Not everyone who hits the gym floor wants to compete, transform into a fitness model, or become a pro athlete, but that doesn't mean they're not serious about making big changes to their bodies. Just look at the number of people who participate in transformation contests every January. There's a lot of fat burning and muscle building going on this time of year!

Getting in the best shape of your life requires you to pay particular attention to your diet and training. Those have to be on point whether you have a plan to lose fat or build muscle, but there are a lot of smaller details that can cumulatively affect your overall success. One of those small details is actually a group of amino acids called the branched-chain amino acids (BCAAs). These particular aminos can have a huge impact on gains in muscle size and strength, fat-burning, and athletic performance.

The three BCAAs—leucine, isoleucine, and valine—are different from the other amino acids. I'll explain how as I outline the key reasons why BCAAs should be part of your transformation game plan!

1. BCAAs Can Help Promote Muscle Gains

You can't transform your body without building at least some muscle, and BCAAs can help promote muscle growth in several different ways.

First, BCAAs serve as the building blocks of muscle protein. Muscle is made up of protein, and protein is made up of individual amino acids added together through a process called protein synthesis. But not all amino acids are so intimately involved in this process.

When most amino acids are ingested, they're absorbed by the intestines and shuttled straight to the liver. The liver then decides what to do with them before they go to the rest of the body. If the body needs more energy, the liver will even break them down for fuel rather than spare them to repair and build muscle and other tissue.


You can't transform your body without building at least some muscle, and BCAAs can help promote muscle growth in several different ways.

BCAAs, on the other hand, tend to be spared by the liver and get direct access to tissues like muscle. The muscle fibers then get to make the decision of what to do with the BCAAs based on their needs. One of these needs could very well be to build up muscle fibers, which is good!

In terms of protein synthesis, leucine is by far the most valuable of the three BCAAs for stimulating muscle growth. Much like the ignition starts the car engine, leucine turns on the process of muscle protein synthesis. In scientific terms, leucine activates a complex process called mTOR, which ramps up protein synthesis, and therefore muscle growth.[1]

BCAAs may also have a role in stimulating the secretion of both insulin and growth hormone (GH).[2] Although the majority of research in this area has been conducted in animal models, supplementing with BCAAs before your workout may increase concentrations of both insulin and GH, supporting increases in muscle size, strength, and possibly even fat loss.

Finally, supplementing with BCAAs can help lower levels of cortisol during exercise. That's a good sign, since cortisol is a catabolic hormone that can interfere with testosterone and encourage muscle breakdown. Sipping on BCAAs during your workout may also help to reduce muscle breakdown and speed up muscle recovery!

2. BCAAs May Support Fat Loss

BCAAs can do more than build muscle: Leucine and isoleucine can also a play a major role in your efforts to get lean. One of the first studies to highlight this benefit was a 1997 experiment done on competitive wrestlers, which found that subjects supplementing with BCAAs while following a low-calorie diet experienced a greater drop in body fat, particularly in the waist, compared to those taking a placebo.[3]


BCAAs can do more than build muscle: leucine and isoleucine can also a play a major role in your efforts to get lean.

Moreover, a study out of Brazil found that six weeks of leucine supplementation in combination with a low-calorie diet caused a large drop in body fat in rats.[4] The researchers proposed that the increase in protein synthesis stimulated by leucine increased energy expenditure so much that it helped burn off body fat.

In a recent study on BCAAs' fat-loss effects, Japanese researchers discovered that mice given isoleucine while eating a high-fat diet gained significantly less fat than mice not getting supplemental isoleucine.[5] These results were apparently due to isoleucine's ability to activate special receptors, known as PPARs, that increase fat burning and inhibit fat storage. PPARs work to increase the activity of genes that encourage greater fat burning in the body, while at the same decreasing activity of genes that increase fat storage.

3. BCAAs Help Increase Energy And Delay Fatigue

I wrote earlier that BCAAs are used for multiple needs by muscle fibers. One common use is as an immediate energy source, particularly during intense training sessions. The more intense and the longer the workout, the more BCAAs will be called upon to be used for fuel. This is exactly why I include a full 6-gram dose of BCAAs in Pre JYM—more fuel for the muscles means you'll be able to train more intensely and for a longer period of time, which is critical for drastic improvements in body composition.


The more intense and the longer the workout, the more bcaas will be called upon to be used for fuel.

Valine plays a key role in providing energy for workouts. During exercise, tryptophan is taken up by the brain in large amounts. Tryptophan is converted in the brain to 5-hydroxytryptamine (5-HTP), or what you likely know as serotonin. Having higher serotonin during exercise signals the brain that the body is fatigued, which can lead to a reduction in muscle strength and endurance.

Valine, however, competes with tryptophan for entry into the brain and typically wins out.[6] The result? Less tryptophan gets in and converted to serotonin, which allows your muscles to contract with more force for a longer time before becoming fatigued.

