Those of you familiar with my writings are well aware of the fact that I am strongly in support of intelligent training methods. In this article, I give this advocacy a unique twist and discuss whether it is possible to train for intelligence. Research has shown that a person's cognitive capacity may remain acute far into advanced age, if practiced throughout life. In a sense, this result suggests that a person's “mental fitness” improves with training. And since, nutritional supplements plays a big role in modern athletics, this issue also begs the question whether nutritional supplementation may also help maintain mental fitness. In this respect, a pivotal study recently appeared in the scientific press that examined the effects of creatine supplementation on human intelligence (1). This study might change the way you think...
Brain Energetics
As for any activity we undertake, thought requires energy-or should, in any case. In fact, thinking takes lots of energy. On a per weight basis, the brain is one of the body's highest energy consumers. Although representing only 2% of our total body mass, the brain consumes nearly one quarter of our entire energy resources. The disproportionate amount of energy consumed by our brains is reflected by the fact that the head is generally warmer than the body core temperature; this gives an entire new meaning to the phrase “hot head”, doesn't it.
Any thought we abstract, any sensation we perceive, or any action we initiate, is encoded by electrical impulses that literally flow throughout our nervous systems. However, unlike the electrical currents that flow through the wires in our homes and that are carried by negatively charged electrons (a part of an atom), the electrical impulses that propagate through our nerve cells, or neurons, are largely mediated by positively charged atoms that, interestingly enough, lack electrons. Such charged atoms are known as ions, nothing more than atoms with an incomplete number of electrons in their outer shell. Electrical currents (carried by positive ions) literally flow through our neurons relaying information from brain to target, and back again.
A neuronal impulse is initiated with the flow of positively charged sodium ions into a neuron. This influx of sodium ions causes a localized accumulation of positive charges near their point of entry at the neuronal membrane. To relieve this buildup of positive charges, potassium ions (also positively charged) respond by flowing outward, since like charges repel each other. This instantaneous switch in ionic polarity can be likened to a spark that rapidly spreads along the entire length of the nerve cell. Obviously, this situation cannot continue forever, otherwise all of the sodium ions would end up on the inside the neuron and all the potassium ions on the outside. Indeed, after a flurry of electrical activity the relative distribution of sodium and potassium (near the membrane) nearly reverses. In order for brain activity to continue, therefore, these ions need to be actively placed back onto their appropriate sides of the membrane. This process is energetically very expensive.
The molecular pumps that are responsible for situating sodium and potassium back to their respective sides of the neuronal membrane are called ATPases; obviously, since they rely on ATP to function. In fact, maintaining these pumps active is the greatest sink of energy in the brain. As in muscle, however, ATP is often limiting. Also analogous to the muscular situation is the fact that phosphocreatine (PCr) is what assures a steady supply of ATP to the cell. PCr thus keeps these ATPases pumping sodium and potassium back into their respective compartments, thereby allowing continual neuronal activity. Figuratively speaking, phosphocreatine keeps us thinking.
So, what does this have to do with creatine?
Recall that PCr is the energized form of creatine that is present within the cell. When we supplement with creatine, what we are in actuality doing is increasing the PCr content of the cell. Therefore, at least in theory, creatine supplementation should influence how well we think under pressure. Food for thought, so to speak. One recent study, furthermore, showed that mice deficient in the enzyme that creates PCr from creatine, creatine kinase, are slower at learning a water maze (2). In other words, the mice with lower levels of PCr erred more often and generally spent more time in the water. The stage was thus set for human studies...
Does creatine supplementation influence mental acuity in humans?
This was the question asked by a recent study conducted at the Universities of Sydney and Macquarie, Australia.
Study Design:
The study examined the effect of creatine supplementation (5 grams/day for six weeks) on the ability to perform two cognitive tests, the Raven's Advanced Progressive Matrices (RAPMs) and Weschler Auditory Backward Digit Span (BDS). These tasks are designed to test non-verbal intelligence (IQ) and verbal memory capacity (short-term memory), respectively.
