Showing posts with label benefits. Show all posts
Showing posts with label benefits. Show all posts

Monday, April 25, 2016

Study Underlines Real World Benefits of 2g day of Ginger for Type II Diabetics Effects Almost on Par W Metformin

If you dont have ginger powder, just shred a fresh rhizome. Thats by the way what the researchers did, as well.
Yeah, we all know "Ginger is good for your glucose metabolism". We all know "there are dozens of rodent studies that support its benefits". And we also know that there is evidence from acute interventions that indicate that ginger can ameliorate the glucose response to oral glucose tolerance tests.

But do we know, whether the regular consumption of realistic amounts of pure ginger will have beneficial effects on the glucose levels of those who would benefit the most, i.e. type II aka "lifestyle" diabetics?
You can learn more about glucose control at the SuppVersity

Proteins, Peptides & Blood Glucose

SFA, MUFA, PUFA & Blood Glucose

The VitaminS E & Glucose Control

B-Vitamins & Glucose Control

Vitamin A & Glucose Control

Fat to Blunt Insulin?
The results of the latest study from the Tehran University of Medical Sciences where scientists obviously dont depend on being able to produce patentable agents would suggest: There are benefits!

I have to admit, though, the ginger the 20-60 years old diabetics consumed was not provided in form of whole roots, but rather as a powder made of ginger roots.
"The under study patients were diagnosed with non-insulin dependent diabetes mellitus (NIDDM) by an endocrinologist on the basis of the results of the blood tests and met the criteria of the study. These criteria included: disease duration at least 2 years, HbA1c level of 6-8%, taking no antioxidant supplements such as selenium, zinc and beta-carotene for at least 3 months prior to the study, no smoking and drinking. Exclusion criteria of the study were insulin therapy at baseline or during the study, changes in the type or dose of medication, changes in diet or daily physical activity, any acute illnesses or some chronic diseases including kidney, liver, cardiovascular, and gastrointestinal diseases, smoking pregnancy and lactation, consumption of ginger or other botanical supplements, ginger hypersensitivity, and consumption of less than 80% of supplements during the study period." (Khandouzi. 2015)
Patients were divided randomly into two groups (experiment and control, 25 subjects in each) using computers random numbers to receive either ginger or placebo one capsule twice a day for 12 weeks. All subjects were permitted to consume their usual medications according to their physicians recommendation.

Regular ginger powder, nothing else!

The fresh rhizomes for the ginger powder purchased from local market and were ground as a fine particle after drying. The powder was delivered to a pharmaceutical lab (Tehran university of medical sciences, Iran) to prepare capsules containing 1 gram ginger in each. Lactose was also used to make placebo. Information on when the supplements were ingested is unfortunately, not available, but I assume "twice daily" means with breakfast and dinner or something like that.
Figure 1: Changes in fasting blood sugar, HbA1C, Apo-B/Apo-A1 and MDA levels (Khandouzi. 2015).
What is available, is the most relevant information, i.e. glucose, apolipoproteins and MDA levels we can use to access the effects on glucose and lipid metabolism and the peroxidation of polyunsaturated fatty acids.
Warning: Dont throw away your diabetes drugs. While the study at hand is impressive, only metformin, not gingeris a standardized, tried and proven blood glucose medication. No one can guarantee you will see the results in the study at hand with ginger powder you buy on the Internet. So, if you want to try to add Ginger to your regimen and take a look at your blood glucose levels. If possible talk to your doctor and reduce your meds. By no means, however, replace them by ginger from one day to another!
Parameters of which the data in Figure 1 tells you that they were significantly improved over the course of the 12-week study period. More specifically, this means:
  • A 12% and 10% reduction in fasting blood glucose and HbA1c that may reduce many of the nasty chronic side effects of type II diabetes, such as its negative effects on heart health (Patel. 2008)
  • A 28% reduction in the Apo B / Apo A-I ratio that signifies a significant reduction in coronary atherosclerosis risk (Van Stiphout. 1986)
  • A 23% reduction in malondialdehyde (MDA) levels that signifies a reduction in coronary heart disease risk (Khan. 2000)
Overall, there is thus little question that something as simple as adding 2g of pulverized fresh Zingiber officinale rhizomes will have a significant impact on important health markers in middle-aged type II diabetics.
Comparison of the HbA1c reduction in response to 2g of ginger powder made from fresh rhizomes (Khandouzi. 2015) and 2g metformin (Schweizer. 2007) in two different populations of type II diabetic patients. One already on meds, the other medication naive.
Bottom line: The data from the study at hand suggest that for type II diabetics, ginger powder is a "must have" supplement. Why? Well with 10% the reduction in HbA1c is only 8% smaller than the reduction Schweizer et al. observed in their 2007 study with metformin the hailed "holy grail" of diabetes treatment where the addition of metformin a drug many of the subjects in the study already used lead to an HbA1c reduction of 18% within the first 12-weeks of the 52-week study.