4. BCAAs Can Help Support The Immune System

Yes, BCAAs can help, as they've been suggested to enhance immune function following exercise.[7,8] Since intense training can take a toll on your immune system—especially when you're also dropping calories—and increase your chances of getting sick, supplementing with BCAAs is a smart idea to possibly help prevent catching a cold or flu and missing gym time.

5. BCAAs May Support All-Around Health

In one study out of Milan, Italian researchers discovered that mice that had been given supplemental BCAAs had higher amounts of mitochondria in their muscles and higher activity of the longevity gene SIRT1.[9] Although these effects have yet to be confirmed in humans, this sure would be a nice fringe benefit from a supplement already providing numerous other physique benefits!

Taking Your BCAAs

Supplementing properly with BCAAs comes down to three main variables: dose, ratio of leucine to isoleucine to valine, and timing. Here's a quick breakdown:


Dose: The optimal dose of BCAAs is around 5-10 grams.

Ratio: This is a key variable. Leucine is the major mass builder of the three BCAAs, but that doesn't mean that more leucine is always better. Reap the benefits of all three BCAAS with a ratio of 2:1:1 (leucine to isoleucine to valine) taken pre-workout. Post-workout, a slight bump in leucine to a ratio of 3:1:1 may help to further promote muscle recovery and growth. Anything above that provides insufficient levels of isoleucine and valine relative to the leucine content.

Timing: I've heard some people argue that BCAAs taken pre-workout are of little value, and BCAAs taken post-workout are overkill if you're already taking a good protein supplement. I completely disagree. I believe in taking 5-10 grams of BCAAs both before and after training regardless of how much protein you're taking, or what kind. Taken pre-workout, BCAAs are an immediate energy source that can help blunt fatigue, and taken post-workout they ignite protein synthesis, boost insulin and GH levels, and blunt cortisol release.

Another time of day to consider BCAAs is with meals that provide fewer than 30 grams of protein. It's currently estimated that it takes about 3 grams of leucine to optimally stimulate muscle protein synthesis. Most animal protein sources—dairy, beef, eggs, poultry, fish, seafood, and pork—supply about 3 grams of leucine per 30-gram serving size. So if you're having a snack or meal that provides fewer than 30 grams of protein, consider having at least 5 grams of BCAAs in addition.

Now add some BCAAs to your shaker, get to the gym, and make your transformation goals count!

  1. Wang, X., & Proud, C. G. (2006). The mTOR pathway in the control of protein synthesis. Physiology, 21(5), 362-369.
  2. Nair, K. S., & Short, K. R. (2005). Hormonal and signaling role of branched-chain amino acids. The Journal of Nutrition, 135(6), 1547S-1552S.
  3. Mourier, A., Bigard, A. X., De Kerviler, E., Roger, B., Legrand, H., & Guezennec, C. Y. (1997). Combined effects of caloric restriction and branched-chain amino acid supplementation on body composition and exercise performance in elite wrestlers. International Journal of Sports Medicine, 18(1), 47-55.
  4. Donato, J., Pedrosa, R. G., Cruzat, V. F., de Oliveira Pires, I. S., & Tirapegui, J. (2006). Effects of leucine supplementation on the body composition and protein status of rats submitted to food restriction. Nutrition, 22(5), 520-527.
  5. Nishimura, J., Masaki, T., Arakawa, M., Seike, M., & Yoshimatsu, H. (2010). Isoleucine prevents the accumulation of tissue triglycerides and upregulates the expression of PPARalpha and uncoupling protein in diet-induced obese mice. The Journal of Nutrition, 140(3), 496-500.
  6. Gomez-Merino, D., Bequet, F., Berthelot, M., Riverain, S., Chennaoui, M., & Guezennec, C. Y. (2001). Evidence that the branched-chain amino acid L-valine prevents exercise-induced release of 5-HT in rat hippocampus. International Journal of Sports Medicine, 22(5), 317-322.
  7. Bassit, R. A., Sawada, L. A., Bacurau, R. F. P., Navarro, F., & Rosa, L. F. B. P. C. (2000). The effect of BCAA supplementation upon the immune response of triathletes. Medicine and Science in Sports and Exercise, 32(7), 1214-1219.
  8. Bassit, R. A., Sawada, L. A., Bacurau, R. F., Navarro, F., Martins, E., Santos, R. V., ... & Rosa, L. F. C. (2002). Branched-chain amino acid supplementation and the immune response of long-distance athletes. Nutrition, 18(5), 376-379.
  9. D'Antona, G., Ragni, M., Cardile, A., Tedesco, L., Dossena, M., Bruttini, F., ... & Valerio, A. (2010). Branched-chain amino acid supplementation promotes survival and supports cardiac and skeletal muscle mitochondrial biogenesis in middle-aged mice. Cell Metabolism, 12(4), 362-372.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

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