The authors of the study also chose 45 vegetarians and vegans as experimental subjects. This group of individuals was specifically chosen since their dietary intake of creatine, which was negligible, would not interfere with the amount of creatine administered during the course of the study.
This study consisted of a placebo-controlled, cross-over design. This simply means that each subject served as his own control scenario. Subjects either took creatine or placebo (maltodextrin) for six weeks before performing one of the mental tests (week 6). They then washed out for another six weeks in order that their creatine levels should return to baseline (week 12). Supplementation then commenced anew (six more weeks) using the opposite supplementing condition. During the 18th week they then repeated the same test under the influence of the second supplementing condition. The entire cycle repeated after a washout of another six weeks with the other mental task. Therefore, each subject took each test twice, once under the influence of creatine and once under the influence of placebo.
Study Results:
Subjects who were administered creatine exhibited improved short-term memory and were also better able to problem solve under pressure of time. Specifically, the creatine group was better able to repeat back long sequences of numbers from memory (BDS). Creatine subjects were on average able to repeat back 1-2 more integers than placebo counterparts. Their general IQ scores were also higher than the placebo group (RAPMs). Quoting directly from the manuscript: "Supplementation with creatine significantly increased intelligence compared with placebo".
Take Home:
So, should you take a teaspoon of creatine before your next all-nighter? Although "thought provoking", it's still too early to say. Not all thought processes are alike. This study does seem to suggest, however, that creatine may help with complicated computational tasks.
Who knows, in the future taking a swig of creatine before a cram session may be an accepted practice among university students.
Scientific References
1. Rae, C., Digney, A .L., McEwan, S.R. & Bates, T.C. (September 2003) Oral creatine monohydrate supplementation improves cognitive performance; a placebo-controlled, double-blind cross-over trial. Proceedings of the Royal Society of London - Biological Sciences . Volume 270(1529): pages 2147-2150.
2. Jost, C. R., Van Der Zee C. E., In't Zandt H. J., Oerlemans F., Verheij M., Streijger F., Fransen J., Heerschap A., Cools A. R. & Wieringa B. (May 2002) Creatine kinase B-driven energy transfer in the brain is important for habituation and spatial learning behaviour, mossy fibre field size and determination of seizure susceptibility. European Journal Neuroscience Volume 15 (10): pages 1692-706.
This article was written by Dr. Alfredo Franco-Obregón, research scientist, author, and owner of Nutritional Supplements Newsletters .
Dr. Alfredo Franco-Obregón has had over 20 years of in depth research experience in major laboratories world-wide. His principal scientific interest is the understanding of the cellular mechanisms leading to muscle cell death.
Dr. Franco-Obregón is also the author of Creatine: A practical guide . Click here for more information about the guide.
The Creatine-Insulin Dilemma
by Alfredo Franco-Obregón, PhD
Creatine is, by no means, new to this world. Creatine is, and always has been, a natural constituent of skeletal muscle. Humankind si smply needed to be made aware of its existence. Amazingly, creatine was first identified nearly two centuries ago! In the early 1800s, the French scientist and philosopher, Michel-Eugène Chevreul, isolated a novel agent from skeletal muscle that he later named creatine for kreas , the Greek word for flesh (1). A few years later (1847), a German scientist named Justus von Liebig observed that maintaining foxes in captivity decreased their muscular creatine content (2). Postulating that physical activity increases creatine uptake by skeletal muscle, Liebig advanced the hypothesis that muscles utilize certain nitrogen containing molecules for energy. These nitrogenous molecules, otherwise known as amino acids, include creatine. Intriguingly, as an extension of his findings, Liebig later lent his name to a commercial extract of meat, which he asserted would help the body perform extra "work". In fact, " Liebig's Fleisch Extrakt " could quite reasonably be considered the original creatine supplement (complete with marketing plan). Near the turn of the last century the first studies examining the effects of creatine feeding were conducted where it was noticed that not all the creatine fed to animals could be recovered in the urine. Soon afterwards, Otto Folin and W. Dennis (1912-1914) of Harvard University (Boston) unequivocally corroborated by that the body's musculature retains the greater part of any ingested creatine. Therefore, nearly one century ago scientists had already come full circle, from discovering that skeletal muscle is the richest natural source of creatine to the largest sink for dietary creatine in the body. Nevertheless, up to quite recently, the manner in which to best promote creatine absorption by skeletal muscle remained largely elusive. In this respect, a huge leap forward was made with the finding that insulin assists in the absorption of creatine into skeletal muscle. And, although this effect was previously hinted at in animal studies, the studies that first clearly showed this effect in humans were conducted only a few years ago (3,4). These human studies used glucose to stimulate the production of insulin, the same agent used by the body for this same purpose.
