Intra-Workout Supplementation: Increased Carbohydrate Oxidation with L-Arginine, Lower Fat Oxidation with Glucose & Lowest Rate of Perceived Exertion with Plain Water

Image 1: This bird certainly knows about the importance of adequate hydration ;-)

Have you been at the gym today? If so, what kind of beverage have you been sipping in the rest-periods between your sets, your sprints or during your regenerative (not fat burning ;-) "classic" cardio exercise? Was it Funky XYZ the latest and greatest intra-workout product on the market? If so, you better check out its ingredients, who knows maybe the "latest and greatest" turns out to be quite counterproductive towards the goals you have been setting after reading one of the last two installments of the Intermittent Thoughts? Let's assume you are the "Peter Griffin"-type of chubby - in that case, I hope that your Funky XYZ did not contain glucose, maltodextrin, waxy maize, or any other of the sugars of which the supp companies are going to tell you that they "superior" to the white poison your granny uses in her delicious muffins. Why? Well, according to a soon to be published study by scientists from the Massey University in Wellington, New Zealand, as little as 12g of glucose will reduce the amount of endogenous fatty acid (i.e. the stuff your body is using to hide your abs ;-) oxidation by -22%! Sounds terrible, doesn't it? Well, let's look at some details to decide whether those -22% will really make a difference and what effects the presence of l-arginine and l-glutamine in your intra-workout supplement could have had.

150 min @ 177 Watt + Glucose + (Glutamine or L-Arginine) = ???

Figure 1: Composition of the intra-workout supplement; sodium citrate base + 12g glucose (glucose) and additional 1g l-glutamine (Glu + L-Glutamine) or 0.1g l-arginine (Glu + L-arginine)

It stands out of question that adequate hydration is of utmost importance, when it comes to maximizing athletic performance (incidentally, the same is true, when it comes to "burning fat"). What athletes should drink before (pre-hydration), during (hydration) and after your workouts (re-hydration) is thusly one of the classic topics of exercise science and the recent study by D.S. Rowlands et al. is thusly probably #1001 on the never-ending list of investigations into the optimal mineral and nutrient composition of intra-workout drinks. For us, it is of interest, because it is one of the few which investigated the differential effect of the amino acids l-arginine and l-glutamine on substrate utilization, plasma glucose, lactate and sodium levels and rates of perceived exhaustion in eight male cyclists and triathletes during 150min (!) of cycling at 50% of the individually predetermined peak power (this is noteworthy, because 50% of their peak power equalled 177 W, which is not exactly "light" exercise), in the course of which the athletes consume 150ml of a fluid containing a 0.95g sodium base and either 12g of glucose alone or a combination of glucose and either 1g of l-glutamine or 0.1g of l-arginine (cf. figure 1).

Figure 2: Oxygen consumption (L/min) and substrate utilization (g/min) in 8 trained cyclists / triathletes during 150 min of cycling at 177W with 150ml of four different intra-workout drinks (data adapted from Rowlands. 2011)

As a seasoned student of the SuppVersity, it should not surprise you that the exogenous (i.e. from the outside) supply of glucose produced a -22% shift in substrate oxidation from fatty acids to the now more readily available carbohydrates (cf. figure 2). What you have probably not expected, though, is that the addition of the minuscule amount of l-arginine (which is btw. about what you will get with many of the proprietary blends in the still incredibly popular "NO-boosters") would promote this shift by increasing the total amount of oxidized carbohydrates by another ~10% over the 12g glucose solution alone.

Figure 3: Comparison of total / relative substrate utilization for the 12g glucose + 0.1g arginine, the 12g glucose and the water + sodium citrate groups (data adapted from Rowlands. 2011)

Now you are stunned, hah? So after all it is yet not your fault that you cannot see your abs. It's your NO-suppement! Well, not exactly. I mean take a look at the way I arranged the data in figure 3. You will probably acknowledge that the 12g glucose + 0.1g l-arginine group "burned" more energy - if you want it in calories (remember this is stupid ;-) 0.68kcal/min or 102kcal during the whole session and then come back to the -22% reduced fatty acid oxidation and lament: "But Dr. Andro, they burned 22% less fat than the water-only group! Now I know why I don't get lean." If that is your train of thought, I would invite you to continue the idiotic kcal number crunching and calculate on how much fat the poor l-arginine group would have missed to burn... well, it's the "exorbitant" amount of 170mg/min or - for the whole session 25.5g! While this may be more than one tablespoon of coconut oil, I guess you will probably admit that this probably is not the reason your abs are still covered by a thick layer of flabby adipose tissue, won't you?

Arginine reduces oxygen cost at the expense of glucose

Now, the real interesting findings of the studies are thusly not the changes in substrate utilization but rather the profound impact the addition of the two amino acids had on the lactate levels during the 150min of cycling (cf. figure 4) and the rates of perceived exertion (RPE).

Figure 4: Plasma lactate levels (mmol/L) in 8 trained cyclists / triathletes during 150 min of cycling at 177W with 150ml of four different intra-workout drinks (data adapted from Rowlands. 2011)

The latter (RPE), and this is actually quite surprising, were minimal in the water + sodium citrate group and maximal in the 12g glucose + 1g l-glutamine group (0.8 pts greater on a 0-7 scale). The RPE values of the arginine group, on the other hand, were only marginally elevated and that despite the significant increase in glucose clearance, which, by the way, has also been observed by McConell et al. (McConell. 2006) and Linden et al. (Linden. 2010). 

In view of recent studies such as Greer et al. (Greer. 2011), who observed a small, but statistically significant decreases in endurance during a strength training circuit in response to Arginine-Alpha-Keto-Glutarate (AAKG) supplementation, it is yet very unlikely that the observed effects of an arginine-enriched glucose containing intra-workout supplement observed in this study "have the potential to benefit endurance exercise performance" (which is what the scientists, much to my surprise, conclude). Another thing is yet more than likely, I would even say it is 100% certain: Neither the results of this nor of any future study will change the sales ranks on Bodybuilding.com & Co., where the purported NO-Boosters (and factual stimulants) still are the front-runners of the "TOP 10 selling products" ;-)

Carbohydrate Supplementation During Workouts - Who Benefits? How Much and Which Type(s) of CHO are Best?

Compared to liquid beverages, gels have the advantage of causing lower GI stress, when significant quantities of CHOs are consumed during exercise. Bars, can be held in the cheek pouch and chewed during critical phases of a race.

The headline gives it away. Today's SuppVersity article is a brief review of the (mostly sponsored) literature on Gatora.... ah, I mean carbohydrate supplementation during exercise. The headline also implies that the usefulness and efficacy of carbohydrate supplements depends on exercise duration and the type of exercise.

As a seasoned student of the SuppVersity you will know that certain paradox involved with regard to the duration / type of exercise. Short exercise durations, for example, shouldn't require large CHO boluses, long duration exercise, on the other hand, is fueled mostly by fat - so why should you supplement with carbohydrates, anyway?

Want to improve your exercise performance? Try sodium bicarbonate, as well!

The Hazards of Acidosis

Build Bigger Legs W/ Bicarbonate

HIIT it Hard W/ NaCHO3

BA + Bicarb are Synergists

Bicarb Buffers Creatine

Creatine + Baking Soda = 2x Win!

I promise to answer this and other questions in the following paragraphs, but before I do so, I would like to point out that there is as of now no evidence that the much-praised "fat adaptation" increases the exercise performance to an "Olympia" level. Carbohydrate supplements, on the other hand, are still part of the regular supplementation regimen for the 99% of the top athletes.

That being said, the human physiology dictates that the use of carbohydrate supplements during aerobic workouts that last less than 60 minutes is useless, because muscle glycogen is generally not limiting to performance when exercise durations are less than ~60 minutes.

