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Amino Acid Supplements for Body-building and Exercise

By Philip A. Williams


Important Terms and Abbreviations Contained in this Paper and the Contents


Amino Acid: Nitrogenous organic compounds that are the essential components of proteins.

Proteins: Compounds that are essential for the growth of tissue in the human body

Human Growth Hormone (HGH)

Branched-Chain Amino Acids (BCAA)


Contents: This paper is divided into two sections. The first section contains information about research of amino acid supplements found on the Internet. The second section contains published research studies addressing questions of effectiveness and safety of the supplements.



Section 1: Internet-based Research Involving Amino Acids



General Overview of Section 1


The sports of bodybuilding and fitness are undergoing changes as supplemental products enhance the performance of athletes. With access to the Internet, these products are readily available, but the effectiveness is in question. Amino acids are one form of supplementation that is being used by many people today. Research on the Internet shows that amino acids are available in seemingly countless varieties with most of the information being presented by the companies who sell them. Each form claims to have some enhancing effect, such as better performance, increased strength, or just benefiting results for athletes. However, not all of the amino acid products on the market claim to help the visible physical aspects. Some affect internal or emotional processes. Support for many of these claims are from the users themselves, with little scientific support.


Amino Acids and their Functions


According to David Spindel, "amino acids are organic molecules that form the basic constituents of protein. " They are the "building blocks" of the body. They build and repair various body parts and aid certain body functions. There are twenty-two amino acids. Eight are essential and fourteen are non-essential. The body does not manufacture the essential acids and does manufacture the non-essential acids. The body contains a free amino acid pool that contains tissues and bodily fluids. Amino acids enter this pool by three ways. Amino acids enter during digestion of foods containing protein, when body protein decomposes, and when carbon sources and NH3 synthesize the non-essentials. When protein intake is insufficient, there are not enough amino acids entering the pool to compensate for the lost ones. This affects the muscle size and strength (4). Amino acids aid the body in many ways, and are definitely needed by the body to function properly. Supplements are needed only when the body does not get the required amounts. The purposes of amino acid supplements are to replenish the lacking acid supply and in most sports uses, to stimulate lean mass growth without sacrificing present muscle mass.


Purpose and Rationale


Many sources on the Internet encourage people who want to lower their caloric intake and increase their protein intake to use amino acids. By using amino acids, individuals can achieve better health by meeting the bodies needs. Amino acids achieve their goals in different ways. Every product on the market has specific instructions for usage. Essential Fitness recommends taking amino acid supplements with meals. They claim that food acts as a "buffering agent" for the acids, that food without proper acids can be enhanced with supplements, and that as more insulin is released during meals, the acids will be better accepted by the body. Other products such as Aminolyze recommend taking "one tablespoonful with water on an empty stomach at bedtime." Regardless of the usage instructions, all amino acid supplements add amino acids to the body to be broken down for use by the body. Some of these uses include "assisting in transporting long chain triglycerides…stimulating the pituitary to secrete growth hormone…supplying the body with nitrogen…and much, much, more." Many of these functions add to lean muscle mass, which is the primary purpose of many supplements available.


Claims of Effectiveness of the Products


Product companies today make many claims that are very attractive. The effectiveness of these treatments is sometimes hard to believe in light of the outlandish claims. Fitness Awareness, Inc. has an amino acid supplement called GlutaminGT, which supposedly "is clinically proven to increase lean muscle mass 6-8 pounds and reduce body fat by 2% all in only six weeks by increasing muscle endurance and reducing recovery time." "Pro-Max and Pro-Max 100 are the two finest and most versatile protein supplements in both palatability and composition. They are useful for lasting energy and for building energy reserves for people of all ages." Aminolyze is a product that is in a form that a person's body can easily build proteins without many calories. Aminolyze will supposedly "build a leaner, firmer body, while you sleep!" Ornithine Alpha-KetoGlutarate is a product offered by Kilo Sports that " increases endurance, reduces muscle fatigue and shortens recovery time." Opti-APD is a formula that claims to have "developed an amino acid delivery system that increases absorption of protein and peptide amino acids." AMINO Fuel has "a nutritionally complete, highly potent anabolic amino acid drink formulated to help build muscle tissue, increase lean body mass and speed recuperation and recovery."


Supporting Evidence of the Product Claims


Most of these claims have little or no support other than from the companies themselves. Most of the web sites are advertisements for products that help people reach their fitness goals. These pages offer almost miracle cures for health problems. Pages that are not advertisements offer different opinions, most of them being negative. Hamilton and Whitney's Nutrition Concepts and Controversies states that amino acids are bad for the overall health of a person. They claim amino acids do not perform any functions involving nutrients, that amino acids simply are being forced into the market by enticing advertisements, and that the best way to utilize amino acids are from a healthy food intake. Also, before using amino acid supplements, a person should consider consulting a physician. Although amino acid supplements are a form of food, they are not the best way to receive nutrients. A good meal could be a much better source of amino acids to form bodily proteins. "One study of hospital patients actually found that nitrogen retention was poorest when using amino acid supplements instead of food. Also, there is little reason to obtain amino acids in free form because studies have shown that intact protein (in foods) is actually absorbed more readily than free form amino acids." Most of the pages that were searched claimed that scientific studies have found their product to be efficient, but none really specify the details of the studies or the credibility of the studies. L-Glutamine is an amino acid that has had studies done that back up the claims. The company FTH says "reports from [a] preliminary study in Canada have shown that 500 mg. three times a day sublingually typically results in 6-8 lbs. of lean body mass in 5 weeks time along with simultaneous loss in bodyfat." This last claim is typical of many web pages offering amino acids in that they mention studies, but not much else.