Following a meal our blood glucose levels rise, which then serves as the signal for the release of insulin from the pancreas. Insulin, in turn, enables the cells of our body to take up nutrients, principally glucose, but also amino acids, from the blood stream. Creatine, due to its structural likeness to amino acids, is also transported into the cell with the assistance of insulin, although via a different transport pathway. In this respect, insulin sets the stage for muscle growth (aka, anabolism) by making available to the cell the basic substrates for the production of new muscle tissues. The problem with the original studies examining insulin-mediated creatine uptake in humans, however, was that the amounts of glucose required to evoke a strong enough release of insulin were exorbitant; nearly 20 grams of glucose for each gram of creatine consumed and close to the limit of palatability for most individuals. Furthermore, this amount of glucose, if consumed on a regular basis, could lead to a state of insulin-resistance, which is the path to the development of type II diabetes. In other words, cells become immune to the presence of insulin if constantly bombarded by it, which, in turn, diminishes the uptake of essential nutrients into muscle cells and increases the need for insulin to stimulate muscle growth. Furthermore, since fats cells are the last to become resistant to the effects of insulin, the initial stages of insulin-resistance causes our fat reserves to swell and our muscle mass to shrivel up. Therefore, although these results were promising, they were far from being a complete solution. Since then, there has been a search for agents that might effectively release insulin into the blood stream (for the purpose of creatine adsorption) without adversely influencing insulin-sensitivity. Many creatine manufacturers have consequently taken to adding a variety of insulin-agonists to their products in hopes of getting around the insulin-dilemma. These “insulinotropic” strategies are aimed at either enhancing the release of insulin from the pancreas or augmenting the effects of upon the cell in order to increase transport rates of creatine into skeletal muscle. The agents often used for this purpose include chromium picolinate, alpha-lipoic acid, 4-hydroxyisoleucine, and the amino acids, taurine, L-arginine, NO-releasers, and L-carnitine. These days it is quite common to find one, or more, of these agents in many creatine products. Unfortunately, with the exception of alpha-lipoic acid (5), none of these agents have been specifically shown in scientific studies to potentiate the uptake of creatine into the cell. This in time may come, but for the moment, it's still too early to say whether these other agents actually promote creatine absorption by muscle cells.