It should not work for short duration exercise, but it still does

Interestingly, 16 out of 23 studies, Trent Stellingwerff and Gregory R. Cox from the Canadian Sport Institute-Pacific and the Australian Institute of Sport reviewed for their recent paper in Applied Physiology have found that carbohydrate supplementation and/or oral (mouth) exposure to carbohydrate can improve performance of tasks less than 1 hour in duration:

You won't fully deplete your muscular glyocogen levels
during short duration resistance training (Haff. 2003)

"In 2004 a seminal paper was published showing that a carbohydrate mouth-wash (swirling 25ml of a 6% CHO beverage (only ~1.5g of CHO in 25ml [6.4% maltodextrin solution (CHO)]) around in the mouth for ~10 sec, every 7.5min) significantly improved time trial (TT) performance [in seven male and two female endurance cyclists] by ~3% (Carter et al. 2004a)." (Stellingwerff & Cox. 2014)

This effect of CHO mouth-washing to improve performance in events from 30-60min has now been replicated in several other performance studies (10 of 13 studies) using both cycling and running interventions and with both sweet (sucrose) and non-sweet (maltodextrin) caloric CHO sources,as compared to 5 non-caloric artificial sweetener placebo trials showing no performance enhancing effects.

Figure 1: Hard to believe, but true - In 2010 Pottier et al. observed that CHO mouth-rinsing, but not CHO ingestion increases the 1h high intensity time-trial performance in trained subjects.

 "All these findings have been mechanistically supported with a functional magnetic resonance brain imaging study showing that CHO mouth-washing from both sweet tasting glucose and non-sweet maltodextrin can stimulate the brain areas of the insula/frontal operculum, orbitofrontal cortex and striatum, which are involved with brain centers responsible for reward and motor control (Chambers et al. 2009). Interestingly, if the mouth (oral receptors) and GI tract is by-passed by CHO infusion straight into the blood stream then 1h cycling TT performance was unaltered as compared to no CHO supplementation (Carter et al. 2004b)." (Stellingwerff & Cox. 2014)

Studies evaluating the effects on perceived exertion (Fares et al. 2011) found similar benefits all of which support the idea that the effect does not occur in the musculature, but rather in the head.

So what do you do to benefit during short-duration (<60) minute workouts? To benefit during short duration exercise exercise (<1h) ~1.5g of high GI carbohydrates (30g/h total = max) consumed or used as a mouth-wash in servings of 25ml for 5 to 10 sec every 8 to 10 min of exercise will do the trick. Since it can be difficult to actually drink / mouth-wash with CHO during critical phases of the race, Stellingwerff and Cox suggest "placing a sports confectionary in the cheek cavity" as a more practical option for some athletes.

It should be obvious that the physiological, or rater intra-muscular benefits of carbohydrate supplements increases with the exercise duration.

CHO supplementation during exercise that lasts 60 minutes or longer

In view of the fact that it is 100% logical and well established by studies by Coyle et al. (Coyle 1992a; Coyle 1992b) that the intake of carbohydrate (glucose alone, and glucose + fructose blends) can significantly improve prolonged endurance capacity and performance (>60min of exercise (Jeukendrup 2010)).

Figure 2: Overview of the performance increases in the 50 studies Stellingwerff & Cox reviewed (2014)

Against that background I will not bother you with another overview of the results, but focus on the efficacy of different carbohydrate supplementation strategies and types of carbohydrate supplements for exercise durations beyond the "magical" hour.

Glucose + fructose - the combination advantage

As a SuppVersity reader you've previously heard about the benefits of combining glucose and fructose in your intra-workout beverage. It is thus only logical that most commercially available formulas are mixtures  glucose + fructose (GLU:FRU) or maltodextrin + fructose - so-called "multi-transportable CHOs". The advantage of using both glucose and fructose is that the carbohydrates will be absorbed via SGLT1 and GLUT5 intestinal transporters.

Comparison of single vs. mutliple CHO sources (CHO, carbohydrate; FRU, fruc- tose; GLU, glucose; Perf, performance; P, placebo; TT, time-trial; TTE, time to exhaustion; Signif, Significant; SUC, sucrose; Stellingwerff & Cox. 2014)

Fructose + glucose mixtures excel, but it takes carbohydrate intake rates of more than 60g/h for the advantages to reach statistical significance. Why? Well, less than 60g/h don't overload the regular glucose transporters in the gut, and the advantage of having both SHLT1 and GLUT5 intestinal transport becomes irrelevant. Several studies have now shown that high intake rates (>70g/h) of GLU:FRU blendsduring moderate intensity, prolonged (>2h) exercise, results in ~8% improvement in endurance performance over both a  1h  TT  (Currell  and  Jeukendrup  2008)  and  over  100km  of  cycling  (Triplett,  Doyle  et  al.  2010) compared to glucose alone, and 19.5% versus water (see Table 1). Another research group has shown  further increases in performance with GLU:FRU blends over multiple sprints  after an endurance pre-load (O'Brien and Rowlands 2011; O'Brien, Stannard et al. 2013).

Specifically during long(er) duration exercise, when the carbohydrate consumption can exceed 60g/h there is a significant performance increase with multi- vs. single source carbohydrate supplements (Stellingwerff & Cox. 2014)

An advantage that has been scientifically established among others by Jeukendrup et al. (2010) who found that this pattern of CHO ingestion results in ~20 to 50% higher CHO oxidation rates compared to the ingestion of a drink that contains nothing but glucose or maltodextrin.


Now an increase in carbohydrate oxidation alone does not sound like something you would aim for as an endurance athlete. In practice, increases in carbohydrate oxidation have yet been shown to increase the performance during prolonged exercise bouts compared to isocaloric glucose-only beverages. (Currell et al. 2008; Triplett et al. 2010; O'Brien et al. 2011; O'Brien et al. 2013).

So how much does it take during long(er) 1-2h+ exercise: You've already learned that glucose + fructose mixtures should be preferred to carbohydrate supplements with only one type of CHO. While 30-60g/h, which is the amount of carbohydrates that is currently suggested by the American College of Sport Medicine (ACSM 2000; Sawka, Burke et al. 2007) appears to be be enough for exercise durations ranging from 60-120 minutes, recent evidence suggests that hard exercise bouts which last longer than 2h require up tp 90g/h or carbohydrate solutions with a CHO content of >8%.

Needless to say that there is still research to be done with respect to individual influencing variables of carbohydrate requirements. The currently available evidence, for example, is largely based on results from runners and cyclists. Two other factors / issues that come to mind are...

• the dose-response relationship, which appears to be capped at 75g/h - at least according to a large-scale multi-center study by Smith et al. (Smith. 2013) who found that their subjects, endurance trained cyclists or triathletes experienced significant performance increases, with increasing amounts of carbohydrates (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 and 120g of CHO/h) during a 2h constant load ride.
  
  

  

  Figure 3: Mean log time to complete time trial (natural) as function of CHO treatment condition with fitted quadratic curve (with 95% CI of mean curves). Differences 100 represent percent change in performance. The quadratic function relating CHO ingestion rate to time complete time trial for 43% (95% CI = 11%–75%,P= 0.059) of the variation in mean performance score (Smith. 2013)

  The CHO given was a 1:1:1 glucose:maltodextrin:fructose blend. Results indicated incremental performance improvements of 1.0%, 2.0%, 3.0%, 4.0%, and 4.7% at 9, 19, 31, 48, and 78g CHO/h, respectively, with diminishing performance enhancement seen at CHO levels >78g/h.
  
  The optimal amount for performance (+4.7%) was 78g/h, with a range of 68 to 88g/h. However, even at 10g/h, a 1.0% increase in performance was observed, showing even a small amount of carbohydrate has the potential to positively impact performance. 
• the optimal mix of glucose, dextrose, fructose, maltodextrin or other "special" carbohydrates  - needless to say that waxy maize, hydroxypropyl distarches (learn more) or the expensive fast absorbing highly insulinogenic patented carbohydrate source Vitargo come to mind, when we are talking about finding the optimal mix of different carbohydrate sources - a mix, by the way, of which you can safely assume that it will differ according to the physiological demands of the workout and the exercise duration.
  
  One thing we shouldn't forget, though, is that next to optimal performance, optimal GI tolerance, i.e. the absence of bloating, diarrhea & co would be an important criteria the "optimal" carbohydrate blend would have to meet.

