In continuing this two-part series on amino acids, I will focus on some specific nutrients that have recently won acclaim in the sports nutrition field for their ability to impact athletic progress in some monumen-tal ways. Read on.GlutamineThe most abundant amino acid in your body, glutamine is stored mostly in your muscles, although rather significant amounts are found in your brain, lungs, blood, and liver. This important amino acid serves as a building block for proteins, nucleotides (structural units of RNA and DNA), and other amino acids and is the principle fuel source for cells that make up your immune system.
Glutamine is also one of the amino acids found in our Ultimate Amino For-mula™, which I discussed in Part 1 of this series .Under certain conditions – including in-jury and intense exercise – the body’s tissues demand more glutamine than the normal amount supplied by diet (which is five to 10 grams a day) and more than can be synthesized normally by your body. (1)During intense exercise, for instance, your muscles release glutamine into the bloodstream. This can deplete muscle glu-tamine reserves by as much as 34 percent. Such a shortfall can be problematic, since a deficiency of glutamine promotes the breakdown and wasting of muscle tissue. But if ample glutamine is available, muscle loss can be prevented.(2)Glutamine is also the favored fuel of your immune cells. This means you need it when you’re ill, stressed, or recovering from surgery . During such times, the demand for glutamine exceeds its production and the body’s nitrogen stores become rapidly depleted — a sign that muscle protein is being broken down.
It is important to understand that gluta-mine is technically described as a “gluco-genic,” meaning that it assists your body in manufacturing glycogen, the chief muscle fuel. In a study involving subjects who cy-cled for 90 minutes, intravenous glutamine, administered during a two-hour period fol-lowing exercise, doubled the concentra-tion of glycogen in the muscles. It’s not clear exactly how glutamine works in this regard, though . Scientists speculate either that glutamine itself can be converted into muscle glycogen or that it may inhibit the breakdown of glycogen. (3)Also, supplemental glutamine has been shown to elevate growth hormone (GH) levels, theoretically influencing muscle growth. Physiologically, GH is the most important hormone in the body for exercis-ers and bodybuilders because it acts as a powerful stimulus for muscle growth and fat loss. Growth hormone is a substance that makes cells multiply faster. Among other functions, growth hormone helps mobilize fat from storage and makes more fat available for energy. It also promotes the transport of certain essential amino ac-ids inside muscle cells to stimulate muscle growth.
Many of the effects of exercise in increasing muscle mass and decreasing body fat are mediated by growth hormone. One of the most exciting findings about glutamine is that it may help you fight fat. Some research hints that supplementing with glutamine can curb the desire for sug-ary foods — an excess of which leads to fat gain. For these reasons, glutamine may turn out to be an important amino acids di-eters and exercisers who need to curb their desire for fat-forming sweets. Between 200 mg and one gram of glutamine can be taken with water 30 minutes before meals to lessen the desire for sugary foods. (4) How to Supplement With GlutamineClearly, glutamine has numerous ben-efits for any athlete who wants to maximize performance, muscle repair, and immunity. Generally, a protein-rich training diet such as that recommended by the Parrillo Nu-triiton Program should prevent your gluta-mine levels from dipping too low. Howev-er, supplemental glutamine provides extra insurance, plus a windfall of other benefits. What’s more, if you’re the victim of fre-quent colds or infections, consider supple-menting with this amino acid. Each capsule in our Ultimate Amino Formula™ contains 103 milligrams of glu-tamine. We recommend that you take two or more capsules of this supplement with each meal .
That should supply a gram or more daily – which is appropriate for athletes and active individuals. Both heat and acid destroy glutamine, so you should not take it with hot or acidic foods, such as vinegar.PhenylalaninePhenylalanine, an essential amino acid, is a building block for certain brain neu-rotransmitters. Neurotransmitters are chemical messengers that relay information between the brain and the rest of the ner-vous system. The L-form of phenylalanine can act as a potent mental stimulant for improved concentration during workoutsThis amino acid has sometimes been used to treat depression because it provides an amphetamine-like boost in mood. Since many people overeat when depressed, phe-nylalanine’s anti-depression properties are beneficial for maintaining a positive men-tal attitude while dieting.
The amino acid is also believed to favorably affect memory and alertness. It also aids in the natural pro-duction of norepinephrine and dopamine, two neurotransmitters that promote and elevate mood.Phenylalanine is another amino acid that may also play a role in fat loss, particularly when combined with other nutrients. A recent study found that a patented com-bination of chromium picolinate, inulin (an nondigestible plant fiber reported to quell sugar cravings), capsicum (cayenne pepper), and L-phenylalanine boosted fat loss and helped maintain muscle over a four-week period when subjects followed a liberal 1500-calorie diet and engaged in a brisk walking program 45 minutes, five times a week. (5)Natural sources of phenylalanine include almonds, avocado, bananas, cheese, cot-tage cheese, non-fat dried milk, chocolate, pumpkin seeds, and sesame seeds. But phenylalanine is another amino acid found in the Parrillo Ultimate Amino Formula. It is also included in our Max En-durance Formula, as both L- phenylalanine and D- phenylalanine.
