BCAAs (branched chain amino acids) are the essential aminos leucine, isoleucine, and valine. The combination of these three amino acids makes up approximately 1/3 of skeletal muscle tissue in the human body. BCAAs play a very important role in protein synthesis (the production of proteins in cells from amino acids to build muscle).
What do BCAAs do?
Amino acids are the building blocks of protein. When you eat food containing protein, it gets digested through the intestines and stomach. During this process the protein is broken down into individual amino acids and short chains of amino acids. These amino acids are small enough to be absorbed into the bloodstream.
Once the amino acids are absorbed into the bloodstream they have far reaching effects across the entire body. Amino acids are involved in muscle repair (lean muscle building), essential brain functions and even hair growth just to name a few.
What is a metabolic pathway?
To understand just how important BCAAs are to muscle building and recovery you need to know what a metabolic pathway is. Put simply, a metabolic pathway is a chain of chemical reactions that takes place within a cell (in this case, a muscle tissue cell). When adequate amounts of BCAAs are ingested they create their own metabolic pathway which results in increased protein production. This means more muscle tissue will be grown and muscles will be repaired faster.
BCAAs and muscle growth.
Generally, after a session of resistance training the body is in a catabolic (the breaking down of muscle tissue) state, with a protein synthesis deficit. This is because post exercise the MAPK signaling pathway (the body's own way to signal muscle growth) is activated. While this is a pathway that will increase protein synthesis, it is not as effective as when combined with the BCAA signaling cascade.
The two pathways act independent of each other. Because of this, when adequate amounts of BCAAs are ingested post workout (usually in the form of a post-workout drink) the body is placed in a greater state of hypertrophy with a positive amount of protein synthesis. This is extremely important for athletes because it will decrease recovery time as it increases the rate at which lean body mass is gained.
Essential amino acids cannot be made by the body. You must get them from complete protein foods or combinations of incomplete vegetable foods. See table on the right for list of essential aminos. Your body can make non-essential amino acids by itself from vitamins and other amino acids.
The term "non-essential" can be misleading since all amino acids are essential for proper metabolism. There are some non-essential amino acids, such as glutamine, that are very essential in the process of muscle tissue repair. The 13 non-essential amino acids are listed in the table on the right.
The essential BCAAs are of special importance for athletes because they are metabolized in the muscle, rather than in the liver. This means they are more likely to be used to build muscle rather than burned as fuel for energy.
BCAAs - COMMON QUESTIONS:
- Are BCAA supplements safe to use?
Studies have shown that supplemental intake of the BCAAs in the range of 5-20 grams per day in tablet form and 1 to 7 grams per liter in liquid form with no adverse side effects. Higher intakes should be avoided due to the possibility of competitive inhibition of the absorption of other amino acids from the diet and the risk of gastrointestinal distress.
- Are BCAAs found in food?
Yes. BCAAs are found in protein-rich foods. The higher the quality of the protein source, the higher amount of BCAAs. Out of all the protein sources whey proteinhas the best BCAA content.
- How are BCAA supplements taken?
The most common form of BCAA supplements are pills. These pills are taken at staggered intervals throughout the day. BCAAs are also available in powder and liquid form.
- My protein supplement contains Glutamine, do I need more?
Studies have shown that Glutamine plays a major role in protein synthesis and muscle repair. All whey protein supplements contain a small amount of Glutamine. Recommended dosages range from 10-40 grams per day, depending on activity, fitness and bodyweight. For more information see our Glutamine information page.
In the quest to build muscle,
bodybuilders can't seem to get enough protein. We eat copious amounts of
chicken, steak, eggs, and fish to get it. We isolate the various types of
proteins like whey and casein and make them into powders to take advantage of
different digestion rates. We don't stop there though, we then isolate
individual amino acids that protein is comprised of and consume them separately
Even the most serious of lifters are
left wondering why they need to take additional amino acids when they are
already getting so many amino acids in all the protein they are consuming. The
truth is that individual amino acids can influence muscle growth through a
variety of different pathways, and of all the amino acids none have been shown
to be more important than the branched chain amino acids.
Branched chain amino acid
supplements (BCAA’s) have been around longer than others such as creatine and
beta-alanine, but few realized the full range of their capabilities regarding
muscle growth and performance. Branched chain amino acids have jumped to the
forefront of research in recent years and the results have been turning heads
within the bodybuilding world. We now know that BCAA’s go far beyond simply
being building blocks for muscle tissue and can affect muscle growth through
pathways few thought possible.
