Should you supplement BCAA's?
Branched-Chain Amino Acid (BCAA) Supplementation
What are BCAA’s? Branched-chain amino acids (BCAA) are essential amino acids (EAA). There are three branched-chain amino acids: Leucine, Isoleucine and Valine.
BCAA’s facilitate several metabolic roles:
· Promote protein synthesis and turnover
· Signaling pathways
· Metabolism of glucose
BCAA’s facilitate several physiological roles:
· Immune system and brain function support
· Lymphocyte growth
· Protein synthesis, synthesis of neurotransmitters, and production of energy
Are you trying to build muscle and recover quicker from hard training sessions?
BCAA’s are a popular supplement, and you can find them added to sports drinks and protein shakes, because of the role they play in muscle metabolism. Particularly, leucine, is critical for muscle protein synthesis and muscle protein breakdown.
Many resources will advise that you supplement 2.5 grams of Leucine prior to working out. Another 5 grams of Leucine during your workout, and another 5 grams post workout. Then take another 5 grams of Leucine before bed. Additionally, it’s recommended to add Leucine with or between meals. By my count that’s at least 17.5 grams of Leucine on training days, and a bit less on rest and recovery days.
Boom! So, taking BCAA supplements, especially leucine, will help you grow more muscle.
Not so fast!!! It’s not that simple.
While there does appear to be a scientific consensus that BCAA supplementation stimulates the molecular pathway leading to muscle protein synthesis, because of leucine, it is not clear that BCAA supplementation alone is effective for optimal muscle protein synthesis. Consuming BCAA’s without sufficient amounts of the other essential amino acids (EAA’s) will not produce the full muscle protein synthesis response. Remember, we are trying to be optimal!
The picture is even more murky when it comes to muscle protein breakdown. Muscle protein breakdown is a key component to remodeling and rebuilding stronger muscles. Taking BCAA’s to reduce muscle protein breakdown and recover quicker is a common claim of the supplement industry, however research hasn’t shown that reduced muscle protein breakdown is actually a positive factor for optimal recovery from training. It’s entirely possible that reducing muscle protein breakdown could stunt the recovery processes and thus limit the rebuilding process. More research needs to be done.
Should you supplement with BCAA’s to optimize muscle hypertrophy (growth) and speed recovery? The available evidence would suggest, No.
Your best plan of action is to eat meals that include high quality proteins. Your diet should be based as much as possible on whole, unprocessed foods that includes lots of fresh fruits and vegetables so that you are getting the full spectrum of essential amino acids (EAA’s) from your diet. If you still want to include a BCAA supplement or use a protein shake that has BCAA’s go ahead. It can be a challenge to have a perfect diet, and supplementing can potentially fill the gap in your diet that may be missing.
If you lack the ability to eat a diet as described above, then it would be a good idea to supplement with a high-quality protein such as a whey protein, soy protein or egg protein to provide sufficient BCAA’s and EAA’s for overall health.
Wait, there’s more! There is evidence that BCAA supplementation does have beneficial effects on other important physiological functions as they relate to exercise.
BCAA’s cause a reduction in blood glucose. Research has shown that BCAA’s taken before exercise can be used as energy during exercise, thus reducing the need for the liver to increase levels of glycogenolysis. BCAA supplementation has been shown to decrease lactic acid, allowing for more efficient glucose metabolism. This would indicate that if you are participating in an anaerobic exercise or sport that creates a lot of lactic acid, for example sprinting or CrossFit, then BCAA supplementation prior to exercise could really benefit you. What I could not find from the research was if adequate BCAA’s could be achieved by diet rather than supplementation prior to exercise.
Recent studies have shown that BCAA’s help to reduce the sensation of fatigue in the brain by reducing the levels of free fatty-acids in the blood that enter into the brain as well as preventing an over-accumulation of ammonia in the blood. Having a reduced sensation of fatigue would be a huge advantage in pushing a little further in sport. This research was based on a meta-analysis and actually concluded that there was no effect on the feeling of fatigue, but because there was evidence of favorable effect on fatigue substances in the body that they conclude BCAA’s can enhance exercise performance.
BCAA supplementation has also been shown to reduce the sense of muscle fatigue by decreasing the levels of creatine kinase in the muscle cells. Again, this would suggest a big advantage for training and sport. While the research concludes that BCAA supplementation is better than passive recovery or rest, the research itself is based on a meta-analysis of randomized clinical trials. Meta-analysis are non-experimental and can be just as flawed as a single research study.
Where does all this finally leave us?
If you are considering supplementing with BCAA’s for muscle growth and muscle recovery you likely do not need to, as long as you are eating an adequate diet with a full spectrum of essential amino acids (EAA).
If you are timing your intake of BCAA’s to take them prior to strenuous exercise that would create lactic acid, the research does seem to indicate that this would be a reason to supplement BCAA’s.
My conclusion – Your training goals may dictate whether you really need to supplement with BCAA’s. If you are just looking to get stronger, build more muscle and recover faster it is not likely that you need to supplement BCAA’s as long as you have a healthy diet. Eating a diet that is based as much as possible on whole, unprocessed foods that includes lean meats and lots of fresh fruits and vegetables will be your best option.
If you are training or participating in a sport that creates a lot of lactic acid, then pre-loading with a supplement of BCAA’s may help you have more energy and tap into your glycogen storage later, as well as limiting sensations of fatigue. What’s not clear is if you can still achieve these results from a proper diet.
There’s no harm in supplementing with BCAA’s, but there’s also little evidence to support that you are doing much more than spending extra money.
Sources:
https://en.wikipedia.org/wiki/Branched-chain_amino_acid#cite_note-21
https://www.ncbi.nlm.nih.gov/pubmed/3471061
https://link.springer.com/article/10.1007%2Fs11332-019-00542-4
Maughan, RJ; Gleeson, M (2010). The biochemical basis of sports performance (2 ed.). Oxford University Press. pp. 81–82.
https://www.sciencedirect.com/science/article/abs/pii/S0899900717300953?via%3Dihub
https://www.ncbi.nlm.nih.gov/pubmed/10418071
https://www.livestrong.com/article/75817-use-leucine-bodybuilding/