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Post-Workout High Isoleucine AA+CHO Decreases Glucose Spikes, But Impairs Musclular Glyocogen Resynthesis - Reason Enough to Skip Amino Acids?

If you put any faith into the promises of the supplement industry, amino acid supplements are the solution to all your problems - including those you havent even known about, yet. Against that background its always interesting if scientists study the real world effects of amino acid supplements in a realistic scenario like after strenuous exercise.

In their latest study Wang and colleagues from the University of Texas at Austin and the Shanghai Research Institute of Sports Science did just that: They studied the effects isoleucine and four additional amino acids, on blood glucose homeostasis and glycogen synthesis after strenuous exercise.
As the scientists point out, the results of their study "could provide a practical and safe means of increasing the rate of muscle glycogen synthesis after exercise and enhancing the rate of recovery" (Wang. 2015).

Table 1:  Subjects’ characteristics (Wang. 2015).

Ten healthy active adults volunteered for the study. All subjects were accustomed to cycling for prolonged periods of 3–5 h during an exercise session. The ,aximum oxygen uptake (VO2max) was measured in all subjects on a cycle ergometer by using a TrueOne 2400 metabolic measurement system (ParvoMedics, Sandy, Utah) to verify adequate aerobic fitness levels (results see Table 1).

Figure 1: Basically the AA supplement contained almost exclusively isoleucine. It was administered in the dosage shown above and at twice that amount in the LAA and HAA trials (Wang. 2015)

"Two to three days after the VO2max test, the subjects reported to the laboratory to perform a practice ride to familiarize them with the laboratory environment and the experimental protocol. The practice ride was also used to adjust and verify appropriate workloads for the experimental trials. The practice rides simulated the protocol ride but without blood samples or muscle biopsies being taken. The ride consisted of cycling at 70 % VO2max for 2 h, which was followed by five 1-min sprints at 85 % VO2max. The sprints were separated by 1 min cycling at 45 % VO2max. During the first 15 min of each hour, oxygen uptake was measured for 5 min to verify workload.

Water (250 mL) was provided every 20 min of exercise. Heart rate (HR) was monitored and ratings of perceived exertion (RPE) on a Borg-scale (ranging from 6 to 20) were collected every 30 min of exercise. The practice ride and each of the following three experimental trials were separated by a minimum of 7 days and maximum of 12 days" (Wang. 2015).

The actual tests consisted of cycling on an ergometer to deplete muscle glycogen. Blood sampling and a muscle biopsy were performed immediately on cessation of exercise. After the muscle biopsy, subjects were given the first of two supplement doses. More specifically they received either...

• 1.2 g carbohydrate/kg body weight (CHO), 1.2 g carbohydrate/kg body weight plus 6.5 g AA (CHO/LAA) or 
• the same carbohydrate supplement plus 6.5g (CHO/LAA) or 13 g AA (CHO/HAA) 

immediately after the first muscle biopsy and at 120 min of recovery. The carbohydrate base consisted of simple dextrose dissolved at a ratio of 100g/296 mL in an orange flavored drink (SUN-DEX, Fisher Healthcare, Houston, Texas). The additional amino acids contained 0.046 g cystine 2HCl, 0.023 g methionine, 0.045 g valine, 6.342 g Isoleucine, and 0.044 g leucine per person, or twice that amount in the CHO/HAA trial. The amino acids were simply added to the dextrose drink.

Why would you even believe that there may be benefits from AA supplementation?

As Wang et al. point out, "this amino acid mixture was selected as it was previously reported to be more effective in lowering the blood glucose response to a glucose challenge than isoleucine alone" (Wang. 2015) by Bernard et al. (2011).

Figure 2: Blood glucose AUC during the oral glucose tolerance test (OGTT). Sprague-Dawley rats were gavaged with either glucose (CHO), glucose plus a 5-amino acid mixture (CHO-AA-1), glucose plus a 5-amino acid mixture with increased leucine concentration (CHO-AA-2), or placebo (PLA). Blood was taken from the tail immediately before the gavage and 15, 30, 60, and 120 min afterward (Bernard. 2011).

The three test beverages were similar in color, taste, and texture to allow a double-blinded and counter-balanced study design. All test drinks were randomly assigned and dispensed by a laboratory technician who was not involved in the data collection.