There's a safer, and much more reliable, method of promoting insulin release that has been overlooked by many creatine manufacturers. Ignored, in fact, simply because it isn't sexy enough to appear innovative and, consequently, will not serve to jack up the price of the product; the agenda of most creatine manufacturers. By now, the ability of glucose to release insulin is without dispute. Ten years ago, however, a study showed that protein greatly potentiates the ability of glucose to release insulin into the blood stream from the pancreas (6). The effect of protein was so powerful that half the amount of carbohydrates could be used to elicit the same amount of insulin release. What remained to be shown was whether the combination of carbohydrates and protein is equally as effective at promoting creatine absorption by skeletal muscle. This awaited study finally appeared in 2000 and showed that protein in combination with simple carbohydrates augments creatine absorption by skeletal muscle to a similar extent as high doses of carbohydrates (7). In this study experimental subjects were given one of four different supplement combinations 30 minutes after ingesting creatine, 5 grams of glucose ( placebo ), 50 grams of protein and 47 grams of glucose ( PRO-CHO ), 96 grams of glucose ( Hi-CHO ), or 50 grams of glucose ( Lo-CHO ). The results were clear, PRO-CHO and Hi-CHO were equally effective at promoting creatine absorption, which were both greater (~10-25%) than either Lo-CHO and placebo . Again, adding protein reduced the glucose requirement by half!
Another advantage of adding glucose to your creatine is that it aids in the replenishment of your glycogen reserves following exercise. This effect arises from the ability of insulin's to increase the number of glucose transporters (GLUT 4) expressed on the cell surface. GLUT 4 is the principal protein complex responsible for transporting glucose into the cell once stimulated by insulin. And, since exercise makes the cells of our body more sensitive to the effects of insulin, exercise likewise increases the _expression of GLUT 4. On the other hand, inactivity, either by choice or because of injury, reduces GLUT 4 _expression. Along these lines, a recent study has shown that creatine protects against the loss of GLUT 4 during limb immobilization and, furthermore, accentuates the increased _expression of GLUT 4 during subsequent rehabilitation (8). Not surprisingly, the creatine and glucose treated subjects exhibited larger muscle glycogen (and creatine) reserves during rehabilitation. Finally, a new study just appeared indicating that protein exerts a similar effect on GLUT 4 _expression, but without adversely affecting insulin-sensitivity (9). Specifically, this study compared the effects of creatine supplementation with glucose or glucose plus protein during the rehabilitation of a previously immobilized limb. The authors of this study found that retraining (6 weeks) a previously immobilized limb (2 weeks placed in a cast) in conjunction with a post-exercise creatine, protein and glucose meal increased GLUT 4 _expression and muscle glycogen content to the same extent as a creatine and glucose meal. Most importantly, since the protein meal contained less than one third the amount of glucose (20 grams versus 70 grams!), insulin sensitivity was improved as a result. Furthermore, the effect on glycogen storage was specific for the exercised limb. That is, the un-exercised limb exhibited no change in GLUT 4 _expression or muscle glycogen content. This result clearly indicates that simply upplementing with creatine, irrespective of the manner in which it is done, in the absence of exercise is a fruitless endeavor. The solution seems clear. Adding protein to your creatine and carbohydrate mix will promote muscle creatine uptake (and glycogen synthesis) WITHOUT adversely affecting the sensitivity of your cells to insulin.
Author's Note: Due to space constraints, other very important anabolic benefits of combining protein and creatine were not covered in this article. These other anabolic attributes, and how to best make use of them, are discussed in my creatine guide. Click here for more information about the guide.
Scientific References
1. Chevreul, X. (1835) Sur la composition chimique du bouillon de viandes. J. Pharm. Sci. Accessoires Volume 21: pages 231-242.
2. Balsom, P. D., Soderlund, K. and Ekblom, B. (1994) Creatine in humans with special reference to creatine supplementation. Sports Medicine Volume 18: pages 268-280.
3. Green, A. L., Simpson, E. J., Littlewood, J. J., MacDonald, I. A., and Greenhaff, P. L. (1996). Carbohydrate ingestion augments creatine retention during creatine feedings in humans. Acta Physiol Scand Volume 158: pages 195-202.
4. Steenge, G. R., Lambourne, J., Casey, A., MacDonald, I. A., and Greenhaff, P. L. (1998). Stimulatory effect of insulin on creatine accumulation in human skeletal muscle. American Journal of Physiology Volume 275: pages E-974-E979.