Sources Presenting the Information


The information on amino acids is being presented mainly by nutritional companies, athletic agencies, and basically anyone trying to sell their product. After most information is presented, price lists and ordering forms follow. Another type of pages presented is by researchers. These pages sometimes praise the amino acids, while other times they condemn them. Interestingly, the research pages that praise the amino acid supplements have some relation to companies selling amino acid products. Finally, there are the pages that just give facts and opinions about amino acids relating to supplements. One page claims that the best amino acid supplement is from illicit drugs. A page on hemp seed nutrition and cookery says that the cannabis hemp seed contains the best source of essential acids compared to other herbal substances. Cannabis supposedly increases amino acid production, aids the immune system, attributes to all-around better health, and reduces chances of some chronic disease. The only problem with this supplementation is that the cannabis is illegal. If this substance became legal people could have access to hemp and possibly lead healthier lives.


Conclusion of the Internet Research


Alanine, Arginine, Asparagine, Aspartic acid, Carnitine, Citrulline, Cysteine, Cystine, DL-pheylalanine, GABA (gamma-aminobutyric acid), Glutamic acid, Glutamine, Glutathione, Glycine, Histadine, Isoleucine, Leucine, Lysine, Methionine, Ornithine, PABA (para-aminobenzoic acid), Phenylalanine, Proline, Serine, Taurine, Threonine, Tryptophan, Tyrosine, and Valine are the known amino acids. The numbers of amino acids differ from different sources. Most recognize 22 or a few more amino acids. These create proteins in our body that we need to function. Many companies today are selling amino acid supplementation that supposedly will enhance certain aspects of our body. The amino acids are available in many forms such as drinks, power bars, pills, injections, and others. Each product suggests different usage, and claims similar results. The claims being made are seemingly egotistically enticing, and very little proof exists of their medical benefits. Much scientific evidence, however, is against heavy supplementation. Most of the web pages are by companies for the primary purpose of profit. True health probably lies in a healthy lifestyle with good nutritional habits. Supplementation could aid people who lack the proper amino acids, but excess supplementation is most likely a harm or simply a waste of money.



Section 2: Published Research Studies involving Amino Acids




As more amino acid supplements flood the market, consumers should be aware of more than just advertisements by the companies who sell them. Questions arise about the truth behind amino acids. When thinking about supplements, one should consider many issues. Why are amino acids needed in the first place? That question can best be answered by researching scientific evidence. When researching, a consumer should ask about amino acids and their role in exercise. Do amino acid levels in the body diminish as a result of exercise? Is performance affected if these levels are lowered? What exact levels are needed to be replaced with supplementation? Are the companies claim's effective in supplementing the appropriate amount? And are there negative effects of supplementation? These questions might not be able to be answered since there is little scientific evidence for most of these questions.    

Levels of Amino Acids in the Body after Exercise and Performance at these Levels


To decide if a person needs amino acids supplements in the first place, the levels of amino acids in the body after strenuous exercise should be considered. Lehmann, et al that confronted this issue, did a study. Nine athletes in the 1993 Colmar Ultra Triathlon had their serum amino acid profile monitored before and after the triathlon. "The ultra triathlon includes 7.5 km swimming, 360 km cycling and approximately 85 km running." The study was done by taking blood samples from the forearm vein of each participant 2 hours before the challenge and 30 minutes after completion. After analysis, eighteen of the amino acids showed an average 22 plus or minus 12% decrease. With some amino acid levels decreasing as much as 56% (3). This is an example of extreme physical activity, and shows the extreme decrease in normal levels. On a smaller scale, less amino acids would be lost.


Once the fact is established that depletion does occur, the next question would be whether or not the performance is affected. Hall and others reviewed a study that addressed this issue. They hypothesized that BCAA's could reduce the increase of brain tryptophan uptake during exercise and enable athletes to endure through fatigue. Previous studies have indicated that Tryptophan may cause fatigue when it is increased in the brain. The test used involved ten endurance-trained male athletes that were studied during cycle exercise at 70-75% maximal power output. During the exercise, they ingested ad random and double-blind drinks that contained 6% sucrose, 6% sucrose supplemented with 3 g/L of Tryptophan, 6 g/ L of BCAA, or 18 g/L of BCAA. The results for the BCAA concluded that neither level affected the time to exhaustion. When the amino acid levels in the body were supplemented, the endurance remained the same as the group without supplementation (5).


