BCAA Supplementation: Are They Necessary?


13 Nov BCAA Supplementation: Are They Necessary?

Do protein and amino acid supplements enhance athletic performance? That’s a big question that has yet to have very substantial evidence. Sure, there are studies that show or ‘claim’ that BCAA supplementation enhance performance, improve recovery from exercise, prevent muscle breakdown, and aid in protein synthesis, but there are also studies that show BCAA supplementation does not improve exercise performance. Let’s begin with a little background on the topic.
Most athletes look for ways that will help improve their performance, whether it be in the gym, on the field, in the pool, or whatever sport they are participating in. When methods or products are thought to help improve performance, they are called ergogenic aids. A very popular ergogenic aid out on the market right now is BCAAs, or branched chain amino acids. We know that protein is made up of amino acids, but “of the essential amino acids, leucine, isoleucine, and valine, are classified as BCAAs because they each contain a chemically “branched” R-group.” It is well known that exercise increases energy expenditure to a great degree and also promotes the oxidation of BCAAs. You can definitely argue that since muscle is mostly made up of protein, if you increase the amount of protein and BCAAs you ingest, you should also see an increase in muscle mass, an increase in strength, and an increase in performance. It seems like a simple hypothesis, but it’s very far from simple. We shouldn’t forget that branched chain amino acids are present in all protein-containing foods such as red meat, fish, chicken, eggs, and dairy products to name a few. These branched chain amino acids, leucine, isoleucine, and valine, make up approximately “one-third of muscle protein”. As stated before, it has been shown in other research that leucine plays the biggest role in promoting protein synthesis. It has been shown in certain studies that “…when BCAAs were infused in humans at rest, protein balance increases by either decreasing the rate of protein breakdown, increasing the rate of protein synthesis, or a combination of both”. Now there are tons of claims on supplemental BCAAs, and regarding most supplement manufacturers, they label that “…BCAAs can decrease mental fatigue, maintain muscle tissue, prevent muscle breakdown, promote protein synthesis, used as fuel for energy, support lean muscle mass and growth, and improve exercise performance”. It should be duly noted that these are claims, and don’t list studies that show and more importantly, prove these claims. In 1987, there was a theory called the central fatigue hypothesis, proposed by Blomstrand, et al, and it suggests that “…oral ingestion of BCAAs would reduce central fatigue and would enable athletes to maintain a higher pace during prolonged competitive exercise.” BCAAs get a lot of hype because of the theory that BCAA uptake to the brain will compete with tryptophan uptake, thus decreasing the amount of tryptophan to the brain which results in less serotonin, which is thought to play a major role in feelings of fatigue. During prolonged aerobic exercise, the amount of free tryptophan in the body increases, thus increasing the uptake of tryptophan to the brain. When this happens, “…BCAAs are transported into the brain by the same carrier system as tryptophan and thus “compete” with tryptophan to be transported into the brain”. We shouldn’t forget that most of these studies done on BCAAs are done using animal models, and that similar research needs to be done on healthy individuals that already engage in daily resistance exercise.
There have been studies done that show “When BCAAs are taken during aerobic exercise, the net rate of protein degradation has been shown to decrease”, and also very important is that, “…BCAA administration given before and during exhaustive aerobic exercise to individuals with reduced muscle glycogen stores also delay muscle glycogen depletion”. Another study notes that “…BCAA administration taken during prolonged endurance events may help with mental performance..”. With all of these studies out that show improvement in performance, mental fatigue, and the other benefits claimed by supplement manufacturers with the ingestion of BCAAs, you would think BCAA supplementation is a must if you’re an athlete or just someone trying to increase or enhance their performance, but it’s just not that simple. Not every study out on BCAA supplementation shows that they work, or that they even benefit the individual taking them. “One such study reported that leucine ingestion taken before and during anaerobic running to exhaustion and during a strength training session did not improve exercise performance.” A study conducted by Blomstrand, et al, gave an average of 6.7 grams of BCAAs to subjects 15 minutes before exercise and every 15 minutes during exercise and identified that no difference in physical performance was noted between the BCAA group and the placebo group. Another study by Hall, et al, had a low group supplementation of BCAAs (7.8 grams) and a high group (23.4 grams) and had the subjects ingest the BCAA supplements before and during exercise. The study showed “neither a positive or negative effect on performance during prolonged cycle ergometer exercise”. A study conducted by Watson, et al, gave 12 grams of BCAAs to subjects at rest and 5.4-18 grams of BCAAs during exercise. The study showed that exercise capacity was not influenced by BCAA ingestion. Another two studies that were evaluated both giving BCAA supplementation to the subjects alone and with a carbohydrate solution to compare, showed that there was no performance benefit to supplementing with the BCAAs.