5. Burke, D. G. Chilibeck P. D., Parise G., Tarnopolsky M. A., and Candow D. G., (2003). Effect of alpha-lipoic acid combined with creatine monohydrate on human skeletal muscle creatine and phosphagen concentration. International Journal of Sports Nutrition and Exercise Metabolism Volume 13(3): pages 294-302.
6. Chandler, R. M., Byrne, H. K., Patterson, J. G., and Ivy, J. L. (1994). Dietary supplements affect the anabolic hormones after weight-training exercise. Journal of Applied Physiology Volume 76(2): pages 839-845.
7. Steenge, G. R., Simpson, J., and Greenhaff, P. L. (2000). Protein- and carbohydrate-induced augmentation of whole body creatine retention in humans. Journal of Applied Physiology Volume 89: pages 1165-1171.
8. Op't Eijnde, B., Urso, B., Richter, E. A., Greenhaff, P. L., and Hespel, P. (2001). Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilization. Diabetes Volume 50: pages 18-23.
9. Derave, W. Op't Eijnde, B., Verbessem, P., Ramaekers, M., Van Leemputte, M. Richter, E. A., and Hespel, P. (2003). Combined creatine and protein supplementation in conjunction with resistance training promotes muscle GLUT-4 content and glucose tolerance in humans. Journal of Applied Physiology Volume 94: pages 1910–1916.
This article was written by Dr. Alfredo Franco-Obregón, research scientist, author, and owner of Nutritional Supplements Newsletters .
Dr. Alfredo Franco-Obregón has had over 20 years of in depth research experience in major laboratories world-wide. His principal scientific interest is the understanding of the cellular mechanisms leading to muscle cell death.
Dr. Franco-Obregón is also the author of Creatine: A practical guide . Click here for more information about the guide.
Creatine: The Next Great Antioxidant?
by Alfredo Franco-Obregón, PhD
Muscle damage is a natural consequence of exercise. A small amount of muscle damage is not a terrible thing and, in fact, is necessary to stimulate new muscle growth. If, on the other hand, the amount of damage you inflict upon your muscles with exercise exceeds their capacity to repair and rebuild, then you're in big trouble. You then have a scenario of net muscle breakdown, otherwise known as catabolism. Situating yourself in a catabolic holding pattern by continually overdoing it in the weight room will eventually lead to overall loses in muscle mass and diminished athletic performance. This article focuses one aspect of overtraining and how to minimize its effects.
Two principal forms of muscle damage arise from physical exertion:
The first is mechanical and occurs immediately. In response to the physical stress of exercise, your muscles and associated capillary beds become slightly damaged. These microscopic foci of damage may then prime a robust phase of increased micro-vascularization and new muscle growth (aka, anabolism). That is, conditions permitting, capillary beds will reform to increase blood flow and new muscle tissue will be laid down to replace damaged tissue. The end result, increased blood flow to larger, more efficiently, working muscles. If, on the other hand, the initial amount of damage is too great or insufficient time is given for your muscles to fully recover from the insult, you will lose strength and mass!
The second form of muscle damage is a downstream consequence of the first and is, in actuality, the initiation of the rebuilding process discussed previously. This form of muscle damage results from reactive molecular species produced in response to strenuous exercise, but that exert their degenerative effects a few days later.
Rising from the ashes …
Following the initial insult of exercise, damaged muscle tissue must be cleared away before rebuilding can commence. This process begins with the leakage of chemical agents from damaged cells that attract specialized cells known as phagocytes (neutrophils and macrophages) to sites of damage. Here, phagocytes accumulate, greatly increase in number, and build an appetite. Next, commences a voracious phase of cell eating, otherwise known as phagocytosis (hence, their name), whereby damaged muscle tissue is literally eaten away. The process of phagocytosis is initiated with the release of agents from macrophages that serve to breakdown, or digest, damaged cells in preparation for absorption. Following the removal of all dead tissue, the stage is then set for new muscle growth. New muscle is formed from the fusion of hundreds of progenitor cells that were previously laying dormant waiting for the appropriate signal to act. From start to finish, this entire process takes about 3-4 days.