Impressed? Rightly so. I mean, the patients in the Schweizer study had higher baseline levels, but they were drug-naive, i.e. unlike the patients in the study at hand, they did not receive any diabetes treatment before the metformin therapy was initiated | Comment on Facebook!
References:
  • Khan, Mudassir Ahmad, and Abdul Baseer. "Increased malondialdehyde levels in coronary heart disease." J Pak Med Assoc 50.8 (2000): 261-264.
  • Khandouzi, Nafiseh, et al. "The Effects of Ginger on Fasting Blood Sugar, Hemoglobin A1c, Apolipoprotein B, Apolipoprotein AI and Malondialdehyde in Type 2 Diabetic Patients." Iranian Journal of Pharmaceutical Research: IJPR 14.1 (2015): 131.
  • Patel, Anushka, et al. "Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes." (2008).
  • Schweizer, A., et al. "Comparison between vildagliptin and metformin to sustain reductions in HbA1c over 1 year in drug?naïve patients with Type 2 diabetes." Diabetic Medicine 24.9 (2007): 955-961.
  • Van Stiphout, W. A. H. J., et al. "Is the ratio of apo B/apo AI an early predictor of coronary atherosclerosis?." Atherosclerosis 62.2 (1986): 179-182.


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Tuesday, March 29, 2016

Creatine Benefits Accumulate Now it Prevents NAFLD Reduced TG Production Increased Efflux Oxidation

Creatine is a dangerous steroid? Well, the study at hand shows that it will prevent not promote hepatic lipid accumulation as you will see it with many oral steroids.
As a SuppVersity reader you either take creatine or do at least know that its the #1 proven ergogenic your money can buy! What I am pretty sure, though, is that you didnt know yet that creatine will not just make your muscles big, but also your liver clean... clean or rather free of fat.

Non-alcoholic fatty liver disease (NAFLD) has been associated with obesity and decreased insulin sensitivity. A fatty liver is considered the hepatic manifestation of the metabolic syndrome ("Liver Enzymes the #1 Marker of Insulin Resistance!?" | learn more), if creatine would effectively protect the increase in liver fat, which is the hallmark of NAFLD, it could thus eventually make the transition from the fitness community into the mainstream.
You can learn more about creatine at the SuppVersity

Creatine Doubles Ur GainZ!

Creatine, DHT & Broscience

Creatine Better After Workout

ALA + Creatine = Max Uptake?

Creatine lowers cortisol!

Build Ur Own Buffered Creatine
Current data suggests that 20–30% of North Americans have NAFLD, which could progress to more severe liver damage if left untreated. If taking creatine could make them stronger and healthier (remember creatine will also improve your glucose management), the amino acid of which many doctors still believe that it was a dangerous steroid could soon make it onto their prescription lists.

Current clinical treatments for fatty liver are after all limited and so the search for safe and effective therapy is important. In vivo, phosphatidylcholine (PC) synthesis is a major consumer of hepatic methyl groups accounting for approximately 40% of all transmethylation reactions, and is an important determinant of hepatic TG metabolism. Hepatocytes have the highest activity of phosphatidyl-ethanolamineN-methyltransferase (PEMT) and they synthesize a significant portion of PC via the sequential methylation of phosphatidyl-ethanolamine (PE) - a process that relies on the methyl donor betaine which happens to have similar, albeit less pronounced ergogenic effects than cretine (learn more).
Previous rodent studies already suggested "that rats fed a creatine-supplemented high-fat diet have significantly improved glucose tolerance compared to high-fat diet fed control animals. Together these data suggest that dietary creatine influences carbohydrate metabolism as well as lipid metabolism." (da Silva. 2014).
De novo creatine biosynthesis occurs in the liver via the S--adenosylmethionine-dependent methylation of  guanidinoacetate (GAA) and is a major consumer of hepatic methyl groups, estimated to account for 40% of total methylation reactions in the body.

Suggested Read: "Supercharging Creatine With Baking Soda: Study Shows Increased Peak Power and Endurance - Plus: How Bicarbonate Could Help You Lose Fat & Build Muscle" | read more
Dietary creatine supplementation can reduce plasma GAA levels by 90% and therefore reduces demand on hepatic methylation. Previously, Jacobs & da Silva (2013) hypothesized that dietary creatine supplementation may spare AdoMet for PC synthesis, thus protecting the liver from TG accumulation. Dietary creatine supplementation prevented TG accumulation and the lowering of AdoMet in the liver of rats fed a high-fat diet (HFD).

