So, you’re interested in supplementing with BCAAs (if you don't yet know the basics about branched-chain amino acids, commonly referred to as BCAAs, I recommend reading this article first). Scientists have found that increased concentrations of the three branched-chain amino acids—leucine, isoleucine, and valine—can result in remarkable benefits, particularly for muscle growth and muscle recovery. Consequently, BCAA supplements are becoming ever more popular. While I wholeheartedly support your decision to try BCAA supplementation, I want to make sure you get the benefits you’re after.
5 Top Benefits Linked to BCAA Supplements
A wealth of research has linked BCAAs to a variety of enticing effects. While many of the effects of BCAAs have to do with muscle building and exercise performance, athletes aren't the only ones who can benefit from a supplemental dose of BCAAs. In my opinion, these are five of the most exciting as well as the most scientifically validated results of BCAA supplementation.
1. Limit Muscle Protein Breakdown
Many would rank this as the topmost and best BCAA benefit. Leucine, the power player of the BCAA trio, stimulates the rapamycin complex (mTOR) signaling pathway, which produces an increase to the rate of muscle protein synthesis, the process by which the body builds new muscle tissue.
Leucine has an impressive anabolic effect on skeletal muscle, which leads to impressive muscle-building results.
As a study published in the Journal of Nutrition explained, leucine promotes significant changes to skeletal muscle protein metabolism, namely, decreases to protein breakdown and increases to protein synthesis.
According to a placebo-controlled study published in Frontiers in Physiology in 2017, the post-workout ingestion of BCAAs can cause an increase in muscle protein synthesis of approximately 22%.
2. Optimize Exercise Performance
Another reason BCAAs have become such a red-hot workout supplement is that compelling evidence demonstrates they can lead to impressive improvements to exercise performance.
Researchers from the Carnegie Faculty of Sport and Education at Leeds Metropolitan University in Leeds, UK, conducted a study to examine the effects of leucine on resistance training performance for novice trainees. At the study's conclusion, participants who took leucine showed markedly higher strength gains than those who took a placebo—40.8% for the leucine group compared to 31.0% for the placebo group.
3. Minimize Muscle Damage and Soreness
As if athletes needed still more reasons to adore BCAAs, it appears they can also reduce post-workout muscle soreness and damage.
The results of a study published in the Journal of the International Society of Sports Nutrition showed that taking BCAAs both before and after a workout can lead to significant decreases to creatine kinase efflux as well as muscle soreness. Participants who took BCAAs also recovered their maximal voluntary contraction ability more rapidly than those who took a placebo.
"The present study has shown that BCAA administered before and following damaging resistance exercise reduces indices of muscle damage and accelerates recovery," the study's authors concluded.
4. Enhance Weight-Loss Efforts
Recent inquiries into the benefits of BCAAs indicate that they can maximize the effects of healthy weight-loss efforts.
A randomized, double-blind study published in 2009 looked at how BCAAs, whey protein, and a carbohydrate-based sports drink influenced body composition. All study participants (who had a minimum of 2 years of experience with resistance training) completed an 8-week, whole-body training program while eating a standardized diet.
At the study's conclusion, participants in the BCAA group had decreased their body fat percentage far more significantly than both the whey protein and carbohydrate sports drink groups. According to the authors, this reveals BCAAs can effectively encourage fat loss.
5. Maintain Healthy Blood Sugar Levels
We know that BCAAs make crucial contributions to the regulation of glucose levels. A steady supply of these essential amino acids is a prerequisite for ideal glucose uptake and insulin sensitivity.
Researchers have not yet conclusively demonstrated that BCAA supplementation produces beneficial changes to blood sugar levels, but findings so far have been quite promising. A 2012 study examined the effects of BCAAs on glucose tolerance and insulin sensitivity for patients with chronic hepatitis C, a serious form of liver disease.
At the study's conclusion, the authors found that BCAAs produced a clear, beneficial effect on patients' HbA1c values, a blood marker that measures the glycosylation of hemoglobin and can be used to give an average of blood sugar levels over the last 3 months.
