BCAA vs Pre Workout

Written by Ben Carlisle

Last updated on: Sep 18, 2022

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Branched chain amino acids or BCAA's and pre-workout are two separate and distinctly different supplements. Both have an important role in achieving muscle growth and fitness goals.

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BCAA's are three of the essential amino acids that the body cannot produce itself. They assist with muscle growth, recovery, and reducing fatigue, while pre-workout assists in overall performance. The primary difference between pre-workout and BCAA's is that BCAA's don't have stimulants.

When used properly together, both of these products will produce tangible and measurable results in muscle growth, improved energy during workouts, and faster muscle recovery. Let's dive in and explore a bit more and see how they can work for you!

What Are Branched Chain Amino Acids

Branched chain amino acids or BCAA's, as they are commonly known, are three of the nine essential amino acids your body needs to function properly but cannot synthesize internally, so they need to be acquired from external sources like diet and supplements. They are named 'branched chain' due to their chemical structure, which has side chain 'branches' made up of a single carbon atom and three hydrogen atoms (1).

The three essential amino acids are leucine, isoleucine, and valine, and each has a distinct function in the body. Still, together they work exceptionally well in promoting muscle growth, reducing muscle fatigue during workouts, and enabling faster muscle recovery. They also work to deliver energy into the muscles during training, and this helps to sustain energy and provide greater exertion and additional reps and set when doing weights.

Unlike other amino acids, BCAA's are not processed in the liver and gut but absorb directly into the bloodstream, making them particularly effective in improving muscular oxidation, increasing growth hormone circulation to aid muscle growth, decrease muscle damage, and improve recovery. Let's now look at each of the individual BCAA's and understand how they work and their role in training.


The first BCAA is leucine, and this amino acid has several functions in the body. It regulates blood sugar levels, promotes fat loss, effectively controls diabetes (2), and plays an essential in blood glucose regulation. This amino acid also aids in wound healing, increases muscle mass, and creates lean muscle muscles, which is why it is very popular with bodybuilders (3). Plus, it reduces the effect of sarcopenia, which is the loss of skeletal muscle mass in older people (4).


Similar to leucine, isoleucine also plays a role in glucose regulation and control. Studies show that isoleucine had more of an effect in reducing plasma glucose levels (5). Isoleucine has also proved to be effective in reducing muscle soreness and moderate muscle damage after training. This was most effective when the supplement was taken before exercise (6). Another key result of isoleucine is reducing post-exercise fatigue as BCAA's limit tryptophan uptake into the brain (7). This is how isoleucine prevents or reduces physical activity and mental fatigue.


The branched chain amino acid valine helps to promote muscle growth and tissue repair (8). Valine can also assit in delaying fatigue. The reason for this is because valine competes with tryptophan for transportation to the brain, decreasing brain 5-HT synthesis (13). 5-HT, also known as serotonin, can cause the feeling of fatigue during exercise. The prescene of valine in the body will delay the release of serotonin and the effects of fatigue being felt. This will enable an individual to maintain a higher output for a longer period during physical exercise.

BCAA Side Effects

For the most part, BCAA's taken in proper dosages have no recorded side effects. However, in some people, especially when taken in larger doses, BCAAs can result in digestive issues such as diarrhea, nausea, pain, and headaches. BCAAs are also not recommended for pregnant or breastfeeding women (12).

Foods That Are Rich In BCAA's

Since the BCAA's are all fairly similar, you will find them in foods like red meat, fish like salmon and trout, dairy products like cheese, milk, and yogurt, as well as nuts and seeds. Soy and whey proteins, as well as corn, wholewheat and brown rice, are also high in BCAA's, so you may need to add these to your diet and supplement your intake before, during, or after your training sessions.

BCAA Summary

It is clear that the three BCAA's together contribute to promoting increased energy levels during training, building lean muscle, and aiding in muscle recovery. This is why they are recommended for anyone looking to lose weight and build muscle and recover faster with less muscle stiffness. Now, let's examine the pre-workout supplements in detail and the differences between BCAA's and pre-workout. We will also look to answer a few questions on these two supplements like when to take them, can they be taken together, and if you only have one, which would you use, BCAAs or pre-workout?

Pre-Workout Supplements And How They Work

Pre-workout is fundamentally different from BCAAs in that it is not an essential dietary requirement like the branched chain amino acids are. It is a supplement designed to boost overall performance during training. Secondly, pre-workout contains stimulants like caffeine, while BCAA's do not, diverging these two supplement paths. The inclusion of stimulants is designed to give you that extra boost of energy and endurance.

This will certainly you improve your fitness and build muscle, but without the nutrients to back it up, you may find that building new muscle fibers could be problematic, so you'd need to ensure your diet is correct to see the best effects in your training. Pre-workouts usually contain a combination of ingredients like beta-alanine, caffeine, amino acids, B- Vitamins, and a few others varying from brand to brand. Some pre-workout supplements have BCAA's stacked as well, so you get the best of both in one shot.

Pre-Workout Pros

Many pre-workout supplements contain both creatine and caffeine, and these two bring some powerful benefits to your training. Creatine improves muscle growth and provides energy for the short, intense HIIT training segments like powerlifting or sprinting. It also increases body strength for better endurance during high-intensity training sessions (9).

