Proteins represent about 40% of humans’ dry body mass. They form cellular structures, messengers, specialized tissues, enzymes, and much more. Needless to say, proteins are one of, if not the most, important nutrients in the animal kingdom. Ipso facto, amino acids are just as important as proteins because amino acids compose the structure of all proteins. Not only that, free amino acids, particularly the essential amino acids (EAAs), can be digested more easily than regular proteins without compromising physiological functioning. This has great practical applications, such as consuming amino acids before or during exercise to help maintain muscle mass and fuel activity without upsetting the stomach as may occur with protein near exercise. Let’s discuss amino acids in greater detail.
The adjective, “essential,” within the field of nutrition means that the body not only requires that which is essential but also that it must be obtained via the diet. For example, essential amino acids (EAAs) are those which must be consumed in the diet in order for them to be present and perform their necessary functions within the body. There are 21 amino acids that can form proteins. Of these, 12 (leucine, isoleucine, valine, lysine, methionine, phenylalanine, threonine, tryptophan, cysteine, tyrosine, histidine, and arginine) are essential during childhood. With age, the body teaches itself how to synthesize cysteine, tyrosine, histidine, and arginine, reducing the number of essential amino acids to 8 (leucine, isoleucine, valine, phenylalanine, threonine, tryptophan, methionine, and lysine) during the teenage years and adulthood. However, arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serine may all become essential during periods of high stress, such as illness or overtraining. These are called conditionally essential amino acids. Nonessential and conditionally essential amino acids can be synthesized from the EAAs, if necessary. Therefore as the name implies, the EAAs are the most important of the amino acids. AthletesRx Essential Amino Acid formula contains all of the EAAs relevant to improving the athletic experience, plus a few others that are of unique importance to athletes.
Alanine is a nonessential amino acids included in AthletesRx Essential Amino Acid Formula due to its specialized role in gluconeogenesis. Gluconeogenesis is the formation (genesis) of new (neo) glucose (gluco). Glucose is an athlete’s primary fuel source during exercise. A classic study on exercise metabolism found a 70% increase in alanine during heavy exercise . The study subjects were not consuming any foods or supplements, so how did alanine levels increase? During exercise, particularly in a fasted or semi-fasted state, the body will breakdown muscle tissue to obtain alanine for conversion to glucose. Provision of alanine via AthletesRx Essential Amino Acid Formula may help reduce muscle protein breakdown.
Arginine is a conditionally essential amino acid with primary functions in endothelial health and secondary roles in glucose management and cognition. Arginine is a central component for the production of nitric oxide, a vasodilator which relaxes blood vessels . Also via production of nitric oxide, arginine may preserve cognitive abilities during aging and promote the formation of new neurons [18, 35]. Arginine can independently stimulate the release of insulin from the pancreas , and it can also protect the pancreas from toxins .
Aspartic Acid promotes hormonal health and participates in the urea cycle. One isomer of aspartic acid supports the release of hormones such as luteinizing hormone, which have a role in fertility and testosterone production [8, 30, 37]. In the urea cycle, aspartic acid helps to clear the body of toxins like ammonia .
Glycine is the simplest of amino acids, yet it has some of the most interesting functions. Glycine’s small structure permits it to form very strong but flexible bonds with other amino acids, proline and hydroxyproline, to form collagen proteins. Collagen proteins are found in our cartilage, tendons, and ligaments . Glycine also appears to have a capacity to reduce some symptoms of aging by promoting mitochondrial health .
Isoleucine is one of the three branched chain amino acids, 3 of the most important EAAs. This amino acid can improve metabolic function and reduce muscle protein breakdown. In the presence of isoleucine, glucose can be more readily absorbed by a muscle [4, 10]. Taken pre-exercise, this could help with athletic performance. In a low-energy state, such as with exercise, the body breaks down muscle proteins to obtain amino acids for gluconeogenesis. Isoleucine, by increasing glucose uptake, may limit muscle protein breakdown .
Leucine is another branched chain amino acid with principal functions in muscle anabolism and insulin secretion. Leucine is often viewed as the “main” branched chain amino acid for its ability to stimulate muscle protein synthesis [28, 29]. However, proteins cannot be formed in the absence of amino acids additional to leucine, as more than one amino acid is required to form proteins – one of the reasons AthletesRx Essential Amino Acid Formula is so effective. Similar to isoleucine, leucine can stimulate insulin secretion. However, other regulatory actions are activated at the same time that result in less glucose uptake than with isoleucine alone .
Lysine, although not a significant structural component like glycine, helps in the formation of collagen proteins through enhancement of crosslinks . Lysine can also aid in bone health. In a study examining lysine supplementation, those receiving the lysine retained more calcium .
Methionine is one of only 2 sulfur-containing amino acids. This is important, as sulfur-containing amino acids participate in regenerating glutathione, one of our bodies most powerful antioxidants . Oxidation is so detrimental, methionine’s functions extend into improving cardiovascular , immume , and joint health .
Phenylalanine’s chief function is thought to be conversion into another amino acid, tyrosine. Both are precursors to neurotransmitters, such as phenylethylamine and dopamine [16, 20]. Each of these are “feel good” neurotransmitters than can have antidepressant and analgesic effects. Tyrosine also plays a significant role in cognitive health and memory .
Taurine is a great amino acid for athletes. Its actions include stabilizing cellular membranes , enhancing antioxidant status , improving insulin sensitivity , forming new blood vessels , and increasing blood flow . Supplementation with taurine may improve exercise capacity  and muscle force output .
Threonine is another amino acid involved in the formation of collagen and connective tissues . Moreover, threonine is a major amino acid in the production of antibodies, a marker of a healthy immune system. Supplementation with threonine has been observed as necessary for maximal antibody creation .
Tryptophan is everyone’s favorite Thanksgiving amino acid. Tryptophan is the amino precursor to the neurotransmitter serotonin and the hormone melatonin , which you may also recognize as sleep aids, and turkey has plenty of tryptophan. Serotonin can also improve mood and regulate appetite . Melatonin helps regulate the immune  and gastrointestinal (digestive) systems .
Valine is the third and final branched chain amino acid. Its functions are similar to that of both leucine and isoleucine, albeit to a reduced magnitude. However as one of the branched-chain amino acids, valine can still be utilized as substrate by active muscles .
AthletesRx Essential Amino Acid Formula has the EAAs and more – everything the athlete needs to accelerate recovery, reduce soreness, build muscle, and train harder. Unleash The Athlete Within.