There’s one part of protein in particular that helps to build muscle: That’s the amino acid leucine[1] and if you want to find out more about how it works – read on!
Leucine – one of the essential nine
Before we can discuss leucine, we need to go back and look at the make-up of proteins. All proteins consist of amino acids. These are the compounds that are involved in many critical processes in your body – from breaking down food to repairing body tissue and building up muscle. Of the many amino acids found in proteins, there are nine that are considered essential. These nine essential amino acids can only ever be obtained through your diet[2]. And leucine is one of these nine.
Three facts to remember about leucine:
✓ |
One of nine essential amino acids |
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Can only be obtained from diet |
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Boosts muscle mass [5] |
Leucine is the most powerful amino acid for stimulating muscle protein synthesis1. This is a key process for building up muscle growth and regeneration. In other words, leucine is the amino acid that boosts muscle mass by sending a signal to your muscles that they need to start growing and maintaining their strength so you can get the best results from your training[3],[4]
Animal-based proteins have the amino acids you need
A rule of thumb is to remember that animal-based proteins – such as milk, eggs, fish and meat – are complete proteins[6], and include the all-important leucine[7]. As whey protein powder is derived from milk, it is also a complete protein. All complete proteins contain all the amino acids you need in a form that is directly compatible with your muscles. In other words, if you choose an animal-based protein, you can’t go wrong.
If you don’t include meat in your diet, you’ll need to pay strict attention and ensure you’re getting the proteins that you need in the right amounts. In particular, you need to be sure that you get enough of the essential amino acids. Most plant-based proteins contain some of the amino acids needed to build healthy muscles, but you might have to combine them.
How much is enough
So now we know that leucine helps building and maintaining muscle, and we know where to find it, the next question is: how much? For your body to start developing muscle, you need around 1,700 – 3,000 mg of leucine[8],[9] at any time. That’s the equivalent of 15-25 grams of whey protein powder.
A name to remember for anyone looking to stay in shape
Leucine’s ability to boost muscle mass explains why it has long been popular among body builders. However, athletes from all branches of sport understand the benefits of this amino acid and how it can help them increase their endurance and strength[10]. And in recent years, it has even spread beyond the sporting community. Today it is known by other groups who are keen to maintain their muscle mass – such as the elderly. They know better than most how the ageing process decreases muscle mass – a process also known as sarcopenia – and are turning to high-protein diets to ensure they get all the essential amino acids needed to maintain fitness and general well-being.
Whey protein – a single source delivering high quality protein
Whey protein ranks highly in different measures of protein quality and it is one of the most abundant sources of all nine essential amino acids, including leucine[11]. If you take whey protein powder as a food supplement, you’ll find that the important leucine amino acid is rapidly absorbed by your body and it rapidly stimulates your muscles [12],[13].
What’s more, it comes in different flavours, as well as unflavoured, so it can easily be added to dishes and meals to boost protein intake. Today you’ll find whey protein has fast become a staple store cupboard ingredient in the households of many people looking to take care of their health around the world.
In short, if you’re looking to stay strong and want to make sure that your diet is delivering all the nutrients your body needs when exercising, leucine is quite simply the amino acid to remember. The easiest way to get leucine is to go for a complete protein such as whey powder, as it contains all the essential amino acids you need to get from your diet.
[1] https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-016-0124-8
[2] British Nutrition Foundation ► see online
[3] Van Vliet S et al., The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. J Nutr. 2015 Sep;145(9):1981-91. doi: 10.3945/jn.114.204305. Epub 2015 Jul 29
[4] Mitchell et al., Human Skeletal Muscle Protein Metabolism Responses to Amino Acid Nutrition, Adv Nutr 2016;7(Suppl) : 828S–38S
[5] Breen L, Churchward-Venne TA. Leucine: a nutrient ‘trigger’ for muscle anabolism, but what more?. J Physiol. 2012;590(9):2065–2066. doi:10.1113/jphysiol.2012.230631
[6] Hoffman and Michael J. Falvo (2004). Protein – Which is Best?. Journal of sports science & medicine, 3(3), 118-130
[7] van Vliet S et al., The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. J Nutr. 2015 Sep;145(9):1981-91. doi: 10.3945/jn.114.204305. Epub 2015 Jul 29 © van Vliet S et al., The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. J Nutr. 2015 Sep;145(9):1981-91. doi: 10.3945/jn.114.204305. Epub 2015 Jul 29
[8] Mitchell et al., Human Skeletal Muscle Protein Metabolism Responses to Amino Acid Nutrition, Adv Nutr 2016;7(Suppl) : 828S–38S. ► see online
[9] Morton et al., Nutritional interventions to augment resistance training-induced skeletal muscle hypertrophy, Front Physiol. 2015 Sep 3;6:245. doi: 10.3389/fphys.2015.00245. eCollection 2015.)
[10] Van Vliet S et al., The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. J Nutr. 2015 Sep;145(9):1981-91. doi: 10.3945/jn.114.204305. Epub 2015 Jul 29
[11] van Vliet S et al., The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. J Nutr. 2015 Sep;145(9):1981-91. doi: 10.3945/jn.114.204305. Epub 2015 Jul 29 ► see online
[12] Morton et al., Nutritional interventions to augment resistance training-induced skeletal muscle hypertrophy, Front Physiol. 2015 Sep 3;6:245. doi: 10.3389/fphys.2015.00245. eCollection 2015.) ► see online
[13] West et al., Rapid aminoacidemia enhances myofibrillar protein synthesis and anabolic intramuscular signaling responses after resistance exercise. Am J Clin Nutr. 2011 Sep;94(3):795-803. doi: 10.3945/ajcn.111.013722). ► see online