BCCA (Branched-chain amino acids) – is a complex consisting of three essential amino acids:
These amino acids are released together, not because they complement each other, but because it is an easily extractable fraction, which is obtained from a protein hydrolysate or biosynthetically. Moreover, the preparation of one amino acid or the separation of BCAAs into individual amino acids is much more difficult.
BCAA is the main material for building new muscles, these essential amino acids make up 35% of all amino acids in muscles and take an important part in the processes of anabolism and recovery, have anti-catabolic effects. BCAA cannot be synthesized in the body, so a person can receive them only with food and special additives. BCAAs differ from the other 17 amino acids in that they are primarily metabolized in the muscles, they can be considered as the main “fuel” for the muscles, which improves athletic performance, improves health, and they are absolutely safe for health.
BCAAs are the most common form of sports nutrition, but the appropriateness of use is questioned.
BCAA in food
Foods containing BCAAs and dietary proteins are, for example, meat, poultry, fish, eggs, milk and cheeses. The content in these products is approximately 15-20 g BCAA per 100 g protein.
BCAA in bodybuilding
The claimed effects of BCAA amino acids in bodybuilding:
- Muscle damage prevention;
- Increased lean muscle mass (controversial);
- Decrease in the percentage of body fat (not proven);
- The increase in power indicators (not proven);
- Increase the effectiveness of sports nutrition (partially justified for defective protein).
The role of BCAA in the body:
- Muscle protein synthesis substrate;
- Substrate for energy production;
- Precursors for the synthesis of other amino acids, especially alanine and glutamine;
- Metabolic modulators:
* BCAAs stimulate muscle protein synthesis through PI3K activation;
* Stimulate muscle protein synthesis by activating mTOR.
- Suppress catabolism and muscle breakdown;
- Stimulate insulin production;
- Fat is burned by expression of leptin in adipocytes by mTOR.
BCAA perform many important functions and can be used in muscle gain, weight loss, work on the relief, aerobic training. However, for qualitative and economic reasons, whey protein is preferred as a source of BCA.
Mechanisms of Action of BCAA
Let us consider in more detail the points listed above, with a thorough analysis of biochemical processes and links to research and scientific literature, to give a complete picture of the role of BCAA in sports.
BCAA as an energy substrate
Exercising increases BCAA oxidation in order to maintain energy homeostasis by converting it into an easily accessible energy source – glucose. Studies show that during and after exercise, BCAA (especially leucine) concentration decreases in athletes, immediately after this metabolic processes are turned on, which are aimed at normalizing the concentration of BCAA, that is, muscle proteins begin to break down, as the main sources for replenishing the BCAA amino acid pool. Supplementation with BCAAs in the form of supplements can restore their concentration and stop the process of muscle destruction.
In addition, recently, scientists have been paying special attention to the role of leucine as a source of ATP (the main energy substrate of the body). Oxidation of leucine in muscles produces even more ATP molecules than the same amount of glucose. And considering that the oxidation of leucine and glucose goes in different ways, the athlete immediately receives 2 powerful sources of ATP, that is, he recovers his strength much faster.
Muscle protein synthesis
As mentioned above, BCAAs make up a third of all amino acids of muscle proteins, so they can be considered the main building block of muscle. A protein can be synthesized only under the condition of the presence of free amino acids, otherwise growth stops. At rest, to fill the need for amino acids, it is enough to take a protein that is gradually absorbed from the intestine and fully satisfies metabolic needs, however, during and immediately after training, amino acid requirements increase sharply, and the amino acid pool is depleted, so there is a need in large shipments of amino acids. Thus, taking BCAA in the form of sports nutrition, the athlete creates favorable conditions for the restoration of the amino acid pool and the construction of new muscle fibers immediately after training.
BCAAs as Glutamine Precursors
Glutamine plays an important role in muscle growth. Glutamine is found in large quantities in muscles and other tissues, plays a regulatory role in the synthesis of all types of body protein, shifts the nitrogen balance to the anabolic side, increases the volume of muscle cells and increases the production of growth hormone. Increased glutamine consumption during exercise can be covered by BCAAs, which can convert directly into muscle.
Stimulation of insulin secretion, PI3K and protein synthesis
One of the pathways that accelerate protein synthesis (i.e. muscle growth) is the phosphatodyl-inositol-3-kinase pathway (PI3K). PI3K regulates glucose uptake and accelerates the transport of amino acids into cells. Insulin carries out its anabolic effect precisely due to PI3K.BCAA (leucine) is able to enhance insulin secretion and directly activate PI3K, so anabolism is triggered even in the absence of insulin. The use of carbohydrates and BCAA after training leads to a synergistic increase in insulin levels, increased cellular consumption of nutrients, and accelerated muscle growth.
mTOR activation accelerates protein synthesis
mTOR (mammalian target of rapamycin – mTOR) – is a protein that regulates cell growth and division, as well as the synthesis of a new protein. mTOR functions as an energy sensor that activates when the ATP level is high and blocks when the ATP level is low. The most energy-consuming process in the cell is the synthesis of protein, so it needs large amounts of ATP, in addition, building material – amino acids, that is, BCAA, is needed. Studies show that the intensity of anabolic processes is regulated by mTOR, which triggers protein synthesis with a sufficient amount of ATP and BCAA. Scientists have determined that leucine plays a key role in mTOR activation.
BCAA and Fat Burning
BCAA intake stimulates the expression of leptin hormone genes in adipocytes (fat cells), via the mTOR-mediated pathway. Leptin is a very complex hormone that regulates many metabolic processes, in particular body weight, appetite, as well as the consumption and deposition of fat.
