Mention BCAA’s in the same sentence as ‘the gym’ or ‘fitness’, and rightly so you will hear discussions surrounding muscle endurance, muscle preservation, muscle anabolism and anti-catabolism. Basically if you’re talking BCAA’s, then the term ‘muscle’ isn’t going to be far away. Leucine, Isoleucine and Valine are understood to be the most anabolic, or muscle building combination of amino acids around. Although Leucine triggers the greatest muscle protein synthesis response of all, the other two amino acids are complimentary to this, and are equally as important in muscle growth and recovery.
BCAA’s are metabolised directly in our muscle, and to a lesser extent the kidneys, adipose tissue and brain, rather than the liver. This means it is more readily absorbed and utilised by your muscle tissue, making BCAA’s ideal for bodybuilders and sportsmen and women.
Valine… the unsung hero?
Leucine steals the show for good reason, it has justifiably become the main amino acid for muscle growth, but a great team isn’t based on one player. Think of Leucine as Lionel Messi, and Valine as Paul Scholes, Messi goes about his business in an emphatic manner whilst Scholes contributes equally as much, but is a little less obvious. Scholes (or valine) don’t weigh in with the glory of 50 goals like Messi (or leucine) a season, but has as much influence on the game through his creativity and engine. The term ‘engine’ is quite apt in relation to valine, and for the subject of this article in particular.
Tamanna and Mahmood, (2014) have recently uncovered more potential applications for the humble BCAA supplement, these include muscle endurance and reduced perceived exertion (making exercise feel easier). Muscle fatigue is one of the main limiting factors when exercising, and it seems that valine is important in glycogen sparing. In other words, valine can be used to form glucose meaning your stored glucose lasts a little bit longer. However, it is the problem that is central fatigue that see’s valine come into its own!
Valine seen to reduce central fatigue
The term central fatigue refers to mental tiredness and lethargy, it is a very real problem in sport and exercise and not something you can easily snap out of once in its grasp. One of the main causes of this is a rise in levels of brain serotonin, a neurotransmitter that influences mood, sleep and more. Seratonin is derived from tryptophan, which together is responsible for reduced mood and increased fatigue, so it stands to reason that we should want to reduce the amount of tryptophan, and therefore serotonin in the brain if we want to perform at our best.
This is where valine comes in. Valine and tryptophan cross the blood brain barrier into the brain via the same transporters, therefore by increasing the amount of circulatory valine you are physically reducing the amount of available ‘seats on the bus’ for tryptophan. By increasing the amount of valine in the brain, you are directly reducing the amount of tryptophan that can enter the brain, in turn reducing mental fatigue aka perceived exertion.
Tamanna, N. & Mahmood, N. (2014). Emerging roles of branched- chain amino acid supplementation in human diseases. International Scholarly Research Notices. Retrieved 29th Sept, 2015, from http://www.hindawi.com/journals/isrn/2014/235619/