• 

  Figure 4: CHO suppl. ameliorates  testosterone reductions in 800m runners (de Sousa. 2010)

  the impact of carbohydrate supplementation on hormonal changes during and in response exercise - several human studies suggest that CHO supplementation attenuates the suppression of the hypothalamic-pituitary-gonadal axis and the rise in stress hormones during periods of intense training; a recent rodent study shows that the provision of carbohydrate supple- ments can prevent / reverse exercise-associated menstrual dysfunction (de Sousa. 2010; Zhao. 2014)

I guess, I could come up with additional research gabs, but in the end, a list of "gaps" is not exactly useful for you. Much in contrast to a conclusion, which I am about to formulate in the bottom line, now.

Bottom line: As of now it looks as if the recommendations I made in the light(er) blue boxes for short (<1h), long (1-2h) and ultra-long (>2g) workouts are the best we have.

For the majority of resistance trainees, intra-workout carbohydrate supplementation is at best facilitative. The repletion of the depleted glycogen stores after your workouts, however, is necessary | learn more about glycogen repletion

What I find particularly interesting is that for shorter duration exercise situations (<1h) and high(er) exercise intensity, similar benefits can be achieved with swallowing vs.  outh-washing with only 30g/h of liquid CHO sources. Performance increases in the 2.6% ± 3.3% range may not sound earth-shattering, but if you were running for an hour, your competitor who made sure to bring a carb bottle would be 83s faster than you are - that's 83s which could make the difference between first and last place.

For longer duration exercise, the studies, Stellingwerff and Cox reviewed in the previously cited article yielded an intermediate improvement of 4.9%±4.9% with significantly higher values in studies investigation long(er) + higher intensity exercise. The notion that carbohydrate supplements were useless and the various position statements of sporting bodies all over the world just a concession to the sponsoring money of the industry is thus unwarranted | Comment on Facebook!

References:

• Carter,  J.,  Jeukendrup,  A.E.,  Mundel,  T.,  and  Jones,  D.A.  (2003).  Carbohydrate  supplementation  improves moderate and high-intensity exercise in the heat. Pflügers Archiv : European journal of physiology446: 211-9.
• Carter, J.M., Jeukendrup, A.E., and Jones, D.A. (2004a). The effect of carbohydrate mouth rinse on 1-h cycle time trial performance. Medicine and science in sports and exercise36: 2107-11.
• Carter, J.M., Jeukendrup, A.E.,  Mann, C.H., and  Jones, D.A. (2004b). The effect of glucose infusion on glucose kinetics during a 1-h time trial. Medicine and science in sports and exercise36: 1543-50. 
• Chambers,  E.S.,  Bridge,  M.W.,  and  Jones,  D.A.  (2009). Carbohydrate  sensing  in  the  human  mouth:  effects  on exercise performance and brain activity. The Journal of physiology587: 1779-94. 
• de Sousa, Maysa Vieira, et al. (2010). Effects of carbohydrate supplementation on competitive runners undergoing overload training followed by a session of intermittent exercise." European journal of applied physiology 109.3: 507-516.
• Fares, E.J. and Kayser, B. (2011). Carbohydrate mouthrinse effects on exercise capacity in pre- and postprandial States. J Nutr Metab2011: 385962.   
• Pottier, Andries, et al. (2010). Mouth rinse but not ingestion of a carbohydrate solution improves 1‐h cycle time trial performance" Scandinavian journal of medicine & science in sports 20.1: 105-111.
• Sawka,  M.N.,  Burke,  L.M.,  Eichner,  E.R.,  Maughan,  R.J.,  Montain,  S.J.,  and  Stachenfeld,  N.S. (2007).  American College of Sports Medicine position stand. Exerciseand fluid replacement. Medicine and science in sports and exercise39: 377-90.
• Smith, JohnEric W., et al. (2013). Curvilinear dose-response relationship of carbohydrate (0-120 g/h) and performance." Med Sci Sports Exerc 45.2: 336-341. 
• Stellingwerff, T., & Cox, G. R. (2014). Systematic Review: Carbohydrate Supplementation on Exercise Performance or Capacity of Varying Durations. Applied Physiology, Nutrition, and Metabolism (2014). Ahead of Print. 
• Zhao, Can, et al. (2014). Effects of carbohydrate supplements on exercise-induced menstrual dysfunction and ovarian subcellular structural changes in rats." Journal of Sport and Health Science 3.3: 189-195.

Aspartame's Anti-Insulinogenic Effects During a Workout; Optimal Protein Intake on a Diet is Relative. Plus: Folate Fortification, Spirulia, Succinate, Sucrose, Pork Brain & the Low Cholesterol-Suicide Connection Reviewed!

Unbelievable: The results of the latest study from the University of Western Sidney appear to suggest that you could keep your insulin levels at bay, if you mixed your sugary intra-workout supplement with aspartame-laden diet coke instead of water! The mechanism that's behind this phenomenon does yet still have to be elucidated.

You may be surprised to see a long headline, a long post and a couple of bullet points: "Looks like On Short Notice, reads like On Short Notice, but is not published on Saturday? What's that?" The answer to this question is easy. Lot's of interesting stuff I have come across as of late! And while some of them, like the study on the marginal utility of higher protein intakes on a diet would actually deserve their own post, I decided to give you the "long(er) version of a short notice" in order not to miss any of them... and yes, this means there is going to be more than today's news on the unexpected anti-insulinogenic effects of aspartame, the only partly expected outcomes of the US folic acid fortification program, the aforementioned protein study, the usefulness of spirulina, succinate and sucrose supplements for athletes and physical culturists and some brainy insights into a possible connection between low cholesterol, depression and suicide risk in men and women... ah, ok I see, you are already reading the aspartame item - well, go for it!

• The astonishing anti-insulin effects of intra-workout aspartame consumption Meanwhile even bodybuilders who are injecting and "supplementing" with all sorts of unquestionably unhealthy stuff are so afraid of the hitherto still rather vaguely established pro-carcinogenic effects of aspartame that supplement companies place huge stickers on the boxes of their products saying "ASPARTAME FREE!" Now, I am pretty sure that a recently published study that was conducted by scientists from the School of Science and Health at the University of Western Sydney in Campbelltown, Australia (Siegler. 2012), won't do much about that, but you will probably have to agree that it is still remarkable, to say the least, that the co-administration of an artificial sweetener which has not produced any glucose, insulin or whatever response in previous trials (cf. "Sweeter than your tongue allows") would do that!?

  

  Figure 1: While the mechanism is still unknown and the results need to be repeated in a second experiment, there is no question that the drop in insulin during the workout (see arrow(s)) which occurred during the carbohydrate + aspartame trial in the presence of identical glucose ingestion and blood glucose levels warrants further investigations (based on Siegler. 2012)

  During the four trials, which were separated by 7-10 days of rest, the 9 healthy, recreationally active males (age: 22±2 years; height: 180±9 cm; weight: 78.6±8.5 kg; participating in regular physical exercise at least twice per week) who had volunteered for this (in the eyes of some aspartame extremists, probably unethical undertaking ;-) cycled fasted for 60 minutes in a climate controlled laboratory. The only difference between the four sessions was the "intra-workout nutrition" the participants were fed, with...
  

