Amino Acids

WHAT ARE AMINO ACIDS?
Protein is made up of Amino Acids which are considered to be the building blocks of life. There are nine essential amino acids which must be obtained in the diet. In addition there are a further 13 amino acids present in protein which are considered non-essential as they can be synthesised by the body. There are also many other amino acids but they do not form parts of protein.

Research over recent years has shown that the human body has evolved to best utilise amino acids which are in dipeptide and tripeptide form (these are most commonly found in hydrolysates, ion exchanges and cross flow prepared whey proteins) which simply means two or three amino acids have been joined together. These are better absorbed, and retained, than both whole food proteins and free form amino acids.

There are a group of amino acids called Branched Chain Amino Acids (BCAA) which play an important role during exercise. They are the main amino acids to be sacrificed from muscle tissue during muscle catabolism. BCAA consist of three amino acids; leucine, Isoleucine, and Valine. The cause of this breakdown is that during exercise large amounts of the non-essential amino acids alanine and glutamine are used, in fact more than the body stores, and the deficit is made up by the body converting BCAA's into these two aminos.

To prevent this breakdown it has become common to try to raise blood levels of BCAA prior to exercise to reduce muscle breakdown. Supplementing with Glutamine directly after training then further reduces post exercise catabolism.

Glucogenic Amino Acids is a term used to describe the three amino acids threonine, glutamine and arginine. This term means that they lend themselves to glucose production, which is used for energy during exercise. Ample levels of these aminos may help prevent muscle breakdown, and has also been shown to increase feed efficiency in animals (ie grow more from the same amount of food).

Protein technologies have identified a group of amino acids called the Critical Cluster Amino Acids which play a big part in muscle sparing during dieting or intense exercise. This cluster consists of the three BCAA's along with Glutamine and Arginine which are two 'conditionally essential' amino acids. Around 45% of whey protein consists of the critical cluster aminos, with milk (casein) and soy protein isolate next in line at around 36%.

ESSENTIAL AMINO ACIDS

Histidine
This is a basic amino acid due to its aromatic nitrogen-heterocyclic imidazole side chain. It is biochemically metabolised into the neurotransmitter histimine.

Isoleucine
This amino acid has no other significant biological role than incorporation into proteins and enzymes where main purpose is to help dictate tertiary structure of macromolecules.

Leucine
This is a hydrophobic amino acid found as a structural element on the interior of proteins. It is the second most common amino acid found in proteins

Lysine
This amino acid is commonly found at the surface of proteins and is present in meat, fish, poultry and dairy.

Methionine
This amino acid helps to initiate translation of RNA by being the first amino acid incorporated into the N-terminal position of all proteins.

Phenylalanine
Plays a key role in the biosynthesis of amino acids and neurotransmitters.

Threonine
Plays an important role in Porphyrin metabolism.

Tryptophan
Is the biosynthetic precursor to the important neurotransmitter serotonin.

Valine
Determines the 3D structure of proteins due to its hydrophobic nature. Sources include soy flour, cottage cheese, fish, meat and vegetables.

NON-ESSENTIAL AMINO ACIDS

Alanine
Involved in the metabolism of tryptophan. One of the simplest amino acids most widely used in protein construction. It has little therapeutic role in humans however has been shown to have a cholesterol reducing effect in rats.

Arginine
A complex amino acid often found at the active catalytic site in proteins and enzymes. Is actually an essential amino acid during the juvenile period in humans. Natural sources include brown rice, nuts, raisins, and whole wheat.

Asparagine
A derivative of Aspartic Acid. Has an important role in the biosynthesis of proteins.

Aspartic Acid
This amino has a paramount role in metabolism during construction of other amino acids and biochemical's in the citric acid cycle.

Cysteine
Often involved in the three dimensional stability of proteins and critical to the metabolism of coenzyme A, biotin, lipoic acid, & glutathione.

Glutamic Acid
Negatively charged and therefore very polar and usually found on the outside of proteins where it is free to interact with intracellular surroundings.

Glutamine
Has an important role in cellular metabolism of animals and is the only amino acid with the ability to easily cross the barrier between blood and brain. It also has a central role in the regulation of bodily ammonia levels.

Glycine
This is the simplest amino acid and is essential for the biosynthesis of nucleic acids as well as bile acids & creatine phosphate. It is the second most common amino acid found in proteins which has the ability to inhibit neurotransmitter signals in the central nervous system.

Proline
This is a major component of the protein collagen, the connective tissue that binds and supports other tissues.

Serine
This amino has a major role in a variety of biosynthetic pathways including those involving pyrimidines, purines, & creatine.

Valine
Determines the three dimensional structure of proteins due to its hydrophobic nature. Sources include soy flour, cottage cheese, fish, meat and vegetables.

