes in Tendon Water & Collagen Content

I've heard rumors about people who get pumped, just to look pumped ;-)

I guess many of you will already have read Brad J. Schoenfeld's and Bret Contreras' latest review on "the pump"? I know for sure that Jakob read it, because he messaged me on December 29 that is was available for download over at the website of the Strength and Conditioning Journal. What he could not know, though was that I had already downloaded and read the article, when Brad and Bret, who are unquestionable two of the go-to resources for everyone who wants to learn something about the science of "getting big, lean and strong" posted the link on Facebook on December 28 (go to the original post). This link will take you to a downloadable ~2000 word paper in the conclusion of which you will find the following statement:

"[...] it is likely that exercise centered on achieving a “pump” through higher repetition sets combined with shorter rest periods also provides a potent hypertrophic stimulus that is synergistic to heavy compound lifting." (my emphasis in Schoenfeld. 2013)

In view of the fact that this excerpt summarizes the main information the paper provides excellently, I am not going to ruminate Brad's & Bret's overview of the few studies that allow for relevant and at least to some extend reliable conclusions about the real-world effects of the pump and its significance for someone whose main interest is in building size, not strength (just read the review, if you want the details).

There is something about the pump the review doesn't discuss, though

Don't worry, it's not as if Brad and Bret had overlooked the latest paper M.S Kristiansen and his colleagues from the Institute of Sports Medicine, the Section of Sports Science at the Universities of Copenhagen and Aarhus. Rather than that, the paper with the intriguing title "Concomitant changes in cross-sectional area and water content inskeletal muscle after resistance exercise" had (a) not even been published, when they the two were doing the research for their review and is (b) as we are going to see not 100% relevant to the question, whether the pump does or doesn't promote muscle growth.

Collagen loss and (super-)compensation occur in the early and late phase of the post-exercise period. If you don't want to risk injury or chronic overuse, you better remember this whenever you're working on a new workout schedule.

Does exercise also influence the water content of the tendons? In contrast to its effects on the intra-muscular water content the 3-EX regimen in the study at hand lead to "a decrease in the CSA of the central part of the PT [patella tendon]" within the first 52 h post exercise. "A concomitant increase in the water content of the tendon could not be demonstrated, though." (Kristiansen. 2013). Based on the absence of an overall decrease in water content, Kristiansen et al. speculate that previously observed decreases in tendon size (Miller. 2005; Tardioli. 2012) could have been brought up by a net loss of collagen during the early restructuring processes after heavy workouts.

Since the rate of collagen synthesis is negligible within the first 36h after exercise "the breakdown of the tissue driven by catabolic processes [...] may exceed the synthesis" that peaks after 72 h, "if multiple training sessions are too close to one another" (Kristiansen. 2013). The consequences? Acute injuries and / or chronic overuse.

Suggested Read: "Why training over the full ROM counts" | more

Now you may be asking yourselves why the results Kristiansen et al. are about to present in one of the upcoming issues of the Scandinavian Journal of Medicine & Science in Sport still made it into the SuppVersity News, if they don't provide any new insights into the contribution of the pump to skeletal muscle hypertrophy. The answer is simple: They do tell us something that puts a huge "?" behind the results of a whole host of studies on skeletal muscle hypertrophy. Something the average "disco pumper", i.e. a person who works out a couple of hours before he hits the Saturday night life to make sure that his muscles are big and full, knew for years: Your muscle size remains significantly elevated for hours even after comparatively low volume workouts.

What the average disco pumper probably didn't know, though....

... is that the water-induced cell-swelling peaks not 4h after the workout, but actually 52h after the last workout. That's probably good news for everyone who hates being wiped from the afternoon workout, when he is trying to get off with the girls on the dance floor. For the average scientist, on the other hand, that's seriously bad news. He or she has after all made a habit of ignoring the difference between muscle gains and water gains in his / her studies, whenever the measured muscle circumferences support his / her research hypothesis. In other words, until now nobody actually payed attention to the fact that what he / she measured on day 1 after the last workout of an 8 week study may be influenced to a large extend by the last and to a minimal extend by all previous workouts. It's thus totally correct that Kristiansen et al. demand that ...