The Three BCAA’s
The BCAA’s are leucine, isoleucine,
and valine. The name "branched-chain amino acids" is derived from the
structure of these compounds. Each one has a forked outcropping that looks a
bit like a branch, hence the name branched chain amino acids. The three BCAA’s
are incredibly essential and actually fall into the category of essential amino
acids. Essential amino acids are amino acids that the body cannot synthesize on
its own and therefore must get adequate amounts through dietary sources. In fact,
even though there are about 20 amino acids that the muscles use for growth, the
BCAA’s comprise roughly a third of the aminos within muscle tissue. So if
muscle growth is your goal BCAAs are a must.
It may not seem like the metabolic
process of different amino acids matters as long as the end point is muscle
tissue. The truth is that the manner in which amino acids are metabolized plays
a large role in their functions within the body. The metabolism of BCAAs is
different that the metabolic processes of other amino acids. What truly makes BCAA’s
special is how they are metabolized. While most amino acids are metabolized in
the liver BCAAs are metabolized primarily by muscle. Despite their structural
similarities the three branched chain amino acids have different metabolic
routes. The breakdown of leucine is accomplished solely through fat
pathways. Valine is broken down solely through carbohydrate pathways, and
isoleucine through both. The different metabolic pathways of these three amino
acids lead to varying requirements for each.
BCAAs, unlike most other amino
acids, are metabolized in within muscle tissue, allowing them to be oxidized
(used as energy) by muscle cells to produce cellular energy in the form of ATP.
ATP is the primary source of energy that fuels muscle contraction and allows
you to lift weights.
The fact that leucine, isoleucine,
and valine are metabolized within muscle tissue allows them to be a quick
energy source when the body needs it. There is a significant increase in BCAA
metabolism during prolonged exercise simply because the body requires more
energy during periods of stress such as training. This makes BCAAs incredibly
effective when taken around workout time.
The unique metabolic processes,
requirements, and versatility of BCAAs allow them to impact nearly every aspect
BCAAs and Performance
Improving performance during
training is of utmost importance no matter what your goals. If you are an
athlete, improved performance will help you in your sport of choice during
actual competition. Improved performance is just as important to bodybuilders
since improved performance translates into more weight lifted for more reps,
which eventually translates into more muscle growth.
BCAA’s have been proven in many
studies to be a potent performance enhancer, and as previously mentioned, BCAAs
make a great energy source for working muscles because of their unique
metabolism. This can have a positive impact on performance. Not only can BCAAs
be used as energy themselves but they also enhance fat oxidation in glycogen
depleted subjects. This allows individuals to train harder for longer without
fatigue due to the higher energy demands being met. This goes for both high intensity
training as well as endurance training.
Another way that BCAAs can enhance
performance is through their ability to spare glycogen during training. Found
as stored carbohydrates within muscle tissue and the liver, glycogen is the
favored fuel source for working muscles engaged in high intensity exercise.
This makes glycogen availability and preservation vitally important if you wish
to continue to train hard for longer periods of time. Studies have shown that
by ingesting BCAAs before and during training glycogen levels can be spared by
25%. It is thought that the ingestion of BCAAs boosts blood alanine levels
which gets converted to glucose in the liver and then sent back to working
muscle to be used as fuel. This glycogen sparing effect of BCAAs will not only
allow for longer more intense training sessions but also allows for faster
recovery leading to a better workout tomorrow.
Effects on Hormones
They are the primary determinant for
how much muscle someone will build. They are what separate top level
bodybuilders from the rest, elite athletes from everyone else, and cause the
muscular differences between men and women. They are hormones! The hormones
that are of most importance to us as serious lifters are anabolic hormones.
Anabolic hormones are hormones within the body that promote protein synthesis
(muscle growth), and the most notable anabolic hormones are testosterone,
insulin, and growth hormone (GH). These hormones play a large role in
controlling your muscle building destiny. Luckily it has been shown that BCAA
intake can have a positive effect on anabolic hormone release.
Testosterone may be the most well
know of the anabolic hormones. BCAA’s can have a positive impact on
testosterone levels when consumed pre-training. During intense training it is
normal for testosterone levels to rise. After training is ceased testosterone
levels will begin to fall back to normal baseline levels. Studies have shown
that when athletes were given BCAA’s prior to training, post-workout
testosterone levels remained elevated for several hours, whereas the control
groups noticed a significant drop in testosterone once training ceased. This
can go a long way to maximizing growth from every single training session.
