What are Muscle Building Amino Acids?

Amino acids are small organic molecules, that contain an amino group and an acid group. They are described as the "building blocks of protein", and often when people refer to amino acids, they are speaking specifically about a group of 20 amino acids from which proteins are made, called "proteinogenic" or natural amino acids. All natural amino acids are muscle building!

Why are Amino Acids good for Building Muscle?

Muscle is protein. To lay down muscle, you need to consume amino acids. Some amino acids have additional, secondary roles that may support to training and lean gains.

Where Do Muscle Buildng Amino Acids come from?

Amino acids are present in the form of protein and other chemicals throughout our bodies. We get our intake of amino acids through the protein we eat in food. Meat is considered to be the best source of protein, because it contains amino acids in a balance similar to our requirements, but many plant sources are also rich in amino acids.

Essential Muscle Building Amino Acids

Of the 20 natural, proteinogenic amino acids, 9 are considered essential in the diet, because the body is unable to produce them in the quantities in which they are needed. This means it is important to eat sufficient amounts of these. Even if you are eating large amounts of protein, if it does not contain these amino acids in sufficient quantities, no new muscle will be laid down.

Key Muscle Building Amino Acids

Branched Chain Amino Acids (BCAAs) – Leucine, Isoleucine and Valine are essential amino acids which the body cannot make, and together, comprise 30% of the amino acid pool in muscles, where they are metabolised, unlike other amino acids, which are metabolised in the liver. BCAAs also provide the starting material to produce of other amino acids such as alanine and glutamine.

Without an adequate supply of BCAAs, new muscle will not be formed. In addition, BCAAs are known to speed recovery, prevent muscle breakdown, and may improve performance, and so these are some of the most important important amino acids for muscle growth (1,2,3)

Leucine is worth mentioning on its own. There is research indicating that leucine may not only play a structural role in muscle protein, but that it may also signal the body to lay down new muscle. Leucine is often hailed as the most important amino acid for muscle growth. BCAA mixtures usually contain Leucine in higher doses than Valine and Isoleucine, and the ratio is considered to be important. 2:1:1 is the ratio naturally found in muscles, but some people supplement in ratios up to 8:1:1 (4).

Tyrosine is another important amino acid. Tyrosine is a precursor molecule to a lot of important hormones and chemicals in the body, such as melanin, thyroxine and the catecholamines – a family of neurologically active molecules with roles in processes as diverse as heart rate control, memory, movement, flight or fight, motivation, relaxation and stress. Tyrosine is often contained in pre-workouts to enhance concentration and focus, and in fat burner supplements, for the positive effects of thyroxine on the metabolism (5).

Tryptophan is a precursor to hormones such as melatonin, the hormone in charge of establishing sleeping patterns. Sleep supplements are often used to build muscle, as growth and repair relies on good quality sleep. It is also the precursor to serotonin, the "happy chemical". Serotonin is a neurotransmitter, and low levels have been implicated in depression. While tryptophan supplements are not legal without a doctor's prescription in Australia, many foods are naturally high in tryptophan, like turkey, eggs, spinach and soybeans (6).

Glutamine is the most abundant free amino acid in the muscles, comprising 60%, and it is known that concentrations drop significantly after training. Glutamine plays a vital role moving nitrogen around the body. If there is insufficient free glutamine available, the body will break down muscle until there is enough free glutamine available to fulfil the body's needs. Therefore supplementing with glutamine can prevent muscle catabolism after a workout (7). It is also thought to enhance the immune system and stimulate the production of growth hormone (8).

While they do not fall under the definition of a natural amino acid because they are not used to make protein, Taurine and Carnitine are two non proteinogenic amino acids that are present in the body and are popular supplements for people trying to build muscle.

Muscle Building Amino Acids Side effects

There are no side effects from eating a healthy balanced diet containing adequate amounts of amino acids in the form of protein. Consuming large doses of amino acids on their own may cause stomach upset, and diabetics and anyone with a chronic condition should check with a medical professional before beginning a supplement regime.

When to take Muscle Building Amino Acids?

To prevent catabolism, it is important to ensure the body is provided with amino acids throughout the day – this is one reason why bodybuilders eat many small high protein meals.

Some amino acid supplements have specific timings. BCAAs are best taken during or after a workout, to assist recovery. Likewise, the best time to take glutamine is around a workout, to replace aminos lost from the muscle during exercise. Tyrosine, on the other hand, when being taken for its secondary effects on concentration and focus, should not be taken at the same time as protein or BCAAs, because these compete for absorption and can decrease the effects.

Muscle Building Amino Acids Dosage

To avoid deficiency, 0.8g/kg bodyweight of protein is recommended per day, but those in training for muscle gains need more. Many people consume up to 2g/kg bodyweight/day. Individual amino acids are frequently supplemented according to requirements.

Muscle Building Amino Acids Supplements

The best way to get enough aminos is to eat a balanced diet containing large amounts of high quality protein, but this is not always practical. Supplements are a great way to make up the shortfall, or make sure you're getting the right type of protein when it is needed. It is a rare bodybuilder who has not considered supplementing with extra protein and there is huge variety on the market. There is a lot of detailed information available to help you choose the best protein supplement in this article. Amino acids are often contained in pre- and intra-workout formulations, and stand alone supplements such as BCAAs, Glutamine, Taurine and Carnitine are hugely popular.

Stacking Muscle Building Amino Acids

With a few exceptions, amino acids, both individually, and as protein, will stack with anything. To gain muscle mass fast, particularly for skinny guys, a mass gainer stacks protein with carbs. Fat loss proteins are stacked with fat metabolisers and help people bulk up and lose fat at the same time. BCAAs and Glutamine are often stacked with other ingredients that promote muscle recovery, like antioxidants. These are only a few examples of the uses of these versatile, ubiquitous and essential nutrients.

(1) Shimomura Y, Inaguma A, Watanabe S, Yamamoto Y, Muramatsu Y, Bajotto G, Sato J, Shimomura N, Kobayashi H, Mawatari K. 'Branched-chain amino acid supplementation before squat exercise and delayed-onset muscle soreness.' Int J Sport Nutr Exerc Metab. 2010 Jun;20(3):236-44.
(2) Sharp CP, Pearson DR. 'Amino acid supplements and recovery from high-intensity resistance training.' J Strength Cond Res. 2010 Apr;24(4):1125-30
(3) Portier H, Chatard JC, Filaire E, Jaunet-Devienne MF, Robert A, Guezennec CY. 'Effects of branched-chain amino acids supplementation on physiological and psychological performance during an offshore sailing race.' Eur J Appl Physiol. 2008 Nov;104(5):787-94. Epub 2008 Aug 13
(4) Koopman R, Wagenmakers AJ, Manders RJ, Zorenc AH, Senden JM, Gorselink M, Keizer HA, van Loon LJ. 'Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects.' Am J Physiol Endocrinol Metab. 2005 Apr;288(4):E645-53. Epub 2004 Nov 23.
(5) L-tyrosine. Monograph. Alternative Medicine Review. 2007;12(4):364-368.
(6) Smith SA, Pogson CI. The metabolism of L-Tryptophan by isolated rat liver cells. Biochem J. 1980; 186: 977-986.
(7) Brosnan JT (June 2003). "Interorgan amino acid transport and its regulation". J. Nutr. 133 (6 Suppl 1): 2068S–2072S.
(8) Kim H. Glutamine as an immunonutrient. Yonsei Med J. (2011)

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