Home / Articles / Q & A / Appetite for Construction - Aug 17 2001

Appetite for Construction
Aug 17 2001

By Dr. John M Berardi, Ph.D.
First published at www.t-mag.com.

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Q: Hey, I like the Biotest Surge product, but should I take it even after a half-ass workout? I mean, if I go to the gym and just work ancillaries, like T-mag wrote about in a recent Short Topic, do I need to improve my recovery? Shouldn't I save my Biotest Surge for those times when I bust butt?

A: Remember, the purpose of the protein hydrolysate/carbohydrate/amino acid post-workout drink I have been writing about is to replenish muscle glycogen, to increase protein synthesis, and to decrease protein breakdown. So I guess my questions to you are: Do your ancillary workouts cause any glycogen depletion and do they significantly tax the muscles enough so that they may alter their protein metabolism?

If the answer to either or both of these questions is yes, then you should take your post workout drink after such workouts. If the answer's no, then a normal meal after the training session will do fine. I don't ever train in a half-assed way, so I take my post workout drink after every workout.
However, if I'm pressed for hard and fast rules on when a good post workout drink is needed, I'd suggest the following:

1. After all cardiovascular workouts that are performed at an intensity of greater than 50% of VO2 max (65% of HR Max), assuming that during exercise a large muscle mass is used and the duration is sufficient to tax that mass.
2. After all high-intensity interval training workouts (sprinting, cycling, etc.).
3. After resistance-training workouts involving a large amount of muscle mass (i.e. chest and back day, leg day, arms and shoulder day, etc.). Forearm days and abdominal days would not qualify.

Personally, I recommend that people do cardio and weights on the same day so that they can activate large amounts of muscle mass and create an ideal environment for post-workout nutrition to stimulate new growth. By increasing the potential for nutrient uptake in this way (i.e. busting butt), your drink will force the body to become more anabolic.

And that, my friends, is what this game is all about.

Q: Lately, some people at my gym keep telling me that honey is the best carbohydrate to take after workouts. I argue that dextrose and maltodextrin are the best. Can you settle this debate for us?

A: Ahh, that's what the honeybees would have you believe. But can't you see that those pesky little critters have a hidden agenda? There are little "news" articles all over the Internet reviewing some recently presented abstracts about supplemental honey taken before and after the workout and making claims that honey is the best pre-workout and post-workout carbohydrate source. However, these little articles have failed to do one thing… tell the whole story. Let's examine the abstracts and see what they have to say.

The following two studies are abstracts taken from the 2000 National Strength and Conditioning Association's yearly conference. Until these abstracts are written up in full paper format and submitted for peer review, we won't know all the details of the studies and will only know what was presented at the conference. Until then I'll treat them as preliminary data and talk about what we do know.

Abstract #1 - Pre-Workout Carbohydrates

Effects of Pre-Exercise Carbohydrate Feedings on Glucose and Insulin Responses During and After Resistance Exercise. Earnest, C. et al. Journal of Strength and Conditioning Research, 2000, 14(3), 259-372.

This study examined the effects of different kinds of carbohydrate gels given PRIOR to a bout of resistance exercise. Subjects were given one of four treatments: a placebo, dextrose, honey, or PowerGel. Measures were collected immediately after, and at times 30, 60, 90, and 120 minutes after training. Blood variables that were measured included glucose, insulin, triglycerides, urea nitrogen, creatinine, and muscle and liver enzymes.

Results:

1. None of the above variables were statistically different between groups. However, a few trends were noted.
2. All three carbohydrate-containing treatments appeared to decrease muscle catabolism.
3. Dextrose supplementation appeared to lead to the largest insulin release and appeared to blunt exercise induced release of muscle and liver enzymes (markers of muscle damage).
4. Honey supplementation appeared to lead to the most prolonged insulin release.

Since this is only an abstract, some important pieces of the puzzle are missing. However, the conclusions appear relatively clear. When taken before exercise, 50g of carbohydrate promotes anti catabolic blood profiles during the post-workout period. While there were no differences between groups, it appears that dextrose may be the winner of this carbohydrate challenge in terms of peak insulin release and anti-catabolic effects.

However, it does appear that honey, with its low glycemic index (GI = 73) vs. that of dextrose (GI = 98), may win on the glycemic index front. The prolonged insulin release is probably due to its slow appearance into the blood (low GI) and this characteristic is certainly of benefit when ingested BEFORE the workout. This way, insulin won't rise too high, which would lead blood sugar levels to crash and cause you to bonk. So, if you want to take in some carbohydrates before the workout, honey may be superior.

