• When you are looking to build muscle, to help recover from exercise and to cut fat then you need to think about supplementing with BCAAs.


Amino acids are needed for building protein and any serious sportsperson, fitness enthusiast, bodybuilder, weight or strength trainer will make it quite clear why they take any supplement that helps build or replace muscle. There are 20 amino-acids needed for protein synthesis  but some are more important than others when it comes to this particular aspect of physiology after intense exercise. Here we look at BCAAs in the role of nutrition.

Of the 20 amino acids, 11 can be manufactured in the body. But the other nine have to come from the diet or from supplements as they cannot be manufactured by the body. The nine essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

If you are looking for a supplement that will reduce muscle soreness and and metabolic recovery then look no further than the branched-chain amino-acids or BCAAs to help here. The BCAAs are leucine, isoleucine and valine. These three amino acids are used by muscle during exercise which gives them a unique position in energy metabolism compared to other amino-acids. It has also long been known that supplementation with BCAAs increases anabolism which is the growth and production of muscle proteins but also suppresses their catabolism too (Tipton et al., 1999; Wolfe, 2001; Jones et al., 2004).

In some cases, sports people supplement with just leucine but with vigorous exercise all these soon become depleted. It is worth stating from the outset that for many of us, if we eating plenty of protein then the need for supplementing with BCAAs makes little sense. Protein contains plenty of BCAAs and for many are unnecessary but there are those who swear by them. 

There is also a fair bit of clinical evidence to support their use too. They also have quite a track record of use and were seriously considered from the late eighties onwards (Lemon, 1991). The whole subject of BCAA biochemistry in metabolism has been reviewed very recently (Zhang et al., 2017) where they give a very good account of how BCAAs impact in all sorts of human physiology (worth checking out !)

Fit looking girl doing crunchies and sit ups in a black exercise clothing against a black background. She may be taking BCAAs.
Photo by 5132824 c/o Pixabay.

The Role Of Leucine

Leucine is probably the most important amino acid in the muscle building set. As we exercise, the level of leucine drops off which means it has to be replaced through the diet. It might be considered to act like a hormone as it activates muscle protein synthesis directly (Norton and Layman, 2006). In fact these three amino acids are key to regulating protein metabolism as well as having a key role in protein synthesis and its regulation.

Oral consumption of amino acids is followed by an increase in their blood levels, which immediately increases the rate of muscle protein synthesis. This is partly through the activation of what is known as (mTOR mammalian target of rapamycin) signaling (Ge et al., 2009). Leucine is certainly known to activate the mTOR signaling pathway and has a key role in initiating muscle protein synthesis (Buse & reid, 1975; Anthony et al., 2000).

Clinical studies showed that when compared to a placebo, a daily intake of 20g of BCAAs with half taken in the morning and then evening for a week before intensive exercising helped reduce muscle soreness by 30%. Markers for muscle damage were also reduced by 22% and there was improved muscle performance during the recovery phase (Howatson et al., 2012). There are studies showing that a leucine-enriched amino-acid supplement can help improve muscle recovery in untrained men doing eccentric muscle exercises (Matsui et al., 2019).

Dosing & Timing

Consume at least 2.5g of leucine per meal on average four times per day. This promotes a better weight loss, more fat loss and improved retention of muscle performance in the recovery phase. Similar studies show a high leucine content in the diet impacts on better control of blood glucose levels (Zhang et al., 2007).


BCAAs are best used in a pre-workout drink like a protein shake although we know of some who take these alone when they don’t want protein as well. The feeling is that it is easier to deal with being a much lighter softer load before intense exercise. Understood ! 

Endurance athletes can also be helped using BCAAs. Apparently there is plenty of clinical and anecdotal evidence suggesting back packers, marathon runners or anybody involved with prolonged exercise who benefits from supplementation. Cyclists for example were shown to benefit from high levels of BCAA ingestion when they were engaging in sprints during endurance racing (Kephart et al., 2016). This was a study into performance at the School of Kinesiology in Auburn University, USA. BCAAs also appear to ‘blunt’ the neutrophil response to intense cycling training. This suggests an immune function benefit when they are involved in a long cycling season. We have already commented on the benefits for basketball players.

Limiting The Effects Of Tiredness And Fatigue

Various pieces of research that have looked at the association of BCAA supplementation with tiredness suggest that they can help reduce the effect of fatigue. Whilst there are many other factors that contribute to tiredness of muscles such as intensity, duration and fitness levels, BCAAs can ameliorate this. In biochemical terms, BCAAs help return the levels of tryptophan in the brain to its normal level. Tryptophan in the brain is converted to serotonin during exercise which causes fatigue. There is one research study which showed that participants who supplemented with BCAAs had improved mental focus during exercise.

Burning Off Fat

BCAAs and leucine in particular could help with fat burning. If it is combined with glutamine, then supplementation can help those who are overweight following a hypocaloric diet. It is claimed to help reduce excess fat but also reduce a marker of metabolic problems by helping to normalise visceral fat.