Interestingly, dietary creatine did not alter hepatic PC levels or PEMT activity; therefore, the mechanism(s) through which creatine reduces fatty liver does not appear to be related to AdoMet availability.

In the study at hand, Silva et al. utilized the McArdle RH-7777 (McA) immortalized hepatoma cell line, 0 an established model for the study of hepatic lipid metabolism that does not express PEMT, to assess whether creatine might have a direct action on TG synthesis in liver cells.
Workout advantage!? The increased efflux of triglycerides from the liver will not just keep this vital organ "fat free", it may also be a workout advantage for endurance athletes who could use the liver fat as a substrate to fuel their muscular activity... well, it could if endurance athletes had significant amounts of liver fat. Practically speaking, however, creatine has been found to lead to a significant fall in blood glucose in endurance athletes during a standardized exercise test - albeit not to their disadvantage (Engelhardt. 1998)! A 18% increase in interval performance, is after all something many athletes would kill for.
What they observed were significant increases in PPAR?-activity, as they have previously reported for agents like fish oil. The increase in PPAR?-activity in turn triggered an increase in hepatic fatty acid oxidation and TG secretion and would thus help clear the triglycerides from the liver before they can harm you.
Figure 1: The reduced hepatic lipid accumulation in the cell study at hand is a consequence of (A) reduced
synthesis and (B) increased secretion of triglycerides (da Silva. 2014b)
The data in Figure 1 underline that this effect is mediated by decreases in hepatic lipid synthesis (A) and an increase in lipid efflux in response to being exposed to creatine. Overall, this leads to significantly reduced cellular triglyceride levels (TG; Figure 1, left).

Reduced synthesis, increased efflux, increased oxidation

Similar effects were observed for the hepatic phospholipid (PL) content, which was likewise reduced by (a) a reduced synthesis and (b) an increase efflux of PLs. But (a) and (b) are not the only factors contributing to the healthy lipid depletion.

Figure 2: Increased triglyceride oxidation, yes, increased AMPK & ACC, no (da Silva. 2014b)
As you can see in Figure 2, the provision of extra-creatine will also increase the oxidation of fatty acids (CO2 production is a measure of fatty acid oxidation), without however having similar beneficial effects on the expression of AMPK and its fatty acid oxidating cousin ACC (see Figure 2, right) - thats in contrast to alpha-lipoic acid (learn more) and suggests that the effects are not mediated via the existing anti-oxidant effects of creatine of which youve read in "The Overlooked Non-ROS-Scavenging Antioxidant Effects of Creatine Monohydrate" (learn more)
Bottom line: The study at hand adds weight to the previously formulated hypothesis that creatine supplementation (obviously cheap, but pure creatine monohydrate) is not for muscle-headz, only.

Figure 3: Creatine monohydrate supplementation increases glucose uptake via GLUT-4 receptor expression in immobilized and active human skeletal muscle (Opt Eijnde. 2001)
On the contrary! In conjunction with the previously established anti-oxidant effects and its ability to improve glucose management via increases in AMPK and GLUT-4 (glucose receptor) expression in skeletal muscle cells (see Figure 3), the data from this recent study by scientists from the University of Alberta should eventually shut the critics, who still claim creatine was a "dangerous steroid" or at least a "gateway drug to steroid abuse" up. Unfortunately, something in the back of my head tells me that studies are less convincing to the medical orthodoxy than the glossy product flyers for the latest patentable diabesity and NAFLD drugs | Comment on Facebook!
    References:
    • da Silva, Robin, Karen Kelly, and Rene Jacobs. "Hepatic carbohydrate and lipid metabolism are altered in rats fed creatine-supplemented diets (LB151)." The FASEB Journal 28.1 Supplement (2014a): LB151.
    • da Silva, Robin P., et al. "Creatine reduces hepatic TG accumulation in hepatocytes by stimulating fatty acid oxidation." Biochimica et Biophysica Acta (BBA)-Molecular and Cell Biology of Lipids (2014b). 
    • Engelhardt, Martin, et al. "Creatine supplementation in endurance sports." Medicine and Science in Sports and Exercise 30.7 (1998): 1123-1129.
    • Jacobs, Rene L., Robin da Silva, and Randy Nelson. "Creatine Supplementation may prevent NAFLD by stimulating fatty acid oxidation." The FASEB Journal 27 (2013): 222-2.
    • Opt Eijnde, B., et al. "Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilization." Diabetes 50.1 (2001): 18-23.