But remember, the authors didn't give a post workout drink after training. Subjects had to fast for those 2 hours while blood was drawn. So although carbohydrates taken before training may be good if you don't plan on eating after the workout, a good post-workout drink taken immediately after exercise would certainly show more anabolic and anti-catabolic effects than any treatment in this study.

Abstract #2 - Post-Workout Carbohydrates

Effects of Ingesting Protein With Various Forms of Carbohydrate Following Resistance Exercise on Substrate Availability and Markers of Catabolism. Kreider, R. et al. Journal of Strength and Conditioning Research, 2000, 14(3), 259-372

This study examined the effects of different post-workout nutritional combinations. Subjects performed a resistance training bout and immediately after consumed one of four beverages: a placebo, 40g of whey protein and 120g of sucrose, 40g of whey protein and 120g maltodextrin, or 40g whey protein and 120g of powdered honey. Blood samples were taken at 30, 60, 90, and 120 minutes after supplementation and analyzed for substrates, hormones, and markers of muscle damage/catabolism.

Results:

1. The honey group had the largest glucose area under the curve (i.e. the carbs from the honey drink stuck around in the blood for longer than the carbs from the other drinks).
2. There were no differences between carbohydrate groups for insulin release.
3. Testosterone and cortisol levels decreased after exercise in all groups.
4. The T:C ratio was more favorable in the honey and maltodextrin groups than in the sucrose and placebo groups.

Since all the current literature is clear on the fact that a protein plus carbohydrate beverage makes for the best post-workout option, the next step is to determine the optimal types of protein and carbohydrate. In this study it appears that honey and maltodextrin are good carbohydrate choices (when taken with protein) for a favorable hormonal profile after training. There were no differences between the honey and maltodextrin groups but they were both better than sucrose and water.

However, since the goal of optimal post-workout nutrition is to drive amino acids and carbohydrates quickly into the muscle (and, incidentally, out of the blood), maltodextrin appears superior to honey. Since maltodextrin is more rapidly cleared from the blood (GI = 105) and the honey isn't cleared as rapidly, maltodextrin may be better at replenishing muscle glycogen, a necessary component of recovery.

Taken together, I believe that if you eat carbohydrates prior to working out, any low GI carbohydrate source like honey is a good choice but there's probably nothing magical about honey. However, after the workout, it appears that high GI carbohydrates like dextrose, maltodextrin-or a combination of the two-might be far better carbohydrate sources in terms of peak insulin release, maximum anti-catabolic effects, favorable Testosterone to cortisol ratio, and muscle glycogen replenishment.

Why then have the results of these studies been slanted in order to say that honey is best? Well, that's because those doing the slanting are affiliated with the National Honey Board, the organization that funded the research studies listed above. Again, honey is a good moderate GI carbohydrate source but it's probably not much better than many others. Trouble is, during the post-workout period, it may be worse than many others.

I hope the bees don't get mad at me for dissin' on their honey!

Q: When I read the back of the label of Biotest Surge, it looks like there are only a few measley grams of glutamine and BCAAs! Heck, my protein powder provides more than this. What gives?

A: This is an issue many people are confused about, but the answer is simple. The label lists the ADDITIONAL amino acids that have been ADDED to those already present in the special whey protein hydrolysate mix we chose for this forumla. So basically, although the label lists 3 grams of L-Glutamine, 3g of Phenylalanine, 2.25g of L-Leucine, 1.75g of L-Valine, and 1.25g of L-IsoLeucine, there are much more of each amino acid in each serving. In fact, the total content of these 5 amino acids amounts to greater than 25 total grams of amino acids!

Now, we couldn't give you the exact totals of each amino acid, could we? This would mean giving away the research-tested ratios of BCAA and glutamine that have proven so effective in several studies.

For you savvy rival supplement manufacturers who think you can look at the amino acid content of regular whey protein hydrolysates to come up with the exact totals, think again. The amino acid content of different whey hydrolysates can vary by several percentage points, so while you may be able to get close to our formula, you won't know the exact formula unless you break into Tim Patterson's office and steal it!

Q: While I've been using Biotest Surge and have been getting great results with it, I keep hearing that drinking carbohydrates after workouts may not be so great after all. Some experts recommend products that contain amino acids only and no carbohydrates. Which is better: A carbohydrate, hydrolyzed protein, and amino acid blend like Biotest Surge or a product containing only amino acids?

