If you are serious about your fitness and overall health, you have perhaps come across BCAAs – an acronym for branched-chain amino acids. There are a lot of good reasons why BCAAs come up in discussions about building muscle and getting more out of your workouts. In this article we will discuss the benefits and why BCAAs must be a major component of your fitness strategy.


What are BCAAs?

The branched chain amino acid group consists of leucine, isoleucine and valine. They comprise 35 percent of the amino acids that make up skeletal muscles. All three are essential amino acids not synthesized by the body but are needed for survival. This means they must be ingested through diet or by taking supplements. They can be found in protein-rich foods, with high concentrations in beef, chicken, fish, eggs, and whey protein.

BCAA formulas and supplements have been around since 1996, but they have been primarily used for treating liver disorders like cirrhosis and hypoalbuminemia. Today, they are mostly used by athletes and bodybuilders to boost power output and energy levels. While leucine appears to play an essential role in moderating the health benefits of branched-chain amino acids, taking leucine alone is not the most effective way of supplementing BCAAs. Isoleucine and valine are equally important and the most effective supplements in the market today feature a 2:1:1 ratio of leucine to the two other BCAAs.


BCAAs and Muscle Protein Synthesis

One of the primary roles of BCAAs is to induce cellular uptake of amino acids and stimulate protein synthesis. Note that muscle is made of protein so bodybuilders use BCAA supplements to maximize muscle gain from their workout routines. This is typically achieved by combining BCAAs with resistance exercises. The combo triggers the ‘mammalian target of rapamycin’ or mTOR signaling pathway which is crucial in muscle building.

The BCAAs’ protein synthesis stimulating property is also of paramount importance for individuals on a low calorie diet. Those trying to lose weight usually have to deal with loss of muscle mass as well as fat. BCAAs help in preserving muscle when caloric intake is restricted, resulting to more fat being burned and subsequently, a higher lean muscle to fat ratio.


Improved Endurance and Reduced Fatigue

Majority of amino acids can only be metabolized in the liver. BCAAs are an exception because they can be directly metabolized in muscle cells and then used to provide energy. It has been shown by scientific studies that loading up muscles with BCAAs prior to exercise can improve endurance and performance. The possible rationale behind this is that BCAAs increase the amount of fuel that can be converted by muscle cells into adenosine triphosphate (ATP), which subsequently provides the needed energy for muscular contractions.

Branched-chain amino acids are also capable of reducing the mental perception of fatigue. BCAAs do this by competing with tryptophan for transport across the blood-brain barrier. Note that tryptophan serves as a precursor of hydroxytryptamine (5-HT) or serotonin, a neurotransmitter that’s responsible for the feeling of tiredness and fatigue. Hence, high levels of BCAAs can lead to less serotonin being synthesized and thus a lower perception of fatigue, which in turn translates into improved endurance during training and fitness workouts.


Prevention of Muscle Loss During Endurance Exercise

Aside from improving endurance, BCAAs have been shown to be effective in preventing muscle loss during long-duration exercise. For instance, it was discovered that trained athletes who engaged in a 24-hour long exercise test that involved 12 cycles of cycling, running and kayaking experienced a considerable amount of muscle protein degradation and exhibited signs of metabolic stress associated with muscular damage. Moreover, there was a significant drop in plasma level concentration of BCAAs through the course of the test, which is associated with muscle loss. Experts suggest that providing simultaneous nutritional support of BCAAs will prevent the breakdown of muscle fibers by increasing the energy-burning pool so amino acids don’t have to be released from muscle tissue.


Decreased Muscle Soreness and DOMS

Multiple studies involving both trained and untrained individuals show that BCAAs are capable of reducing delayed onset muscle soreness (DOMS) in response to endurance and resistance exercises. As such, BCAAs are now considered as the gem of workout supplements because they allow the body to train more often at higher intensities by reducing post-workout soreness and preserving the integrity of muscle cells.


Increased Testosterone and Decreased Cortisol

Studies have revealed that taking BCAA supplements has a positive effect on the hormone balance in the body. In particular, BCAAs appear to boost the levels of testosterone while concurrently decreasing cortisol levels. This is perfect for those who want to lose weight and build muscle mass. Testosterone stimulates protein production and muscle gain while cortisol serves as the body’s primary response to stress, and one of its major functions is to increase the amount of glucose in the blood. It achieves this by shoring up the level of free amino acids produced by the catabolism of muscle protein. The liver then converts the free amino acids to glucose.

While cortisol plays a crucial role in the body’s ‘flight or fight’ response, its effects are detrimental in the long run. A decreased level of cortisol and an increased level of testosterone lead to the effects that most people want – an increase in muscle mass and the loss of body fat.


Increased Insulin Release

Recent clinical studies have spurred a lot of excitement regarding the potential use of BCAAs in the treatment of type 2 diabetes. The metabolic disorder is characterized by insulin resistance, which results in the disruption of the blood glycemic balance. Regulating glucose levels in the blood is one of the main functions of insulin, a hormone secreted by the beta cells of the pancreas. High blood glucose is the stimulus for insulin secretion. There is always a low level of insulin in the blood, but the amount increases as blood glucose rises. Similarly, as the level of blood glucose falls, the amount of insulin secreted by the pancreas goes down. Insulin is very important because it affects the metabolism of carbohydrates, lipids and proteins. Multiple studies have proven that BCAAs, specifically leucine, prompts the pancreas to produce and release insulin. BCAAs have also been shown to exert a stabilizing effect on blood glucose levels.



Branched-chain amino acids have a lot of known and proven health benefits aside from simply serving as the building blocks of proteins. These amino acids are beneficial to athletes and bodybuilders because they stimulate protein synthesis and prods the body to build muscle tissue. They have the capability to improve endurance during training and exercise. BCAAs are also of utmost importance to those who wish to lose weight because they help in preserving lean muscle while on a calorie restricted diet. Finally, BCAAs help in keeping glucose levels constant and striking a balance between anabolic and catabolic hormones.