Figure 3: Blood glucose postexercise and during the 4-h recovery. Treatments were with CHO (circle), CHO/LAA (triangle), and CHO/HAA (filled circle) supplements provided immediately after and 2 h after exercise. Values are mean ± SE. CHO/HAA vs. CHO (*p < 0.05). CHO/LAA vs. CHO (# p < 0.05) - left; Blood glucose area under the curve (AUC) during the 4-h recovery. Treatments were CHO, CHO/LAA, and CHO/HAA supplements provided immediately after and 2 h after exercise. AUC was calculated with baseline (pre). Values are mean ± SE. CHO/HAA vs. CHO (*p < 0.05). CHO/LAA vs. CHO (# p < 0.05) - right (Wang. 2015).

As the data in Figure 3 indicates,There was a similar effect in humans as it has previously been observed in rodents. An effect of which you as a SuppVersity reader know that it is probably mostly ascribable to isoleucine (see "The Glucose-Repartitioning Effects of Isoleucine" | more).

Figure 4: Total muscle glycogen storage in the vastus lateralis during the 4-h recovery from intense cycling. Treatments were CHO, CHO/LAA, and CHO/HAA supplements provided immediately after and 2 h after exercise. Values are mean ± SE. CHO/HAA vs. CHO (*p < 0.05 | Wang. 2015)

What is a bit disappointing is the fact that the decrease in blood glucose did not come with an increase in glycogen storage.

As the data in Figure 4 shows, the exact opposite was the case. After 4h of recovery the muscle glycogen levels were not higher, but lower in the amino acid supplemented trials.

For diabetics this wouldnt be a problem. For athletes its yet clearly a disadvantage that the 4-g recovery glycogen levels were lower and significantly lower in the low and high dose amino acid supplement trials.

Eventually this result is surprising because specifically in the high amino acid group (a) the insulin levels, (b) the AS160, a protein that controls insulin mediated glucose uptake, (c) the mTOR & p-AKT levels, (d) the "exercise hormon" levels of serum irisin  and (e) the levels of glycogen synthase which stores carbs in forms of glycogen in the high dose AA trials were significantly elevated.
References:

• Armstrong, Jane L., et al. "Regulation of glycogen synthesis by amino acids in cultured human muscle cells." Journal of biological Chemistry 276.2 (2001): 952-956.
• Bernard, Jeffrey R., et al. "An amino acid mixture improves glucose tolerance and insulin signaling in Sprague-Dawley rats." American Journal of Physiology-Endocrinology and Metabolism 300.4 (2011): E752-E760.
• Doi, Masako, et al. "Isoleucine, a potent plasma glucose-lowering amino acid, stimulates glucose uptake in C2C12 myotubes." Biochemical and biophysical research communications 312.4 (2003): 1111-1117. 
• Ivy, John L., et al. "Early postexercise muscle glycogen recovery is enhanced with a carbohydrate-protein supplement." Journal of Applied Physiology 93.4 (2002): 1337-1344.
• Ivy, J. L., et al. "Post exercise carbohydrate–protein supplementation: phosphorylation of muscle proteins involved in glycogen synthesis and protein translation." Amino acids 35.1 (2008): 89-97.
• Morifuji, Masashi, et al. "Dietary whey protein increases liver and skeletal muscle glycogen levels in exercise-trained rats." British journal of nutrition 93.04 (2005): 439-445.
• Morifuji, Masashi, et al. "Post-exercise carbohydrate plus whey protein hydrolysates supplementation increases skeletal muscle glycogen level in rats." Amino acids 38.4 (2010): 1109-1115.
• Wang, Bei, et al. "Amino acid mixture acutely improves the glucose tolerance of healthy overweight adults." Nutrition Research 32.1 (2012): 30-38.
• Zawadzki, K. M., B. B. Yaspelkis, and J. L. Ivy. "Carbohydrate-protein complex increases the rate of muscle glycogen storage after exercise." J Appl Physiol 72.5 (1992): 1854-9.

What could be better than starting your day with the first rays of the sun? Doing this with a person you love, I suppose.

If you have listened to Super Human Radio earlier this week (download episode), you will have heard that Carl "caught" me off guard calling me without prior notice during the live show. We ended up talking about the use of melatonin and my beloved "daylight lamp" (light therapy lamp), which kept my energy levels up even at the darkest winter mornings over the past couple of months.

If you listened to the show, you may also remember that Carl mentioned that it would be great to have a light-based alarm clock - something like a light therapy lamp that increases its intensity gradually at a given time and will thus wake you up from a deep slumber.
Well, I already mentioned during the show that a corresponding device is already available, but pretty useless for someone who usually uses blindfolds to get a good nights sleep. For the rest of you, who are sleeping in a pitch black room without covering their eyes with a blindfold, on the other hand, Carls suggestion could be a viable means to "improve both cognitive and physical performance after waking." (Thompson. 2014).