Leptin secretion is related to the amount of body fat, the higher the percentage of body fat, the higher and the leptin secretion and vice versa. When you go through a cycle of burning fat and following a diet, the amount of leptin is reduced, which leads to increased appetite and economized metabolic processes in order to restore or maintain energy reserves of fat. That is why, some athletes can significantly reduce the calorie intake and increase the load, and however, the body weight will not change, as the body tries to maintain homeostasis. For this reason, sometimes it is necessary to limit the diet very much in order to move homeostasis from the so-called control point.
A BCAA, namely leucine, helps to shift the control point and increase leptin secretion. BCAAs seem to deceive the body, causing it to think that high-calorie food enters the body. BCAA can suppress appetite, increase calorie intake by burning fat, increase metabolism, and most importantly protect muscles from destruction.
When to take BCAA
When gaining muscle mass
The most appropriate time to take BCAA is in the morning, as well as before, during, and immediately after training. You can prepare an energy drink before training by dissolving a serving of amino acids and a few tablespoons of sugar in water. This will ensure a constant flow of fluid, carbohydrates and amino acids into the blood during the entire workout. As mentioned above, the body especially needs BCAAs during and after training, which is when BCAAs show the greatest effectiveness, so you need to take them 30-40 minutes before the start, and immediately after training, as well as during it, if it is a soluble form. It is also advisable to take a serving of amino acids immediately after sleep to suppress morning catabolism. Studies have shown that BCAAs are effective even when mixed with a protein shake.
There is an opinion that there is no point in taking BCAA, like other amino acids and proteins, before training, because during exercise the body reduces digestion function, nevertheless, it persists. That is why marathon runners use solutions of amino acids and isotonic right while running.
When losing weight and working on relief
BCAA should be taken as described above: in the morning on an empty stomach, before training and immediately after training, soluble forms during training. In addition, when losing weight, you can take BCAA in between meals, in order to suppress catabolism, appetite and muscle preservation, but it is more profitable to use protein for these purposes.
How much to take BCAA
Most professional trainers agree that for every kilogram of their own weight an athlete should receive about 33 mg / kg of leucine per workout. The optimal single dose of BCAA is 4-8 grams, both when losing weight and when gaining muscle mass. The frequency of administration is 1-3 times a day. Smaller doses of BCAAs are also effective, but they will no longer fully cover the body’s needs.
Many manufacturers are tricky and produce BCAA in small doses, although the price remains high, so always look at the back of the package for the number of servings and the size of one dose of BCAA.
The duration of BCAA is unlimited, no breaks or cycling required. There are a lot of sources on the Internet that advise taking BCAAs in increased dosages (15-20 grams per dose), arguing that the body needs an increased amount of amino acids after exercise. However, at the moment there is no strong evidence base that would confirm these tips. Also, there is no information on how well BCAAs are absorbed in the body when consumed in high dosages
The dosage of BCAAs is indicated without taking into account their content in protein supplements and products (any protein contains these amino acids, however, the aspect of the additional intake is discussed, provided that a sufficient amount of protein is obtained per day).
BCAA can be combined with almost all types of sports nutrition. When gaining muscle mass, it is best to combine them with Citrulline, protein (or gainer), creatine and anabolic complexes.
Quality Assurance of BCAA
- Pure BCAA powders form a film on water and do not fully dissolve when mixed. Emulsifiers are added to modern complexes, which makes them highly soluble.
- The taste of BCAA is bitter.
- Color and consistency as described on the label.
- The packaging is properly sealed and meets factory standards.
- Remember to check the expiration date.
Production methods and health hazards
Amino acids are produced in four main ways:
- Hydrolysate Extraction;
- Biosynthesis or bio fermentation (amino acids produce mutant strains of bacteria);
- Chemical synthesis;
- Enzymatic synthesis (synthesis using purified enzymes).
Chemical and enzymatic synthesis for BCAA is practically not used. For food, bacterial biosynthesis is widely used.
Currently, for nutritional purposes, BCAAs are produced mainly by bio-fermentation. Leucine, isoleucine and valine are obtained using strains of E. coli and C. glutamic via the pyruvic and aspartic acid pathway. Thus, isoleucine and valine are actually by-products of the synthesis.
Bio-fermentation method increases the cost of amino acids by 300-400%, compared with chemical hydrolysis.
The poor quality of raw materials
In the process of production of food amino acids, vegetable sources (soy, cereal) and animals (milk proteins) are used. Most often, manufacturers do not indicate sources of raw materials.
Electro dialysis and some other methods can be used to obtain an amino acid hydrolysate from food and other biological wastes, including human hair, fish, feathers, blood, meat wastes, etc. The use of low-quality raw materials can significantly reduce the cost of the output product. There is evidence that most Chinese BCAAs are made from waste.
BCAA production in this way begins with a protein hydrolysis process. Hydrolysis can be performed enzymatically or chemically, by heating the protein with acids and solvents. Then, amino acids are extracted from the obtained hydrolysate. For this, centrifugation, absorption, ion-exchange filtration, recrystallization, precipitation, etc. are used. The amino acid fraction with side chains (the so-called leucine fraction) is separated from soy protein and other hydrolysates quite easily, since they have a similar molecular size and charge.
- The use of poor-quality raw materials and extraction does not exclude the content of toxic compounds and contaminants in the final product.
- The bio fermentation method does not exclude the content of D-isomers in the final product, the biological effect of which may be potentially undesirable.