What about protein containing BCAAs ? There is some evidence that if we increase our protein intake and reduce our carbohydrate intake at the same time, we can enhance weight loss, lose more body fat without sacrificing muscle or rather lean body mass (Layman et al., 2003; Noakes et al., 2005).

It is not a stretch of the imagination to look at BCAAs as a useful way of reducing obesity in the same way protein ingestion might and in that same way also control diabetes by minimising insulin resistance or controlling glucose tolerance (Kainulainen et al., 2013). All these additional benefits help with improving general health and fitness.

Looking For Lean Muscle Mass ?

One study by Stoppani et al., (2009) found that BCAA supplementation could help improve lean muscle mass and also decrease the percentage of body fat in the process.  That study involved 36 strength training men who had been doing resistance training for over 2 years. These gents did an 8-week resistance training program and the researchers randomly assigned them to three groups. Each received either 14 grams of BCAAs, or 28 grams of whey protein, or 28 grams of carbohydrates in a sports drink. In that study, those men who took the BCAA supplement had a better reduction in body fat with a greater increase in lean mass compared to the other groups.

What Are The Best Foods Which Are High In BCAA

Foods are always a great source of amino acids including the BCAAs. the reason supplements are taken is because athletes want something where the intake can be controlled, especially if a calorie-controlled diet is being followed.

Some of the best foods to consume for BCAAs are the following:-

Chicken: Per 170g; 36g protein, 6.6g BCAAs, 2.9g leucine, 1.8g isoleucine, 1.9g valine.

Cottage cheese: Per half- cup: 12 protein, 4.7g BCAAs, 1.7g leucine, 1g isoleucine, 1g valine.

Eggs: Per egg; 6.3g protein, 1.3g BCAAs, 0.54g leucine, 0.3g isoleucine, 0.4g valine.

Tinned tuna: Per 170g; 33g protein, 5.6g BCAAs, 2.5g leucine, 1.5g isoleucine, 1.6g valine.

Wild salmon: Per 170g; 34g protein, 5.9g BCAAs, 2.7g leucine, 1.5g isoleucine, 1.7g valine.

Men’s Fitness have rated the following as the best of 2018 and they are:-

Bulk Powders Instant BCAA

N.B. This article contains links to our affiliate marketing partner. Please read our affiliate disclosure.

One of the top products to look out for is the grapefruit flavoured Maximuscle BCAA 3000 which contains per 6g serving: 5g BCAA, 3g leucine, 1g isoleucine, 1g valine.

Another that is often taken is the Optimum Nutrition Gold Standard BCAA which contains per 9.5g serving: 31kcal, 5g BCAA, 2.6 leucine, 1.2 isoleucine, 1.2g valine. The ratio is a typical level of 2:1:1. This one comes in various flavours including apple & pear, cola, raspberry & pomegranate, peach & passionfruit, and strawberry kiwi. This product also contains WELLMUNE yeast beta-glucans (250mg per serving), Rhodiola rosea extract (200mg per serving), vitamin C (19mg per serve) and magnesium (66mg per serve).

Iron labs Nutrition, who have been producing food supplements since 2009 have a product called BCAA Power which not only includes BCAAs in the ratio of 10:1:1 (L-leucine:L-isoleucine:L-valine) but also magnesium (100mg per regular serving) but also pantothenic acid (5mg per regular serving). The flavour is Berry Blast ! If you also want BCAAs with glutamine thrown in then choose the USN BCAA Power Punch Amino Acid Plus Blend which comes in a Blue Raspberry flavour, Cloudy Lemonade, Watermelon, and Tangerine flavour. This product has added vitamin B6 to promote the transport of branched chain amino acids within the cell.

Supplements made in the UK or European Community are regulated and safe to use. Do always check the label and purchase from a reputable brand. Overseas suppliers might not be so secure as regulations for such products are different. The supplements from the USA are fine but always check if buying on-line whether they include ingredients which are not permitted in Europe.

Are There Any BCAA Side Effects ?

As far as anyone can ascertain from the research there is little to worry about when it comes to BCAA supplementation if conducted properly. Follow the manufacturer’s instructions and take BCAAs responsibly. These should not induce weight gain because a typical 10 serving of BCAAs will contain about 40kcal. It is felt that 0.03-0.05g of BCAA per kg of bodyweight per hour is appropriate. During exercise, it increases to 2-4g per hour.

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The products and the information provided about specific products on or through this site have not been evaluated by the United States Food and Drug Administration or by any other national regulatory body and are not intended to diagnose, treat, cure or prevent disease. The information provided on this site is for informational purposes only and is not intended as a substitute for advice from your physician/doctor or other health care professional or any information contained on or in any product label or packaging. You should not use the information on this site for diagnosis or treatment of any health problems or for prescription of any medication or other treatment. You should consult with a healthcare professional before starting any diet, exercise or supplementation program, before taking any medication or if you suspect you might have a health problem. 


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