700% Increase in Insulin, Elevated Blood Glucose + Identical Cortisol & CK Levels Challenge Usefulness of Intra-Workout High GI Carb Ingestion in Advanced Strength Trainees

Image 1 (IndiaToday): If you insist on ingesting 3x cans (=sugar equivalent of the maltodextrin supplement in the study at hand) of a not-to-be-named energy drink during your workouts and don't die from caffeine poisoning, you may gain more, but I suspect not in those areas, where you ant it ;-)

Whether you should or should not supplement with carbohydrates is a matter of constant debate among strength trainees. While some swear that they cannot perform if they aren’t guzzling a glucose-laden “intra-workout” supplement or energy drink from the supermarket, others prefer to get the lion's share of their carbs from whole foods, settle for BCAAs or plain water as their workout beverage of choice and wash down a sweet ripe banana with a tasty protein shake after their workouts. And while a previous paper by Bird et al. suggested that the former practice, i.e. the ingestion of a carbohydrate supplement (6%, preferably with 6g of EAAs) during your workouts, could significantly blunt the exercise induced cortisol spike (CHO alone -116%, CHO + EAA -112% vs. placebo), a very recent study, which was conducted by a group of scientists from the University Federal of Paraíba in Brazil, yielded very different results (de Oliveira Quirino. 2013)

To carb-guzzle or not that is the question!

Contrary to Bird et al., who had recruited previously untrained subjects for their study, de Oliveira Quirino's team picked 7 healthy young men (BMI 25.4kg/m²; age 27.3y) who had been training for at least 6 months with a minimum 3 resistance training sessions per week – this is important to note, because it should, for most of you, increase the real-world significance of the data, as I assume that many of you will have been following a similar protocol for probably longer than 6 month, already. What may be less in line with your own exercise regimen, though, is the exact training protocol, which comprised ten exercises for the upper limbs, i.e.

bench press, inclined press, dumbbell pullover, back lat pulldown, back lat push-down,

front press, bar-bell curl, pushdown, preacher curl, and lying triceps extension

which were performed for 3 sets of 12-15 reps to voluntary failure (60% RM) and at a cadence of 2-0-2-0 (2s concentric, 2s eccentric; no transition time between phases). Obviously all participants performed this protocol twice (in random order) and with a 96h interval in-between the supplemented (1,080ml of an 8% carbohydrate solution =86.4g of maltodextrine, ingested at regular intervals every two exercises) and the placebo (sucralose) trial.

Figure 1: Plasma glucose levels (in mg/dl) at rest, after the first, second, third, fourth and fifth pair of exercises (left) and increases in insulin and cortisol from pre to post exercise (de Oliveira Quirino. 2013)

As you can see in figure 1 the ingestion of  ~350kcal of readily available energy was more or less unnecessary, as it did not blunt, but rather augment the cortisol response (effect was not statistically significant, though); and that in the presence of profound elevations in blood glucose and insulin levels, and without any effect on circulating creatine kinase levels (a marker of muscle damage, not shown in figure 1).

A "substantial" increase in "anabolic hormone activity"?

Now in the absence of concrete data on protein synthesis / degradation, mTOR activity & co and without any information on confounding factors such as an increased training intensity during the carbohydrate trial, it is difficult to provide a conclusive answer to the initially raised question, whether the provision of fast acting carbohydrates during a strength training session would, as the scientists conclude, provide an "additional [benefit] for those engaged in this type of exercise with the aim of hypertrophy”. After all, it may be correct that the findings of the study …

[…] show that carbohydrate ingestion during the course of a training session comprising resistance exercises does not affect catabolic activity, but does increase substantially anabolic hormone activity. (De Oliveira Quirino. 2013)

but the „anabolic hormone“ the Brazilian scientists are talking about is insulin, which is beyond doubt among the most "anabolic” hormones in our body, but unfortunately, not exactly muscle specific, as it is simply a matter of fact that skeletal muscle is not the only tissue that’s going to benefit from insulin’s facilitative effects on nutrient uptake (Timmerman. 2010). It thus appears more than reasonable to assume that two other major players in the complex orchestrate of our metabolism will avail themselves of the superfluous amount of glucose that would be floating around in our bloodstream if we mimicked the supplementation protocol in the de Oliveira Quirino study. Their names? Your liver and your body fat stores!

