Two supplements that are used by a huge percentage of people who train in the gym are BCAA's or Branched Chain Amino Acids and Pre Workouts. Both of these supplements can help improve strength and focus, but they work differently in the body.

In this guide, we break down the key components of both BCAAs and pre-workouts to find out what they are and when you should take them. Find out which one is best for you in this head-to-head comparison of BCAA vs pre workout!

BCAA's are a great supplement to take to support you during your workouts, but you will not notice a strong effect from taking them. If you are happy with improving your results by 1-10% without any noticeable side effects, then a BCAA is a great way to do so. 

If you want to feel like you are having your performance boosted and enhanced, pre-workout supplements are the superior choice. They also come with a lot more versatility than BCAA's. 

You can get a strong pre-workout with a good stimulant level for those days that you can't seem to drag yourself from your bed and a weaker one for days you don't need it. 

Taking a pre-workout supplement is going to give you an immediate and noticeable boost in performance. You will be able to lift more, lift heavier, and for longer periods. If you are sensitive to stimulants, though, they may be a bad choice. 

Most pre-workouts also contain essential amino acids in ample amounts too. This means you are getting the benefits of supplementing with BCAA's when you take a pre-workout supplement. 

BCAAs Vs Pre-Workouts Compared





Improving Focus 

Improving Motivation 

Improving Muscle Growth 

Improving Strength 

Side Effects 

For Improving Strength

For improving your strength in the gym, pre-workouts definitely give you the edge. With pump-inducing ingredients and a boost of stimulants, you will be able to lift heavier weights and with more endurance than if you were just taking BCAA's, which are better for recovery and slow results over a long period. 

Mixing creatine and pre-workout provides more energy to your muscles during heavy training sessions. Many people believe it's bad for your health, but these claims are unsupported by scientific research.

Winner: Pre-Workout 

For Improving Focus And Motivation

Again, with the stimulants usually added to pre-workouts, you are going to get an immediate boost in both your levels of focus and your motivation. Drinking BCAAS will not give you this immediate boost. 

Pre-workouts often contain caffeine and beta-alanine, which is known to improve mental focus. Be careful on how much you are taking as focus can quickly turn into an uncomfortable feeling once your blood is flowing during your workout. 

Winner: Pre-Workout 

For Muscle Growth

Pre-workouts might make you work out harder, but they are designed to help you while you are in the gym, not so much afterward. BCAA's are the building blocks of protein synthesis, and by drinking them regularly, you will see an improvement in the rate at which your muscles rebuild and grow. 

While amino acids are found in our body naturally, BCAAs help to replenish this supply much faster. This allows your body to soak up as much as possible post-workout to rebuild those chains. 

Winner: BCAA’s 

Which Can Have Worse Side Effects

BCAA's are naturally found inside the body, and this means there is a very low chance that your body will have a bad reaction to them. On the other hand, pre-workouts come in thousands of different brands and have thousands of different formulas.

This means your chances of a nasty side effect from pre-workout are much higher, especially if they contain a "Proprietary Blend," which basically means the company does not have to tell you what is inside. 

Winner: BCAA’s 

Experiencing Crash

Pre-Workouts come with stimulants inside. These compounds only last for several hours before your body metabolizes them. At this point, you are going to come down from your stimulant peak.

This is called the pre-workout crash, and depending on how much stimulant you take, it could range from slight tiredness to severe lethargy and inability to focus. 

BCAA's don't contain any stimulants, so you won't get any sort of crash from taking them. This can be a huge pro if you workout in the morning before heading to work.

Winner: BCAA’s 

man drinking pre-workout supplement

BCAA's Overview

Branched Chain Amino Acids contain precursors for creating protein and boost levels of protein synthesis, increase strength and size and even allow you to work out with more endurance. They can be taken before, during, or even after your workout. 

The three amino acids that are used are Leucine, isoleucine, and valine and are crucial compounds used in your body for muscle growth and recovery as well as an energy source. 

In particular, Leucine, one of the amino acids found in BCAAS, stimulates chemical signals in your brain to activate protein synthesis. It also helps you transport essential glucose to your muscles through insulin resistance and increases the energy stores your muscles can draw upon. 


  • Improvement in endurance levels during your workout [1]. 
  • Quicker muscle recovery and less DOMS (Delayed Onset Muscle Soreness) [2] 
  • Higher levels of strength and power during workout. 
  • Increased levels of protein synthesis. 


  • Very large doses of BCAAs can increase insulin resistance 
  • BCAAs don't provide any stimulant energy for your workout 

Recommended Dosage

BCAAs are not harmful in large quantities, but the recommended dosage is based on your bodyweight. Most reports suggest taking 91 milligrams per pound of bodyweight. For example, if you weigh 175 pounds, you should take 15,925 milligrams of BCAAs. Most brands have more than this in one scoop, so one scoop a day should be enough.

Keep in mind, you should take BCAAs everyday even if you don't get in a workout. After about 10 days, your body should start to feel the effects of BCAAs.

When Should You Take It?