Ingestion of BCAA’s not only
increases testosterone in the post-training period but also builds muscle by
improving the body’s testosterone to cortisol ratio. While testosterone is an
anabolic hormone and promotes muscle growth, cortisol is a catabolic hormone
and breaks down muscle tissue. Anyone looking to build muscle will want
testosterone levels to remain high while minimizing the release of cortisol. It
has recently been found that taking BCAA’s while resistance training results in
significantly higher testosterone levels with a lower creatine kinase and
cortisol response. This leads to more muscle tissue being built and less muscle
tissue being broken down.
Lastly, the amino acid leucine has
also shown promise for increasing insulin sensitivity. Essentially, insulin
sensitivity ensures that the insulin within your body maintains its effectiveness.
This leads to easier fat loss, more muscle growth, and defense against
As a natural lifters it is important
to take advantage of every opportunity we get to optimize anabolic hormone
levels. BCAA’s are a safe and effective way to naturally manipulate hormone
levels leading to greater results all around.
BCAAs and Fat Loss
The effects of BCAA intake on fat
loss is something that has only been explored in more recent years. Newer
research is showing that BCAA’s can have a positive effect on fat loss. This
doesn’t mean you can eat pizza at every meal with a side of BCAA’s and the fat
will just melt away though. BCAA’s seem to maximize fat loss when one is
already on a fat loss diet. On any fat loss diet, carbohydrates will need to be
lowered to some degree. It seems that BCAA’s ability to spare glycogen and
increase insulin sensitivity may play a role in speeding up the results of a
fat loss plan.
BCAAs should also be used as a
supplement during any fat loss plan because of the muscle preserving effects.
On any calorie restricted plan muscle tissue loss is a serious concern that
must be addressed. All of the positive effects that BCAA’s have on muscle
growth will also serve to protect muscle during periods of calorie restriction.
It is always important to remember that anything which builds muscle will also
BCAAs as Signaling Molecules
Last, but most certainly not least,
of BCAA’s many functions is their ability to act as signaling molecules within
the body. This has been bringing about some of the most exciting new research
within the bodybuilding community in recent years. To get an understanding of
how important this is you must first understand the role of protein within the
It has long been known that amino
acids act as substrate for muscle tissue. This essentially means that when you
consume protein, your body will take the amino acids from that protein to
compose muscle tissue and other proteins. This is why people often refer to
amino acids as building blocks. BCAA’s have been proven to be much more than
simple building blocks though. Within recent years it has been discovered that
BCAA’s, particularly leucine, act to send signals to the body that inform it to
One of the ways leucine works to
signal muscle growth is through its interaction with mTOR which stands for
mammalian target of rapamycin. The mTOR is located within the cells and, among
other things, is responsible for detecting an excess of amino acids. It has
been shown to play a key role in regulating muscle hypertrophy (growth). Though
this process is not entirely understood, the mTOR pathway has been discovered
to be extremely sensitive to the amino acid leucine. Recent tests have shown
that when leucine is taken orally it activates mTOR, which activates protein
synthesis (muscle growth), and increases a cell’s capacity to produce new
proteins (muscle tissue). This means that along with resistance training there
is a way to send messages that control growth right at the cellular level. This
is truly exciting news.
Many people will ask “If leucine has
the greatest effect on muscle growth, then why not take leucine alone without
isoleucine and valine?” It has consistently been shown that the greatest
results in protein synthesis are seen when a 2:1:1 ratio of leucine,
isoleucine, and valine are taken. When leucine is taken alone it can lower
concentrations of the other two amino acids.
It is also important to note,
although BCAA’s can act to signal muscle growth, there must be a full spectrum
of amino acids to act as substrate for muscle growth. This means that you can
send signals to your body to build muscle all you want, but if it has nothing
to build with you are out of luck. So make sure you ingest enough protein
Serving Size: 4 Capsules
Servings Per Container: 30
Amount Per Serving
% Daily Value
1.6 g (1,600 mg)
* Percent Daily Values are based on 2,000 calorie diet.
+ Daily Value not established.
Suggested Use: As a dietary supplement, take 4 capsules 1-2
times daily, on an empty stomach especially before and after exercise.
Free of: sugar, salt, starch, yeast, wheat, gluten, corn,
soy, milk, egg or preservatives.
Other Ingredients: Gelatin (capsule) and Stearic Acid.
Warnings: Caution: Please discard the inedible freshness
LifeSource Vitamins Branched Chain Amino Acids are
Pharmaceutical (USP) Grade.
*These statements have not been evaluated by the FDA. This
product is not intended to diagnose, treat, cure or prevent any disease. As
always, consult your physician before taking any and all supplements.