"[...] post-training changes in CSA [cross sectional area] should be interpreted with caution, as they may adhere to exercise-induced water retention resulting from the last exercise bout." (Kristiansen. 2013)

In view of the fact that few researchers have hitherto exercised the said "necessary caution", it  appears to be more or less certain that a non-negligible proportion of the currently available data on skeletal muscle hypertrophy in training noobs such as Kristiansen et al.'s  ten healthy untrained study participants would have to be revised or at least tested.

Figure 1: Working out leads to increases in water content (left) corresponding increases in muscle "size" (right) at the 10 & 20 cm measuring points of the the quads; all values expressed as relative changes (%) vs. baseline (Kristiansen. 2013)

What's good though, is that it appears reasonable to assume that the cell swelling will be particularly pronounced, when the muscle is exposed to a new training stimulus (just like the DOMS, by the way; learn more) . This, in turn, would mean that the Kristiansen's one (1EX) and three (3EX) training day intervention  consisting of ...

• 2 min recovery between sets, 5 min between exercises
• verbal encouragement during all sessions
• total workout time ca. 45min

• 5 min warm up on a cycle ergometer
• 1x warm up set (5 reps; 50-60% 1RM) for the randomly selected working leg
• 5 sets of single-legged leg presses and knee extensions per workout
• 10 reps at an intensity of 10RM per set

... would probably have different effects in trained and highly trained individuals. Data form one of the few studies with "non-rookie" (aka "recreationally active") subjects does therefore have a much lower chance of having a measuring bias than data from studies with strength training novices. For those, the results of the Kristiansen study could mean that the real-world hypertrophy effects have been largely overestimated.

Figure 2: Schematic depictions and actual axial scan of the M. Quadriceps (Kristiansen. 2013)

Not convinced? Well, you cannot tell me that you actually believe that a single leg workout will increase the actual muscle size in the "teardrop zone" of the quads (see anatomical chart at the top in figure 2) of any trainee - rookie or not - by 16%, right (see figure 1)? I see no one is shaking his / her head.... well, then what do you think: How many researchers waited for a 3 full days or better a whole week after the last workout before they sent their subjects to the magnetic resonance imaging (MRI) device to obtain axial scans such as the one in Figure 2?

I have to admit that I haven't been paying much attention to the time-lag between the last workout and the MRI or measuring tape "powered" assessment of the post-intervention muscle circumference, but I am still convinced that it will be very difficult to find any study, where the post-values were taken more than 54h after the workout.

We must not forget, though that (1) the cellular hydration state is among the fundamental determinants of protein catabolism in health and disease (Häussinger. 1993), that (2) Basco et al. were able to show that the AQP4-dependent water transport into the muscle supports both, muscle contractile activity and metabolic changes that occur in fast-twitch skeletal muscle during prolonged exercise (Basco. 2013), and that (3) Brad & Brent's review clearly suggests that the exercise induced cell swelling has a facilitative role in skeletal muscle hypertrophy.

Bottom line: If we also take into account that the vast majority of studies will use the 10cm point (see figure 2, left) to quantify the increase in muscle size, it is well possible that the average resistance training study could have overestimated the hypertrophy effect of the corresponding training (and supplementation!) regimen in novice or "recreationally trained" study participants.

In view of the fact, that very few of the studies had a duration of only three training sessions (1-2 weeks) and against the background that the multiple training sessions in studies with durations of 2-12 weeks will accustom the muscle to the previously novel stimulus, I would yet not go so far as to say that the results of the average study could be up to 10% off... I do, on the other hand, have my doubts that all the hitherto reported increases in muscle size would retain a p-value of p < 0.05 and would thus have to be considered as "statistically significant", if the CSA measurements had been taken 7days+ after the last training session.