  1. carbohydrate - 2% maltodextrin and 5% sucrose (figure 1, C),
  2. carbs + aspartame - 0.04% aspartame with 2% maltodextrin and 5% sucrose (figure 1, CA),
  3. water - plain water, only (figure 1, W), and
  4. aspartame + malto - 0.04% aspartame with 2% maltodextrin (figure 1, A)

  As it is common practice in studies like this, "all participants were instructed to follow the same diet and training schedule for the three days prior to each experimental trial." (Siegler. 2012, my emphasis)
  The respective intra-workout beverages were to be consumed in boluses of 4ml/kg body weight before and at 15-minute intervals throughout the trial. For the CHO groups this summed up to a total carbohydrate intake of 104.4±11.3g per participant and did - probably not to your surprise - cause a corresponding increase in insulin levels... with one exception, however: the intraworkout period in the CHO + Aspartame group (figure 1, red), when the insulin level dropped, during the exercise sessions and bumped back up to the same level as in the carbs only control afterwards (see figure 1).
  As the researchers point out, we do not yet have a mechanistic explanation for this phenomenon... nor can we even be sure that this was not some sort of strange artifact, so that
  

  "the disparity between insulin levels [does not only] warrant further investigation with a larger cohort of clinically relevant subject populations (e.g. metabolic syndrome, diabetes, etc.) [, but must also] be considered when designing nutrition-based, exercise intervention studies [in the future]" (Siegler. 2012

  That this observation could actually have very practical implications, both, in view of its potentially compromising effects on blood glucose levels in diabetics, where any insulin blocking effect of aspartame would probably reduce the already compromised glucose uptake even more, as well as in view of the anti-lipolytic (=blocks the release of fat from the cells) of insulin during a workout, which could actually be blocked with a minuscule amount of aspartame ... but alas, until the results have been confirmed and the mechanism behind this effect has been elucidated, what we are doing here is more or less intellectual masturbation - nothing to feel bad about, but still not the real deal ;-)

• 

  Figure 2: This is what the USDA expected to happen - more folic acid in food = higher intake (here in the elderly) = lower homocysteine levels; the reality looked pretty different, though, at least in adolescents the folic acid intake went up, but the homocysteine levels did not go down; moreover the B12 levels have declined as well... how much of this is related to confounding factors still has to be elucidated, but as of now it does not seem as if the fortification program was the success the USDA wanted it to be (Mc Bride. 2007).

  US adolescents and their "healthy grains" are now folic acid fortified, but are they also healthier? According to a study that has just been published in the Journal of Public Health, the great idea to put another artificial vitamin into our the food chain and fortify "healthy" cereal-grain products with folic acid, was so "successful" that the average US teen (14y at the time the fortification program began, 18y now) does now have 16% higher folate and 14% higher B6 concentrations.
  Instead of the expected decrease in homocysteine levels, of which scientists still believe that it plays in imminently important role in the development of heart disease, its serum levels did likewise increase by 17%, while the serum concentrations of vitamin B₁₂ decreased by 11 % post-fortification. The additional ~118 μg folate/d the subjects ingested from the fortified food products, appeared to be particularly useless (or even detrimental?) for boys / young men whose total homocysteine (tHcy) levels increased by 24%  to a much greater extent than in the girls / young women.
  Honestly, I don't really know what to make of these results at the moment, ... at least nothing better than to shake my head over the hilariousness of trying to turn junk(-food) into (good) food by simply enriching it with artificial vitamins. On the other hand, I am happy that even Daniel A. Enquobahrie and his colleagues feel that it is "warranted to investigate the significance of these improvements in folate status on clinical outcomes, in the post-fortification era." (Enquobahrie. 2012) - and that not just because the fortification program did not produce the desired results, but also because the folic acid intake already started to exceed the RDA in many of the subjects. This, and the alarming decrease in B12 levels of which Katherine L. Tucker had cautioned in the 2007 interview with Judy Mc Bride, already, that "better diagnosis for B12 deficiency should be given high priority"(Mc Bride. 2007) do not "warrant", imho, they rather make it imperative to follow the effect of this "nationwide health program" very closely.

• 

  Figure 3: The principle of relativity for protein based body recompositioning diets - When it comes to weight los, the word "high" in high protein diets must always be seen in the context of habitual protein intake and to whom we are comparing our dieters; or put simply: The average SAD dieter benefits from every gram, the average bodybuilder will hardly benefit from the 7th whey shake.

  Effectiveness of high(er) protein diets for weight loss depends on spread / change vs. baseline not on total protein intake That's basically how you could summarize the conclusion of the latest review of the existing data on the influnece of (high) protein intakes on changes in body composition by John D. Bosse and his colleagues from the University of Utah. To find out whether either the protein change (=high protein diets are only effective when the change in protein intake from baseline to intervention is large enough) or the protein spread theory (=those dieters within a cohort with the highest protein intake will see the most beneficial changes in body comosition) could explain the different outcomes of previous studies best, the researches collected an impressive dataset comprising 51 peer-review studies the analysis of which yielded the following two main results (Bosse. 2012):
  1. The 35 successful dietary interventions had on average 58.4% higher average protein intakes than those trials in which the authors had not been able to observe an additional beneficial of going high protein over the standard calorical restriction approach
  2. The 17 successful (=greater anthropomorphic changes than with calorie restriction alone) of the 25 studies, where the baseline protein intake of the subjects was available, the increase in protein intake was 28.6% (if you ate 100g protein per day before, that would mean you would eat 128.6g while you are dieting), minimal increases in 4.7% range, on the other hand, did not provide any additional benefit over energy reduction, alone.
  Overall, the review does therefore support the original hypothesis of the researchers that there are certain thresholds which have to be surpassed before dieters will see any benefits from an increase in protein intake. This does yet also mean, that for someone who is already eating 200g of protein on a daily basis, the addition of a protein shake with 20g of protein is probably not going to make so much of a difference as it would be way below the 28.6% change in protein intake, the protein change theory would prescribe (see [2] in the list above). As a matter of fact going higher and higher (e.g. like eating 300g of protein per day), will, if anything stall, not propel your progress, after all, there will be too little room for other nutrients, when you are already getting the lions share of your daily energy intake from protein... and NO you cannot lose weight without being in a caloric deficit, even if that is not readily calculable by the idiotic "calories-in-vs-calories-out" equation.
• The BMJ Supplement Review says: Thumbs up for sucrose, thumbs down for succinate and undecided  for spirulina In installment #36 of the A-Z of Nutritional Supplement Supplements, a series dedicated to review the pros and cons of purported ergogenic aids, the authors conclude that ...

  

  Figure 4: In view of the fact that the TCA or citric acid cycle is one of the #1 aerobic source of cellular energy (APT) and succinate is one of its intermediates it makes sense that supplementation could improve exercise performance, but hitherto this has not been confirmed.

  • ...the studies on spirulina fail to "study well-trained individuals", to use appropriate standardization regimen with relevance for physical culturists and athletes, identify the active ingredients and their effect on the antioxidant status, of which the respective scientists speculate that it would be the underlying mechanism of the observed ergogenic effects on chronic low-intensity exercise regimen
  • ...the research on succinate (only) supplementation is basically non-existent and claims with respect to its permanence enhancing effects is mostly based on theoretical considerations about its role in the TCA cycle 
  • ...despite the general trend within our society, where the overconsumption of sucrose (table sugar) is one of the major offenders to public health, "there may be value in, or at least room for, its inclusion in sports products targeting the provision of carbohydrate fuel during exercise"
  Nothing exciting, but a realistic and educative analysis, which has all the classic elements you should keep in mind, whenever you try to find out whether a product is worth its money: What research is there? What are the results? Are the positive results significant for me as a person? And... in the case of succrose: Could the use of this ergogenic aid be an obstacle for another goal of mine? I mean, you can benefit from guzzling tons of sugary drinks during your workouts, but if "looking good naked" is your primary goal and your performance only a means to an end - it is probably not wise to do so ;-)

• 

  Figure 5: Suicide risk in psychiatric patients /w (SA) or w/out (PS) prev. suicide attempt and surgical control (SC) in lowest, 2nd and 3rd cmp. to highest quartiles (Olié. 2011)

  Can pork brain in milk tell us something about suicide? Those of you who are on the SuppVersity Facebook news RSS channel will already know the image on the right. I only saw it today, but as Mark mentioned on my Facebook wall, he has used it (the image not the brain) in lectures before... be that as it may, that reminded me of an older study on the highly significant correlation between cholesterol levels and suicide attempts Emilie Olié and her colleagues observed in a 2010 study on the reliability of serum cholesterol levels as a predictor of the suicide risk in 3207 subjects [510 patients with a history of suicidal attempts (SA), 275 patients with no history of suicidal attempts (PC), and 2422 surgical controls (SC); Olié. 2011].
  The exact mechanism for the highly significant increase in suicide risk, esp. among women with previous suicide attempts in the lowest (1st quartile) is still not fully elucidated, Olié et al reference previous studies which suggest that low serum cholesterol levels, a "potentialmarker of central nervous systemcholesterol", impair the serotoninergic activity and" increase impulsivity" and thus precipitate to severe depression and the tendency and ability to pot a premature end to your life.
  In view of the fact that this and similar results were derived exclusively from analysis of psychiatric patients and considering that the cholesterol levels in the SA group were already significantly lower that in the PC and SC control (178±36 mg/dL vs. 217±43 mg/dL and 219±52 mg/dL, respectively) we should be very wary of transferring these results 1:1 to the "normal" people. 