You should take BCAAs after your workout for the best results. Typically, amino acids will take about 30 minutes to fully enter your blood stream.

I recommend taking them immediately after or 30 minutes after your workout for the best recovery results.

BCAAs Vs Pre-Workouts (Key Differences & Which Is Better)

Pre-Workouts Overview

Pre Workouts are a different kettle of fish. These supplements come packed with stims and performance-enhancing compounds that give you bursts of energy, unreal muscle pumps, and a huge boost in oxygenated blood being sent to your muscles. 

There are thousands of different pre-workout formulas on the market. Some contain essential B vitamins, some come with caffeine or creatine, and some come with more exotic ingredients like beta-alanine. 

Most pre-workouts actually contain a full serving of BCAA's as part of their ingredient list.


  • Increased levels of energy. 
  • Laser focus and motivation. 
  • Higher levels of endurance. 
  • More strength and explosive power. 


  • Can often contain a high level of stimulants or caffeine which some users may be sensitive to.
  • Pre-workouts can also be disruptive to your sleep schedule if not taken at the correct time.

Recommended Dosage

Pre-workout supplements vary greatly in what they contain and how much you should take. Most pre-workouts have directions on the back of the bottle so you don't take too much pre-workout.

I recommend starting with the recommended dosage on the container or even dropping this down a few grams until you know if it works for you.

When Should You Take It?

Pre-workout supplements, as the name suggests, should be taken before a heavy workout.

The optimum time will depend upon what you have already eaten that day but should be within 45 minutes of you starting your training. 

Related Article - Pre-Workout Pros & Cons

Similarities Between Pre-Workouts & BCAA's

  • Both contain branch chain amino acids which are the building blocks used in protein synthesis
  • Both will give you a noticeable performance in terms of your results in the gym
  • Pre-Workouts and BCAA's usually come in powder form and are mixed with water 
  • Both are commonly found in every sports supplement shop

Differences Between Pre-Workouts & BCAA's

  • BCAA's will improve your performance, but you will not "feel" anything being on them
  • Pre-Workouts give you a noticeable boost of energy and motivation during your workout
  • Pre-workouts contain a range of different ingredients designed to boost performance during your workout and your recovery after your workout
  • Pre-Workouts usually contain medium-high doses of stimulants
man drinking pre-workout

Effective Ingredients Found In Workout Supplements

While BCAA's always contains the same ingredients, that cannot be said for pre-workouts. Supplement companies are always trying to develop the newest and most effective blend of ingredients to add to their pre-workout formula. 

However, a lot of the time, ingredients are added without proper research or scientific proof that they work. They might come with false claims of performance-boosting potential that fall flat when investigated. 

Here are some of the ingredients to look for that have a strong level of research behind them and will genuinely boost your performance. 

Caffeine (100-400mg) 

Caffeine is a stimulant found naturally occurring in things like coffee and tea. It is also the ingredient that has the most research supporting it.

Caffeine binds to the chemical adenosine, which signals to your body whether you feel tired. Once bound, it blocks the adenosine receptors in your brain, which prevents you from tiring and allows you to work out longer. 

Caffeine also boosts your body's metabolic rate and slightly increases your body's temperature. This thermogenic effect means your body will burn more calories than usual and is one of the main reasons you’ll find caffeine in many weight loss supplements. 

Since caffeine is a stimulant, you must get the dose right to experience the "boost" and prevent "crashing" as it wears off. 150-200mg of caffeine is the sweet spot for this. [3]

Creatine (5g Daily)

Creatine is one of the most well-studied and proven supplements gymgoers and athletes use. It is a naturally occurring amino acid found in skeletal muscle.

It helps recycle energy in our bodies by replenishing ATP levels, allowing you to work harder and longer. It also helps draw water into the muscle, making them fuller, leaner, and, to a degree, stronger.

While its efficacy as a pre-workout ingredient is questionable, as it doesn't provide any immediate energy-boosting effects, it is still beneficial (from a cost-saving perspective) to get a 5-gram maintenance dose in a pre-workout.

Beta-Alanine (3.2-6.4g Daily) 

Beta-alanine is a non-essential amino acid that is thought to enhance endurance, buffer lactic acid production, and boost overall athletic performance. 

However, its undeniable efficacy is up for discussion in a pre-workout setting.  Beta-alanine is only effective for one-to-four minutes long bouts of exercise, which is uncommon in a typical gym session.

That said, if you're taking a pre-workout for cross-fit, for example, beta-alanine could help tremendously.

One thing to note is - it takes 28 days of daily supplementation with 6.4 grams to reach peak saturation levels - an unheard-of dose in a pre-workout. Also, at 6.4 grams, beta-alanine tingles are quite common in pre-workout.

L-Citrulline (6-8g) 

When consumed, L-citrulline converts into another amino acid, L-arginine, which subsequently increases nitric oxide production (NO). 

This elevation in nitric oxide has been linked to improved vasodilation - the expansion of blood vessels. 

As a result, L-citrulline enhances blood flow, oxygen delivery, and nutrient uptake to exercise muscles, improving exercise performance and reducing muscle soreness.