References:

• Basco, D., Blaauw, B., Pisani, F., Sparaneo, A., Nicchia, G. P., Mola, M. G., ... & Frigeri, A. (2013). AQP4-Dependent Water Transport Plays a Functional Role in Exercise-Induced Skeletal Muscle Adaptations. PloS one, 8(3), e58712. 
• Miller, B. F., Olesen, J. L., Hansen, M., Døssing, S., Crameri, R. M., Welling, R. J., ... & Rennie, M. J. (2005). Coordinated collagen and muscle protein synthesis in human patella tendon and quadriceps muscle after exercise. The Journal of physiology, 567(3), 1021-1033.
• Schoenfeld, B. J., & Contreras, B. (2013). The Muscle Pump: Potential Mechanisms and Applications for Enhancing Hypertrophic Adaptations. Strength & Conditioning Journal. 
• Tardioli, A., Malliaras, P., & Maffulli, N. (2012). Immediate and short-term effects of exercise on tendon structure: biochemical, biomechanical and imaging responses. British medical bulletin, 103(1), 169-202.

No Pump + Insulin Resistant? Maybe It's Your Healthy Low Salt Diet. Low Sodium Induced Increase in Aldosterone Has Direct Negative Impact on GLUT4 Mediated Glucose Uptake

A single Triple Whopper or about six whole steaks, what do you chose to get >75% of the 2g/sodium per day the feds are telling you you should maximally consume on a daily basis?

Today I felt kind of bored with covering only the latest studies. So I dug up one from 1999 that deals with the effects of dietary salt restriction on endothelial vasodilation (increased blood flow in the arteries) and insulin sensitivity by Ross D. Feldman and Nancy D. Schmidt. Yeah, the study is 14 years old, but when you've read today's SuppVersity article you'll probably still have learned something new - at least about "common wisdom".

If you also listen to the SuppVersity Science Round-Up on the Super Human Radio Network, you should be aware that very different rules apply with respect to salt consumption for athletes and physical culturists on a whole foods diet and the average sedentary inhabitant of the Western obesity belt (check out past episodes of the Science Round-Up).

Suggested Read: On "Clean Eating" being a myth - "A Tale of Macro- & Micro-Nutrient Modifi-cations" | read more

Talking about the ScienceRound-Up: In today's installment Carl and I will be talking about the latest meta-analysis on dairy and diabetes risk and how it's possible that only low fat dairy reduces the risk of diabetes. We will discuss how this relates to the differences in the fatty acid composition of milk which in turn depend on the feed the animals receive and whether there is in fact so much estrogen in milk that it can delay menopause. From there we will segue right into a discussion of the latest study on statins showing that they make you fat and diabetic and tell you which of the statins does what. If all works well, we will close the show by addressing Sarah M. Davis' question about a recently published and heavily discussed article that's titled "Why 'Clean Eating' is a Myth" (read it). I mean, is it really? Turn in live! at 12PM EST

What some of you may yet still not have on their radar is the fat that the "common wisdom" about salt being the root cause of all evil does not even apply to the majority of those guys and girls of whom you would expect they may in fact see benefits from a reduced salt consumption.

"Salt is bad, no matter what!"

In fact, Feldman & Schmidt were able to show that the provision of either normal or salt reduced diets to subjects aged 25 to 40 year.

Figure 1: Increased aldosterone levels during salt restriction will not only make you retain salt, but also reduce glucose uptake (Luther. 2011; my edits)

"Subjects were given a standardized diet that contained 75 mmol/L sodium chloride, 60 mmol/L potassium, and 20 mmol/L calcium for 14 days. Diets contained 16% protein, 54% carbohydrate, and 35% fat. Caloric intake was 2800 kcal/day. Subjects were advised to drink approximately 2L of water/day.

