Any nutritionist will tell you that protein is one of the most important nutrients for muscle-building success. What’s often not clocked by the average gym-goer is that high-quality protein is made up of all the essential amino acids.
Protein is very important for optimal body composition and is termed as an essential macronutrient. This means that the body can’t make protein, so it has to come through the diet.12 But what exactly are essential amino acids and do we need to supplement with them?
This article will cover the use of essential amino acids — how they work and who might benefit from them. Also, how to use them and if there are any potential side effects at all.
In this article, you’ll find:
Why do you need protein?
Whether your goals are to build muscle, lose weight, or just be healthier, you need to make sure that you’re eating enough high-quality protein on a daily basis to get there.8
The body also can’t store protein for later use, so it’s necessary to get the required amounts each day. Despite this, many people make the mistake of not getting enough protein each day, consistently throughout the week.
Protein has many different purposes in the body —including muscle growth, healthy immune function, and hormone production.1 Every time that you exercise or are physically active, proteins are involved in some manner.
What are amino acids?
All of the protein we eat — whether it comes from meat or vegetable sources — is made up of amino acids. Amino acids are known as the building blocks of protein, and there are 20 different amino acids in total.12
There can be different combinations of amino acids in the food we eat, which in turn will affect the quality of the food and how the body uses them. Each amino acid has a very specific and unique role in the body.
The 20 amino acids can be broken down into two distinct categories: essential amino acids (EAAs) and non-essential amino acids (NEAAs).3
What are essential amino acids?
All proteins are made up of amino acids, and there are 9 essential amino acids in total. If the food you eat contains all of the 9 essential amino acids, then your body is able to make the other remaining 11 non-essential amino acids on its own.
This is the main difference between essential and non-essential amino acids. The body can’t make essential amino acids, but it can produce non-essential amino acids. That doesn’t mean that non-essential amino acids aren’t important for muscle building though.
When a food contains all 9 essential amino acids, then it’s known as a complete protein.2
The essential 9 amino acids are:3
- Histidine — used to develop and maintain healthy tissue.
- Isoleucine — used for blood clotting and muscle repair.
- Leucine — branch chain amino acid involved in muscle growth.
- Lysine —involved in collagen production which is critical for healthy bones.
- Methionine — powerful antioxidant.
- Phenylalanine — helps produce stress and relaxation hormones.
- Threonine — used in the formation of bone and cartilage.
- Tryptophan — involved to induce sleep as well as produce serotonin.
- Valine — helps prevent muscle breakdown and remove excess proteins from the liver.
Most of the amino acids that we eat get directed towards our muscles. One of the primary roles of essential amino acids is to look after lean muscle mass. This is done in two ways — it provides the building blocks to grow new muscle in a calorie surplus, and helps prevent muscle loss in a calorie deficit. 9
What are the benefits of essential amino acids?
Some of the benefits of consuming and supplementing with essential amino acids include:
1. Increased mitochondria production in cardiac and skeletal muscle (mitochondria are largely responsible breaking down fatty acids and converting them to energy). This can be very useful for endurance athletes, as they will be able to break down more fatty acids to be used as fuel, which can improve performance and delay fatigue.4
2. Providing the signals and means to build new muscle. Essential amino acids have the ability to tell the body to start the process of building new muscle to cope with the stresses placed on it. Added to this, they provide the building blocks that the muscles need to grow. 13
3. Improving physical performance. Essential amino acids reduce fatigue under tension, which allows the body to work harder for longer. EAA are involved in strength, muscle gain and endurance improvements. 13
4. Reducing bodyweight. Essential amino acids help to mobilise fatty acids. They also contain few to no calories per gram, so they can be useful in creating a calorie deficit whilst maintaining lean muscle mass. 4
5. Improving immune function. Essential amino acids function as powerful antioxidants that help to keep the immune system strong. 4
6. Help prevent muscle protein breakdown. There are two parts to developing lean muscle tissue — the first is muscle growth and the second is preventing muscle breakdown. It’s been shown that essential amino acids help to combat unwanted muscle protein breakdown.13
Essential amino acids dosage and suggested use
Essential amino acids don’t need to be digested, so a good time to take them is before and after your workout. They’re absorbed very quickly and are rapidly transported to the muscles to promote growth and recovery.
They can be used at any other time, perhaps when it’s difficult to eat a high-protein meal. However, they should still be seen as a supplement and not a substitute for whole foods.