A: Let me first say this. Every "nutrition expert" with a product to sell will obviously be biased toward his or her product. And I'm no exception. So, since I developed Biotest Surge, obviously I'm about to tell you why it's far better than anything else out there on the market.

However, even though I do have financial interests in its success, my bias doesn't mean that I can't be objective about its value. And just because I'm biased toward Biotest Surge doesn't mean that I'm just trying to scam a few bucks out of you.

Truth be told, I'm biased toward the product for several good reasons. These reasons include; the fact that Biotest Surge is a product designed in agreement with the majority of the published literature on post workout nutrition and recovery in healthy humans; the fact that it's stood up to rigorous academic testing; and the fact that Surge is working for every athlete that's used it properly. For a complete review of the literature in support of Surge, I encourage you to check out my Solving the Post Workout Puzzle articles (Part 1 and Part 2) and my Recovery Update article.

Now that you have the theory behind Surge, let's discuss the MAJOR flaws associated with products that provide only free form amino acids during the post-workout period. Let's also address the flaws associated with their marketing claims.

I'll start by listing a truth, followed by a defense of that truth and how it disproves the claims of the "amino-only" school of thought:

Truth #1: Carbohydrates and Insulin Must Be Present to Prevent a Big Glucagon Release.

A lot has been said about the hormone insulin, but there hasn't been much discussion of it's antagonistic hormone, glucagon. While insulin stimulates glucose storage and protein synthesis while inhibiting protein breakdown, glucagon causes glucose release from tissues as well as causes protein breakdown. In fact, one of the biggest functions of glucagon is to convert potentially muscle-building amino acids into glucose well before they ever get to the peripheral blood circulation and the muscle.

If you hope to understand nutrition, you must understand that just like in drug metabolism, the liver is the first organ through which most macronutrients must pass. In this way, the liver functions as the "gate-keeper" that decides which macronutrients get to pass by into peripheral circulation. It also decides which ones get broken down and excreted or stored in its own tissues.

When glucagon levels in the blood are high, the liver does a fine job of destroying many of the ingested amino acids that it's presented with by converting them into glucose through a process called gluconeogenesis. This is not a good thing if you want those amino acids to get to the muscle. Interestingly the BCAAs are not subject to this liver (hepatic) destruction, but many other amino acids are (3).

Unfortunately, when ingesting a protein meal, a meal high in peptides, or a meal high in individual amino acids (both single amino acids and amino acid blends), the glucagon release is very large (1-4; 6-11). And with this glucagon surge, you can bet the liver will do a number on most of those amino acids by converting them into glucose or some other substrate that doesn't build muscle.

However, when carbohydrates are added to a high protein, high peptide, or high amino acid meal/drink, the resulting insulin response is much larger than that seen with the protein/peptides/amino acids alone. And since insulin tends to blunt the glucagon response to a protein/peptide/amino acid meal, it translates to great news for muscle building and recovery (5). Now, with the inclusion of insulin releasing carbohydrates, the amino acids in the drink will now actually reach the muscle as amino acids!

It makes sense because if you're giving the body glucose, it'll recognize that it won't have to make any of its own by destroying your amino acids.
Well, why would a so-called expert make a product that will in part be destroyed by the liver? I don't know. But one thing you have to understand is that many "experts" use data from I.V. infusion studies (into the peripheral blood stream) to support their claims that individual amino acids promote muscle protein synthesis or prevent muscle protein breakdown in the absence of carbohydrates. This is all good and fine, but with I.V. infusions you don't have to worry about the amino acids being destroyed in the liver. When consuming them orally, you surely do.

And the only way to get the majority of those oral amino acids into the peripheral blood stream is to consume them with carbohydrates. End of story.

Truth #2: Mimicking the Amino Acid Composition of the Muscle is Useless

For the same reasons described above, any attempt to create an oral supplement that contains a "precision" amino acid blend that mimics the composition of muscle is just silly. And that's what some people are trying to do.

But what's wrong with trying to mimic muscle composition? Well, although the blend may have the same amino acids as the muscle when it's in its little bottle-and while this composition may even remain intact in the stomach-once a supplement like this goes through the liver, you know what's gonna happen if there are no carbohydrates present.