To assess the effects of dietary salt restriction independent of other dietary changes, subjects were randomized on a double blind cross-over basis to a daily supplement of 16 tablets of slow release sodium (Novartis, Mississauga, Ontario; 10 mmol/L sodium chloride/tablet) or matching placebo. Each were administered for 7 days." (Feldmann. 1999)

All of the participants had normal blood glucose levels, and were free of other abnormalities on history and physical examination. They did not smoke and their blood pressures levels ranged from normotensive to high normal/borderline. So, what would happen to the poor wretches consuming the additional sodium chloride tablets? Common wisdom tells us, their blood pressure will increase and they will develop metabolic abnormalities. Truth is (I quote from the study; Feldmann. 1999, my emphases), almost the exact opposite happened:

• Did you know? Aldosterone increases are caused by falling blood pressure, increased potassium levels, a higher blood acidity and decreased sodium concentrations in the blood trigger, decreases occur when your blood pressure drops, the potassium levels get low and/or the sodium levels are high.
  Dietary sodium restriction was associated with a significant decrease in 24-h urinary sodium excretion. However, blood pressure (based on the average 24-h automatic ambulatory measurements) was not significantly decreased with dietary salt restriction.
• Moderate salt restriction was associated with a significant increase in plasma norepinephrine concentrations. Dietary salt restriction was associated with a significant decrease in the glucose-to-insulin ratio, suggesting increased systemic insulin resistance. This decrease was primarily accounted for by an increase in plasma insulin concentration.

At the same time the researchers observed a significantly reduced effect of the vasculature to the insulin-mediated increase in blood flow, of which Hornstra et al. have shown only recently that it correlates negatively with blood pressure in overweight, but insulin sensitive individuals and may be the reason why those people don't suffer from the usual obesity related increases in blood pressure as well as its cardiovascular and renal consequences (Hornstra . 2013).

---

Most of you will remember the recent post about the ability of salt to block the negative effects of high intensity exercise on the cellular integrity of your heart and kidneys don't you?

Bottom line: If you are working out and sweating, even if it's not like a pig, SALT is the last thing to fear. In fact you can even increase your heart disease risk due to the negative impact on blood lipids (+10% total +12% LDL cholesterol in salt-sensitive and unsensitive normotensive subjects; Ruppert. 1991).

Now it is important to point out that it is not clear whether these effects are transient and a response to the abrupt changes in dietary salt in take that are characteristic of these short term intervention studies.

I am certainly not recommending you copy the salt intake of the average junk-food fanatic!

But let's be realistic, here: How much salt do you actually consume on a daily basis if you follow my advice and leave as much of the processed pre-packaged junk as you can right in the supermarket!? This will leave you with actually having to put salt on your foods and there really is no good reason for the average physical culturist not to so in a way that it's tasty and supplies you with one of the most important minerals in your body.

Suggest figure: Only obese people have increased risk of CVD with increasing sodium consumption | check it out the SuppVersity Facebook Wall

Reference:

• Egan BM, Lackland DT. Biochemical and metabolic effects of very-low-salt diets. Am J Med Sci. 2000 Oct;320(4):233-9. Review.
• Hornstra JM, Serné EH, Eringa EC, Wijnker MC, de Boer MP, Yudkin JS, Smulders YM. Insulin's microvascular vasodilatory effects are inversely related to peripheral vascular resistance in overweight, but insulin-sensitive subjects. Obesity (Silver Spring). 2013 Mar 20.
• Luther JM, Brown NJ. The renin-angiotensin-aldosterone system and glucose homeostasis. Trends Pharmacol Sci. 2011 Dec;32(12):734-9.
• Ruppert M, Diehl J, Kolloch R, Overlack A, Kraft K, Göbel B, Hittel N, Stumpe KO. Short-term dietary sodium restriction increases serum lipids and insulin in salt-sensitive and salt-resistant normotensive adults. Klin Wochenschr. 1991;69 Suppl 25:51-7.