So what are the implications?

Image 2: Another recently published study by Wax et al. suggest that slow digesting starches can help to maximize workout intensity and volume (read more in my article for Physique Magazine)

If you are not training fasted (the participants worked out on 11am on both occasions) and/or low-carbing without regular re-feeds, so that you have adequate muscle and liver glycogen stores, when you hit the gym, and you are no rookie anymore (cf. Bird. 2008), so that working out is no longer a totally novel stressor for your body, my personal interpretation of the study data is that you simply don’t need the additional fast acting carbohydrates! Neither to stabilize your blood sugar, nor to ward off any exorbitant increases in cortisol.

And as far as the increase in insulin is concerned, it appears more than questionable whether the latter would actually exert significant additive effects on muscle protein synthesis or could not even negate the nutrient repartitioning effects of your workouts (Poehlman. 2000; Hawley. 2008) by diverting the obviously superfluous energy to places where you’d rather not have them stored ;-)

A note on the "importance" of insulin to build muscle: One of the most comprehensive reviews on the role of insulin in skeletal muscle anabolism states it quite aptly "the full response of translation initiation and protein synthesis to either effector is not observed in the absence of a minimal concentration of insulin", but - and this is important - "the amount of insulin required for the effects is low, and a concentration of the hormone that approximates that observed in fasting animals is sufficient for maximal stimulation." (Kimball. 2002)

Bottom line: Avoid the unnecessary insulin spike from the ingestion of high GI carbs before and/or during a workout, but make sure that you have an ample amount of muscle glycogen before you hit the gym via an adequate total and post-workout carbohydrate intake (the lion's share in form of low GI carbs) and planned carbohydrate re-feeds (esp. for low carbers). This practice will not necessarily augment post-exercise protein synthesis (cf. "Glycogen-Free Muscle Growth"), but it is certainly going to help you to increase or at least maintain your workout intensity and overall training volume (Wax. 2013).

References:

1. Bird SP, Tarpenning KM, Marino FE. Liquid carbohydrate/essential amino acid ingestion during a short-term bout of resistance exercise suppresses myofibrillar protein degradation. Metabolism. 2006 May;55(5):570-7.
2. de Oliveira Quirino EL, da Conceição Rodrigues Gonçalves M, de Oliveira CVC, Porto dos Santos E, Silva AS. Influence of carbohydrate supplementation during resistance training on concentrations of the hormones cortisol and insulin. Sport Sci Health (2013) 7:93–97
3. Hawley JA, Lessard SJ. Exercise training-induced improvements in insulin action. Acta Physiol (Oxf). 2008 Jan;192(1):127-35. Review. 
4. Kimball SR, Farrell PA, Jefferson LS. Invited Review: Role of insulin in translational control of protein synthesis in skeletal muscle by amino acids or exercise. J Appl Physiol. 2002 Sep;93(3):1168-80.
5. Poehlman ET, Dvorak RV, DeNino WF, Brochu M, Ades PA. Effects of resistance training and endurance training on insulin sensitivity in nonobese, young women: a controlled randomized trial. J Clin Endocrinol Metab. 2000 Jul;85(7):2463-8.
6. Timmerman KL, Lee JL, Dreyer HC, Dhanani S, Glynn EL, Fry CS, Drummond MJ, Sheffield-Moore M, Rasmussen BB, Volpi E. Insulin stimulates human skeletal muscle protein synthesis via an indirect mechanism involving endothelial-dependent vasodilation and mammalian target of rapamycin complex 1 signaling. J Clin Endocrinol Metab. 2010 Aug;95(8):3848-57.
7. Wax B, Brown SP, Webb HE, Kavazis AN. Effects of carbohydrate supplementation on force output and time to exhaustion during static leg contractions superimposed with electromyostimulation. J Strength Cond Res. 2013 Jun;26(6):1717-23. 

Science Round-Up Seconds: The Latest Data on Periworkout Nutrition - Protein, Carbs, HMB & More: Is it Possible You Have Done It All Wrong?

