Branched Chain Amino Acids, aka BCAAs, protect well-trained athletes' muscles against the effects of power training and speed up their recovery. Researchers at Northumbria University in England came to this conclusion after doing an experiment, the results of which they published in the Journal of the International Society of Sports Nutrition.
BCAAs were originally marketed as a supplement for endurance athletes, but they've found more popularity among strength athletes. Nevertheless, not much research has been done on the effects of BCAAs on athletes who have been doing weight training over a long period of time. The Brits decided to put things to right and set up a study in which 12 national football and rugby players participated.
The subjects did strength training at least twice a week. Half of them used 20 g BCAAs daily for a week before doing an exertion test. The preparation contained the BCAAs leucine, isoleucine and valine in the proportions 2:1:1. Every 10 g of the powder was dissolved in 300 ml water and the athletes drank the solution on two occasions during the day.
The control group drank a solution with a powder that contained only flavouring.
At the end of the week the athletes were made to complete a short plyometric training session, consisting of drop jumps [see below]. The subjects sprang from a 60-cm high block, absorbed the jump and then immediately jumped as high as they could. They then got back up on the block and repeated the procedure. In total they completed 5 sets of 20 drop jumps.
Just before the plyometric training and immediately afterwards the subjects in the experimental group took another 10 g BCAAs. The supplementation continued for four days after the workout too.
On the days after the training session the researchers asked the subjects to give an indication of how sore their muscle were. The BCAA group reported significantly less pain than the control group. In addition, the BCAA group regained maximal muscle power [MVC] significantly faster.
A classic indicator of muscle damage is the concentration of creatine kinase [CK] in the blood. The levels of CK after the plyometric workout were less high in the BCAA group than in the control group, and once again the difference was statistically significant.
"A 20 g BCAAs a day supplementation regimen administered 7 days prior to (with additional 20 g BCAAs immediately before and following the damaging exercise) and for 4 days after a damaging bout of eccentric biased exercise reduced soreness and the plasma level of intramuscular enzymes", the Brits summarise their findings. "Most importantly, BCAAs attenuated reductions in muscle function and accelerated recovery post-exercise in a resistance-trained population."
J Int Soc Sports Nutr. 2012 May 8;9(1):20.