Written by Garett Reid | NSCA, CSCS, CISSN, M.S.E.S.S
Fact checked by Andrew Lenau, ISSA CPT & Sports Nutritionist
FACT CHECKED
Branched-chain amino acids, or BCAAs for short, are an extremely popular dietary supplement used extensively by lifters and athletes. Taking BCAA supplements offers a slew of benefits, including reduced muscle soreness and more muscle growth.
With benefits like that, it's no wonder so many gym goers swear by it. But, this leads us to the question of timing. Is there a best time to take BCAAs to make the most of its benefits? Before a workout? After? In between?
This article will answer these questions, and more, including:
- What are BCAAs?
- Benefits of BCAA supplementation
- Best time to take BCAAs
- Special circumstances for taking BCAAs
What Are BCAAs?
We all know that protein plays a central role in muscle hypertrophy as well as muscle repair. We also know that BCCAs are supposed to do the same thing. So, what's the deal?
BCAAs are one of the most popular supplements in sports nutrition yet one of the most misunderstood. There can be confusion about what they really are, making it difficult to understand when to take them or what they do. Therefore, we're going to break down what BCAAs actually are.
Peptides:
When explaining BCAAs, the best place to start is peptides. A peptide is a short chain of less than 50 amino acids with smaller designations to describe specific lengths. For example, an oligopeptide is a chain of less than 20 amino acids.
When multiple peptides are connected, they form what's known as a polypeptide. A polypeptide with a chain of more than 50 amino acids is known as a protein.
BCAAs And Protein:
In this sense, the term "protein" is a nomenclature for a long chain of amino acids. While there are a large number of different amino acids, only 21 are considered proteinogenic, meaning they are responsible for building a protein.
In this sense, these amino acids are the literal building blocks of new muscle, making them crucial for seeing results following your workout split.
Essential Amino Acids:
Of these 21 amino acids, 9 are essential amino acids. They get their name as you must consume them through your diet, making them "essential." The other amino acids can be synthesized internally through other amino acids.
In general, your nine essential amino acids are the ones you need to be most concerned about supplementing. That's because they have the largest influence on muscle protein synthesis thanks to 3 unique amino acids.
These 3 unique amino acids are called...
Branched Chain Amino Acids
Branched chain amino acids! These 3 stand out from the other essential amino acids due to their structure (check out our article on EAA vs. BCAA for more information on differences). Unlike the other amino acids, they contain an aliphatic side chain with a branch (a central carbon atom bound to three or more carbon atoms). As a result, they're known as the "branched-chain amino acids."
These three amino acids are leucine, isoleucine, and valine.
What Do Branched Chain Amino Acids Do?
So if BCCAs are inside of EAAs and protein, why take them separately? Good question.
To be clear, you don't need to utilize BCCA supplements, especially if you consume enough protein, like these high protein low fat foods, for example. We'll get into this more below.
BCAAs and Muscle Protein Synthesis
BCCAs get more attention as they play critical roles in stimulating protein synthesis. While the other essential amino acids are also required for optimal function, these three are the driving force, especially leucine.
Leucine And Muscle Building
Leucine is a primary amino acid responsible for muscle growth and muscle recovery as it directly triggers mTOR. This is crucial as mTOR is the key regulator for muscle growth and your ability to build muscle.
This is because one of the primary functions of mTOR is to maximize muscle protein synthesis. Therefore, when mTOR senses leucine, it ignites protein synthesis.
BCAAs Can Act As An Energy Substrate
Because BCAAs are broken down in the muscle, many researchers believe this suggests that BCAAs can actually act as an energy substrate¹. Many people don't realize that our bodies can use amino acids to provide fuel. In fact, this is why it's smart to only undergo a small calorie deficit, as seen in this cutting workout and diet plan, when dieting to prevent muscle breakdown.
Out of all the amino acids, the BCAAs are most easily oxidized to supply energy. Further, they are broken down in the muscles rather than the liver, thus increasing their ability to provide energy.
