You probably know that protein is linked with muscle growth and might be familiar with amino acids like leucine. But have you ever wondered why it’s so important for building muscle mass? Or what the best approach is when it comes to dosage and timing? In this article, we explain exactly how leucine supports muscular hypertrophy and the best ways to use this to your advantage.
What Is Leucine?
Leucine is a branched chain amino acid (BCAA) involved in muscle growth and repair. Amino acids are found in protein and are involved in lots of different functions varying from immunity to gene expression. They are also structural components and regulators of your metabolism, affecting how your body breaks down carbohydrates, proteins, and fats.
How Does Leucine Support Muscle Growth?
Leucine stimulates the creation of new muscle fibers, sometimes referred to as ‘muscle protein synthesis’. It does this in two ways;
- As an actual building block that forms new muscle cells
- As a signaling molecule that initiates muscle development
Leucine’s involvement in these two aspects of muscle growth makes it essential to achieving strength and hypertrophy gains. It enables your body to repair muscle cells after training and recover faster so that you can get even better results from your workouts. Some researchers have suggested that leucine intake is more influential on muscle growth than total protein consumption. This is why ensuring you have sufficient leucine in your diet is a key component of strength nutrition.
Does Leucine Work Without Exercise?
Leucine will stimulate muscle growth regardless of whether you train or not. But its effects are greatly improved when combined with resistance training. This is because it makes the muscle more sensitive to amino acid fluctuations, so it takes in more when levels increase due to supplementation or feeding. Combining leucine with strength training can also increase the volume and duration of muscle protein synthesis so that more fibers are developed over a long time. This leads to bigger increases in muscle mass so that you see even greater results. So, although leucine supplementation can work on its own, you’ll see even better gains if you combine it with strength training.
How Much Leucine Do I Need Per Day?
So, now you know why leucine is crucial for muscle growth and essential for maximizing recovery. But how much should you consume for hypertrophy or bodybuilding purposes? The research isn’t all consistent but suggests that you need a minimum leucine dosage of between 1.7-2.4g in order to stimulate muscle growth. Anything less than this threshold is unlikely to be sufficient to get you results. That’s why our mTOR PRO™ supplement contains 2.5g of instant L-leucine as well as an additional 3g of time-released leucine.
In terms of leucine-rich foods, dairy proteins (such as whey and casein) tend to contain a higher amount. Plant proteins such as soy, pea, and rice, all have lower leucine contents, so a larger serving is required to achieve the same results. If you eat a purely plant-based diet, then you’ll need to aim for 30% of your energy intake from protein to meet the minimum leucine threshold.
When to Take Leucine
Conventional wisdom says that the best time to consume protein is immediately after exercise. This is when the muscle cells have the greatest need for amino acids in order to repair and grow. However, a large-scale review looked at 20 different scientific studies about protein timing which involved almost 500 participants in total. This review found that protein timing did not affect strength results or muscle gain, indicating that when we consume leucine is less important than previously thought. Guidance from industry leaders like the International Society of Sports Nutrition is still to consume protein within two hours of exercise. Even if the exact timing isn’t 100% confirmed, the fact that it helps to develop consistent nutrition habits is still beneficial.
What About Taking Leucine Before Bed?
Consuming protein or leucine before bed can also be beneficial. It has been shown to stimulate muscle development overnight so your body can recover while you sleep. This is something that casein, in particular, is effective at since it’s a slower-digesting protein than other sources. However, many people don’t like to eat before bed which is one of the reasons that our mTOR PRO complex includes a time-released form of leucine known as ActiveTR™. This supports steady, consistent muscle repair as you rest or sleep so that you’re less likely to wake up sore or tense.
Why Leucine is Important for Building Muscle Mass
Leucine is vital for building muscle mass. It acts as a signal for your body to rebuild muscle as well as being a structural component of the fibers themselves. Ensuring you consume sufficient leucine (upwards of 2.4g per serving) will maximize your body’s ability to build muscle and recover from training sessions. Leucine’s benefits are further enhanced when you combine consumption with resistance training, allowing you to get the best possible results from your workouts.
mTOR PRO – Elite mTOR-Activating BCAA Recovery Matrix
Developed over several years of clinical testing and scientific study, mTOR PRO is a powerful BCAA supplement that features a unique formula of vitamins and essential amino acids to promote muscle recovery and repair, build endurance and improve overall athletic performance. Each serving contains 2.5g of L-leucine and 3g of time-released L-leucine known as ActiveTR. mTOR PRO™ is currently one of the only supplements on the market to use this time-released form of leucine so that you can support recovery and maximize gains throughout the day and night. It also contains isoleucine and valine to further support muscle growth, as well as other indispensable amino acids that your body can’t produce itself, including histidine, lysine, methionine, phenylalanine, and threonine. Each ingredient has gone through years of studies and trials to ensure safety and deliver proven results so that the components work together to enhance effects and benefits. Learn more about mTOR PRO here.
Caroline has a Master’s degree in Human Nutrition and Bachelor’s degree in Sports Science. She has an in-depth understanding of sports nutrition and wrote her Master’s thesis on protein supplementation. After graduating she also qualified as a Personal Trainer and loves to combine her knowledge of exercise, nutrition, and science to help people achieve their health goals. For over 10 years she has worked with leading fitness and nutrition companies all over the world. She also loves functional training, practising yoga, and exploring different countries in her spare time.