80g Glycerol + 2L Water Decreases Body Weight in Athletes & Increases Overall Performance in Sedentary Subjects

If it does not make you as swole as the colorful ad promised it must not be working, right? The jury was not even any longer "out there" for glycerol, but a recent study makes you rethink, whether you just have to look in the right place to see the benefits.

Another of the "odd" Thursdays without an update from "Your's Truly" Adelfo Cerame. And since there is holiday today, over here, I even thought there would not be a SuppVersity Science Round Up today. But hey, you are lucky you (and Carl) got to work, so you can tune in live at 1PM EST, or even better, start listening live at 1PM in order not to miss the Strength and Hypertrophy Round Table!

As far the  topics for today's installment of the SuppVersity Science Round Up are concerned, you are actually only a couple of lines away from reading about one that's on the list:  The effects of glycerol on exercise performance. I don't have to tell you though that this is not everything. Other things I believe you may be interested in are...

• childhood obesity, physical education and attention at school
• wheat gluten hydrolysate and how they don't come up to the expectations early trials have raised
• ammonia accumulation brain-fog, toxicity, liver 'pathologies' and workout performance
• running next to a street entails 'particular downsides' ("particular" is to be taken literally, here ;-)
• homocysteine levels, mortality, cognitive impairment and more
• epigenetic programming by nicotine and different protein contents before birth

These topics alone obviously won't fit into a single episode, but by now you should be aware that the SuppVersity Science Round Up Seconds, which are always published one day after the show aired, will provide you with the things we have missed and additional information, suggested reads and graphs to the topics we covered...  apropos "won't fit in", since the above is not even everything I have up my sleeve, I thought it would be wise to take the glycerol news from the compilation and tackle it on its own, today.

Can the backbone of bad triglycerides really be good for you?

Glycerol, a 3-carbon sugar alcohol that provides the backbone of triglycerides and is naturally found in foods as a component of dietary fats (Burke. 2011), is one of those supplements that have been all the rage for some time, didn't produce the expected instant results everybody was looking for (in this particlar case mostly "skinbursting pumps" and have eventually, in the course of one or two cycles of the regular yearly reformulations of the pre-workout supplements, completely disappeared from the market. I was therefore surprised, when I hit onto a recent study by researchers from the Physical Education and Sport High School in Konya (Turkey) that was published in one of the latest issues of the Journal of Human Kinetics (Patlar. 2012).

Is glycerol save? There have not been any reported toxicity effects up to doses of 5g/kg body weight. Glycerol does accumulates in body fluids, with the exception of the brain and the eyes and increases osmotic pressure (which was the reason why people used it in "pump supplements"), as well as the total volume of water in the body. If anything was 'dangerous', or I should probably rather say 'detrimental' to it, it would probably be its energy content (it is subject to gluconeogensis in the liver), which puts you at 'danger' of adding one or another pound of body fat you would probably want to avoid. The results of the study at hand to yet suggest that this is not an issue as long as you are active.

In essence the study protocol is nothing extraordinary: Take a couple of guys, 40 in this case (age 22.82 ± 1.49 years), and feed and water them using...

• 1.2 g/kg body weight) followed by water (26 ml/kg body weight) to 10 sedentary individuals (GS) and 10 soccer players from the University team
• just plain water to the another 10 sedentary men and 10 soccer players

Conduct a baseline test in the course of which all subjects are familiarized with the exercise equipment, a cycle ergometer (Monark 814-E) and required to perform an...

• Astrand Cycle Ergometer Test and an
  
• Wingate Anaerobic Power Test
  *the videos are don't show the study participants

in a room that is kept at 30°C and a barometrical pressure of 668 mm-Hg. For the next twenty days, have half of the guys (athletic groups E and GE) perform a 20-m shuttle run test every day. And finally perform a second follow up to see and evaluate the individual and joint effects of exercise and glycerol supplementation.

