Stiff muscles definitely benefit from a rub down, but scientists have never quite known why. Now, a team of researchers has shown that it works by changing your gene expression — quite literally, your body is hard-coded to release pain-easing chemicals when you’re massaged.

If you listen to people in the world of alternative medicine, they’ll normally tell you that massage “releases toxins”. That is bull, and scientists know it. But knowing an answer is wrong doesn’t give you the right one. No, doing some science does.

So, a team of researchers from McMaster University decided to look at what massage does on a cellular level. Their findings appear in Science Transnational Medicine, and they’re actually pretty surprising. In reaction to massage, the body changes gene expression to reduce inflammation and promote repair of muscle fibers.

How the hell did they work that out? First, they rounded up 11 men and made them “cycle to the point of exhaustion”. Then they randomly chose one leg from each guy to massage, and left the other one alone. Just when the volunteers thought the pain was over, the researchers took a muscle biopsy from both the massaged and non-massaged calves both 10 and 190 minutes later.

From those biopsies, they could work out what was happening at a cellular level, by analyzing the level of messenger RNA (mRNA) in the samples. mRNA acts, as its name suggests, just like a messenger: it tells the body to increase or decrease the rate of production of proteins that affect how our body works.

Turns out that the massaged legs had all been informed by mRNA to produce more of a protein called PGC-1alpha and less of one called NFkB. In English? Well, increased levels of PGC-1 alpha leads to the creation of more mitochondria, which in turn generates energy for cell growth. Basically, it increases the rate of muscle fiber repair. Reduced levels of NFkB, on the other hand, reduces inflammation.

So, while it’s not only nice to feel the hands of an attractive masseuse over your body, it also does actually do you some good, on a cellular level. Now you just need to convince your partner. [Science Transnational Medicine via Discover; Image: o5com]