This is at least what a recent study from the University College London would suggest. For the corresponding experiment, the researchers from the Department of Epidemiology and Public Health recruited 8 young adults (four males; four females) with a mean age of 24 ± 9 years who had not been involved in nocturnal shift work or undertaken transmeridian travel during the past 30 days (thats important to ensure that their circadian rhythm was not messed up in the first place).
The trials themselves were ordered in a counterbalanced fashion and were separated by 5–9 days. In the two days leading up to the tests, the participants were asked to sleep the exact times in their own homes that they would in the laboratory. to monitor compliance wrist accelerometers were issued.

Did you know that previous studies support the use of dawn simulations to tread seasonal effective disorder, where it was on top of that associated with lower remission rates than regular light therapy (Avery. 1993 & 2001). In addition, dawn simulations have been shown to have beneficial effects on the necessary and natural and healthy (Clow. 2010) early morning increase in cortisol (Thorn. 2004)?

"The experimental trials were identical with the exception of the 30 min prior to waking. During this time par ticipants either slept normally in complete darkness, the control condition (c), or were exposed to dawn simulation (DS).

Each night’s sleep ended with an audible alarm. At the same moment, a researcher entered the room to ensure that the participant was awake. Participants were then allowed to attend the bathroom if required.

After waking, a 75 min testing protocol commenced which consisted of: three bouts of cognitive assessment, one physical performance test and monitoring of physiological and subjective variables." (Thompson. 2014)

In view of the fact that I already gave away the results, its probably not really surprising that the data in Figure 1 confirms that being waken up by artificial sunlight had significant beneficial effects on the cognitive and physical performance of the subjects.

Figure 1: Changes in number of total additions and reaction time in cognitive tests (Thompson. 2014)

What did not differ, though, were the sleep efficiency, sleep latency, and the total sleep time. In a similar vein, the differences in perceived sleepiness and body temperature were visible, but not statistically significant.
References:

• Avery, David H., et al. "Dawn simulation treatment of winter depression: a controlled study." American Journal of Psychiatry 150 (1993): 113-113.
• Avery, David H., et al. "Dawn simulation and bright light in the treatment of SAD: a controlled study." Biological psychiatry 50.3 (2001): 205-216.
• Clow, Angela, et al. "The cortisol awakening response: more than a measure of HPA axis function." Neuroscience & Biobehavioral Reviews 35.1 (2010): 97-103.
• Thompson, Andrew, et al. "Effects of dawn simulation on markers of sleep inertia and post-waking performance in humans." European journal of applied physiology (2014): 1-8.
• Thorn, Lisa, et al. "The effect of dawn simulation on the cortisol response to awakening in healthy participants." Psychoneuroendocrinology 29.7 (2004): 925-930.

Study suggests, significant increases in mitochondrial builder PGC1-a with HIIT + bicarbonate

If this is not your first visit to the SuppVersity, I am confident youve read about the ergogenic effects of sodium bicarbonate aka baking soda before. If you havent here is the short version: Sodium bicarbonate will act as a systemic acid buffer during workouts. Thats in contrast to beta-alanine which works exclusively in the muscle, but has very similar, in some studies albeit significantly more pronounced and first and foremost acute beneficial effects on exercise performance.

No loading, no waiting, no hoping. You simply wash down 20g of bicarbonate (better 0.3g/kg body weight) before the race of your life and - as long as your tummy can stomach it - see / feel the benefits during the race.
In his thesis paper, Michael E. Percival investigated the effects of bicarbonate supplementation on the cellular adaptation process in response to high intensity interval training (HIIT).

"Acute and chronic high-intensity interval exercise is a potent stimulus to influence a number of physiological adaptations with implications for health and athletic performance. [...] Due to the intense nature of this training modality and associated disturbance to muscle pH, which has been implicated in fatigue, it has been hypothesized that augmenting the body’s natural buffering capacity through nutritional means may be a strategy to augment training adaptations. One way of doing this is through the ingestion of NaHCO 3 prior to exercise, which has shown to have ergogenic effects allowing athletes to perform more work with each training session. In addition, greater mitochondrial and performance adaptations are seen when HIIT is preceded by NaHCO3 ingestion even when work is matched (Edge. 2006; Thomas. 2007; Bishop. 2010)."