What's a shuttle run? I guess those of you who play soccer or basketball will know similar drills (at least I have been tormented by my trainers with them before in both sports and could imagine they are also among the standard repertoire of football coaches - though I have never played that myself):

Video 1: The shuttle run is every trainer's darling and would actually make a nice conditioning workout to be implemented into your own routine - whatever it may you are training for (note: the video is a random pick from YouTube and has no relation to the study at hand).

"The subjects warmed up for several minutes by jogging followed by stretching. The test program was installed on the computer and  initiated. A single beep was emitted at regular intervals. The subjects had to complete a lap or shuttle (foot on or over the line) with each beep. If the subjects completed a lap early they had to wait for the beep before starting the next lap. A triple beep indicated the start of a new level with a slightly faster speed required to complete each  lap.

The subjects were encouraged to complete as many levels as possible. An observer monitored the progress of a given subject, recording each completed lap on the recorder form. The subjects were instructed to turn by pivoting and not to run in a wide arc. The test was terminated when a subject was two or more steps from the line, for two consecutive laps. The observer alerted the subject at this time." (Patlar. 2012)

The shuttle run was followed by a couple of minutes of walking to cool down and a stretching exercise. The data was collected, logged and archived for evaluation.

Now if we take a look at the results of this undertaking they are unquestionably somewhat surprising - at least at first sight (see figure 1). In absolute terms it looks as if we had an across the board, almost identical increase in performance due to the daily shuttle runs in the exercise groups and a surprisingly large beneficial effect of glycerol only in the sedentary subjects (which would by the way be in line with many of the more or less disappointing trials on the benefits of glycerol supplementation in athletes; cd. Burke. 2011):

Figure 1: Changes in anaerobic and aerobic performance - relative values on the left, absolute before (white) and after (black) on the right (Patlar. 2012)

If you take a look at the relative pre-post changes in figure 1 (left), instead of the absolute changes a more distinct picture emerges:

• the benefit the sedentary subjects derived from the supplementation looks even more pronounced,
• the aerobic performance of the soccer players in the exercise group did likewise benefit, albeit less than the performance of the sedentary group, and
• shockingly the increase in anaerobic performance which looks pretty much identical is not statistically significant, yet still reduced in the glycerol supplemented athletes in the exercise + glycerol group (note: there is an increase, it's only relatively smaller)

Now, we all know that hyperhydration goes hand in hand with an increase in body water. In figure 1 I did even plaster a huge red sticker with "hyperhydration" onto the graph to give you an idea of a possible mechanism of action. So, if we wanted to be fair, we would have to take that into account... what? Yeah and you want to know if it will make you blow up like a wale, right, ... so let's see:

Figure 2: Changes in body weight and relative power (watts per body weight) in the course of the trial (data based on Patlar. 2012)

If we assume you are a sedentary slob at 80kg you could in fact gain 1.6kg... whether that's only water or if there is some fat there, as well, I cannot tell. Notwithstanding, I mentioned in the red box on safety issues, already that you can hardly expect to down 80g of glycerol with an energetic value of 4.32kcal/g (i.e. 350kcal per day) extra everyday without gaining at least some weight (assuming all other parameters are constant; plus, this could be muscle as well - well, not if you don't work out, though ;-).

You cannot expect to lose weight, but surprisingly it may still happen that you do if you consume those 350kcal of glycerol with 2l water right before your daily shuttle run. 

