If you're a fan of lifting heavy things over and over, chances are you've heard of BCAAs. Branched-chain amino acids are among the most prevalent sports performance products on the market. Studies show that BCAAs benefit athletic performance by reducing muscle breakdown, improving recovery times, and stimulating muscle protein synthesis to help you stack on more gains.*
Energy is derived from the foods you eat. As you digest macronutrients, they are broken down into their simplest form. In the case of protein, it's amino acids. Three essential amino acids—leucine, isoleucine, and valine—make up the branched-chain aminos. They are often called the building blocks of protein. The branched-chain amino acids are essential because your body does not produce them naturally, so it is essential to get them from the foods you eat or from supplements.
Research suggests that BCAAs can have a positive impact on muscle protein synthesis, which is the muscle-building process. BCAAs also prevent protein degradation, which means muscle breakdown. In order to build muscle, your body must be in a net positive amino acid balance. If the rate of muscle protein breakdown is greater than the rate of muscle protein synthesis, it becomes catabolic and breaks down muscle tissue for energy. This is especially crucial for endurance athletes or those who participate in high-intensity functional training modalities.*
Carbohydrates and fats are also broken down into their simplest forms after you eat them: simple sugars and fatty acids, respectively. Their molecules are transported through your bloodstream and converted to energy in the mitochondria in the form of adenosine triphosphate, or ATP. At rest, the body uses mostly glucose (carbohydrates) and some fatty acids (body fat) for energy. While you train, it will use glucose and fatty acids for energy before amino acids. Only when your body is near depletion of its preferred energy sources does it shift to consuming amino acids.
Supplemental BCAAs help keep your body in an anabolic state during prolonged exercise bouts or multiple workouts per day. By taking BCAAs, you ensure that your body is in a positive amino acid balance, which will support muscle growth and repair and reduce muscle soreness post-workout.*
4 Big BCAA Benefits
1. Enhanced Muscle Building*
One of the many benefits of BCAAs is their defining role in building and maintaining muscle. A study published in the Journal of Nutrition determined that the BCAAs, particularly leucine,
have anabolic effects on protein metabolism by increasing the rate of muscle protein synthesis and decreasing the rate of protein degradation.*
Muscle protein synthesis is the body's response to intense physical stress caused by micro-tears and mini trauma done to the muscle tissue during training. By supplementing with BCAAs before or during your workout, you will stimulate the process of protein synthesis to help rebuild muscle and strength.*
A well-rounded diet rich in lean protein sources will contain a full spectrum of the essential amino acids needed to build muscle and optimize recovery. Real food is always preferred over supplementation, however, BCAA supplements are highly concentrated and more quickly absorbed, further encouraging muscle growth in addition to real food.*
2. Increased Power Output*
Power is a function of energy output over a specific distance. For bodybuilders, that means how much energy they can put into a barbell over the course of each rep. Peak power is a critical metric for strength athletes and powerlifters who perform at 90-100 percent of maximum output for short periods of time. These kinds of activities require a combination of strength, velocity, force, and neuromuscular adaptations.*
Researchers at Auburn University in Alabama performed a 10-week randomized double-blind controlled study with trained cyclists to examine the effects of BCAA supplementation on body composition, performance, and immune health. Eighteen trained cyclists were given 12 grams of BCAAs per day or a maltodextrin placebo. The results showed a 19 percent increase in peak power performance and average power for the BCAA group over the beginning of the trial, while the placebo group saw no significant changes.*
More peak power is linearly related to a direct increase in athletic performance. If you can produce more power during a max effort, you'll be able to improve time trials, sprint performance, and load, and outperform the competition.*
3. Improved Post-Workout Muscle Recovery*
Resistance training causes micro tears in your muscle fibers and the resulting muscle soreness can have a dramatic impact on your peak power, exercise frequency, and rep volume.