After taking a look at these studies that show NO improvement or benefit from supplementing with BCAAs, I was just thinking to myself, “Well which studies do I believe?” There are studies that show benefit in mental and physical fatigue, and an improvement in exercise capacity by supplementing with BCAAs, but also, other studies that show not one trace of improvement or benefit from supplemental BCAAs. It is certain however, that “…the ingestion of BCAA seems to cause increased concentration of plasma BCAA during exercise and at the moment of exhaustion”. There needs to be many more studies done on human subjects that already engage in resistance training regularly to see if there actually is a benefit to BCAA and protein supplemenation.
So how does this topic relate to nutrition? We have had enough background to know that protein is the major player in building muscle and helping to recover and rebuild damaged muscle tissue after resistance training or aerobic exercise. Amino acids are the building blocks of protein and there are 20 amino acids that make up protein structure. Eleven of the twenty amino acids are non-essential, meaning our body produces these amino acids naturally, and they are alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine. That leaves nine other amino acids that are considered essential, meaning we have to consume these amino acids via diet and/or supplementation. These nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Roles that amino acids play in the body are as follows; regulate protein breakdown, control protein synthesis, convert to neurotransmitters, stimulate or inhibit activities or metabolic enzymes, and provide nitrogen for synthesis of nonprotein compounds. Amino acids can also be used for glucose synthesis and ATP production which would benefit the avid exerciser to a great degree; more ATP, more energy, more reps, more muscle breakdown, more muscle rebuilds. Amino acids are also vital to our DNA make-up and structure. A very popular disease going around nowadays is called sickle cell anemia, which is a disease caused by a single error in amino acid sequence of hemoglobin. This causes the red blood cells to take a sickle shape and makes them rigid and sticky, thus making it harder for the body to pump and distribute blood efficiently and also leaving your body more susceptible to developing clots which leads to other problems in the long run, such as heart attack and stroke. Only one single error in amino acid sequence, out of the thousands of polypeptide chains that contain your body’s DNA, can cause a very quick downfall in body function.
So where do I stand on this matter? I do feel as if BCAA supplementation is beneficial, despite what some of these studies show. I follow a very strict diet of whole, nutritious food, and I take in around 250-300 grams of protein per day, which should guarantee that I’m getting my full need of amino acids just from my diet alone, but the research on leucine, and how that certain BCAA triggers benefits in hormone production and protein synthesis led me to believe that the supplementation of it would bring about more solid muscle mass, better recovery from workouts, more strength, and mostly all of the benefits mentioned in the first few pages of this article. If we are following the studies here, then your guess is just as good as mine. We have studies pointing out benefits of BCAA supplementation and we have studies showing no sign of improvement in performance from BCAA supplementation; and again, these studies are done on animal models, which no matter how close they are to the human body make-up, just will not react 100% like the human body would. To counteract even more error in some of the studies, some of them were done on individuals who were not regular exercisers and were just done on aerobic training alone, which does not give us any answers on if an individual who resistance trains daily would get any benefit from BCAA supplementation. So in conclusion from the research, BCAA supplementation “…prior to and during exercise bouts will improve plasma BCAA concentration during and after exercise. This does not, however, appear to have a performance benefit for athletes. There seems to be a true disconnect between the claims made by the manufacturers of BCAA and supporting research”.
You make the call.


Paul A. Hovan Jr., B.S., NASM CPT, CSN

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