The saying 'no pain, no gain' has endured for reasons other than its pithy rhyminess and high catchphrase value. Anyone who has trained to build muscle knows that you need to work at your limits to stimulate muscle growth. Unfortunately the act of tearing muscle fibres down to build newer, bigger and better ones comes with a nasty side effect – DOMS, or delayed onset muscle soreness. Apart from making you feel quite sorry for yourself, DOMS can keep you from performing at your peak and can be severe enough to keep you out of the gym altogether. Believe it or not, scientists are yet to crack the full process behind DOMS, but some recent research has been able to confirm a hypothesis and offer up a solution to minimise this at-times crippling condition.
A group of Japanese researchers postulated that activating a biochemical pathway called the mTOR system, important in muscle growth, would decrease the severity of DOMS. As many of us know, the BCAAs, particularly the amino acid leucine, are strong drivers of this system, and of muscle growth.
A group of mice were either fed distilled water, or a mixture of essential amino acids that included 40% leucine, ten minutes before and thirty minutes after a muscle contraction procedure.
The procedure subjected the unfortunate rodents to a series of eccentric muscle contractions, designed to cause the development of DOMS. Eccentric contractions are 'lengthening' contractions, for example, your biceps when you are bending at the elbow to slowly lower a barbell. While they are vital to muscle building, eccentric movements are more implicated in causing DOMS than other types of muscle contraction.
The mice were then subjected to an experiment designed to measure their level of pain in the days after the eccentric contractions, to determine the extent of DOMS. On top of this, the researchers also measured the amount of muscle synthesis in both groups.
The researchers found that not only did the group supplemented with leucine build more muscle in the days after eccentric exercise, but that they experienced less severe DOMS than the group that was not given amino acids.
This result is probably no surprise to anyone who has used BCAAs or leucine to speed up their recovery and enhance muscle growth, but it is one of the first pieces of research that ties DOMS to the mTOR pathway, which is important in our greater understanding of this phenomenon and how to minimise it.
This is a study that would have been great to see performed in humans rather than animals, although these results do give scientists a good incentive to invest in large scale human research.
That being said, humans and mice both suffer DOMS and synthesise muscle through the mTOR pathway, and this research is great news for anyone who wants to maximise their muscle growth and spare themselves the full extent of the two-day torture that comes after a serious session.
There are a huge number of amino acid supplements on the market, and the use of a good BCAA supplement, which contains high levels of leucine, along with isoleucine and valine, is a vital part of many people's routines for good reason, which the research fully supports.
Kato H, Suzuki H, Mimura M, Inoue Y, Sugita M, Suzuki K, Kobayashi H. Leucine-enriched essential amino acids attenuate muscle soreness and improve muscle protein synthesis after eccentric contractions in rats. Amino Acids. 2015 Mar 14.