A study published in the journal Nutrients examined the effects of BCAA supplementation on recovery from resistance training. Using a randomized, double-blind, placebo-controlled design, researchers assigned participants to either a BCAA or placebo group. At 72 hours post-workout, the BCAA group reported significantly less muscle soreness than the placebo group. The study noted that the difference provided by BCAAs may be made up by athletes consuming a diet rich in protein.*
4. Delayed Fatigue and Improved Energy*
Several factors are known to cause fatigue during intense bouts of exercise, including workout intensity, duration, and fitness level. Some research suggests that BCAAs can help delay muscle fatigue by stopping the amino acid tryptophan from converting to serotonin, as serotonin can cause fatigue.*
Changes in the brain serotonin level is one mechanism that has been suggested as a potential factor in causing fatigue. During exercise, tryptophan crosses the blood-brain barrier, where it is converted to 5-hydroxytryptamine (5-HT), better known as serotonin. Having more serotonin during exercise signals the brain that your body is fatigued and can translate into less muscular endurance and strength.
Transport of 5-HT is influenced by the available amount of tryptophan and other amino acids, including the BCAAs, which are transported along the same carrier pathway. While BCAAs and tryptophan compete to get across the blood-brain barrier, BCAAs typically win the battle. So supplementing with BCAAs before or during your workout may help limit the amount of tryptophan that gets converted into serotonin, resulting in greater muscular endurance and less fatigue.*
What's the Best BCAA Ratio?
Most BCAA supplements contain a greater amount of leucine because it is the most critical branched-chain amino acid in the muscle-building process and ignites protein synthesis. Because of that, you would think that having a greater ratio of leucine to isoleucine and valine would increase muscle strength and improve recovery better, right? Not necessarily. Studies show that taking a 2-1-1 ratio of BCAAs stimulates protein synthesis even better than taking leucine in higher ratios or leucine alone. Therefore, a 2-1-1 ratio of BCAAs will be a better choice than 4-1-1 or even 10-1-1.
In a randomized, double-blind, placebo-controlled study conducted at Baylor University in Texas, 30 participants were given BCAAs, leucine, or a placebo. The supplements were consumed in three equal doses 30 minutes before resistance training, immediately before training, and post-workout. The results indicated that both leucine and BCAA supplementation led to greater levels of phosphorylated 4E-BP1 and cell signaling of the mTOR pathway, a serine/threonine kinase that stimulates protein synthesis through amino acid activation. Furthermore, the study concluded that supplementing BCAAs had greater effects on mTOR than taking greater amounts of leucine alone. These findings suggest that isoleucine and valine may contribute to greater activation rates than just leucine by itself.*
To achieve maximum performance benefits, most clinical studies suggest taking 4-10 grams of BCAAs twice per day, pre- and post-workout. If you want to consume more BCAAs, make sure you're focusing on a high-protein diet of whole foods as well to round out the variety of your amino acid intake. Using BCAAs for a longer duration in combination with your training plan is also critical.*
When you're looking for a BCAA supplement, make sure it has a 2-1-1 ratio and at least 4 grams of BCAAs per serving. You can get these essential amino acids from a protein rich diet, however adding a BCAA supplement will ensure you remain in an anabolic state and stimulating muscle protein synthesis.*
*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.
- Jackman, S. R., Witard, O. C., Philp, A., Wallis, G. A., Baar, K., & Tipton, K. D. (2017). Branched-chain amino acid ingestion stimulates muscle myofibrillar protein synthesis following resistance exercise in humans. Frontiers in Physiology, 8, 390.
- Blomstrand, E., Eliasson, J., Karlsson, H. K. R., & Köhnke, R. (2006). Branched-chain amino acids activate key enzymes in protein synthesis after physical exercise. The Journal of Nutrition, 136(1), 269S–273S.
- Kephart, W. C., et al. (2016) Ten weeks of branched-chain amino acid supplementation improves select performance and immunological variables in trained cyclists. Amino Acids, 48(3), 779-89.
- VanDusseldorp, T. A., et al. (2018). Effect of branched-chain amino acid supplementation on recovery following acute eccentric exercise. Nutrients, 10(10) 1389.
- Blomstrand, E. (2006). A role for branched-chain amino acids in reducing central fatigue. The Journal of Nutrition, 136(2), 544S-547S.
- Mero A. (1999). Leucine supplementation and intensive training. Sports Medicine, 27(6), 347-58.
- La Bounty, Paul, et al. (2008). The effects of oral BCAAs and leucine supplementation combined with an acute lower-body resistance exercise on mTOR and 4E-BP1 activation in humans: preliminary findings. Journal of the International Society of Sports Nutrition, 5(Suppl 1), 21.