BRANCHED CHAIN AMINO ACIDS (BCAAS)
The branched-chain amino acids (BCAAs) are leucine, isoleucine, and valine. BCAAs are considered essential amino acids, because human beings cannot survive unless these amino acids are present in the diet. In other words, we, as humans, cannot create these amino acids ourselves so we have to eat or drink them from an external source. BCAAs are vital for the maintenance of muscle tissue and preserve muscle stores of glycogen (the storage form of carbohydrate/sugar that can be converted into energy - stored in muscle tissue and liver). BCAAs also help prevent muscle protein breakdown during exercise. This is why many athletes consume a whey protein high in BCAA's or consume BCAA capsules prior to and post training. Endurance athletes, such as cyclists and runners also use the BCAA's as an assistance to strengthen their immune systems and delay the onset of fatigue.

BCAAs have been shown to help to delay fatigue during exercise, making them suitable for people, as stated above, taking part in sports such as distance running or cycling. Those involved in team sports, such as rugby, football or hockey will also benefit. The beneficial effect of BCAAs on muscle preservation and growth also makes them suitable for anyone wanting to lose fat without losing muscle. That is why you often see many hardcore bodybuilders dieting hard, and swallowing handfuls of these all important BCAA capsules at a time throughout the day.

BCAAs are used up by your body as a fuel source during exercise. Tryptophan (an amino acid - see above) levels rise in response to this. When tryptophan enters your brain, it leads to feelings of tiredness - again a reason many people supplement with Tyrptophan or 5-HTP to help them sleep. Some experts believe that by supplementing with BCAAs during exercise, you can keep exercising at a higher pace for longer. Indeed, several studies show that BCAAs consumed during exercise has a beneficial effect on performance, reducing fatigue and raising energy levels.

BCAA's have been shown in research to improve recovery rates between exercise sessions. 26 subjects took part in one study where they took place in a 30-kilometer cross country race and another 32 subjects ran a full length marathon. In both races, the participants found that BCAAs improved physical performance and helped them recover more quickly.

It has been found that the immune system of elite triathletes has been strengthened by the use of BCAA's, outlined by Brazillian research. With only thirty days of supplementation being enough to reduce symptoms of infection by an impressive 34%. The group was given either six grams of BCAAs or a 'dummy' supplement thirty days before taking part in an Olympic triathlon. Endurance events typically require a high volume of training, and often involve multiple daily workouts, which can weaken the immune system dramatically. It is supplements that are as highly effective as BCAA's at improving the immune system against the hardships of such intense training that make it absolutely invaluable. The main finding of the study was that the reduced incidence of infection was linked to higher levels of glutamine in the triathletes supplementing with the BCAAs. Glutamine already being proven to improve recovery and tissue repair - especially in severe burns patients, being the primary constituent of your muscles after water.

It is also well known that BCAA supplementation are also useful in special situations, such as preventing muscle loss at high altitudes and prolonging endurance performance in the heat. A group of 16 subjects participating in a 21-day trek at high altitude, in one study, were divided in two groups. One group took BCAAs (5.76, 2.88 and 2.88 grams per day of leucine, isoleucine and valine, respectively) or a placebo. The BCAA group lost significantly less muscle than those using a placebo. Subjects using BCAA lost about 10% more fat compared to the group using the placebo. Arm muscle size tended to increase in the BCAA group, whereas there was a significant decrease of 6.8% in the placebo group. The same tendency was observed for the thigh muscles. These staggeringly real life results makes you wonder what you are missing out on if you miss out on BCAA supplementation.

BCAA content are found in the highest quantity in dairy products and red meat, although they are present in all protein-containing foods. Whey protein, particularly whey protein isolates rather than the concentrates, is especially rich in BCAAs, and has become a staple part of the diet for anyone wanting to build muscle. Because it helps to prevent the loss of muscle, whey protein is also used extensively during weight loss programs.

The International Journal of Sports Medicine contains particular evidence for this where twenty-five competitive wrestlers were assigned to one of several groups. Each group followed a slightly different diet. One of the groups, however, consumed a diet that was high in BCAAs. After 19 days of low-calorie dieting, subjects using BCAAs lost the most weight and body fat.

During exercise it is a good idea to consume approximately 3-5 grams of BCAA, preferably with 30-50 grams of carbohydrate, to delay fatigue and improve exercise performance. Due to the preservation of muscle tissue requiring such high doses of BCAA, most experts recommend the use of several servings of whey protein spread throughout the day, rather than consuming bucket loads of BCAA capsules - as whey is extremely high in BCAA content.

Most users report an immediate improvement in performance during extended periods of exercise. Consumed for several months, a diet high in BCAA will reduce the incidence of infection. You can also expect faster muscle growth during periods of intense training, and less muscle loss when attempting to lose weight.