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tuna, protein, leucine, muscle building

What is Leucine?

There are three branched-chain amino acids (BCAAs): isoleucine, leucine, and valine. These three BCAAs are known to contribute to muscle growth, and we are going to focus in on leucine. Why? Leucine, in particular, has been found responsible for stimulating the mTOR pathway that initiates muscle protein synthesis (MPS). So basically, leucine turns the switch on to tell your body to start building muscle.

How Does Leucine Help with Recovery?

Leucine has been found to suppress delayed-onset muscle soreness as well as blood creatine kinase activity, which are both markers of muscle damage. Therefore, if your muscle function can return at a faster rate, you will be well-recovered  to go hard at your next workout as opposed to still feeling sore.


*Take Away: Leucine has been shown to stimulate MPS, which aids in faster recovery time and increased muscle growth. However, it is important to note that all 9 essential amino acids (EAAs) must be present in order for muscle growth to occur.

What are Leucine Rice Foods?

Research has shown that compared to casein and soy, whey protein sources were more effective in stimulating MPS both at rest and post resistance exercise due to their higher leucine concentration. When casein, whey and soy are compared to lean meat products, the casein/whey/soy are most efficient at stimulating muscle growth due to their rapid absorption.


*Take Away: Consume rapid absorbing protein sources after your resistance training such as: yogurt, cottage cheese, or milk with a combination of carbohydrates to leverage the most muscle growth.

Should I Supplement with Leucine?

As mentioned above, leucine is a BCAA and can stimulate muscle growth and muscle recovery. Supplementing with BCAAs is usually unnecessary since food is an easy way to get adequate leucine consumption. If you’re concerned your leucine intake is inadequate, please talk with your sports dietitian for recommendations on supplementation. You must also have the other 6 EAAs present in order for your body to begin building muscle. The best sources of leucine to consume post workout are complete animal proteins (yogurt, milk, lean meat, eggs) because they will have the 9 complete amino acids needed to build muscle. Consuming these within 30 minutes to one hour post-workout with a meal containing at least 3g leucine will optimize muscle recovery for performance.


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