Percivals goal was now to finally establish what exactly it is that gives bicarbonate the adaptational edge, so to say. To this ends, Michael E. Percival had his subjects, nine active men (22 ± 2 y; 78 ± 13 kg, VO²peak = 48 ± 8 mL/kg/min; mean ± SD) perform the same 10 x 60 s HIIT cycling protocol on two occasions, either with

• 0.2 g/kg body weight sodium bicarbonate (BICARB) or 
• an equimolar dose of a placebo, sodium chloride (PLAC),

both ingested in two equally sized doses that were ingested 30 minutes after the breakfast - a means to minimize gastrointestinal distress | and in the study at hand it worked: There was not difference in gastrointestinal complaints between placebo and bicarbonate trial.

Figure 1: Pre vs. post PGC1a and muscular glycogen content (Percival. 2014)

The two trials were separated by 1 week, the subjects had to perform their 10 all out cycling bouts at an intensity of ~263 ± 40 W - more than enough to bring all of them up to the 90%+ heart rate zone. , interspersed by 60 s of recovery. Total work during each trial was identical for a given subject.

Figure 2: Bicarbonate increases mitochondrial respiration specifically during longer-duration exercise (Bishop. 2010) - the study at hand does not just confirm the results of the previous rodent study, it does also provide information about the underlying mechanism thats responsible for the accelerated mitochondrial adaptation w/ sodium bicarbonate.

The latter is important, because otherwise the significant differences in PGC1-a expression (see Figure 1), of which the study at hand indicates that they are the most probably reason for the previously cited significant adapational benefits from bicarbonate supplementation (compare Figure 2), could be a mere function of the training volume.

Based on the data from blood draws and needle biopsies from the vastus lateralis we can now conclude that it is the increase in PGC-1? mRNA, which was increased after 3 h of recovery to a greater extent in BICARB vs. PLAC (~7- vs. 5-fold, p < 0.05) that is responsible for the enhanced adaptations after chronic supplementation.

Speaking of which, as Ive previously pointed out, I truly believe that the serial loading protocol, as described by Driller et al. (2012) is the most promising dosing scheme for the long(er)-term use of sodium bicarbonate supplements (read my write-up for more information). Issues with increasing blood pressure or calcium loss as they have been reported for very high sodium chloride intakes in susceptible individuals should, as I repeatedly pointed out, not be an issue (Luft. 1990). In pre- and post-menopausal women on high-protein diets, the addition of small amounts of sodium bicarbonate is in fact an effective way to increase calcium retention and thus any potential negative effects on bone health that may arise as a consequence of protein-induced hypercalciuria (Lutz. 1984).
References:

• Bishop, David, et al. "Induced metabolic alkalosis affects muscle metabolism and repeated-sprint ability." Medicine and science in sports and exercise 36.5 (2004): 807-813.
• Bishop, David J., et al. "Sodium bicarbonate ingestion prior to training improves mitochondrial adaptations in rats." American Journal of Physiology-Endocrinology and Metabolism 299.2 (2010): E225-E233. 
• Carr, Amelia J., Will G. Hopkins, and Christopher J. Gore. "Effects of acute alkalosis and acidosis on performance." Sports medicine 41.10 (2011): 801-814. 
• Driller, Matthew W., et al. "The effects of serial and acute NaHCO3 loading in well-trained cyclists." The Journal of Strength & Conditioning Research 26.10 (2012): 2791-2797.
• Edge, Johann, David Bishop, and Carmel Goodman. "Effects of chronic NaHCO3 ingestion during interval training on changes to muscle buffer capacity, metabolism, and short-term endurance performance." Journal of applied physiology 101.3 (2006): 918-925.
• Hollidge-Horvat, M. G., et al. "Effect of induced metabolic alkalosis on human skeletal muscle metabolism during exercise." American Journal of Physiology-Endocrinology And Metabolism 278.2 (2000): E316-E329. 
• Luft, Friedrich C., et al. "Sodium bicarbonate and sodium chloride: effects on blood pressure and electrolyte homeostasis in normal and hypertensive man." Journal of hypertension 8.7 (1990): 663-670. 
• Lutz, Josephine. "Calcium balance and acid-base status of women as affected by increased protein intake and by sodium bicarbonate ingestion." The American journal of clinical nutrition 39.2 (1984): 281-288.
• Percival, Michael E. "Sodium bicarbonate ingestion augments the increase in PGC-1? mRNA expression during recovery from intense interval exercise in human skeletal muscle." Diss. McMaster University, 2014.
• Thomas, Claire, et al. "Effects of high-intensity training on MCT1, MCT4, and NBC expressions in rat skeletal muscles: influence of chronic metabolic alkalosis." American Journal of Physiology-Endocrinology and Metabolism 293.4 (2007): E916-E922.

