Branched-chain amino acids, or in their English acronym BCAAs, have already been encountered in the course of this discussion. Here it is quickly recalled that since they have a peculiar chemical structure, they are particularly suited to a trophic role, unlike the others, which have a predominantly plastic one. It should also be added that there are three of them and, more precisely, they are leucine, isoleucine and valine. Of all of them, the most powerful is leucine, which, however, needs the other two to perform its function to the full. Finally, unlike the other amino acids, which are mostly destroyed either in the digestive system or in the liver after intake, they are very bioavailable.

Function

  If taken before, during or after the application of a metabolic load (endurance performance), they can protect the structural integrity of muscles (Blomstrand, 2001) and inhibit muscle catabolism (Fu Chun, 2006). They may also reduce the extent of DOMS in athletes practising bodybuilding or disciplines that emphasise strength. Finally, taking BCAAs immediately before and during load application helps to alleviate the physical symptoms of fatigue due to the normal increase in serotonin that occurs during exertion.

Negative notes

  There are no reported side effects associated with the intake of branched-chainamino acids if they are taken in the appropriate quantities (for details see the section on amino acids for optimising body composition).

Form and posology

  Branched-chain amino acid supplements are mostly commercially available in soluble powder and tablet form. It is recommended that you take 1g of BCAAs for every 10kg of desirable body mass (if you are overweight, therefore, you should take them with reference to your ideal weight rather than your actual weight) before, during or after exercise. The ideal product should have a ratio between the three amino acids of 2:1:1 in favour of leucine. Other ratios do not enjoy the same scientific evidence of efficacy.