I guess this is enough for today. After all, news are not so different than protein, it's the relative intake that makes all the difference - in other words: If I keep flooding you with those awesome posts, you won't appreciate each and every of them the same way you do now... and we don't want that to happen, do we? 

References:

• Bosse JD, Dixon BM. Dietary protein in weight management: a review proposing protein spread and change theories. Nutr Metab (Lond). 2012 Sep 12;9(1):81.
• Enquobahrie DA, Feldman HA, Hoelscher DH, Steffen LM, Webber LS, Zive MM, Rimm EB, Stampfer MJ, Osganian SK. Serum homocysteine and folate concentrations among a US cohort of adolescents before and after folic acid fortification. Public Health Nutrition. 2012; 15: 1818-1826.
• Mc Bride. Foods To Be Fortified With Folic Acid. USDA ARS. News. February 7, 2007. < http://www.ars.usda.gov/is/ar/archive/jun97/folate0697.htm > retrieved on September 14, 2012.
• Olié E, Picot MC, Guillaume S, Abbar M, Courtet P. Measurement of total serum cholesterol in the evaluation of suicidal risk. J Affect Disord. 2011 Sep;133(1-2):234-8.
• Siegler J, Howell K, Vince R, Bray J, Towlson C, Peart D, Mellor D, Atkin S. Aspartame in conjunction with carbohydrate reduces insulin levels during endurance exercise. J Int Soc Sports Nutr. 2012 Aug 1;9(1):36.
• Zemski AJ, Quinlivan RM, Gibala M, Burke LM, Stear SJ, Castell LM. A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance: Part 36. Br J Sports Med. 2012 Sep;46(12):893-4. 

Sip Casein(-ate) NOT Whey for Maximal Net Protein Retention? Not Despite, but Due to Less Leucine?

Image 1: Cows must be stupid animals, right? I mean everybody knows that whey is better than casein, so why would they "spike" their milk with this allegedly inferior protein source, instead of providing us and their calves with the "most anabolic", leucine-loaden whey protein? Or do cows know better than us?

Question: "Whey or Casein to maximize protein synthesis?" The answer appears to be easy: Whey, of course! Faster absorption, higher rates of hyperaminoacidemia (higher than normal amino acid levels in the blood), more leucine, more mTOR, more insulin, more, more ... and did I say more? Well, other than maybe Dr. Scott Connelly, who just came out with his new total milk protein based meal supplement product Physique 2.0, you will in fact be hard pressed to find anyone, let alone a renowned expert arguing in favor of casein. Yet still, Marielle P.K.J. Engelen and her colleagues from the University of Arkansas for Medical Science, Maastricht University, the Nutrition and Toxicology Research Institute Maastricht (NUTRIM),and the Federal University of Rio de Janeiro (UFRJ) dared conducting a trial which investigated just that (Engelen. 2012): "Which dairy protein is able to positively influence the protein metabolic response to exercise" - unfortunately in COPD patients.

COPD vs. control - different yet the same

Luckily the combined exercise and supplementation protocol in the course of which the 8 COPD patients and their age-matched (68.3y) healthy controls had reported to the lab fasted, where they - after the usual procedure of setting up a catheder, infusing a tracer, etc. - started consuming one of the following enteral protein meals

• 29.5 g sodium caseinate* and 68.5g of maltodextrin, or
• 29.5 g whey protein and 68.5g of maltodextrin
  *please make sure you read the info on caseinate vs. casein in the red box below

both dissolved in ultrapure water (1L) at 20 min intervals beginning at T = -2h; in plain English "two hours before the actual trial begun. In the course of the latter the healthy subjects (on which we are going to focus our attention here) pedaled on braked cycle ergometer at 50% of the COPD patients pre-determined maximal workload (this was a concession to the bad conditioning of the actual study subjects, the COPD patients) in the first and 50% of their own maximal workload in the second trial at T = 0 and T = 1h 20min, respectively.

Image 2: Don't be fooled micellar casein and caseinate are not the same (img. University of Guelph)

Caseinate is not casein! I have not discussed the actual study in isolation, here at the SuppVersity before, but I have broached on the issue in previous posts: There is more than a "three-letter difference" between "casein" and "caseinate", while the former actually (often things get "mislabeled" these days ;-) refers to intact casein micelles, which clot and form complex novel (and partially biologically functional) complexes in the course of the digestion process, the sodium bound "broken" micelles from the sodium caseinate don't, so that - as Stuart Phillips put it quite aptly in a comment on a similar study by Reitelseder et al. - the "digestion rates of this form of casein are not likely to be overtly different from those of whey" (Phillips. 2011). What we are comparing here are thusly proteins with "identical", or I should say, very similar digestion rates, yet slightly different amino acid compositions - this renders the study not less valuable, should yet be kept in mind as far as its practical implications (see my conclusion further down) are concerned.

Right before, as well as right after, and in the course of the 60min recovery period that followed each workout the subjects consumed a bolus of 0.67 mL/kg BW of the respective protein supplement which contained 18 mg protein/kg body weight (whey or caseinate) and 46 mg maltodextrin/ kg BW every 20 min. Afte 10 ingestions and a 75kg subject would thusly have consumed 13.5g of protein, total.

Figure 1: Total body net protein synthesis (synthesis - breakdown) and protein synthesis of the healthy subjects during (0-20min and 80-100min) and after the two exercise trials (data adapted from Engelen. 2012)

And even in view of the fact that we are not dealing with regular slow digesting casein micelles, the results, in terms of net protein retention and protein synthesis (cf. figure 1) were quite surprising:

The present study shows that net whole body protein anabolism was higher during casein than during whey protein feeding in both the COPD and control group which remained during and following exercise. The proteins were provided via sip feeding to evaluate the effects of the quality of the amino acid composition between casein and whey protein. [...] This difference in anabolism might be related to differences in BCAA distribution as LEU level is higher in whey than in casein protein, whereas the concentrations of ILE and VAL are lower

And though I am not quite sure, whether the researchers were aware that "their" caseinate is in fact not significantly slower digested than regular whey protein, this does not change the likeliness of their hypothesis (= hypothetical ;-) that the different amino acid make-up in general and maybe even the lower (!) leucine to isoleucine and valine ratio could be responsible for the statistically significant superiority of caseinate in

• whole body net protein synthesis during exercise and recovery
• whole body protein breakdown during recovery from the second, higher intensity exercise bout, and
• net whole body protein synthesis (=difference between synthesis and breakdown) during the whole study period, with the exception of recovery from 2nd exercise trial

Whether or  not this was a (direct) effect of the different ratios of the three BCAAs to each other, the minimally higher BCAA and EAA content (btw. why not the proline? I mean 11.23 in caseinate vs. 3.31 is a huge difference, cf. table 1) of the caseinate or maybe, despite similar digestion rates, still an effect that came about as a result of different digestion kinematics of whey and caseinate would require further studies.

Is whey no longer the whey to go?

Table 1: Amino acid composition (per 100g) of the sodium caseinate and whey used in the study (Engelen. 2012)

In view of what you should have learned yesterday about the influence of age, training status, experimental protocol, etc. on the effect-size of studies investigating strength gains in response to different exercise regimen (cf. Strength Gains Depend on Training Status, Age, Workout Frequency, Rest Intervals & More), it should also be clear that these results require further verification in different study populations and exercise contexts. It is yet still intriguing that - assuming that the scientists hypothesis holds, two of the generally accepted paradigms of intra- and peri-workout supplemenation, namely

1. the general superiority of whey proteins over every other form of dairy (let alone meat or whatever else) protein during or in the immediate vicinity of a workout
2. the importance of leucine as the single-most important dietary trigger for protein synthesis and against the breakdown of protein

If these paradigms were revised, the currently available 4:1:1 or even 8:1:1 BCAA supplements, as well as the whey-protein based intra-workout supplements, should (you know science is only part of the equation, when it comes to the production and sales ranks of dietary supplements ;-) disappear from the market.