Supplementation Amounts


There have been relatively few studies on the role that proteins play in bodily energy metabolism. The lack of sufficient studies hinders an exact knowledge of needed levels of protein for all categories of people. People who exercise regularly may need higher levels of protein. Athletes such as body-builders often consume larger amounts of protein than sedentary people. Studies have indicated that physical activity has definite effects on protein metabolism. Studies were done that show that increased protein consumption in addition to regular exercise can benefit muscle development compared with exercising without supplementation. Lemon reports that the Recommended Daily Allowance of protein intake for people involved in heavy resistance training should be between 1.7 and 1.8 g protein/kg body mass, which is above the normal RDA. The studies indicated that at very high levels, such as greater than 2 g/kg/day, supplements are not beneficial. These levels are representative of those taken by body-builders and of those found in most commercial supplements. The information is probably biased since most of the data is collected from male individuals between the ages of 18 and 25 (4).


Marketing Claims


There are many products being marketed today that make enormous claims that are difficult to support. Claims made by these companies are similar to the one's found on the Internet. Grunewald and Bailey reviewed information from 33 companies advertising dietary supplements. Most of the supplements studied were in the form of amino acids, and most of the amino acids were in the form of oral supplements, such as tablets and capsules. Many of the supplements studied were single amino acids. The findings were that the performance claims were not supported by research (1). Other studies also reveal that the claims made by companies have no real basis, and that "many supplements marketed as ergogenic aids are based on data from animal studies or in vitro experiments with little to no scientific evidence that they are effective performance enhancers in humans" (4).


Lambert et al reports a study about commercial amino acid supplements and the growth hormone concentrations in male body-builders. In this test, "Seven male body-builders reported to the laboratory on four occasions after an 8-hr fast and ingested, in random order, either a placebo, a 2.4-g arginine/lysine supplement, a 1.85-g ornithine/tyrosine supplement, or a 20-g BovrilR drink. Blood was collected before each treatment an again every 30 minutes for 3 hours for the measurement of serum GH concentration. On a separate occasion, subjects had an intravenous infusion of 0.5 microgram GH-releasing body weight to confirm that GH secretory response was normal." The primary result of this study was that the levels of serum GH concentrations did not show any consistent change after the amino acid supplements were ingested despite the positive marketing for the product (2).


Negative Effects of Amino Acid Supplements


A major debate in amino acid research has been the negative effects that they can produce. Lemon reports that "high protein intakes should be avoided because they can be hazardous; however, the potential adverse effects appear to have been exaggerated." When using supplements, additional nitrogen is excreted, thus causing a water loss of great concern. High protein diets can also lead to urinary calcium loss. The primary concern probably is absorption problems, metabolic imbalances, toxicity, and changed neurotransmitter activity. All of these complications are a direct result of amino acid supplements. Even though most people in the United States receive sufficient protein in their diet for their level of exercise, some people might not receive adequate amounts. "Supplementation of several individual amino acids may be beneficial for physically active individuals, but considerable potential risk is also present (4)."




With the lack of research and the skepticism of many leading researchers, amino acids should be considered with caution. Most of the amino acid formulations are sold for shear profit. They are compiled in amounts that could be harmful to the body or simply wasted by the body. A definite depletion of amino acid levels occurs when people engage in activity, but performance is not greatly affected. More research on depletion levels is necessary involving a wider variety of people. Once the research is completed, accurate assessments of proper amino acid intake levels can be made. Many of the formulations contain single amino acids, but most studies were done on groups of amino acids rather than a single acid. Amino acids are still not fully understood, but increased interest could stimulate research. Also, research should be done on individual amino acids. Many athletes and body-builders use supplements today, but advertisement probably plays the biggest role in this trend. With materials researched from the Internet and published studies, an accurate judgement of commercial amino acid supplements can be made, which is that the supplements are most likely not to be effective and not worth the risk.





1. Grunewald, K., & Bailey, R. (1993). Commercially marketed supplements for bodybuilding athletes. Sports Medicine, 15, 90-103.


2. Lambert, M., Hefer, J., Millar, R., &Macfarlane, P. (1993). Failure of commercial oral amino acid supplements to increase serum growth hormone concentrations in male body-builders. International Journal of Sport Nutrition, 3, 298-305.


3. Lehmann, M., Huonker, M., Dimeo, F., Heinz, N., Gastmann, U., Treis, N., Steinacker, J., Keul, J., Kajewski, R., & Haussinger, D. (1995). Serum amino acid concentrations in nine athletes before and after the 1993 Colmar ultra triathlon. International Journal of Sports Medicine, 16, 155-159.


4. Lemon, P. W. (1996). Is increased dietary protein necessary of beneficial for individuals with a physically active lifestyle? Nutrition Reviews, 54, S169-175.


5. Van Hall, G., Raaymaker, J., Saris, W., & Wagenmakers, A. (1995). Ingestion of branched-chain amino acids and tryptophan during sustained exercise in man: failure to affect performance. Journal of Physiology, 486, 789-794.


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