When deciding how much to use, look up the nutritional information of that specific EAA supplement. You want to be getting roughly 3g of leucine per serving to get the best results for muscle growth and recovery. This is usually about 10g worth of essential amino acids.10
Essential amino acid side effects
You might be wondering whether it’s safe to supplement with essential amino acids, and if there are any risks. According to scientific research, there are no known serious side effects that have been reported when using an EAA supplement in both normal and high amounts.5
Take home message
Whether your goals are to get fit, lose weight, or put on muscle, protein should make up a significant part of your diet. Supplementing with essential amino acids gives a convenient and effective way to increase your daily protein intake, as well as provide a high-quality source of amino acids.
Essential amino acids won’t interfere with digestion, so are a great aid that can be taken before and after a workout for optimal growth and recovery.
Essential amino acids are suitable for all athletes with no known side effects, and can be used effectively as part of a well thought out nutrition plan.
Our articles should be used for informational and educational purposes only and are not intended to be taken as medical advice. If you're concerned, consult a health professional before taking dietary supplements or introducing any major changes to your diet.
- Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K., & Walter, P. (2002). Protein Function. Molecular Biology of the Cell. 4th Edition. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK26911/
- Allowances, N. R. C. (US) S. on the T. E. of the R. D. (1989). Protein and Amino Acids. National Academies Press (US). Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK234922/
- Amino acids: MedlinePlus Medical Encyclopedia. (n.d.). Retrieved March 14, 2019, from https://medlineplus.gov/ency/article/002222.htm
- Bifari, F., Ruocco, C., Decimo, I., Fumagalli, G., Valerio, A., & Nisoli, E. (2017). Amino acid supplements and metabolic health: a potential interplay between intestinal microbiota and systems control. Genes & Nutrition, 12. https://doi.org/10.1186/s12263-017-0582-2
- Borack, M. S., & Volpi, E. (2016). Efficacy and Safety of Leucine Supplementation in the Elderly123. The Journal of Nutrition, 146(12), 2625S-2629S. https://doi.org/10.3945/jn.116.230771
- Dideriksen, K., Reitelseder, S., & Holm, L. (2013). Influence of Amino Acids, Dietary Protein, and Physical Activity on Muscle Mass Development in Humans. Nutrients, 5(3), 852–876. https://doi.org/10.3390/nu5030852
- Negro, M., Segreto, V., Barbero, M., Cescon, C., Castelli, L., Calanni, L., & D’Antona, G. (2018). Essential Amino Acids (EAA) Mixture Supplementation: Effects of an Acute Administration Protocol on Myoelectric Manifestations of Fatigue in the Biceps Brachii After Resistance Exercise. Frontiers in Physiology, 9. https://doi.org/10.3389/fphys.2018.01140
- Santarpia, L., Contaldo, F., & Pasanisi, F. (2017). Dietary protein content for an optimal diet: a clinical view. Journal of Cachexia, Sarcopenia and Muscle, 8(3), 345–348. https://doi.org/10.1002/jcsm.12176
- Volpi, E., Kobayashi, H., Sheffield-Moore, M., Mittendorfer, B., & Wolfe, R. R. (2003). Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults. The American Journal of Clinical Nutrition, 78(2), 250–258.
- Witard, O. C., Wardle, S. L., Macnaughton, L. S., Hodgson, A. B., & Tipton, K. D. (2016). Protein Considerations for Optimising Skeletal Muscle Mass in Healthy Young and Older Adults. Nutrients, 8(4). https://doi.org/10.3390/nu8040181
- Wu, G. (2010). Functional Amino Acids in Growth, Reproduction, and Health12. Advances in Nutrition, 1(1), 31–37. https://doi.org/10.3945/an.110.1008
- Wu, G. (2016). Dietary protein intake and human health. Food & Function, 7(3), 1251–1265. https://doi.org/10.1039/c5fo01530h
- Essential Amino Acids: Definition, Benefits and Food Sources. (2018, June 12). Retrieved March 19, 2019, from https://www.healthline.com/nutrition/essential-amino-acids
Grant is a sports nutritionist and certified strength coach. He has multiple postgraduate diplomas in nutrition and strength coaching as well as a Master’s degree in Sports and Exercise Nutrition, with a specific focus on protein. Grant has worked in the fitness industry for well over a decade and has helped coach professional athletes and sports teams, as well as the average gym-goer looking to get in the best shape possible. He now spends most of his working time teaching fitness professionals and coaching people remotely.
He’s a big believer in practising what he preaches and has been involved in resistance training and martial arts for over 20 years. In his spare time, Grant enjoys being with his wife and daughter as well as the family dogs and catching up on the latest Netflix series.