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    Wednesday, March 16, 2016

    Block Periodization for Resistance Trainees 3x Higher Strength Gains on the Bench vs Zero Benefits for Legs

    The deadlift probably wont benefit from blocked periodization either... at least if you do it only once a week anyway.
    I hope you all remember my recent article about the beneficial effects of block periodization on the training outcome of trained cyclists (if you dont Id suggest you read up on it: "Block Periodization - Impressive Performance Gains in Pro-Athletes") and the hypothesis that the mechanism behind the beneficial effects Rønnestad et al. report in the corresponding paper are not actually a consequence of this specific periodization scheme. Rather than that, the benefits the researchers have observed may well have been a mere consequences of the "change", of "breaking out of the rut" and the provision of a new challenge thats absolutely essential to induce what everyone, from housewife to Olympian athlete is training for: adaptation.

    Lets discard the mechanism for a moment, though and lets rather focus on the hard facts - hard facts that are complemented by the results of a soon-to-be-published paper by researchers from the University of Bologna and the University of Central Florida.

    Whats so interesting about this paper is ...

    ....that it looks at the effects of block periodization in trained strength athletes and could thus help us answer a question that may have been preying on your mind, ever since I published the previously cited article about the beneficial effects of block periodization in endurance athletes: "Do Different Rules Apply for Strength vs. Endurance Athletes?" Or, put simply: Would a weight lifter benefit to a similar extend from block periodizing his training regimen as a cyclist - irrespective of what the underlying mechanisms may be?
    Figure 1: The subjects trained 4x per week - identical training plans in both groups (Bartolomei. 2014)
    The answer is "yes and no" - Yes, if we are talking about the upper body, no - and thats interesting because cycling obviously involves the same muscle groups - when we are looking at the lower body performance gains in Figure 2:
    Figure 2: Changes in max. strength (1RM in kg), mean power (in % of baseline) and jump height (in cm) in the 24 study particpants in response to traditional linear or block periodization (Bartolomei. 2014)
    As you can see, the gains in lower body power was identical - irrespective of the type of periodization (see overview in Figure 1). For the upper body, on the other hand, the subjects who did not simply ramp up the intensity continuously from 5 sets of 8-10 reps at 65-75% of  1RM  with  less  than  2  minutes  of  recovery  between  sets to 5 sets of 3 - 4 reps at 85 -95% of 1RM with 3 minutes of recovery from week 1 to week 12 (TP group), the ...
    "[p]articipants  in  BP  were  more  likely  (79.8%)  to increase the area under the force-power curve than TP. Participants in BP also demonstrated a likely positive (92.76%) decrease in the load corresponding to maximal power at the bench  press compared to TP group, and a possible improvement (~ 60%) in maximal strength and power in the bench press." (Bartolomei. 2014)
    Whether thats muscle-specific reaction to the three 5-week mesocycles, instead of one 15-week mesocycle is yet highly questionable - or do you think the legs respond less to the periodization program thats depicted in Figure 3, than chest, back, arms & co?
    Figure 3: Illustration of the interplay between intensity and volume of the n=14 24-year-old male, resistance trained (>3 years, >3 sessions per week) subjects in the block periodization group (Bartolomei. 2014)
    Personally, I would rather come back to the "novelty approach". It goes without saying that we can assume that the abrupt changes on a blocked periodization regimen favor "growth promoting overloads". In the case of the musculature of the lower body, the simple fact that it was trained just once a week may yet have provided a similarly "novel" or at least less accustomed stimulus on every leg-day.
    "Periodize Appropriately and Cut 12% Body Fat in 12 Weeks!" | more
    Bottom line: Again, its difficult to tell, whether there is any special magic in block periodization. What can be said, though, is that we can again (see "Block Periodization - Impressive Performance Gains in Pro-Athletes: Revolutionary Training Concept, Or Just a Good Way to Eventually Break Out of the Comfort Zone?" | read more) make an argument for the "breaking out of the rut" hypothesis... in this case, however, in an ostensibly muscle-specific manner thats eventually not "muscle-", but actually "training-frequency-specific".

    In the end, it does not matter, if my ad-hoc explanation is or isnt accurate. For you as a practicioner who is probably training the muscles of his upper body thrice a week, the results of this study are significant - no matter what the underlying mechanisms are. In other words: The results of the A classic HST-oriented training program that is eventually "block periodized" will yield better training results than one, where you train in the same rep ranger 365 days a year. But lets be honest: Thats not surprising, is it?
    References
    • Bartolomei, Sandro, et al. "A Comparison of Traditional And Block Periodized Strength Training Programs in Trained Athletes." Journal of Strength and Conditioning Research (2014). [ahead of print]
    • Rønnestad, B. R., J. Hansen, and S. Ellefsen. "Block periodization of high?intensity aerobic intervals provides superior training effects in trained cyclists." Scand J Med Sci Sports 24 (2014): 34–42.