Is there something to the good vs. bad fat shenanigan, after all?

Only recently scientists from the Texas Tech University report that a PUFA-rich high-fat meal led to a greater diet-induced thermogenesis in normal-weight premenopausal women compared with SFA- or MUFA-rich high-fat meals.

Reason enough to take a closer look at this and previous studies investigating the diet-induced thermogenic effects of PUFA-, MUFA- and SFA-rich meals and to conduct a reality check wrt to the question whether these differences actually matter - I mean, will you get and stay lean by upping your PUFA intake? Lets take a look!
In the initially mentioned study, Hui C. Clevenger, Amanda L. Kozimor, Chad M. Paton and Jamie A. Cooper explored the effect of three HF meals enriched with different fatty acids (MUFAs, PUFAs or SFAs) on metabolism in premenopausal women of normal weight. In that, the metabolic parameters of interest included postprandial energy expenditure (EE), which is then used to calculate DIT, and substrate oxidation, which included respiratory exchange ratio (RER), fat oxidation and carbohydrate (CHO) oxidation.

Based on previous research in men of normal weight, the Texas Tech researchers hypothesized that the diet induced thermogenesis (DIT) and fat oxidation would be the highest after the PUFA- and MUFA-rich meals and lowest after the SFA-rich meal in premenopausal women - a result of which you already know that it was only partly confirmed.

Figure 1: Diet-induced thermogenesis and respiratory exchange rate (higher RER = lower fatty acid oxidation vs. higher CHO oxidation) in the 5h after the test meal (Clevenger. 2014)

The data in Figure 1 does after all tell you that the expected MUFA-induced increase in diet-induced thermogenesis did not occur. PUFAs, on the other hand did the job, Clevenger et al. expected them to do. They increased the DIT by an ostensibly whopping 14% over the DIT the scientists observed in response to the ingestion of the high MUFA and SFA liquid meals that had been prepared with the same base of 8 fl oz (237 ml) of chocolate Ensure(R) with soy lecithin and Nesquik (R, but contained different additional dietary fatty acids added depending on the treatment condition:

• Table 1: Liquid meal nutrient composition breakdown (Clevenger. 2014).

  The PUFA-rich meal was ‘base’ plus sunflower oil and flaxseed oil, with 42% of total energy coming from PUFA.
   
• The MUFA-rich meal was ‘base’ plus canola oil and extra virgin olive oil, with 42% of total energy coming from MUFA.
  
  
• Finally, the SFA-rich meal was ‘base’ plus butter, coconut oil and palm oil, with 40% of total energy coming from SFA. 

As the data in Table 1 indicates, the nutrient profiles didnt differ much. The fatty acid composition, on the other hand did, with the SFA meal being the only one with measurable amounts of Butyric, Caprioc, Caprylic, Capric, Lauric, Myristic and Hepatedic acid. Fatty acids of which previous research indicate that they induces an obesity-linked proinflammatory gene expression profile in adipose tissue of subjects at risk of metabolic syndrome (van Dijk. 2009).

High MUFA diets, on the other hand, have been shown to potentiate the effects of weight loss in obese NIDDM patients (Low. 1996). They are the major group of fatty acids in the one oil, everyone appears to agree that its health (Olive oil). And last but not least, even the allegedly unhealthy omega-6s have been shown in randomized controlled to reduce liver fat and modestly improve metabolic status, without weight loss, when compared to high saturated fat diets (Bjermo. 2012).

All of these effects / this evidence could potentially be more important than the increase postprandial thermogenesis in the study at hand - so the ultimate question is: Does DIT even matter?
References:

• Bjermo, Helena, et al. "Effects of n? 6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity: a randomized controlled trial." The American journal of clinical nutrition 95.5 (2012): 1003-1012.
• Clevenger, Hui C., et al. "Acute effect of dietary fatty acid composition on postprandial metabolism in women." Experimental physiology (2014): expphysiol-2013.
• Westerterp, Klaas R., et al. "Dietary fat oxidation as a function of body fat." The American journal of clinical nutrition 87.1 (2008): 132-135.