Free Radicals
To assist in their removal of dead tissue phagocytes release digestive enzymes, toxins, and, most importantly, R eactive O xygen S pecies, or ROS , for short. ROS are produced in the burst of metabolic activity known as a " respiratory burst ". One of the most powerful of ROS produced by phagocytes is the Superoxide Radical . Superoxide greatly weakens the integrity of the muscle membrane causing small tears that allow calcium ions to leak into the muscle cell. It is a rise in intramuscular calcium that activates a class of enzyme known as proteases that cause the muscle cell to disintegrate. Obviously, a small amount of superoxide plays an essential role in the absorption of damaged cells. On the other hand, overproduction of superoxide surpasses its usefulness and can actually be counterproductive as its destructive capacity becomes unleashed without warrant..
Oxidative stress
Exercise also directly produces ROS. That is, independently of neutrophils and macrophages. Normally, most of the oxygen consumed during cell metabolism is converted into water. A small amount of the consumed oxygen (2-4%), however, is converted into superoxide. Given the fact that exercise can increase muscle oxygen consumption by as much as 200-fold, superoxide levels also increase tremendously with intense exercise, easily surpassing the body's capacity to neutralize it. This gives rise to a dangerous scenario known as oxidative stress, which slows muscle recovery and increases the chances of injury. In fact, some experts believe that the overproduction of ROS may also accelerate the normal aging process as well as eventually lead to states of disease.
Antioxidants
Our bodies possess a natural line of defense against oxidative stress; special molecules known as antioxidants that neutralize ROS. Vitamins A, C and E are examples of vitamins that can act as antioxidants. Vitamin E is a particularly potent antioxidant, since it is able to act in both aqueous (within the cell) and lipid (within membranes) environments, and is hence very effective at protecting our cellular membranes from degradation following oxidative stress. Our bodies also come equipped with their own antioxidant molecular complexes. Some of the most important enzymatic antioxidants are Superoxide Dismutase, Glutathione Peroxidase, and Catalase. Glutathione is one of our principle non-enzymatic antioxidants.
Athletes are now paying closer attention to their antioxidant status in an attempt to better assist muscle recovery. Proactive measures one can take to enhance the body's capacity to cope with oxidative stress include eating foods rich in antioxidants, supplementing with antioxidant vitamins, limiting alcohol intake, especially following exercise and getting plenty of rest. It now turn's out that some athletes were improving their antioxidant defenses in a way they hadn't previously imagined...
Is creatine an antioxidant?
A study was recently released suggesting that creatine might act as a superoxide scavenger in its own right. This would be an additional benefit of creatine, independent of its better-understood capacity to increase ATP availability during exercise. It is thus possible that part of the benefit we obtain from creatine derives from its capacity to act as an antioxidant.
The salient points of the study were as follows:
The creatine levels used in this study were within physiological limits. In other words, the concentrations of creatine found by this study to be effective at scavenging free radicals were comparable to those found within muscle (20-60 mM, for those interested). This gave relevancy to the study.
Creatine, although not as effective as glutathione at neutralizing superoxide, was an effective antioxidant, nonetheless.
Creatine's ability to neutralize superoxide was measured in a test tube, not in an exercising person. And, although it's reasonable to assume that creatine should behave similarly within athletes, subtle differences may exist. For all we know, creatine may be an even more efficacious antioxidant inside the body! Only further experimentation will tell.
Take Home
This report indicates that creatine possess' antioxidant properties and is able to effectively neutralize Superoxide, one of the more insidious free radicals produced by exercise. Since these findings where obtained in a test tube, however, it remains to be shown if creatine has the same antioxidant properties within an exercising person. Although preliminary, this result is surely worth pursuing and has important practical implications for muscle recovery following strenuous exercise.