Honestly, even if they had available back in the day, I am not sure if Arnold would have preferred a virtually carb-free whey protein isolate over his mixture of two cups of milk, 1/2 cup of dry, nonfat milk solids (the old-school version of protein powders ;-), one egg and 1/2 cup of flavored ice cream.

I must confess that after going >30min over time on yesterday's installment of the SupppVersity Science Round-Up (click here to download and listen to the podcast if you missed the live show) I have run out of "Seconds". Since the SuppVersity buttery ... ah, I mean archive, is well stocked, this is yet not real problem. I just have to go down into the basement and pick some fresh ingredients for today's installment of the Seconds.

For my liking yesterday's show was a bit "healthitarian", meaning the topics centered mostly around health issues. Now, don't get me wrong. The show was outstanding and topics such as the "egg / chicken prostate cancer connection" or the "omega-6 for heart health study", of which you would actually have to say in retrospect that it bordered murder by negligence are obviously highly relevant, but I am a fan of diversity and well aware that there may be some topics many of you may not be that interested in. So what would be more obvious than switching things up completely and preparing an "erogogenitarian" menu today?

Now, tell me: What are everyone's favorite ergogenic? Right! Those are protein powders and amino acids ranging from BCAAs and EAAs, to creatine, glutamine and more exotic but still interesting stuff like HMB. Luckily, two groups of researchers from Iran, and the UK, Australia and Spain who have submitted their papers to the Journal of Exercise Physiology and the European Journal of Experimental Biology a couple of weeks ago must obviously feel the same. And since both articles made it into the February issues of the respective journals, they are still fresh and thus qualify as ingredients for today's installment of the SuppVersity Science Round Up. So, bon appetit, then ;-)

Are carbohydrates, not protein the most important part of "anabolic" peri-workout nutrtion

(Kazemzadeh. 2013) -- I guess this will be a shocker for some of you, but the headline is not entirely provocative only. In their most recent paper, Yazer Kazemzadeh and his colleagues from the Islamic Azad University and the Hamedan University of Medical Sciences in Teheran, Iran, are actually suggesting that the

"[...] ingestion of carbohydrate during resistance exercise may be [more potent in] inhibiting the catabolic hormone (cortisol), increasing the anabolic hormone (insulin) and creating a hormonal milieu for anabolism [than] whey protein." (Kazemzadeh. 2013)

They do yet also point out that "other anabolic markers need greater investigation" (Kazemzadeh. 2013) and we all know that these "other anabolic markers" that are related to the protein-exclusive increase in protein synthesis are what makes the largest contribution to your muscle gains in the long term... at least as you provide yourself with the fuel you need to train and this is where the hormonal effects of the ~750 ml 6% CHO beverage ten out of the 20 untrained young men (age:22.3±3 y, bodymass: 74±5 kg) in the study consumed during the sets of a 75%RM strength training regimen that consisted of

• 4 exercises for lower body, which were leg presses, leg curls, leg extensions and calf raises, and
• 4 exercises for upper body, namely lat pull downs, bench presses, barbell biceps curls and supine triceps extensions

All exercises were performed for three sets of 8-10 reps to failure. With one minute rest between sets and two minute rest between the individual exercises, the total duration of the workouts was <60min and the workouts were performed in the late afternoon 16:00-18:00h to minimize the influence of natural diurnal variations of cortisol, testosterone and GH.

Figure 1: Cortisol, insulin, growth hormone and total testosterone levels before and after the workout with carbohydrate (CARB) or protein (PRO) drinks being ingested between the sets (Kazemzadeh. 2013)

As you can see from the plots in figure 1 the carbohydrate beverage, which contained a 10ml/kg of a 6% mix (=6g of carbs per 10kg body weight) of fast and slow digesting carbs from glucose (fast) and Quaker oats (slow) did a pretty decent job in establishing an allegedly optimal anabolic hormonal milieu by cranking up the GH, insulin and total testosterone levels and blunting the cortisol response.

Insulin up, cortisol down - how important is that?