This formula con-tains other nutrients, known to enhance the body’s energy-producing systems. Specifi-cally, D-phenylalanine (the mirror image of L-phenylalanine) inhibits the breakdown of endorphins (a protein-like substance with analgesic properties) for a higher pain threshold . There are 200 milligrams of DL-phenylalanine in Max Endurance Formu-la™. This supplement should be taken 30 minutes prior to training .Supplemental Growth Hormone (GH) Releasers“GH releasers” are another popular ami-no acid formulation among bodybuilders, particularly because they are thought to burn fat and build muscle. There are many types of GH releasers, include the amino acids arginine, lysine, ornithine, tyrosine, and glycine. These nutrients appear to have a stimulatory effect on the production of growth hormone in the body.Stored in the pituitary gland, growth hormone is involved in the growth of body tissues and has several important effects on the metabolism of protein, carbohydrates, and fats. In protein metabolism, for ex-ample, it helps transport amino acids across cellular membranes, increasing the concen-tration inside cells so that protein synthesis can proceed. Additionally, growth hormone prevents the breakdown of protein and its utilization for energy. Most likely, this oc-curs because growth hormone can mobilize fat for energy, thus sparing protein.Growth hormone has a carbohydrate-sparing effect as well because it decreases cellular utilization of glucose. In the tissues, growth hormone also converts fatty acids to acetyl-Co-A, a molecule used in the pro-duction of energy.
Growth hormone is secreted throughout a person’s lifetime. The rate of secretion can be affected by a number of factors, includ-ing nutritional status, exercise (working out does increase the secretion rate somewhat), time of day, and stress.When given intravenously, certain amino acids seem to trigger the release of growth hormone in the body. The combination of two amino acids — arginine pyroglutamate and lysine monohydrochloride — has been shown in research to be the only oral pair of amino acids to effectively elevate the body’s levels of growth hormone. This combination is available in supplement form in our Enhanced GH Formula™. The suggested usage is two or three capsules upon rising, before training and going to bed. The arginine component of this supplement is worth further discussion, since it has its own unique set of benefits.ArginineArginine is believed to be an immune booster, since it stimulates the activity of the thymus gland, which shrinks as we age. Located in the chest just behind the breast-bone, this gland immune system cells that help fight off disease. Because of arginine’s immune-boosting power, doctors are be-ginning to use it supplementally in patients suffering from immune suppression. (6)Research indicates that arginine – when taken with carbs – may help initiate re-covery – the period of muscle repair and growth that takes place following a work-out.
In one study, exercisers took either a carbohydrate supplement or a carbo-hydrate-arginine supplement at one, two, and three hours following exercise. The supplements contained either one gram of carbohydrate per kilogram of body weight or one gram of carbohydrate, plus 0.08 grams of arginine per kilogram of body weight. During the four-hour recovery pe-riod, the increase in muscle glycogen was more rapid in those who had consumed the carbohydrate/arginine formula.The researchers chalked this response up to arginine’s ability to increase the avail-ability of glucose for muscle glycogen storage during recovery. (7)There’s more . Arginine apparently helps prevent the body from breaking down pro-tein in muscles and organs to repair itself when injured. In one study, surgical pa-tients who were given 15 grams of arginine daily following their operations had a 60 percent reduction in protein loss compared to non-supplemented patients. Of course, more studies are needed in this area, and you shouldn’t self-medicate with arginine, or any other amino acid, after you’ve been injured unless you have your doctor’s per-mission. (8) Though it has been around for a long time, arginine is re-emerging as an important health supplement . For more information on how you can get in on all the benefits afforded by amino acid supplementation, call our Or-derline at 1-800-344-3404 .
1 . Miller, A .L . 1999 . Therapeutic con-siderations of l-glutamine: a review of the literature. Alternative Medicine Review 4: 239-248; Antonio, J, et al.1999. Glu-tamine: a potentially useful supplement for athletes. Canadian Journal of Applied Physiology 24: 1-14.
2. Walsh, NP, et al. 1998. Glutamine, ex-ercise and immune function. Sports Medi-cine 26: 177-191 .
3. Varnier, M, et al. 1995. Stimulatory effect of glutamine on glycogen accumula-tion in human skeletal muscle. American Journal of Physiology 269: E309-E315.
4. Greenwood-Robinson, M. 1998. Natu-ral Weight Loss Miracles. New York: Peri-gee Books.
5. Hoeger, W.W., et al. 1999. Four-week supplementation with a natural dietary compound produces favorable changes in body composition. Advances in Therapy 15: 305-314 .
6. Efron, D., et al. 2000. Role of arginine in immunonutrition. Journal of Gastroen-terology 35 Supplement 12: 20-23 .
7. Yaspelkis, B.B., et al. 1999. The ef-fect of carbohydrate-arginine supplement on postexercise carbohydrate metabolism. International Journal of Sports Nutrition 9: 241-250 .
8. Fisher, H. 1987. On the mend with arginine. Prevention, October, pp. 98-106.