Scientific References
1. Lawler, J. M., Barnes, W. S., Wu G., Song, W., and Demaree, S. (January 2002) Direct antioxidant properties of creatine. Biochemical and Biophysical Research Communications Volume 290 (1): pages 47-52.
This article was written by Dr. Alfredo Franco-Obregón, research scientist, author, and owner of Nutritional Supplements Newsletters .
Dr. Alfredo Franco-Obregón has had over 20 years of in depth research experience in major laboratories world-wide. His principal scientific interest is the understanding of the cellular mechanisms leading to muscle cell death.
Dr. Franco-Obregón is also the author of Creatine: A practical guide . Click here for more information about the guide.
Do Creatine & Beer Mix?
by Alfredo Franco-Obregón, PhD
Background
Although no published studies have specifically examined the effects of alcohol on the effectiveness of creatine, alcohol does have known effects on muscle metabolism and survival. These indirect consequences of alcohol consumption might, in turn, influence how well one responds to creatine supplementation. However, in order to get the full gist of the arguments I will make, a little background is necessary.
Fast Twitch Muscle Fibers: Anaerobic
In the same manner that not all physical activities are the same, not all muscles are the same. Nature has tailor-made specific muscle types to mediate certain classes of physical tasks. In this respect, muscle fibers can be loosely distinguished on whether they mediate fast or slow movements. Fast muscle fibers are also classified as Anaerobic since they are able to produce force without the assistance of oxygen. This oxygen-independence has an additional advantage. Since anaerobic muscle fibers are not limited by oxygen availability, they are fast to execute. On the down side, however, they do tire rapidly.
Fast (Anaerobic) muscle fibers are called into play when we undertake explosive movements. Heavy lifting and sprinting are examples of exercises recruiting fast muscle fibers. Have you ever thought it strange that we are taught to hold our breath during the execution phase of the bench press? The reason for this is simply that oxygen is not required to perform the lift and, in fact, breathing only gets in the way of the efficient use of force. On the other hand, maximal efforts are usually brief (~10 seconds) due to the high fatigability of fast muscle fibers. Fast muscle fibers do, however, require oxygen in order to recuperate. This creates a scenario known as “oxygen debt” and is the reason our breathing remains elevated following all out efforts.
Slow Twitch Muscle Fibers: Aerobic
Slow muscle fibers, on the other hand, are Aerobic, simply meaning that aerobic muscle fibers DO require oxygen to generate force. Oxygen availability, however, will limit how rapidly aerobic muscle fibers respond, which is, as their name implies, relatively slowly. Aerobic muscle fibers will therefore provide lower levels of force, but will do so for as long as sufficient oxygen is available. Marathon runners rely heavily on slow muscle fibers. Obviously, you would not want to run a marathon while holding your breath.
To summarize, the reason we can only sprint briefly, while we can walk for hours, is that these activities call into action different types of muscle fibers. Sprinting calls into play fast (anaerobic) muscle fibers. Fast muscle fibers generate brief, explosive forces. On the other hand, slow (aerobic) muscle fibers are used for lower intensity movements lasting more than a few seconds. The amount of force generated by slow muscle fiber is much less, but can only be maintained for as long as our breathing allows.
Creatine & Fast Muscle Fibers
Figuratively speaking, creatine has a preference for fast muscle fibers; the one's that do not require oxygen to generate force. Since, creatine increases the work output of fast muscle fibers, one would notice an increase in sprint performance, while jogging performance would go largely unchanged. We are actually feeding fast muscle fibers by supplementing with creatine!
Protein Synthesis & Muscle Growth
It is natural that some muscle damage occurs during exercise. In fact, this exercise-induced muscle damage is essential for subsequent muscle growth. Simply speaking, we literally breakdown our muscles during exercise to rebuild them during recovery. Whether our muscle mass increases, or decreases, depends on which of these two processes is greater. For example, if muscle breakdown exceeds muscle re-growth, then we lose muscle mass. Protein synthesis, or the production of new muscle proteins, is an essential part of this rebuilding process following exercise.