Comparing apples to oranges and juices to whole fruits

Before the latter is going to happen, though, there is still a lot of scientific work to be done. After all, we are not only comparing apples with oranges here (as far as the trainees are concerned), but also juices with whole fruits, or put more simply: While the current study looked at whole body protein synthesis / breakdown, sports scientists usually focus on muscular (in many cases even either myofibrillar or sarcoplasmic) protein synthesis, the study at hand evaluated the protein turnover rates of the whole body. And while this is probably a "shortcoming" as far as the immediate muscle-building effects of the individual protein sources are concerned, the ever-increasing awareness of the far-reaching metabolic consequences of the integrity of our gut lining, which becomes a protein donor for the skeletal muscle tissue during strenuous exercise (after a workout you have a "leaky gut"), may make it worthwhile to look at protein synthesis in places other than your muscle as well. After your workout, at the latest, your gut and the other organs in the splachnic bed are going to (re-)claim their share of protein, anyway.

Citrulline as Substrate Switch. Galactose as Workout Fuel, Glycogen Repletion Not Urgent, 2x a Day 6x a Week = Too Much For Your Antioxidant System, Astaxanthin For IgA

Actually it's not the burn during the workout that matters, but I don't have to tell you that, do I? (pic i-am-beast.com)

What do you do with a whole host of interesting exercise-related nutrition news that are piling up in your archive, but are too good to be "burned" as short links with one sentence of text on the SuppVersity Facebook Wall?

Right! You compile all those news into a potpourri, attach the label "SuppVersity News Potpourri" to it and blow them out in a blogpost of their own. A post that covers the whole peri-workout window as well as the short-/long-term effects on exercise on your anti-oxidant and immune system.

Sounds good? Well, then go ahead...

• Immediate post-workout glycogen repletion in endurance athletes probably useless (Carlsohn. 2013) While the hormonal response and the long-term effects of running around with depleted glycogen levels are a totally different animal, the latest research from the University Outpatient Clinic Potsdam in Potsdam, Germany, clearly suggests that the immediate post-run glycogen-repletion with 1.5g/kg body weight of fast acting carbs per hour is useless...
  
  

  

  Do you remember my "Glycogen-free muscle growth" post(s) from 2011?

  ...at least with respect to the 5,000m running performance of the twelve recreational runners (4m/8w; 1.73 ± 0.11 m, 69.1 ± 13.4 kg). who were involved in Carlsohn et al.'s study.
  

  "Running time during 5,000-m time trials did not differ between bTT (1,305 ± 140 s), following CARB (1,276 ± 125 s) or PLA (1,285 ± 124 s, p= .85). There were no differences in RPE (bTT 18.3 ± 0.3, CARB 18.7 ± 0.3, PLA 18.8 ± 0.9; p= .48), bLa/min, PLA 187 ± 3 beats/min; p= .96).

  In view of these results it should actually not necessary to formulate a "bottom line", but alas...
  

  ---

  Bottom line: "[T]he rationale of recommending immediate carbohydrate intake following exhausting exercise to 5,000-m runners might be questioned" (Carlsohn. 2013). Please keep in mind though that not repleting your glycogen stores at all is not an option - the myth that's been partially busted by the study at hand is that you must do that as fast as possible to maintain maximal performance - not that you must do it at all. 

• "High" galactose foods ?

  Honey	3.10g
  Fermented yoghurt	1.30g
  Beets, canned, regular pack, solids and liquids	0.80g
  Celery, raw	0.66g
  Cherries, sweet, raw	0.59g
  Bockwurst, pork, veal, raw	0.48g
  Corn, sweet, yellow, canned, whole kernel, drained solids	0.36g
  Beans, navy, mature seeds, raw	0.34g
  Snacks, pretzels, hard, plain, salted	0.22g
  Spices, curry powder	0.21g
  Spices, mustard seed, yellow	0.20g
  Spices, paprika	0.19g
  Babyfood, fruit, plums with tapioca, without ascorbic acid, strained	0.19g
  Spices, ginger, ground	0.19g
  Spices, basil, dried	0.19g
  Kiwi fruit, (chinese gooseberries), fresh, raw	0.17g
  Cereals, oats, instant, fortified, plain, prepared with water (boiling water added or microwaved)	0.16g
  Cheese, mozzarella, whole milk	0.15g
  Spices, cloves, ground	0.15g
  Cheese, parmesan, grated	0.15g
  Spices, oregano, dried	0.15g
  Fast foods, cheeseburger; single, regular patty, with condiments	0.15g
  Plums, raw	0.14g
  Peas, green (includes baby and lesuer types), canned, drained soilds, unprepared	0.14g
  Cereals, oats, instant, fortified, plain, dry	0.13g
  Fish, fish portions and sticks, frozen, preheated	0.13g
  Figs, dried, uncooked	0.13g
  Babyfood, plums, bananas and rice, strained	0.12g
  Egg, whole, raw, fresh	0.11g
  Avocados, raw, all commercial varieties	0.10g
  Crackers, saltines	0.07g
  Snacks, tortilla chips	0.07g
  Egg, white, raw, fresh	0.07g
  Snacks, tortilla chips, nacho cheese	0.07g
  Peaches, raw	0.06g
  Melons, cantaloupe, raw	0.06g

  Galactose as alternative workout fuel (Duckworth. 2013) - A recent study from the Leeds Metropolitan University in the UK demonstrates that
  

  "ingesting a solution containing galactose before and during exercise can positively affect postexercise satiety and energy balance throughout the day, compared to a more readily available and widely consumed form of carbohydrate" (Duckworth. 2013)

  The scientists conclude that based on the observations they made, when they provided nine recreationally active eumenorrheic females (mean age 22y; weight 63.3kg) with either 45g galactose (GI~20) or glucose (GI~89) drinks prior to (300 ml) and at every 15 min during a low intensity steady state jog at 65% of their VO2Peak
  
  Note: I guess, it goes without saying that 45g of galactose this is more galactose than you can stomach from ingesting any "high galactose" foods; see table on the right, data in g/100g).
  The scientists measured the substrate oxidation, postexercise satiety and subsequent energy intake on three occasions (GLU, GAL, placebo) and found that
  • the plasma glucose levels were significantly greater throughout the exercise and in the rest period, when the subjects ingested the glucose drink,
  • there were no differences in carbohydrate oxidation, and
  • perceived hunger was significantly lower throughout the galactose compared to both the glucose and placebo trials
  What may yet be most significant for the average trainee trying to shed some weight is the difference in net energy balance, i.e. the difference between energetic costs of the workout, on the one hand, and the energy intake from the glucose / galactose supplement and the food intake during the post-exercise ad-libitum test lunch and the remainder of the day, which was negative only in the placebo and the galactose trial.

  ---

  Bottom line: If you want to shed some body fat and cannot go without an intra-workout beverage pick galactose over glucose, but do a "test run" before you try that in public - the monosaccharide is notorious for its socially not acceptable effects on the evaporations from your gastrointestinal tract ;-)

"Does the Usefulness of Vitamin E Supplementation Depend on Your Activity Level?" It is possible that only those benefit who are already overtaxing their system and will thus need additional protection (learn more)

• Exercise is stressing, but the long-term results are what's associated with improved antioxidant capacity (Lundström. 2013) The data Lundström et al. have collected in their recent 3-week trial involving fourteen 26-year-old volunteers who performed two "strenuous" (intensity targeted to 75% of VO2max) endurance training sessions per day (6 days a week) does in a way underline the validity of the hormesis hypothesis. Despite the fact that the increase in oxidative stress in response to the the allegedly hefty (for non professional athletes) two-sessions a-day, 6-days a week was not significant, the latter was facilitated / buffered by highly significant declines in the total plasma antioxidant capacity (AO).
  