Yep, that's right. Glucagon gets kickin' and some amino acids are gonna' be metabolized and removed; some are gonna be converted to glucose; and others are gonna be subject to delayed entry into peripheral circulation. So by the time this supplement gets to the peripheral bloodstream, it's going to look significantly different than muscle protein, that's for sure.

But what if this destruction can be predicted and the ratios optimized so that AFTER the liver does its nasty work, the composition is ideal? Well, I've thought about it and researched this, too. And unfortunately, this can't be predicted.

According to several studies, the eventual blood amino acid concentration in peripheral circulation CANNOT be predicted from the composition of the ingested amino acid blend (12). Factors regulating what happens to the amino acids include liver function, energy and nutrient status of the liver, habitual diet, and dozens of others. So there's absolutely no way to design an oral amino acid supplement that will deliver amino acids to the muscle in the exact proportions of amino acids that the muscle contains. Only an I.V. can accomplish this. Also, you can get close if the blend is combined with sufficient carbohydrates.

So why doesn't Biotest Surge contain such an "exact blend" along with the carbohydrates? Well, there's not one single shred of evidence telling us that this would be any better than any other amino acid blend containing all the essential amino acids! And since the cost of such a blend is DAMN expensive, do you want to pay double the money for the same results? I sure don't!

Truth #3: Carbohydrates DO NOT "Steal" Blood From the Muscle

While some "experts" are trying to make you believe that eating macronutrients like carbohydrates and protein after the workout will take blood away from the muscle, this is an unfounded argument.

First of all, there have been a few studies in pigs and dogs (13,15) showing that a large food meal consumed before exercise may cause a small amount of blood flow to be drawn toward the GI (gastrointestinal tract) during exercise, thereby reducing muscle blood flow to a SMALL extent (20% or so). I say small because muscle blood flow increases by 2000% during exercise so that a 20% decrease sure won't make a whole lot of difference.

But even though these animal models show decreased muscle blood flow, these findings haven't been duplicated in more rigorously controlled human studies. In the human studies, the ingestion of a meal hasn't been shown to reduce muscle blood flow at all (14,16).

Remember, during and immediately after exercise, cardiac output of blood is dramatically increased and blood is preferentially shunted to the muscle as follows:

So, in looking at the graph, I want you to notice that during and immediately after exercise, the muscle is getting 21X the blood delivered per minute than it did at rest, while the gastrointestinal (GI) tract is getting over 2X the blood vs. rest. Since the GI gets enough blood flow at rest to digest your food pretty well, and exercise doubles your blood flow to the GI, why would those very easily digestible carbohydrates (glucose and maltodextrin) in Biotest Surge require even MORE blood flow to the stomach? They probably don't!

And even if there is a small amount of blood shipped from the muscle toward the GI with carbohydrate ingestion (as seen in some animal models but not in human models), muscle blood flow is certainly NOT the limiting factor in recovery.

Come on now; think about it. We're talking about the stimulation of protein synthesis and the prevention of breakdown via the delivery of nutrients. And both the stimulation of protein synthesis and the prevention of protein breakdown can be accomplished with feeding at rest with normal blood flow to the muscle and increased blood flow to the stomach! So certainly after exercise, there's enough blood to go around.

To put it into perspective, think about this. Every endurance and anaerobic athlete on the face of the earth is encouraged to drink carbohydrate drinks during exercise in order to delay fatigue during exercise. Well, if carbohydrates really took enough blood away from the muscle, any decrease in blood flow to the muscles would IMMEDIATELY decrease performance. This would happen because in decreasing blood flow, oxygen delivery would be decreased.

So if carbohydrate drinks were to "steal" blood from the muscle, then wouldn't you think that millions of endurances athletes, coaches, and nutritionists would have figured this out by now? Since carbohydrate drinks INCREASE performance, if there's any "drawing of blood" from the muscle to the gut, it's inconsequential.

But if you're still hung up on the muscle blood flow thing, think about this one. Not only does a carbohydrate-induced insulin response immediately after training act to prevent protein breakdown, stimulate protein and glycogen synthesis, prevent rises in glucagon, prevent the conversion of amino acids to carbohydrates, and blunt the effects of cortisol; it actually increases skeletal muscle blood flow (16, 17)!

So if you REALLY want every last drop of that extra blood flow (which I don't think is necessary anyway), an insulin producing carbohydrate drink won't prevent it but will STIMULATE it.

Truth #4: Testosterone and GH release are not significantly blunted with carbohydrate ingestion.