Alcohol & Muscle Growth
Importantly for today's discussion, it appears that alcohol use inhibits muscular protein synthesis. In fact, this inhibitory effect of alcohol is most pronounced in fast muscle fibers, especially after prolonged alcohol use. The scenario would be detrimental for any athlete trying to gain muscle mass and strength through training. After all, isn't the goal of training to increase muscle protein synthesis?
The problem is that creatine allows us to work harder, which is generally a good thing. However, this would also mean that muscle recovery is more critical while supplementing with creatine. Now, as alcohol consumption inhibits protein synthesis, a potentially fruitless situation may arise by mixing the two. That is, creatine and alcohol.
Finally, there is also some indication that creatine also stimulates protein synthesis. This effect may underlie part of creatine's benefit. If so, then alcohol consumption would offset this benefit of creatine as well.
Note: Keep in mind these important points:
Alcohol inhibits protein synthesis in fast muscle fibers.
Protein synthesis is essential for muscle growth and development.
Protein synthesis is important for muscle recovery.
Creatine increases the work output of fast muscle fibers.
Thus, fast muscle recovery is more critical during supplementation.
Creatine may increase protein synthesis as part of its benefit.
Alcohol may be particularly damaging during creatine supplementation.
Alcohol & Anabolic Hormones
Anabolic means to promote growth. Alcohol adversely influences the anabolic properties of two of our principal growth promoting hormones, Insulin and Growth Hormone. Furthermore, most of the anabolic effects initiated by Growth Hormone are mediated by Insulin-like Growth Factor-1 (IGF-1). These hormones are essential for inducing muscle protein synthesis after exercise and are also thought to interact with creatine.
Alcohol causes insulin-resistance as well as hinders the release of Growth Hormone from the brain. Chronic alcohol consumption also reduces our IGF-1 levels. These combined effects will slow muscle development and mitigate our response to creatine. Finally, Growth Hormone secretion is most important during puberty, when we are growing most rapidly. Anything that interferes with this normal surge in Growth Hormone mighy have serious developmental consequences. Therefore, adolescent athletes are strongly discouraged from consuming alcohol.
Conclusions
Although possibly having no direct effects on creatine energy production per se, alcohol creates a biochemical environment that could undermine with the benefits afforded by creatine. Alcohol decreases muscle protein synthesis, causes insulin-resistance and interferes with the release of Growth Hormone (and, hence, IGF-1) following exercise. All of which would mitigate creatine's effect.
Closing Comments
Don't misconstrue my message. I'm not a crusade against alcohol consumption. In my opinion, few things in life compare to a good red Bordeaux or a Tuscan Brunello (‘97). In fact, an occasional glass of red wine has been shown to possess healthful qualities. However, if you're serious about making gains in strength and mass, then maybe you should abstain from alcohol, especially immediately after exercise and before bed time. This precaution is especially important if you are below 20 years of age, when Growth Hormone release is most necessary for normal growth and development. In any case, moderation is always the best policy.
Scientific References
1. Preedy V. R., Patel V. B., Reilly M. E., Richardson P. J., Falkous G., Mantle D. (August 1999) Oxidants, antioxidants and alcohol: implications for skeletal and cardiac muscle. Frontiers in Bioscience Volume 1:4: pages e58-e66.
This article was written by Dr. Alfredo Franco-Obregón, research scientist, author, and owner of Nutritional Supplements Newsletters .
Dr. Alfredo Franco-Obregón has had over 20 years of in depth research experience in major laboratories world-wide. His principal scientific interest is the understanding of the cellular mechanisms leading to muscle cell death.
Dr. Franco-Obregón is also the author of Creatine: A practical guide . Click here for more information about the guide.
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