Caffeine is well-known for reducing fatigue, improving mental focus and concentration, and improving metabolic rates in the body. When pre-workouts utilize vascular dilation additives, the ablity of the bdoy to supply oxygen and nitrogen to the muscles during training is increased. This helps with the supply of fuel and the removal of waste from the muscle tissues during training.

The Pre-Workout Drawbacks

Most pre-workout supplements would be fine to use, and you should suffer no adverse effects in the process. However, you do need to be aware that some potentially unpleasant side effects could occur. Firstly, most pre-workouts contain significant doses of caffeine, and if you are sensitive to this stimulant, it may be better to look for supplements with lower doses. A standard cup of black coffee has around 100mg caffeine, while most pre-workouts have between 175mg and 475mg caffeine.

Insomnia, headaches and irritability, and some uncomfortable digestive issues like diarrhea and nausea can be caused by caffeine overdose (10). You want to be sure that you aren't getting as much caffeine as some BCAA's may have. Remember that your body will start to build a tolerance to pre-workouts over time, so you find that the 'kick' you were getting when you started will wear off, and the temptation is to use stronger doses when all you may need is a break a different pre-workout.

Be very careful if you want to exceed recommended dosages on pre-workouts, as the effects can range from moderately unpleasant to properly unpleasant. Only take pre-workouts on the days you are training and let your body recover on the days you are not. So before you buy or take anything, know your limits on caffeine, especially if you have a medical condition that precludes or limits your caffeine dosage.

Other additives like beta-alanine are thought to increase performance in weight training by assisting in the increased production of carnosine in the muscles. Carnosine helps to regulate the build-up of acid in the muscles, reducing muscle fatigue There is no conclusive research or studies to validate these claims , there is some evidence suggesting that it improves the endurance time that an athlete can train for before exhaustion (11). Beta-alanine can cause that skin-tingling sensation which is harmless but unpleasant.

Can You Take BCAA's And Pre-workout Together

Taking the two before your workout or 'stacking 'allows them to perform their specific functions in improving your gains and workout focus and endurance and better and faster muscle recovery. The pre-workout can be taken anywhere from 30-60 minutes before your workout, but a 30-minute window is better as it should peak just as you are done warming up and gives that power boost to your training when you need it.

BCAA's can also be taken during and post-workout because these amino acids are designed to reduce muscle damage and improve recovery post-training. So if you are pushing weights and want to maximize your gains, using BCAAs and pre-workout is a good combination. The stimulants in pre-workouts give you that focus and mental energy and the physical energy to push through your plateaus.

Combined with the energy-boosting properties found in BCAAs, it would provide you with excellent strength to take on more challenging routines with either heavier weights or more reps, or both. The added benefits of faster recovery, less muscle fatigue, and stiffness mean you can bet back for your next session sooner!

Choosing Your Supplements Properly Is Important

As with anything you are going to put into your body that isn't food, you need to be picky and careful about which supplements you will use. This is because, as with anything, some are better and some are not. Do your research into the recommended products as often brands will provide all the supplements you need like the pre-workout and BCAAs and protein powders and meal replacements so that you are sure of getting maximum benefits.

Talk to the assistants who work in stores that sell these suppplements. Many of them use these products themselves and can provide valuable feedback on their efficacy, 'cleanliness', and side effects they have encountered. Often, brands will offer trial sachets or small doses of pre-workout or BCAAs, and trying them out to see how they work and feel for you will give you a good idea of whether that brand's products are effective and safe. You can also invest some time online and check out reviews and reports on products to get more insight into the results they provide and whether the claims they make are justified or not.

Before You Buy Any Supplements, Create A Training Plan

Simply going to the gym without a plan and using supplements like BCAA's or pre-workouts is more a hobby than a plan, and spending money on these supplements without a defined goal in terms of growth, weight loss, or performance is a bit pointless. Involving a personal trainer or coach can offer great benefits as they would assist in a training plan and recommended doses for pre-workout and BCAA's and the brands of products you can use for your training.

Working to a plan and being accountable will benefit your training results by using pre-workouts and BCAAs, and you can have peace of mind knowing that your dosage is correct and healthy. While most supplements, including BCAAs and pre-workouts, are pretty safe to take off the bat if you are unsure or have an existing medical condition that could preclude the use of certain chemicals or stimulants, then do consult your doctor to be safe.


There is clear evidence that both BCAA's and pre-workout supplements have very definite benefits for anyone looking to lose weight, bulk up or build lean muscle. As they can be taken together, you can look forward to some power training sessions. With minimal (if any) risk and almost no side effects when taken in the correct dosage and at the right times, the results from using these supplements in your training will be positive, as will the overall health benefits.

Related Articles


1. https://pubmed.ncbi.nlm.nih.gov/10937674/

2. https://pubmed.ncbi.nlm.nih.gov/19013300/

3. https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=19&contentid=Leucine

4. https://www.ncbi.nlm.nih.gov/pubmed/25809808

5. https://www.ncbi.nlm.nih.gov/pubmed/14651987

6. https://www.ncbi.nlm.nih.gov/pubmed/28934166

7. https://www.ncbi.nlm.nih.gov/pubmed/16424144

8. https://pubchem.ncbi.nlm.nih.gov/compound/L-valine

9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2048496/

10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5445139/

11. https://www.webmd.com/vitamins-and-supplements/beta-alanine-uses-and-risks

12. https://www.webmd.com/vitamins-and-supplements/branched-chain-amino-acids-uses-risks

13. https://pubmed.ncbi.nlm.nih.gov/11510866/

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