The BCAA (branched chain amino acid) group consists of three amino acids, leucine, isoleucine and valine. The name comes from their chemical structure, these amino acids have a side chain that contains one carbon. BCAA are essential amino acids, our bodies can’t synthesise them and they have to be obtained from the diet. Like other amino acids they are the basic building blocks of proteins, and hence necessary for life. However, they also have some very specific signalling functions, which gives them a very important role in controlling metabolism. Because of this they have a number of health benefits, beyond that of just being constituents of proteins.
BCAA Stimulate Protein Synthesis
One of BCAAs main roles is to stimulate amino acid uptake by cells, and protein synthesis. This role is so well established that they are given to bedridden patients to slow down muscle wasting. Bodybuilders and athletes, of course, use BCAAs to help maximise muscle gain from training.
Recent studies have shown that leucine interacts and activates the mTOR pathway in cells. mTOR stands for ‘mammalian target of rapamycin’ and is a pathway, that acts as a cellular nutrient sensor among other roles. High levels of leucine are interpreted as high overall nutrient levels, and as a sign that the environment is good for increased protein synthesis and growth. Leucine activates the mTOR pathway, which in turn activates other proteins like the initiation factors, which have to be activated to start protein synthesis on the ribosomes.
BCAAs also cause the activation of genes which code for ribosomal proteins. Ribosomes are tiny organelles inside cells where protein synthesis occurs. As a result of increased BCAA levels, more ribosomes are made inside cells.
In short, BCAA amino acids, especially Leucine, acting through the mTOR complex, increase the levels of protein synthesis in two ways. They increase the cells’ capacity to synthesis proteins, by increasing the number of ribosomes, and they stimulate translation, by causing the activation of factors that control it. As everybody knows, increased protein synthesis in muscle cells, results in increased muscle gain.
The protein synthesis stimulating property of BCAAs is also of great importance when going on a calorie reduced diet. One of the problems of trying to lose weight is that muscle mass is lost as well as fat. BCAAs will act to preserve muscle when calories are restricted, leading to more fat being burned, and a higher lean muscle to fat ratio.
Improved Endurance and BCAA Supplements
The vast majority of amino acids can only be metabolised in the liver. BCAA amino acids, on the other hand, can be metabolised directly for energy in muscle cells. Loading up muscles with BCAA before exercise, was shown in scientific studies, to improve performance and endurance. This is presumably because, they increase the amount of fuel immediately available to cells, which can be turned into ATP, which in turn provides energy for muscle contractions. It is a well known fact that BCAAs are severely depleted during exercise. Presumably this happens because they are used up as fuel.
Branched chain amino acids can also lesson the mental perception of fatigue. We all know that how you feel in your mind is at least as important as your physical state. BCAAs achieve this because they compete with transport across the blood-brain barrier with tryptophan.
Since tryptophan is a precursor of the neurotransmitter serotonin, high levels of BCAAs might result in less serotonin being produced and a lower perception of fatigue, which translates into better endurance during exercise.
Reduce Soreness and Promote Recovery
For those who wish to decrease their recovery time and soreness after endurance exercise, such as running or cycling, BCAAs may provide the answer. A 2000 study published in the “Journal of Sports Medicine and Physical Fitness” found that BCAA supplementation can cut down on muscle damage related to endurance exercise. Another 2008 paper published in the same journal noted that BCAA supplementation could promote muscle recovery while helping regulate the immune system. This may be particularly helpful in avoiding illness, as immune function can be weakened after intense or prolonged exercise.
Increase Exercise Performance
Research shows that branched chain amino acids can improve exercise performance by both increasing the resistance to fatigue as well as sparing muscle glycogen, or energy stored in muscles. A 2011 study published in the “Journal of Sports Medicine Physical Fitness” found that the branched chain amino acid supplements provided superior resistance to fatigue when compared to a placebo, in addition to increased fat burning. A 1996 paper published in “Nutrition” noted that an increased supply of branched chain amino acids during exercise helped preserve stored muscle energy.