BCAAs Decrease Serotonin Levels
Further, BCAAs have been found to decrease the level of serotonin in the body. While serotonin can be beneficial for relaxation, it can contribute to fatigue during exercise. And no one wants to feel more tired than normal during an assault bike workout.
Since serotonin levels are increased during exercise, BCAAs can keep these levels low, thus contributing to fatigue mitigation².
Benefits Of BCAA Supplementation On Performance
So now we know the various mechanisms of BCAA. Let's see how that plays out for actual performance benefits.
1. Increases Protein Synthesis:
Muscle protein synthesis is mandatory for building muscle. As we showed you that BCAAs, without a doubt, trigger muscle protein synthesis, it would make sense that BCAAs can help pack on lean muscle mass3,4.
One study looked at the effect of resistance training followed by 3 groups consuming either carbs only, carbs and protein, or carbs, protein, and leucine4. This study found that adding the branched-chain amino acid leucine increased protein synthesis and whole body net protein balance.
The International Society of Sports Nutrition also acknowledges leucine as the primary driver of muscle protein synthesis, suggesting we aim to take at least 700-3,000 milligrams per dose. But even a dose of 5 grams holds merit5.
To be clear, this dose of leucine is when taking BCAAs or whole protein. However, the ISSN also states that when muscle protein synthesis is the goal, one should take EAAs instead. This is because all 9 are required to optimize protein synthesis.
2. Improves Recovery & Decreases Delayed Onset Muscle Soreness (DOMS):
There are multiple supposed theories for what causes DOMS, such as inflammation and micro tears to the muscle fiber.
Regardless of why it happens, it sucks. The good thing is consuming BCAAs has been shown to alleviate symptoms of DOMS and promote muscle recovery. This includes physical symptoms such as pain and physiological markers such as lower creatine kinase levels.
Positive results have been found in meta-analysis and are one of the primary reasons people take BCAA supplements⁶.
3. Decreases Exercise Fatigue:
This reduction in muscle fatigue is especially seen during endurance performance due to the high energy demand. While you may think of endurance as running or cycling for long distances, endurance training could even be performing recumbent bike exercises at a steady state for long periods of time.
And as mentioned above, muscle fatigue reduction is due to BCAAs being used as an energy substrate and keeping serotonin levels low. In addition, BCCAs have been found to increase endurance athletes' work capacity when taken pre-exercise7,8.
A study from 2016 examined supplementation with repeated sprint performance across two days8. It was found that BCAAs were able to improve time-trial performance by lowering several variables, including a decrease in central fatigue, preventing excess hyperammonemia, and reducing serotonin levels.
4. Reduces Muscle Catabolism:
When we place stress on our muscles during exercise, like in a tough leg workout, it can cause them to break down. This is termed muscle catabolism.
The severity of this muscle wasting can be dramatically altered by the type of exercise, duration of the exercise, and your fed state. However, because BCAAs can readily be used, they can play a role in mitigating a breakdown in muscle tissue⁹. Simply put, this helps with reducing muscle catabolism and helps maintain muscle mass.
The Best Time To Take BCAAs
Let's get down to it. When exactly is the best time to take BCAAs? Unfortunately, there's no concrete answer. Part of the problem with providing a single time is that BCAAs work through several mechanisms, so your purpose for taking them can dictate when the best time actually is. Here are a few different workout scenarios and whether it makes sense to take BCAAs.
Taking BCAAs In A Pre-Workout Supplement:
If you are using BCAAs to reduce muscle soreness, multiple studies show taking BCAAs as a pre-workout is ideal.
For example, a study from 2017 examines the effect of BCAA timing on muscle damage. Participants consumed BCAA either before or after a workout that consisted of high rep eccentric contractions⁶.
Another study from 2020 looked at a leucine-enriched supplement and its effect on body function and physical performance¹¹. It, too, found that the pre-workout group saw better results with muscle recovery. As a side note, if your goal is optimal muscle recovery, don't forget to also emphasize the importance of sleep.