At least this is what happened to the soccer players in the supplementation group: They lost 2.66lbs of body weight on average. "Weight" is the unfortunate key word here, because we have no way of telling whether that was muscle, water or fat weight, as the scientists did not measure that separately. But let's be honest, it appears more than unlikely that it is (a) water or (b) muscle. After all the relative anaerobic power increased equally in both groups and why on earth would you lose water when you hyperhydrate? Ok, it could be one of those counter-regulatory reactions our bodies love. That again should however lead to performance decrements we did not see... you see, it's like the idiomatic dog that's chasing his tail. Why don't you play ginea pig and let us know what happens ;-)

WADA Warning for competitive athletes: If you are a WADA controlled athlete, you better avoid glycerol. It may sound hilarious, but it is on the WADA list of prohibited supplements since 2012. Why? Well, the increase in blood volume could mask the use of testosterone and co. because the /dl count would be lower if the total blood volume is higher -- this is something the WADA officials consider call a "masking agent" (Wada. 2012).

How much do you need? Don't forget, for glycerol to work its hyperhydrating magic, you must consume it with similarly hilarious amounts of water as the subjects in the study at hand. According to van Rosendal et al. an effective protocol comprises 1-1.5 g/kg glycerol + 25–35 ml/kg of fluid. Assuming you weigh 80 kg you can't get way with anything below 80g of glycerol + 2l water! Obviously way more than what any of the hitherto no longer available 'pump' or pre-workout supplements contained (at least I have not come across one that has a 80g scoop and says "consume with at least 2l of water on the label" - have you?)

Bottom line: I want to be honest, I still have to make up my mind about the usefulness of this supplement. I guess what actually does the trick is the combination of hyperhydration + energy availability. I have been preaching more than enough about the importance of energy availability over the last couple weeks, so I don't think I have to go into any more details here.

What I do think, however, is that few of you will be aware of the 2008 paper by Judelson et al. in which they report that hydration status is a fundamental determinant of the endocrine response to exercise, with dehydration leading to inappropriately high cortisol and norepinephrine levels that go hand in hand with an attenuation of the testosterone response to exercise, and negative effects on carbohydrate and lipid metabolism (Judelson. 2008).

Since you should by now have gotten the notion that insufficient energy does exactly the same, glycerol could well provide a means to counter this ergolytic double whammy. Against that background it is however strange that the athletes could not derive any athletic benefit from it... and weight loss without dieting (at least they were advised to stick to their habitual diets)?

If there is one definitive message you can take home from this study, though, it would be related to the dosage advice in the blueish info-box on the top right of this last paragraph: You better know how to use a supplement correctly! And this goes for the manufacturers of supps, as well as for the consumers: While the formers should finally stop putting ingredients into their supps to have them on the label, consumers should learn to identify hilariously underdosed and thus useless 'kitchen sink supplements' that 'have it all', but in doses where 'all' does not produce 'any' effect... how you can do that? Easy: Just make sure you get your daily dose of educative SuppVersity posts every day!

References:

• Burke LM, Stear SJ, Lobb A, Ellison M, Castell LM. A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance--Part 19. Br J Sports Med. 2011 Apr;45(5):456-8. 
• Judelson DA, Maresh CM, Yamamoto LM, Farrell MJ, Armstrong LE, Kraemer WJ, Volek JS, Spiering BA, Casa DJ, Anderson JM. Effect of hydration state on resistance exercise-induced endocrine markers of anabolism, catabolism, and metabolism. J Appl Physiol. 2008 Sep;105(3):816-24
• Patlar S, Yalcin H, Boyali E. The Effect of Glycerol Supplements on Aerobic and Anaerobic Performance of Athletes and Sedentary Subjects. Journal of Human Kinetics. 2012; 34: 69-70. 
• Van Rosendal SP, Osborne MA, Fassett RG, Coombes JS. Guidelines for glycerol use in hyperhydration and rehydration associated with exercise. Sports Med. 2010 Feb 1;40(2):113-29.
• World Anti Doping Association. WADA Prohibited List 2010. < http://www.wada-ama.org/Documents/World_Anti-Doping_Program/WADP-Prohibited-list/2012/WADA_Prohibited_List_2012_EN.pdf > retrieved Nov. 01, 2012.