It appears that branched chain amino acids may have an anabolic effect on the body, which makes them particularly useful for those interested in increasing muscle size and strength. A 2006 paper published in “The Journal of Nutrition” noted that branched chain amino acids trigger important enzymes in protein synthesis, post-exercise. The paper also notes that, for muscle building purposes, leucine may be the most important of the three branched chain amino acids. BCAAs provide an anabolic effect by increasing the rate of protein synthesis – or muscle building – while decreasing the rate of protein degradation, or muscle breakdown.
So what is the best time to take BCAA supplementation?
We have inferred that the best time to take BCAA powder or tablets is either before working out, during or after. We know, this is a bit vague, but let us explain how versatile this amazing product can be.
BCAAs Before Workout:
Taking a BCAA supplement before working out can be great for those that train fasted in a morning. Research has shown that taking BCAA supplementation (we prefer powdered BCAAs) can have a fatigue reducing effect allowing you to perform just as well as you would with a prior intake of food 2 hours before. Many people think that they won’t workout as well if they didn’t eat carbs before they train. This is simply not the case, or not the case for most people. If you have a decent meal the night before containing carbs, fats and protein then this should be enough to fuel your morning workout fasted. And you can then take BCAAs to give you that extra amino acid boost.
How much BCAAs do I need before working out?
We recommend taking 5g-10g of BCAAs before working out.
Best Sources of BCAAs
The best sources of BCAAs are meat, chicken, fish, dairy products and eggs, reports NYU Langone Medical Center. As a guideline, you can figure on consuming about 1.7 grams of leucine and 1 gram each of isoleucine and valine from a 3-ounce serving of meat, poultry or fish or from 1/2 cup of cottage cheese. A cup of milk contains about half that amount. Whey protein is another good option for boosting your intake of BCAAs.
Soybeans, baked beans, lima beans, lentils, brown rice, whole wheat, corn and nuts such as almonds and cashews are good sources of branched-chain amino acids, reports the Huntington College of Health Sciences. Of all the plant-based foods, beans have the highest amount of total protein, so they’re the best choice for BCAAs. One cup of vegetarian baked beans has about 1 gram of each of the BCAAs. By comparison, 1 cup of cooked brown rice and quinoa have 0.4 gram of leucine, 0.2 gram of isoleucine and 0.3 gram of valine.
What you should know
Because BCAAs are so important to muscle tissue, and because they help maintain blood sugar levels, it’s important to get enough to support your workouts. Consuming a carbohydrate, protein, and amino acid beverage during and after training can induce an insulin response, which helps transport BCAAs into cells. However, availability of leucine is more important than insulin. Within the muscle cell there’s one particular regulatory pathway for protein synthesis that’s stimulated by insulin, but dependent on leucine .In other words, protein synthesis (and hence muscle rebuilding) depends on how much leucine is available. And since BCAA levels decline with exercise, it makes sense to supplement with them during and/or after workouts
Because it’s so important to have leucine available for protein synthesis, if you train in a fasted state, or don’t eat after exercise, you’re going to lose more protein than you rebuild. However, if you eat adequate BCAAs during this time, especially leucine, you’ll enhance protein synthesis.
How can you put this knowledge to use?
Try adding BCAAs into your workout drink at a rate of 5 g BCAA per hour of training.
The benefits of BCAA powder over BCAA tablets
We prefer powder over BCAA tablets everyday of the week. To get a good dose of branch chain amino acids that elicits a positive response on the body you need to consume between 5g and 10g each time. This can essentially mean popping 10 and 20 tablets. Powder is much more potent, and it can taste great.
Summary and recommendations
BCAAs play an important role in:
- Synthesis of proteins in general
- Glucose homeostasis (i.e. keeping blood sugar levels constant)
- Direct regulation of muscle protein synthesis (via insulin signaling cascade)
BCAAs’ potential impact on the aforementioned processes depends upon availability and dietary intake.
Adequate consumption of BCAAs may help manage body fat, spare muscle mass, and regulate glucose/insulin balance.