  However, aside from the fact that the AO levels did not fully return to baseline after the subsequent 4-week recovery period, the most intriguing results of the study at hand is the highly significant negative (meaning "if A is high, B is low") correlation between fat-free mass and oxygen uptake, on the one hand, and oxidation stress, on the other.

  ---

  Bottom line: With both of the former, i.e. fat-free mass and oxygen uptake while you exercise, being hallmark features of physical fitness you cannot increase without working out, the balancing act, every trainee has to master is to find the exact i +1 load of stress that allows for adequate recovery and super-compensation in the time to the next workout / mesocycle.

• Low Immunoglobuli, high cortisol and health While there appears to be a general relation between suppressed sIgA and high cortisol levels, on the one hand, and ill-health effects on the other. The latter is not sports-specific (Volkmann. 2006), and elite athletes are, despite suppressed IgA levels capable of normal responses to novel oral vaccinations, "indicating that mucosal immune mechanisms are intact" (Gleeson. 2000).
  Astaxanthin supplementation can ameliorate minor sIgA dump in athletes (Baralic. 2013) Study shows, supplementation with 4mg/day of astaxanthin can ameliorate the decrease in sIgA (marker of immune health) in young soccer players following 2h of exercise.
  
  There are yet two things you have to consider, when you read studies like these:  (a) Scientific evidence of the significance of immunoglobolin measures is not fully conclusive, and (b) the changes placebo group were not even significant.

  ---

  Note: In view of the fact that "[t]he clinical significance of [immunoglobolin changes] in acquired immunity with acute exercise and training remains unknown" (Walsh. 2011), the scientists' conclusion that "astaxanthin supplementation might serve as a countermeasure to sIgA changes associated with continuous intense training", must be taken with some caution wrt to its real-world benefits. 

• Citrulline shifts substrate utilization towards carbs (Faure. 2013) With this last item in today's Exercise Science Potpourri, we are actually coming back to the an issue that has been in the SuppVersity news pretty regularly as of late: the amount fat / glucose you burn during a workout. I guess, I have made my personal perspective that fatty acid oxidation rates during exercise are hilariously overrated pretty clear. This does yet not stop me from pointing you towards the results of a soon-to-be-published study from the Université Paris Descartes the results of which would suggest that supplemental citrulline could work as a "fuel switch".
  
  

  

  Do you remember the December 2011 SuppVersity news on citrullines anti-catabolic effects (go back!)

   The significant downregulation of oxidative enzymes from the Krebs cycle and mitochondrial respiratory chain, the French scientists observed in a group of male Sprague-Dawley rats, when theyy re-fed them after a 12-week period of dietary restriction with a citrulline supplemented diet (+5g/kg chow and thus equivalent to what human studies have been using) compared to the standard chow with an iso-caloric mix on non-essential amino acids added) would at least suggest that "citrulline supplementatio [...] seems to induce a switch in muscle energy metabolism, from aerobia towards anaerobia" (Faure. 2011).
  
  Now, I did already point out that this is not necessarily a bad thing, but they cannot - as you may speculate now - explain the beneficial effects the original NO-supplement ingredient l-arginine on blood glucose management (learn more), because Faure et al. were able to show that "citrulline action is not direct and is not related to arginine" (Faure. 2013).

  

  Figure 1: Activity of enzymes involved in the oxidation of fatty acids; data expressed relative to baseline levels  on ad-libitum diet (Faure. 2013)

  Against that background another effect that was brought about by the high citrulline diet could yet be even more of a major metabolic disadvantage: The increase in metabolically highly glucoes guzzling unflexible type-IIb fibers (see figure 1; learn more), which has been associated with low / non-existent adiponectin levels by Krause et al. (2008).

  ---

  We have to be careful though, with respect to the interpretation and potential implications of these results. Why? Well, there are actually countless reasons: (a) Human beings are no rodents and normal rodents are no athletes, (b) the potential impact of a higher baseline protein intake or the absence of the calorie restriction before the supplementation period (c) different short (study at hand = 1 week) vs. long-term effects, (d) the possible (beneficial ?) involvement of mTOR, which has been shown to be activated by citrulline in previous trials (cf. SuppVersity Dec 28, 2011 and/or Le Plénier. 2011) (e) the fact that some athletes may benefit from the same shift towards glucose and the relative increase in type IIb fibers (not bodybuilders, though!) (f) ... I could go on with this list, but I guess you will see that there is no reason to panic.
  
  Take the Faure study as further evidence for our lack of understanding of the the complex effects and interplay of nutritional and supplemental amino acids on our health and don't forget to come back to the SuppVersity if you want to keep up with the "state of the art" ;-)

---

That's it for today! I hope you enjoyed the "ride" and stay tuned for future exercise, nutrition and health science potpourris - write-ups of which I believe they are a necessary and interesting intermediate between the mini-items on Facebook (don't forget to head over there and check out today's 9+ news items) and the elaborate "regular" SuppVersity articles.

References:

• Baralic I, Đorđević B, Đuričić I, Šobajić S, Stanković I, Dikić N (2013). Salivary IgA response to astaxanthin supplementation in young soccer players. Proceedings of the Nutrition Society, 72, E7.
• Carlsohn A, Heydenreich J, Engel T, Kratzenstein S, Mayer F. Does immediate carbohydrate intake following glycogen-depleting exercise affect next day’s 5000 m time trial performance? International Journal of Sport Nutrition and Exercise Metabolism.  2013; 23(S1 -S15).
• Duckworth LC, Backhouse SH, Stevenson EJ, O’Hara JP. Effect of galactose ingestion before and during exercise on substrate oxidation and subsequent energy intake in females. International Journal of Sport Nutrition and Exercise Metabolism.  2013; 23(S1 -S15).
• Le Plénier, S., Walrand, S., Noirt, R., Cynober, L., Moinard, C., Effects of leucine and  citrulline versus non-essential amino acids on muscle protein synthesis in fasted rat: a common activation pathway? Amino Acids. 2011.
• Krause MP, Liu Y, Vu V, Chan L, Xu A, Riddell MC, Sweeney G, Hawke TJ.Adiponectin is expressed by skeletal muscle fibers and influences muscle phenotype and function. Am J Physiol Cell Physiol. 2008 Jul;295(1):C203-12. 
• Stuart CA, McCurry MP, Marino A, South MA, Howell ME, Layne AS, Ramsey MW, Stone MH. Slow-Twitch Fiber Proportion in Skeletal Muscle Correlates with Insulin. Responsiveness. J Clin Endocrinol Metab. 2013 Mar 20. 
• Volkmann ER, Weekes NY. Basal SIgA and cortisol levels predict stress-related health outcomes. Stress and Health. 2006; 22: 11–23. 
• Walsh NP, Gleeson M, Shephard RJ, Gleeson M, Woods JA, Bishop NC, Fleshner M, Green C, Pedersen BK, Hoffman-Goetz L, Rogers CJ, Northoff H, Abbasi A, Simon P. Position statement. Part one: Immune function and exercise. Exerc Immunol Rev. 2011;17:6-63. Review.

Science Round-Up Seconds: A Focus on Intra-/Post Workout Stims, Carbs & Protein and Their Effects on Performance, Hydration, GH, Cortisol, Testosterone & Fatty Acid Oxidation

As mentioned on yesterday's show, small 100kcal packets are as much of a problem as large dinner plates and XXL meals (data based on Coelho do Vale. 2008)

I want to start today's Seconds with a question: How did you like that Carl and I did not rush through the news-lineup as it was the case in previous episodes, but simply took our time to discuss the topics in depth an breadth, yesterday?

Personally, I believe that this is much better than the accumulation of "buzzword" the show had become in the previous weeks due to my "study hunter and gatherer" drive - or, in other words, the mere mass of studies I wanted to pack into the show and Carl's desperate effort to cover them all.

Would you agree? And what other changes / improvements would you like to see in the future? We are open for constructive criticism. You can't improve your game without it.

Let's get to what did not fit into the show, then...

