Branched-Chain Amino Acids (BCAA) vs Protein Powder

Written by Ben Carlisle

Last updated on: Sep 18, 2022

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Questions about branched-chain amino acids (BCAAs) vs protein powder are common. The main difference between the two are a good protein powder will contain all 20 amino acids including the 9 which are considered essential amino acids (EAA's). A BCAA supplement will only contain the 3 BCAAs; leucine isoleucine and valine.

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This means protein supplements such as whey protein which contains all 9 essential amino acids (including the branched-chain amino acids) are complete protein sources. Whereas BCAA supplements cannot be referred to as a complete protein source as they lack the other essential amino acids.  However, this does not mean BCAA supplements are not useful.

Read on to find out more about the "BCAAs vs Protein Supplement" debate and how to decide whether to incorporate them into your diet to support your training program.

What Is Protein?

Protein is an essential macronutrient which plays a crucial role in maintaining the human body. Protein is made from twenty-plus amino acids. These amino acids are often referred to as building blocks and are used by the body to build and repair skin, muscle tissue, bones and organs. They also play a role in making hormones and enzymes. The human body needs 20 different amino acids to correctly function. Of these 20 amino acids, 11 are non-essential. This means the body can metabolise and synthesise them internally. However, 9 of these amino acids are essential and must be obtained through the diet (food and supplements). The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine (1).

Protein supplements are often used by individuals who want to increase their daily protein intake. The reasons for taking a protein supplement can vary but the most common reasons include: to assist with athletic performance, to build muscle mass, to prevent muscle loss and to help with satiety on a calorie restricted diet.

The amount of protein and amino acids in each type of protein supplement will vary. The main factor which causes variance in the amount of protein and amino acids in an individual powder, is the protein source which the powder is derived from. There are two main categories of protein powders; animal-based and plant-based.

Animal based protein sources include: whey, eggs and casein. Plant based protein sources include: pea, soybeans, hemp, brown rice, pumpkin seeds and sunflower seeds. Both of these protein sources may be combined with additional ingredients such as sugar, vitamins, minerals, thickeners, and artificial flavouring.

What Are BCAA's?

BCAAs are 3 of the 9 EAA's. They are called branched chain amino acids because of their structure. This structure includes a "side chain" of 1 carbon atom and 3 hydrogen atoms, which gives a branch like appearance. A BCAA supplement is not a complete protein source, however this has not prevented this supplement becoming extremely popular. The reason for this research has revealed each of the BCAA's play an important role in muscle protein synthesis (2). Leucine is known to be a key driver in protein synthesis, research has shown taking all of the BCAA's activates higher levels of 4E-BP1 than leucine alone (3). The activation of mTORC1 has also been found to increase when leucine is combined with other amino acids (4).

BCAA’s can be found in any complete protein source and occur naturally in high protein foods such as red meat, chicken, turkey, salmon, trout, milk, eggs, brown rice, seeds, and nuts.

The 3 BCAA's

BCAA’s are composed of three amino acids; leucine, isoleucine, and valine. They are similar in structure, but have their unique recovery, repair, synthesis, and energy functions. Although they can be taken individually, when combined together, they provide greater benefits (4).

BCAA’s are useful for :

• Reducing Mental Fatigue

• Increasing Strength

• Delaying Muscle Fatigue

• Reducing Muscle Tissue Breakdown

• Promoting The Growth Of Muscle Mass

• Enhanced Recovery

• Increased Cognitive Function  

Taken together, the three BCAA’s provide athletes with valuable contributions to their training and allow them to maximise both recovery and the results achieved in each workout. BCAA supplementation may also reduce the muscle damage associated with endurance exercise as it reduces creatine kinase secretion after prolonged exercise (5).

What Does Valine Do?

Valine stimulates muscle growth and tissue repair (6).  Valine competes with tryptophan for transportation to the brain and decreases 5-HT synthesis (7). 5-HT synthesis can cause the feeling of fatigue during physical exercise, by decreasing the rate, the feeling of fatigue is delayed. This allows individuals who have supplemented with valine to push themselves further in the gym, track or sporting competition. This may lead to enhanced performance (8). Additionally, valine is critical for the immune system to function and is very effective in combatting liver and gallbladder diseases (9) without which, the body would struggle to remove toxins.

The Role Of Isoleucine

Isoleucine, is heavily concentrated in the muscle tissue and is an intermediate assistant with muscle synthesis. It has also been shown to reduce muscle damage and soreness after training, especially effective when the BCAA is ingested before training (10).

Isoleucine also assists in the regulation of blood sugar, and this helps to supply the muscles with energy during training and assist with muscle growth, repair and recovery.

Isoleucine plays a critical role in maintaining the immune system’s basic functions. Research shows it to be a key determinant of physiological functions throughout the body. This includes growth, protein metabolism, immunity, fatty acid metabolism, and glucose transportation.

Isoleucine can  improves the immune system via immune organs, cells, and reactive substances. And by increasing the expression of β-defensins, administering isoleucine can restore some pathogens’ effects on your basic health indicators (11). Isoleucine also assists with wound repair and the detoxification of nitrogenous wastes produced by the body during normal metabolism. It is a key component for the production of hemoglobin and regulating blood sugar levels.

What Does Leucine Do?

Leucine, is a powerful amino acid essential for protein synthesis and assists with creating Adenosine Tri-Phosphate (ATP), an energy molecule.  lt can also regulate other cellular processes including tissue regeneration and metabolism (12). Leucine plays a vital role in forming lean muscle, building muscle mass (13), aiding in muscle repair, faster recovery, weight control and preventing the loss of muscle mass, especially in older people (14). 