The total amount of carbohydrates the CARB group in the study at hand consumed during their workouts does actually come pretty close to the 130-150g of carbs even the most sedentary slob can easily stash away in the glycogen stores of muscle and liver on a daily basis. If you want to learn more about the reaoning behind these figures, I suggest you go back to my previous post on "Carbohydrate Shortage in Paleo Land" (read the whole article).

With insulin and cortisol being the only parameters that responded significantly more favorable to the glucose load, the picture that emerges is unquestionable more conducive to protein anabolism. Based on dozens of previous studies, I can however guarantee that the actual protein synthesis rates, which were not measured in the study at hand, were higher in the whey protein arm of the study (2g protein per kg body weight).

That being said, the addition of carbs could still have had a beneficial effect on exercise recovery and ultimately  - probably only after weeks of training and in an otherwise low carb scenario - yield significantly greater increases in strength and lean muscle tissue. With the total amount of carbs well within in the <150g range and the maintenance of the GH response, of which many people claim it would be blunted by the ingestion of nutrients, in particular carbs, during or after a workout probably even without compromising your body composition (assuming that you compensate for the additional kcal in the subsequent meals).

The latter hypothesis of mine does actually make an excellent segue into the next study, so just keep on reading, if you want more ;-)

Performance enhancing supplement Cyclone first and foremost "fat enhancing"

(Cooper. 2013) -- I promised you that in the last sentence of the previous "course" of this installment of the SuppVersity Science Round-Up Seconds and here it is: Certainly somewhat surprising scientific evidence that 56g of carbs alone won't, but an isocaloric serving of the commercially available carbs + protein + creatine Cyclone will make you you fat.

Figure 2: Nutrient content of supplement and placebo (Cooper. 2013)

Now that I have got your full attention, let's take a look at the context in which these counterintuitive effects occurred. You can see the macro and, in the case of the commercial protein + mineral + amino acid combo, also the micronutrient composition of the supplements in figure 2 on the right hand side. As already mentioned, the amount of calories in the products was identical. Any differences in strength and mass gains, as well as changes in the body composition that arose in the course of the 12-week training regimen would therefore have to be attributed to differences in the macro / micronutrient composition.

If you follow your gut feeling, I guess you'd say that using a supplement full of more or less proven ergogenics while you train four times a week, following an

• upper body = bench press; bent over row; shoulder press, bicep curls, and triceps extension,
• lower body = squat, stiff leg deadlift, lunges, and dynamic upright row

split (training days: Mo, Tue, Thurs, Fri), in the course of which you perform 4 sets per exercise with 6 to 12 repetition at 65 to 80% of your one-repetition max  (2 min rest between sets) should actually produce measurably superior results to the ingestion of the meager amount of 56g of maltodextrin, right?

Figure 3: Changes in strength and body composition after 12 weeks on a upper-body, lower body split trained 2x per week on Mo & Tue, as well as Thurs & Friday (Cooper. 2013)

Right! At least that's what I had expected, as well. The results I plotted for you in figure 3 do yet speak a very different language. Ok, the overall lean mass increase of the 13 healthy already resistant trained men (23.5 ± 2.7 yrs old, body mass (BM) = 80 ± 13 kg, height = 179 ± 6 cm, body fat % ~11-18%)  was higher in the group that used the "professional" multi-component supplement. If your goal is "lean mass", however, the allegedly fattening carbohydrate drink which produced a small, but significant increase in lean mass without any accompanying fat gains, does yet suddenly look unexpectedly attractive, doesn't it (see figure 3, right)?

As far as the strength gains go, things actually don't look much different. Due to the small sample size, none of the he intergroup differences reached statistical significance and the scientists way of resorting to effect sizes instead of group averages, based on which they argue that "the lack of significance due to CYC supplementation does not mean the supplement was ineffective" (Cooper. 2013) Tells me that they were similarly surprised as I am about the outcome of this 12-week trial.

"That's impossible, so where is the design flaw, here?"

I know the above is what you are thinking now, so let's check the usual and not so usual suspects.