Taking BCAA Supplements Post-Workout:
From examining the current literature, it doesn't seem as though drinking BCCAs post-workout provides significant advantages. Of course, BCAAs play a huge role but assuming you're consuming a post-workout meal and prioritizing what to eat after a workout with quality protein, the addition of extra BCAAs likely won't generate extra benefits.
Taking BCAA Supplements During Exercise:
Many athletes will use BCAAs during long-duration exercise. While we aren't aware of significant studies on this, it seems as though it would, in fact, provide benefits.
Special Timing Issues For BCAA
While a BCAA supplement can provide these benefits, keep in mind that protein already delivers these amino acids. As far as how much protein per day to build muscle, aim for between 1.6-2.2g/kg/day. If you're getting this amount through protein-rich foods or a protein powder, it diminishes the need to take BCAAs for normal training circumstances.
However, certain situations increase the importance.
BCAA Supplements While Fasting:
If you follow fasting, specifically training while following an intermittent fasting technique, increasing your BCAA levels can be beneficial. Because the risk of muscle breakdown is increased as you are depleted of glycogen, BCAA supplementation can provide extra energy reserves to help protect against muscle loss.
BCAAs During Endurance Exercise:
BCAAs during long endurance exercises play a similar role as when fasting. Excessive training will deplete your glycogen stores and augment substrate utilization. Providing the extra BCAAs can help prevent muscle breakdown.
In addition, this longer duration can result in a greater build-up of fatigue. As we saw above, BCAAs can effectively reduce fatigue, giving you the energy to show up to the gym every day for your 7-day split.
How Often Should You Take A BCAA Supplement?
Another factor many don't consider is how often one should take BCAAs. While BCAAs supplementation is generally thought of as single doses, there's reason to believe that chronic supplementation may be necessary. Well, at least according to two meta-analyses.
Chronic Supplementation May Be Superior
A 2017 analysis examined 11 studies on BCAA supplements and noted that optimal results were seen when taken for longer than 10 days¹².
Then, in 2020, another meta-analysis was done and again came to the same conclusion. BCAA supplementation for longer than 10 days produced superior results⁶.
How Much BCAAs Should You Take?
When looking at different BCAA supplements, you want to look at one that delivers a BCAAs ratio of 2:1:1.
Further, as mentioned above, you want your leucine dose to be at least 3 grams. Therefore, you'd also take 1.5 grams of isoleucine and 1.5 grams of valine. This equals a total of 6 grams of BCAAs.
You want to consume at least 200 milligrams per kilogram of body weight for your daily dose.
Should You Take BCAA Powder Form Or BCAA Tablets?
If you look at the market, you can generally find two different forms of a BCAA supplement: powder and tablets.
BCAA Tablets:
The only benefit that tablets may provide is that they're arguably more convenient to take with you if needed. This is the same benefit you'll see when comparing other pill versions to powder, like with creatine pills vs. powder. Pills are also going to take longer to absorb while allowing a lower percentage to be fully utilized.
BCAA Powder:
In comparison, a BCAA powder is already broken down. This makes it significantly easier and faster for your body to absorb. While it may be more cumbersome, we think any hassle is still worth it.
Further, BCAAs usually taste good and can encourage hydration. For these reasons, we recommend you use a powder, like most options covered in our post the Best BCAA Supplements on the market.
BCAAs: Who Should Take Them & When
BCCAs are a relatively cheap supplement that may offer positive benefits. Out of all the perks, it seems BCAAs work best at mitigating muscle breakdown and reducing exercise induced muscle damage. Endurance athletes may also be able to delay fatigue.
As far as timing, pre-workout is ideal, especially if you're performing fasted cardio or lifting. Or, if you are performing longer endurance training, having it intra-workout may be beneficial.