Rather than rehash my position, I'll just urge you to read or reread my Recovery Update article.

I hope this little point by point review clears up why I not only believe the addition of carbohydrates to a post workout drink is beneficial, but why I believe that amino acid-only post workout supplements are relatively ineffective when compared to sound post workout nutritional supplements containing rapidly digesting whey protein hydrolysates, carbohydrates, and insulin stimulating amino acids.

References

1. Metabolism 1977 Oct;26(10):1131-4 Elevation of plasma glucose and glucagon after tryptophan ingestion in man. Hedo JA, Villanueva ML, Marco J.
2. Horm Res 1995;44(3):101-4 Protein content of the evening meal and nocturnal plasma glucose regulation in type-I diabetic subjects. Winiger G, Keller U, Laager R, Girard J, Berger W.
3. Metabolism 1988 May;37(5):405-10 Effects of branched-chain amino acids on postprandial 3-OH butyrate and glucagon in the baboon. Stewart JK, Koerker DJ, Goodner CJ.
4. Endocrinol Jpn 1987 Oct;34(5):745-53 Postprandial glucose, insulin and glucagon responses to meals with different nutrient compositions in non-insulin-dependent diabetes mellitus. Kawai K, Murayama Y, Okuda Y, Yamashita K.
5. Metabolism 1979 May;28(5):568-74. Effects of insulin on the response of immunoreactive glucagon to an intravenous glucose load in human diabetes. Yamamoto T, Raskin P, Aydin I, Unger R.
6. Am J Physiol 1979 Jan;236(1):E20-7. Increased glucagon secretion in protein-fed rats: lack of relationship to plasma amino acids. Eisenstein AB, Strack I, Gallo-Torres H, Georgiadis A, Miller ON.
7. J Clin Endocrinol Metab 1975 Mar;40(3):418-25 Effect of alanine and glycine on glucagon secretion in postabsorptive and fasting obese man. Muller WA, Aoki TT, Cahill GF Jr.
8. J Clin Invest 1996 Jul 1;98(1):90-9 Evidence for a catabolic role of glucagon during an amino acid load.Charlton MR, Adey DB, Nair KS.
9. Am J Clin Nutr 1986 Dec;44(6):847-56 The effect of protein ingestion on the metabolic response to oral glucose in normal individuals. Krezowski PA, Nuttall FQ, Gannon MC, Bartosh NH
10. Metabolism 1983 Jun;32(6):558-67 The effect of ingestion of meat on hepatic extraction of insulin and glucagon and hepatic glucose output in conscious dogs. Ishida T, Chou J, Lewis RM, Hartley CJ, Entman M, Field JB.
11. Acta Diabetol Lat 1981 Apr-Jun;18(2):173-9 Previous exposure to glucose enhances insulin and suppresses glucagon responses to arginine in man. Adamson U, Grill V, Efendic S.
12. Am J Physiol 1982 Jul;243(1):R99-103 Prediction of plasma amino acid concentration from diet amino acid content. Johnson DJ, Anderson GH.
13. Dig Surg 1998;15(6):665-8Effect of moderate exercise on blood flow in the gastrointestinal tract in trained conscious miniature swine. Mortensen FV, Bayat M, Friis-Andersen H, Jespersen SM, Hoy K, Christensen KO, Lindblad BE, Hansen ES.
14. Clin Sci (Colch) 1994 Feb;86(2):169-75. Forearm substrate utilization during exercise after a meal containing both fat and carbohydrate. Griffiths AJ, Humphreys SM, Clark ML, Frayn KN.
15. Metabolism 1999 Feb;48(2):161-6. Effect of amino acids and glucose on exercise-induced gut and skeletal muscle proteolysis in dogs. Hamada K, Matsumoto K, Okamura K, Doi T, Minehira K, Shimizu S.
16. Hardin DS, Azzarelli B, Edwards J, Wigglesworth J, Maianu L, Brechtel G, Johnson A, Baron A, Garvey WT. Mechanisms of enhanced insulin sensitivity in endurance-trained athletes: effects on blood flow and differential expression of GLUT 4 in skeletal muscles. J Clin Endocrinol Metab. 1995 Aug;80(8):2437-46.
17. Birkeland KI, Hanssen KF, Stranden E, Falch JA, Vaaler S.Insulin-mediated increase in calf blood flow is not related to blood pressure levels in patients with type 2 diabetes mellitus. Blood Press. 1995 Mar;4(2):80-4.