Whether you’re a bodybuilder looking to mitigate muscle breakdown during exercise so you can build more lean muscle mass, an endurance athlete looking to optimize performance, or just an everyday person seeking to improve blood sugar metabolism and reach or maintain a healthy weight, the draw of BCAA supplements is self-evident.
However, in order to reap the BCAA benefits you desire, you must supplement with an amino acid formula that contains the appropriate concentration of all nine essential amino acids, not just the three BCAAs. Let me explain why that is.
The BCAAs Work Best as Part of a Team
Taking supplements that contain only some of the essential amino acids, such as branched-chain amino acids (BCAA) supplements, has minimal effect on protein synthesis (the process of building proteins, like those that make up muscle), because the synthesis of complete proteins requires adequate availability of all the essential amino acids. I just can’t stress this enough. Further, the many other functions of amino acids in the blood, including the production of neurotransmitters, regulation of blood flow, safeguarding of immune function, and improvement of plasma lipid profiles, are contingent on a balanced composition of blood amino acids.
In theory, the use of a single amino acid supplement may elicit a desired response, but oftentimes, this is not the case. Also, while the targeted response may be positively affected, other responses may not be desirable.
Take a moment to think about the human body at work, all day and night and every day and night. There are a multitude of physiological events taking place at the same time. And amino acids play a role, either directly or indirectly, in nearly every physiological function. Underlying these major functions are countless chemical reactions and the continuous breakdown and synthesis of compounds, all needed to sustain vital organs and life. And every single one of these functions requires a balanced supply of amino acids.
Each amino acid serves multiple purposes and often works in concert with other amino acids. The simultaneous action of amino acids in a wide variety of reactions and functions helps to explain the nutritional value of a balanced mixture of all the essential amino acids. The most important thing to remember is that, although you may be taking an amino acid supplement for a specific purpose, the other functions of amino acids are always in action.
Leucine Alone Won't Produce the Hoped-For Effects
Let’s demonstrate this with a concrete example. In addition to its role as a building block of protein, leucine activates the molecular processes that start protein synthesis. For this reason, leucine is often referred to as a nutraceutical, because it functions as a metabolic regulator and serves as a precursor for protein synthesis.
Consequently, leucine is a popular dietary supplement, either alone or contained in BCAA supplements. But, here’s what happens when you consume leucine without all the other essential amino acids in the proper composition. Regulatory mechanisms kick in to maintain a balance of essential aminos. So, when leucine is consumed in large amounts as a dietary supplement, the degradation of leucine is activated as the body tries to maintain the normal balance of all essential amino acids.
Even more concerning is that the metabolic pathway responsible for the degradation of leucine also degrades the other BCAAs (valine and isoleucine) at an increased rate. If only leucine is consumed, all three BCAAs deteriorate at an accelerated rate. The concentrations of both isoleucine and valine will fall below their normal levels. The decrease in the concentrations of valine and isoleucine will limit any beneficial effect the increased dose of leucine might have had because there won’t be enough valine and isoleucine available for the production of new protein.
For this reason, BCAA supplements are more commonly taken than leucine supplements alone, even though leucine seems to be the primary nutraceutical of the three. However, even all three BCAAs taken together do not resolve the problem created by an imbalance in availability of essential amino acids, since there are six other essential aminos not being given. As a result, neither leucine supplements, nor BCAA supplements that contain all three, have a demonstrable beneficial impact on protein synthesis.
BCAA Supplements: The Bottom Line
When you consume a large amount of the essential amino acid leucine, you increase the rate at which leucine gets broken down, since the body is designed to maintain steady levels of EAAs. Coincidentally, the breakdown of all the BCAAs (leucine, valine, and isoleucine) is increased because the same enzyme works on each.
If you hope to access the remarkable benefits associated with BCAAs—such as an improved ability to build muscle, decreased muscle soreness after high-intensity workouts, and a higher rate of fat loss, to name a few—you should not take BCAA supplements. Instead, look for a supplement with an amino acid formula that contains all the essential amino acids and has a greater proportion of valine and isoleucine to avoid decreases in their availability.