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    Sunday, March 6, 2016

    Beta Alanine Bicarbonate Synergistic Internal External Muscle H Buffer With Disappointing Real World Benefits

    No matter what this study says, I am pretty sure that the combination of bicarbonate + beta alanine would rule for Tour de France cyclists - at least during the dreaded time-trials.
    In a recent study researchers from the Victoria University and the Queensland University of Technology observed that the combination of the carnonsine pre-cursor beta alanine and sodium bicarbonate will elevate the buffering potential of skeletal muscle in eight apparently healthy, recreationally active men (26.2 ± 1.9 year; 79.8 ± 2.11 kg; 179.0 ± 2.2 cm; VO2peak 51.0 ± 2.5 ml/kg/min) by increasing muscle carnosine and blood bicarbonate levels, respectively.

    So much for the good news, the bad news however is that the performance increases on a repeated sprint test were non-signficant and the expected additive effects of beta alanine and baking soda (sodium bicarbonate) during a 110% cycling capacity test were non-existing.
    You can learn more about beta alanine & bicarbonate at the SuppVersity

    The Hazards of Acidosis

    Build Bigger Legs W/ Bicarbonate

    HIIT it Hard W/ NaCHO3

    BA + Bicarb are Synergists

    Bicarb Buffers Creatine

    Beta Alanine Fails to HIIT Back
    The trial participants were asked to complete 2 exercise tests, over consecutive days, at the end of each of the four co-supplement periods (see fig.  1).
    Figure 1: Design of the study. Each trial consisted of two exercise tests performed over consecutive days. A total of 12 weeks between trials 2 and 3 was implemented to ensure adequate supplement washout time participants randomised to ingest ?-alanine during the initial chronic supplementation. MRS Magnetic resonance spectroscopy, RSA repeated sprint ability test, CCT 110 %cycling capacity test. Solid  arrows depict crossover between acute supplementation (Pl and SB). Dotted arrows depict crossover between chronic supplementation (BAl and Pl; Danaher. 2014)
    During the double-blind supplementation periods, the subjects consumed capsulated ?-alanine (4.8g/day for four weeks, 6.4g/day for two weeks) or the placebo calcium carbonate (CaCO3). To investigate the superimposition of NaHCO3 (baking soda) with ?-alanine, the acute administration of NaHCO3 occurred following each of  the 6-week periods of ?-alanine and placebo supplementation.
    Figure 2: The non-existing increases in peak and average performance with beta alanine and - with the exception of one outlier - bicarbonate supplementation is disappointing; value expressed relative to placebo trial.
    This required two trials of either 300 mg/kg body weight sodium bicarbonate or a not wisely chosen "placebo", i.e. CaCO3 (While I have seen this repeatedly, I am asking myself how smart it really si to use calciumcarbonate as a placebo for a bicarbonate, if the carbonate will form HCO3 as soon as it is cleaved from the calcium ion?) , that was administered only once 90 min prior to the exercise bouts of the respective trials and was split into 6 equal doses over the first 50 min of the 90-min pre-exercise period.
    Figure 3: Time to exhaustion, blood pH values during repeated sprint & cycling capacity @110% test (Danaher. 2014)
    Bottom line: This is not the study to support the usefulness of bicarbonate and beta alanine supplementation for power athletes. It may be a study to support the usefulness of bicarbonate supplementation for Tour de France Trials, but its also another study to show that the ergogenic effects of "buffers" outside of long(er) duration high intensity work like Tour de France time trials may be generally overrated.

    With the study being underpowered, not 100% controlled in terms of the nutritional circumstances of the individual trials and questionable with respect to the use of calcium carbonate as a placebo supplement for sodium bicarbonate and beta alanine, I would be hesitant to discard the use of bicarb and beta alanine and a possible synergy. on the basis of the study at hand, though. Previous studies yielded different results.
    Reference:
    • Danaher, Jessica et al. "The effect of ?-alanine and NaHCO3co-ingestion on buffering capacity and exercise performance with high-intensity exercise in healthy males." Eur J Appl Physiol (2014) 114:1715–1724


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    Thursday, February 18, 2016

    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. Todays 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, shouldnt 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 wont 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 youve 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 dont 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 (OBrien and Rowlands 2011; OBrien, 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; OBrien et al. 2011; OBrien et al. 2013).
    So how much does it take during long(er) 1-2h+ exercise: Youve 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 shouldnt 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 - thats 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.


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