The net result of the spending more time on each and every of the single items, or, to say it in the spirit of yesterday's show, a bit more mindfulness was obviously a much larger amount of Seconds for you to devour today. So, let's not waste any time and get right down to business:

• Is 200mg of caffeine the optimum!?A 2008 study by Beavan et al., which involved 24 professional rugby players who were randomly assigned to receive 0, 200, 400 or 800mg of caffeine 1h before performing a standardized resistance training protocol (Beavan. 2008), found that contrary to what bro-science has been suggesting for years, the ingestion of the high amounts of caffeine (800mg) lead to a profound drop in the testosterone-to-cortisol ratio, while the lower doses of 200mg and 400mg of caffeine only blunted the performance hampering decline of cortisol half-way into the workout, while increasing the testosterone levels by 15%
  Caffeine or pseudoephedrine for performance enhancement? As far as improving you game is concerned, a recent study from the School of Sports Science at the department of Exercise and Health of the University of Western Australia was able to show that you are only wasting your time an money, if you are trying to up your cycling-time trial and thus probably every other HIT performance by ingesting the purported CNS stimulant pseudoephedrine (not to be confused with the "real deal"; cf Spence. 2013).
  
  Contrary to the comparatively low amount of 200mg caffeine, which allowed the 10 well-trained cyclists and triathletes who participated in the study improve their TT times in trial 2 of 3, all of which were performed on th same day, by statistically significant 57s, the ingestion of the WADA banned substance pseudoephedrine at a dosage of 180g would have cost them their license for nothing.

  ---

  Bottom line: Spare yourselves pseudoephedrine and other nasal/sinus decongestant belonging to the the class of phenethylamines and amphetamines (e.g. geranium). Even if others worked (for 1,3-dimethylamine this has never been proven in isolation), the long(er)-term detrimental effects they'll have on your central nervous system really isn't worth it.

• Protein-enhanced Gatorade ain't worth your money -- If you are no ultra-endurance runner or at least marathon runner, you don't need, because you don't benefit intra-workout carbohydrate + electrolyte + protein (CEP) drinks for hydration.
  
  The results of a recent study from the Chinese University of Hong Kong show: A CEP solution containing 42g/L carbohydrate, 21g/L whey protein and 15.3 mmol/L sodium and 2.3 mmol/L potassium does not show "extra benefits for the maintenance of hydration status during 60 min cycling" (Sun. 2013)

• Carbohydrate + protein drinks maximizes GH response to exercise -- Now that you know that it's not worth to guzzle on carbohydrate + electrolyte + protein drinks during a workout for hydration purposes, I guess I should tell you that doing the same (w/out the electrolytes, though), may still provide an athletic / anabolic edge. After all, another recently published study that was conducted at the School of Sport at the Department of Exercise and Health Sciences of the Loughborough University in Leicestershire, U.K (Betts.  2013) shows that the ingestion of a carbohydrate + protein mixture (CHO+PRO: 0.8 g sucrose per kg bod weight per hour + 0.3 g/kg/h whey protein isolate) in the 4h recovery period between two exhaustive treadmill runs at the same intensity augmented the growth hormone response by 60%(!) compared to the ingestion carbohydrate only (0.8 or 1.1g of sucrose /kg per hour).
  

  

  Figure 1: Growth hormone (GH) and cortisol response to 2nd bout of exhaustive treadmill running with either 0.8 or 1.1g of sucrose /kg per hour (CHO, CHO-CHO) or  0.8 g/kg/h sucrose per kg bod weight per hour + 0.3 g/kg/h whey protein isolate (CHO+PRO; cf.

  As the data in figure 1 goes to show you this increase in GH was accompanied by a 23% reduction in cortisol. With both, GH and cortisol being released in response to the depletion of muscle glycogen and impeding low blood glucose levels (Galbo. 1977), you could thus argue that protein (probably by its glucagon promting effects; cf. Claessens. 2008) programs the "anabolic glucose procurement plan".
  

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  Bottom line: Yet another reason for the often touted, yet tried and proven "Bananas + whey" = WIN! And that's not true wrt to the protein anabolic response after a workout, but also in view of the "anabolic" or I should probably say generally more favorable way of glucose procurement during subsequent workouts.

• 

  No, no and no! The ingestion of carbs before a HIIT workout will only increase, not blunt the fatty acid oxidation in the post-workout period.

  Pre-workout carb ingestion does not blunt, but promote fatty acid oxidation after the workout -- In as much as this result may go against common bro-science that you must never consume any carbs before your workout if you are trying to lose body fat, it is actually in line with what I have been preaching before. The beneficial effects of AMPK come with the depletion of ATP and the rise in ADP (~used ATP), not with the constantly depleted ATP stores of a no-carbohydrate + protein only starvation diet. Or put more simply - a constant over-expression of AMPK negates all the benefits of it's cyclic up and down (cf. "The mTOR/AMPK Seesaw"; read more)
  
  While the scientists from the Department of Nutrition & Metabolism at the Faculty of Health and Medical Sciences of the University of Surrey in Guildford, UK, did not observe statistically significant improvements in fatty oxidation due to the small study size (10 healthy untrained females; age 18–22 yr; BMI 22kg/m²), the pronounced decrease in RQ after 8-10x 60 second cycling bouts at 95 % VO2peak separated by 90 seconds recovery at 50 watts in 9 out of 10 participants (see figure 2) does speak itself: "In women, consuming carbohydrate before exercise may potentially be more beneficial for fat oxidation than consuming carbohydrate post-exercise" (Honnor. 2013).
  

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  Bottom line: The results of the study at hand, which stand in line with previous research by Fuchs et al. who presented their research in the Proceedings of the Nutrition Society one year before, re-emphasis the fallacious over-reliance of high fatty oxidation rates during a workout. The max. 60-90min in which you may burn slightly more fat, are simply negligible compared to the much longer post-workout period, where the ingestion of 59 g CHO before a HIIT workout did not blunt but promote fatty acid oxidation.

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Believe it or not, but that's it for today! If you are hungry for more, I suggest you either go to the SuppVersity Facebook Wall or listen to Casual Friday later today... actually, I found Gabriel's name, i.e.  "The Alisa Profumo Show", for the Friday edition of Super Human Radio show quite fitting ;-)

References:

• Beaven CM, Hopkins WG, Hansen KT, Wood MR, Cronin JB, Lowe TE. Dose effect of caffeine on testosterone and cortisol responses to resistance exercise. Int J Sport Nutr Exerc Metab. 2008
  Apr;18(2):131-41.
• Betts JA, Stokes KA, Toone RJ, Williams C. Growth Hormone Responses to Consecutive Exercise Bouts with Ingestion of Carbohydrate plus Protein. Int J Sport Nutr Exerc Metab. 2013 April. 
• Claessens M, Saris WH, van Baak MA. Glucagon and insulin responses after ingestion of different amounts of intact and hydrolysed proteins. Br J Nutr. 2008 Jul;100(1):61-9.
• Coelho do Vale R, Pieters R, Zeelenberg. Flying under the Radar: Perverse Package Size Effects on Consumption Self‐Regulation. Journal of Consumer Research. 2008; 35(3):380-39.
• Fuchs, A. & Young, H. Investigation into gender differences in the effects of feeding around exercise on exercise performance, energy expenditure and substrate utilisation. Proceedings of the Nutrition Society. 2011; 70 (OCE6), E380.
• Galbo H, Richter EA, Hilsted J, Holst JJ, Christensen NJ, Henriksson J. Hormonal regulation during prolonged exercise. Ann N Y Acad Sci. 1977;301:72-80. Review.
• Honnor M, Herdsman M, Collins AL.The effect of food timing on fat oxidation during exercise and resting recovery. Proceedings of the Nutrition Society. 2012; 71 (OCE3), E236 
• Spence A, Sim M, Landers G, Peeling P. A Comparison of Caffeine versus Pseudoephedrine on Cycling Time-Trial Performance. Int J Sport Nutr Exerc Metab. 2013 Apr 9. 
• Sun, F; Li, L; O’Reilly, J; Wong, SH. Effect of carbohydrate-electrolyte-protein solution on hydration. International Journal of Sport Nutrition and Exercise Metabolism. 2013; 23: S1-S15