Following a workout, the body will synthesise protein at a slower rate than the breakdown of protein. For the recovery of protein synthesis the body requires dietary protein or BCAA to increase tissue levels of leucine (15). Additionally leucine also works to control blood sugar levels (16) and may provide benefits for weight loss (17).

Foods Which Contain BCAA’s And Protein

BCAA's are found in all food's which are complete protein sources.

You can find both in foods such as:

• Red Meat

• Chicken and Turkey

• Milk

• Cheese

• Yogurt

• Fish (e.g. Salmon and Trout)

• Pumpkin Seeds

• Chickpeas

• Lentils

• Brown Rice

• Wholewheat

Both BCAA and protein supplements are designed to be taken to enhance a healthy diet. It is important to get as much of your protein and essential amino acids as possible.

When Should You Take BCAA’s For The Best Results

BCAAs are used to enhance recovery and stimulate protein synthesis. They can be taken pre-workout, post-workout or at any time during the day. When training you can also combine a BCAA supplement with a protein shake. Research has found a 1:1:1 to 2:1:1 ratio provides optimal results (18).

The most frequent ratio for BCAA supplements is 2:1:1 which aligns with this research. This ratio  is 2 parts leucine, 1 isoleucine and 1 valine. The reason for twice as much leucine is because of the role leucine plays in muscle protein synthesis. BCAA supplementation before and after exercise has beneficial effects for decreasing exercise-induced muscle damage and promoting muscle-protein synthesis (19).

When To Take Protein Powder For The Best Results

The question of when to take protein will depend on your fitness regimen and training goals.

Taking Protein Powders For Weight Training

Protein supplements can be taken pre-workout, post-workout and even during workouts. With weight training with the goal of developing lean muscle mass, there is a concept called ‘The Anabolic Window,’ which is 30-60 minutes after training where the protein uptake has the maximum effect (20). However, since the advent of this idea, subsequent research has shown this window may be larger than previously thought. It suggests taking a protein supplement to assist with the development of lean muscle mass is still effective as much as two hours after training (21).

Using Protein Powder For Weight Loss

In this case, the protein shake becomes a meal supplement or to promote satiety. Satiety is an overlooked benefit of protein shakes. Protein is proven to help induce satiety (22). Getting extra protein via a low calorie protein shake can be extremely helpful to individuals maintaining a calorie restricted diet.

Protein Powder For Endurance

Endurance training like running or cycling requires different intervals of protein absorption. Protein supplementation post workout will be beneficial for recovery. Additionally, research has found protein shakes with a sufficient level of carbohydrates can assist with fuel during training has been shown to improve performance and reduce muscle soreness (23). Further research has found the consumption of a protein supplement during exercise may reduce fatigue and muscle breakdown. It may also assist improving the immune system which could potentially assist with performance enhancement by minimising missed training sessions and workouts impacted due to illness (24).

Work With A Fitness Professional For Optimum Results

Whether you are looking to train for athletic performance, lose weight or build lean muscle, it is always best to get some professional advice regarding training, nutrition and supplementation. This will help you maximise your results in the shortest time possible.

Remember that because protein powder is a complete protein, it does contain BCAA’s. Still, it may not be in the same ratios or levels that specific BCAA supplements have, so you need to establish your specific requirements based on your training goals.

Working with a coach or trainer would go a long way to creating a proper training regime and a diet that will give you the best results, including the use of both protein and BCAA’s in your program.

Another plus is that you can get proper advice from someone who understands how these supplements will work and which ones to buy, as well as the correct dosages and intake times on both training and recovery days.

BCAAs vs Protein Which Is Better?

The choice is not always between BCAA's or protein supplementation. Sometimes you should take BCAA's and protein. An example where BCAA's may be beneficial over protein would be in an athlete who is maintaining a calorie deficit and still training. There primary concern would be to not go into a catabolic state so they BCAA supplement could help prevent this without  consuming a large amount of calories. A low calorie protein shake with all the essential amino acids would also allow for this, but with a slightly higher calorie count. The decision over which to choose would come to how much the individual needs to limit their calorie intake to reach their goals.

For those whose objective is muscle growth taking protein shakes is probably a better solution due to the high protein dose as well as all the ability to choose a protein source which contains all the essential amino acids including the BCAA's. In some circumstances, it may be preferable to combine BCAA's with a supplement like whey protein, to ensure the required levels of BCAA's for a specific goal are reached. In fact, research has found supplementation although muscle protein synthesis is enhanced by consuming BCAA's it is enhanced even further by consuming the essential amino acids (4).

Another circumstance in which BCAA supplementation may be preferred is when an individual is capable of getting enough protein from food sources. Although these food sources will often contain all the essential amino acids, it is hard to determine the exact amount of BCAA's which are consumed. By adding BCAA supplementation to their diet an individual can ensure the required levels of BCAA's are surpassed.

If in any doubt as to what supplement you should take in your own situation, you should consult with a medical professional.

When You Wouldn’t Need To Take BCAA’s Or Additional Protein

Individuals living a normal lifestyle, who are exercising a few times a week, to boost energy levels, and live a healthier lifestyle, may find adding protein shakes and BCAA supplementation into their diet unnecessary. All the nutrition they require should be possible from food source if a healthy balanced diet is followed. In the case they are unable to reach their recommended daily protein intake, supplements such as whey protein would be best. Most adults require 0.75 grams of protein per kilogram of body every day. This works out at 45 grams of protein for the average woman and 55 grams for the average man (25).


Both BCAAs and protein supplements are capable of producing results when used alone or in unison. They have the ability to assist with muscle growth, post-workout recovery and the improvement of performance during training. Whether you use both together or opt for only BCAA supplementation or protein will depend  on your own personal requirements. 

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