5 Benefits of Leucine in Muscle Building

The amino acid leucine, along with isoleucine and valine, is one of the branched-chain amino acids (BCAAs). These essential amino acids are metabolised directly in the muscle tissue and have an "anabolic effect". This means they support protein synthesis, muscle building, and recovery after intense strength training [1]. For athletes, protein sources with a high leucine content are therefore an essential part of their diet.

But what else can our body use leucine for? And how can you make sure you’re getting enough of this important BCAA? Here are the 5 main benefits:

1. Leucine stimulates muscle building and protein synthesis

The most important effect of leucine (also known as L-leucine) for athletes is probably its ability to stimulate muscle protein synthesis (MPS) [2]. This is the process by which the body creates new muscle proteins to build muscle tissue. Leucine acts as a key signalling molecule to initiate this process. So, if you don’t get enough leucine from your diet, this process will stall.

Studies have shown that an intake of about 2.5 to 3 grams of leucine per protein-rich meal is optimal for maximising muscle growth.

2. Supports recovery for athletes

In addition to promoting muscle growth, leucine plays a crucial role in muscle repair and recovery after intense training. Even during workouts, leucine helps prevent the breakdown of muscle proteins. Taking leucine as part of a complete protein immediately after training can speed up the recovery process and may even reduce muscle soreness. [3]

This is particularly beneficial for those who train frequently and want to avoid performance limitations due to slow recovery.

3. Increases strength and endurance

Another benefit of leucine for athletes is its ability to increase strength and endurance. This essential amino acid supports muscle growth and, consequently, the increase in muscle strength. Studies have shown that leucine can also improve endurance during high-intensity training sessions by sparing glycogen stores in the muscles. [4]

Leucine can therefore help you train longer and harder without becoming fatigued.

4. Optimises fat burning and body composition

Protein and leucine play an important role in fat burning and improving body composition. The more muscle mass you have, the higher your metabolic rate will be, which improves fat burning at rest. Leucine also helps the body metabolise fat for energy. [5]

Leucine can help improve body definition and performance.

5. Minimises muscle loss during dieting

Athletes in weight-class sports often face the challenge of maintaining muscle mass while reducing body fat. Leucine can play a crucial role in such situations, as it minimises muscle loss during low-calorie intake phases while maintaining muscle mass.

Leucine helps protect muscles during calorie-restricted periods, preserving strength and performance. [6]

Why WAM Protein Contains Extra Leucine

Leucine is found in higher concentrations in animal proteins like whey, meat, and eggs than in plant-based proteins. This often poses a challenge for vegan athletes, who might not get the same amount of leucine for muscle building from their daily diet. Plant-based protein sources like legumes, nuts, and seeds do contain leucine, but in smaller amounts – meaning you would have to consume much more of them.

To bridge this gap, our WAM vegan protein contains added leucine. Each 30g serving provides not only 22g of plant-based protein but also 2.5g of leucine. The amount in our WAM protein powder is comparable to that found in whey protein and is sufficient to effectively stimulate muscle protein synthesis. So, even with a vegan lifestyle or lactose intolerance, you don't have to compromise!

Pure Leucine vs. Leucine in Foods and Protein Powders

You can find pure leucine as a dietary supplement in concentrated form, such as powders and pills. However, it often has a bitter taste and, of course, there is the risk of overdoing it with the intake. Excessive intake of isolated leucine can lead to potential side effects such as stomach discomfort, and is also an unnecessary waste of money.

Leucine found in natural foods and protein powders like our WAM Protein, in a balanced form with other amino acids, is a better choice. Choosing such foods allows you to reap the benefits of leucine without risking an overdose. Additionally, you conveniently cover your daily protein needs at the same time.

How to Ensure Sufficient Leucine and Amino Acids in Your Diet

For strength athletes, especially those who are vegan, it is important to ensure adequate leucine intake. Here are some tips on how to make sure you’re getting enough leucine for muscle building:

1. Incorporate leucine-rich foods into your diet: If you don't consume animal-based proteins, some of the best plant-based sources of leucine are legumes, nuts, seeds, and tofu. Plan your meals to include a variety of these foods to ensure adequate amino acid intake.
2. Use protein powders: A serving of whey protein typically provides around 2.5 to 3g of leucine. If you avoid whey, products like our WAM vegan protein with added leucine are the best choice to ensure you’re getting enough. A protein shake immediately after training can help maximise muscle protein synthesis.
3. Combine carbohydrates with proteins: Studies show that combining carbohydrates with protein after training improves protein absorption and muscle protein synthesis. How about a post-workout smoothie with WAM Protein, banana, and oats? 

Leucine in Strength Training: Conclusion

Leucine is an essential amino acid that offers many important benefits for strength athletes. From stimulating muscle protein synthesis to supporting muscle recovery and fat burning, leucine is an indispensable part of a successful diet in strength sports. By incorporating leucine-rich foods and protein powders like our WAM Protein into your diet, you can ensure that you’re taking full advantage of leucine for your athletic performance and health.

Remember, alongside sufficient leucine intake, other essential amino acids are also crucial for muscle building and recovery and should be part of a balanced diet. If you have any more questions or need more tips, just get in touch with us!

Sources

[1] Plotkin DL, Delcastillo K, Van Every DW, Tipton KD, Aragon AA, Schoenfeld BJ. Isolated Leucine and Branched-Chain Amino Acid Supplementation for Enhancing Muscular Strength and Hypertrophy: A Narrative Review. Int J Sport Nutr Exerc Metab. 2021 May 1;31(3):292-301.

[2] Wilkinson K, Koscien CP, Monteyne AJ, Wall BT, Stephens FB. Association of postprandial postexercise muscle protein synthesis rates with dietary leucine: A systematic review. Physiol Rep. 2023 Aug;11(15):e15775. 

[3] Jäger R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, Purpura M, Ziegenfuss TN, Ferrando AA, Arent SM, Smith-Ryan AE, Stout JR, Arciero PJ, Ormsbee MJ, Taylor LW, Wilborn CD, Kalman DS, Kreider RB, Willoughby DS, Hoffman JR, Krzykowski JL, Antonio J. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017 Jun 20;14:20.

[4] Mero A. Leucine supplementation and intensive training. Sports Med. 1999 Jun;27(6):347-58. 

[5] Zhang L, Li F, Guo Q, Duan Y, Wang W, Zhong Y, Yang Y, Yin Y. Leucine Supplementation: A Novel Strategy for Modulating Lipid Metabolism and Energy Homeostasis. Nutrients. 2020 May 2;12(5):1299.

[6] Jitomir J, Willoughby DS. Leucine for retention of lean mass on a hypocaloric diet. J Med Food. 2008 Dec;11(4):606-9.