It also gives you a pretty massive pump - something everyone in the gym loves.

L-Citrulline Malate (6-8g)

When you combine citrulline and malic acid - you get L-citrulline Malate, a new and improved version of L-citrulline. This combination is thought to be more potent than L-citrulline alone.

In fact, in one study, participants who had taken the compound were able to perform 53% more repetitions in their sets across a 60-minute workout. [4]

L-Tyrosine (500-2000mg)

L-tyrosine is a non-essential amino acid that serves as a precursor for several important neurotransmitters, including dopamine, norepinephrine, and epinephrine. All of these play critical roles in mood regulation, alertness, and the body's stress response. 

In other words, supplementing with (ideally) 1500mg L-tyrosine supports cognitive function - especially under stress - which resistance training is.

L-Theanine (100-200mg)

When combined with caffeine, L-theanine can help smooth out caffeine's stimulating effects, promoting alertness but alleviating jitteriness. 

The synergy of these two compounds could also offer enhanced cognitive performance. [5]
woman holding vitamins

Ingredients To Avoid In A Workout Supplement

The following ingredients may not be dangerous, they are a waste of money, and any pre-workout that utilizes them as their key ingredients should be avoided. 


While Glutamine is an incredibly important amino acid that has vital roles in many of your body's functions, like muscle growth and your immune system, most of us get plenty of it from our diet. 

If you are eating a diet with ample amounts of protein, you will not need to supplement with Glutamine. 


There are still a lot of products on the market that utilize arginine as their main wonder ingredient. As we have already discussed above, arginine absorbs at a terrible rate inside the body as it is destroyed by stomach acid in your gut. 

L-Citrulline is a much better choice as it converts to arginine once inside the body. 

Dangerous Or Banned Ingredients Found In Pre-Workouts

One ingredient you should steer well clear of if you can even find a pre-workout that contains it is DMAA. 

DMAA in pre-workout was once used due to the vast thermogenic energy boost it gives you. Research has shown that it increases your risk of cardiovascular problems pretty dramatically. 

Another thing to watch for, which is much more common, is an overload of stimulants.

Some people in the bodybuilding and weightlifting worlds look for pre-workouts that are extremely stimmed heavy. This has led to a number of pre-workouts being released specifically with high levels of stimulants. 

When you overdo it with stimulants, you face two problems. The first of which is a terrible crash.

This means that once you have overexerted yourself and the stimulants have worn off, you will be left in a highly stressed, overworked state. If you work out in the morning before work, this can make it impossible to concentrate. If you work out in the evening, you can say goodbye to your sleep. 

The other problem overloading stimulants can cause is the stress it places on your body by raising your heart rate and internal body temperature to such high levels. 

Stimulants are awesome and can really help you get through your workouts on bad days. They can also help you push past your limits on your good days. They do, however, come with their risks, so make sure you pick a pre-workout with a reasonable amount of stimulant inside. 

banned pre-workout ingredients

Common BCAA & Pre-Workout Questions

Can BCAAs be used as a pre-workout supplement?

If you're not interested in a stimulant type of pre-workout, then you can certainly use BCAAs instead of a pre-workout supplement. You won't get the same effects, but BCAAs can be effective for increasing blood flow, preventing protein breakdown, and recovery.

Do all Pre-Workouts have BCAAs in them? 

When we look at the huge number of pre-workout products on the market, the 5 most common ingredients are Caffeine, Beta-Alanine, Creatine, L-Citrulline, and BCAA's. This tends to be the foundation formula used to build upon. These ingredients are found in over 80% of pre-workouts, so while BCAA's are not found in every single pre-workout, they are found in the majority of them. 

How do BCAAs compare to whey protein? 

BCAA's are used in the synthesis of protein; they are isolated compounds. Whey protein is derived from cow's milk and contains a much broader spectrum of amino acids. With whey protein, BCAA’s that are used in supplements make up around 25% of the total composition. Whey protein is more anabolic than BCAA’s alone. This is the main reason many people prefer it to take BCAA’s. Some people prefer to take BCAA’s because of the environmental aspect, but there are some great alternative vegan protein powders on the market to chose from too! 


Both pre-workouts and BCAA's will have a proven positive benefit on your performance. BCAA's are a great place to start for those that have never taken supplements before. The results will be less potent but still noticeable over time. 

Pre-workouts are much stronger and will give you a noticeable effect due to the stimulants and stronger compounds used. Some people will love that pre-workout feeling; some will hate it. 

For those interested in trying pre-workouts, a good way to start is to consume half a scoop as a test. If you react well to this, move up to one scoop. We strongly advise against dosing higher than one scoop with any pre-workout as the stimulants can have a nasty effect at this level. 

Good luck with your training! 




Miloš Lepotic

Miloš Lepotic

Miloš loves three things - science, sports, and simplicity. So, what do you get when you put the three together? A no-BS guy that's all about efficient workouts and research-backed supplements. But he also thinks LeBron's the greatest ever, so...