With this in mind, BCAAs should never replace your protein intake. And assuming your protein intake is high enough and you're prioritizing the best protein powders, the need for BCAAs diminishes.
This doesn't mean BCAAs don't offer benefits. We just want you to be clear on what you're taking before you purchase it.
Related:
-
BCAA VS Glutamine For Recovery & Building Muscle
- BCAA VS Creatine: What's The Difference & Which Is Better?
- BCAA VS Pre-Workout Explained: Do You Really Need Both?
References:
- Kim DH, Kim SH, Jeong WS, Lee HY. Effect of BCAA intake during endurance exercises on fatigue substances, muscle damage substances, and energy metabolism substances. Journal of Exercise Nutrition & Biochemistry. 2013;17(4):169-180. doi:10.5717/jenb.2013.17.4.169
- Cordeiro LMS, Rabelo PCR, Moraes MM, et al. Physical exercise-induced fatigue: the role of serotonergic and dopaminergic systems. Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas. 2017;50(12):e6432. doi:10.1590/1414-431X20176432
- Nie C, He T, Zhang W, Zhang G, Ma X. Branched Chain Amino Acids: Beyond Nutrition Metabolism. International Journal of Molecular Sciences. 2018;19(4):954. doi:10.3390/ijms19040954
- Koopman R, Wagenmakers AJM, Manders RJF, et al. Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects. American Journal of Physiology-Endocrinology and Metabolism. 2005;288(4):E645-E653. doi:10.1152/ajpendo.00413.2004
- Kerksick CM, Wilborn CD, Roberts MD, et al. ISSN exercise & sports nutrition review update: research & recommendations. Journal of the International Society of Sports Nutrition. 2018;15(1). doi:10.1186/s12970-018-0242-y
- Rahimlou M, Ramezani A, Mahdipour M, Palimi E, Moradipoodeh B. Reduction of Muscle Injuries and Improved Post-exercise Recovery by Branched-Chain Amino Acid Supplementation: A Systematic Review and Meta-Analysis. undefined. Published online 2020. Accessed August 30, 2022.
- Ab G, T B, P LDC, et al. Branched-chain Amino Acids Supplementation Enhances Exercise Capacity and Lipid Oxidation During Endurance Exercise After Muscle Glycogen Depletion. The Journal of sports medicine and physical fitness. Published March 1, 2011. Accessed May 21, 2020. https://pubmed.ncbi.nlm.nih.gov/21297567/
- Cheng IS, Wang YW, Chen IF, Hsu GS, Hsueh CF, Chang CK. The Supplementation of Branched-Chain Amino Acids, Arginine, and Citrulline Improves Endurance Exercise Performance in Two Consecutive Days. Journal of Sports Science & Medicine. 2016;15(3):509-515. Accessed August 30, 2022. https://pubmed.ncbi.nlm.nih.gov/27803630/
- MacLean DA, Graham TE, Saltin B. Branched-chain amino acids augment ammonia metabolism while attenuating protein breakdown during exercise. American Journal of Physiology-Endocrinology and Metabolism. 1994;267(6):E1010-E1022. doi:10.1152/ajpendo.1994.267.6.e1010
- Ra SG, Miyazaki T, Kojima R, et al. Effect of BCAA supplement timing on exercise-induced muscle soreness and damage: a pilot placebo-controlled double-blind study. The Journal of Sports Medicine and Physical Fitness. 2018;58(11). doi:10.23736/s0022-4707.17.07638-1
- Ikeda T, Morotomi N, Kamono A, et al. The Effects of Timing of a Leucine-Enriched Amino Acid Supplement on Body Composition and Physical Function in Stroke Patients: A Randomized Controlled Trial. Nutrients. 2020;12(7):1928. doi:10.3390/nu12071928
- Is Branched-Chain Amino Acids Supplementation an Efficient Nutritional Strategy to Alleviate Skeletal Muscle Damage? A Systematic Review. Nutrients. 2017;9(10):1047. doi:10.3390/nu9101047
Garett Reid
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