• 

  There are three things you need to succeed in your efforts to achieve optimal health, a decent physique and a long and active live: A plan, the guts to stick to it and change / tweak it, whenever that's necessary and - often overlooked - the right tools to measure your progress. And I can tell you a scale "body fat or not" is not among those tools (read more about goal setting, planning and stock taking).

  Diet? The subjects were "instructed to maintain the recommended dietary habits throughout the duration of the study" when necessary, specific tweaks were applied to make sure that they would hit the 1.5-2g of protein, 5-6 g of carbs and a fat intake of ~25%-30% of their daily total caloric intake. So, if we simply assume that any deviations from that regimen were similar in the two groups this cannot explain the differences.
• Body fat scales? Not a problem, because the body composition was assessed by whole body densitometry using air displacement in a Bod Pod® - whether that may have skewed the results due creatine induced water retention is yet not 100% certain. On the other hand, lower fat gains would imply even greater lean mass gains and that's not realistic given the fact that the subject's strength levels did hardly improve.
• Missing training sessions or not training with adequate intensity? Since the scientists don't mention that the training sessions were supervised, this could have been an issue. On the other hand, why would that happen only in the CARB, but not in the Cyclone group?
• Misreporting by the scientists: Actually I have now checked three times, whether it may be possible that the researchers simply messed up with the data in the tables and put the results for the CARB group in the Cyclone row and vice versa. Based on the discussion at the end of the paper this does yet not appear to be the case.

So, if all these don't apply what's left then?

• 

  The "anabolic window" turns out to be more of a barn door, which is unlocked by the key of exercise and nutrition science (learn more)

  Following the manufacturers advice instead of common practice: This is actually one the scientists came up with in their discussion. In the majority of previous studies with similar supps, the products and placebo were consumed before and after the workout. In the study at hand, they were consumed as prescribed by the manufacturer after breakfast and after the workout. Not likely that this is the reason? Well, honestly, I would agree. 
• Having way too small group sizes: This is certainly an important fact to consider. If you don't test training vs. not training having 7 subjects in the active and 6 in the placebo arm is not very likely to produce significant differences. On the other hand, this does not explain that the non-significant differences are more or less opposed to what you may have expected.

Now, even if this was all I could come up with, I would still not  suggest you give up on protein powder, creatine and your preferred carb source and switch to maltodextrin, only, as your post workout nutrition of choice! God forbid! After all I do still have an ace up my sleeve, which is

• 

  Don't worry, the 10g+ of EAA with every meal (20-30g+ of quality protein) rule of thumb to get lean and stay lean does still apply (read more). A single study won't change that overnight. And while the current carb-scare is hilarious and misplaced, carbs alone, just like protein only, don't build magnificent, athletic and healthy physiques.

  Not starting on a level playing field: If you take a brief look at the baseline body composition data there is one thing that shoul leap out. The initial body fat levels! While the Cyclone group started out with a six-pack and 11% body fat, the guys in the placebo group were running around with 18% on average and - this is even more important - a standard deviation of 10%! In other words, it's not unlikely that two or even three of the guys in the CARB group actually lost body fat, over the 12-week training period. This would nullify any fat gains in the rest of the group and yield a net increase of less than 0.1% body fat for the CARB group. Some of the guys in the cyclone group, however were in that peculiar <10% range (the standard deviation here was +/- 5.4%), where it's really hard to shed additional body fat and actually pretty easy to bounce back into your bodies comfort zone.

If that does not soothe your concerns that you could have done all wrong over the years, just take my word for it: This study is one of those highly educative outliers which are mostly SuppVersity newsworthy, because they offer a chance to practice your critical thinking skills and remind you of the value of single scientific paper.

References:

• Cooper R, Naclerio F, Larumbe-Zabala E, Chassin L, Allgrove J, Jimenez A. Effects of a Carbohydrate-Protein-Creatine Supplement on Strength Performance and Body Composition in Recreationally Trained Young Men. JEPonline 2013;16(1):72-85.  
• Kazemzadeh Y, Zafari A, Bananaeifar A, Moghadam RH, Abasrashid N, Shafabakhsh F. Comparison of whey protein and carbohydrate consumption on hormonal response after resistance exercise. European Journal of Experimental Biology. 2013; 3(1):10-15 .