This week's Phil Space

A fascinating piece on the Runner’s High, how exercise can become literally addictive:

Eight-and-a-half hours into the 100km (62m) Norfolk Coastal ultramarathon, he pain in my legs and badly battered feet was almost overwhelming. I desperately wanted to give in to the urge to curl up in a ball at the side of the trail and shut my eyes.

Sixty-two miles is not particularly far in the ultrarunning world – and the bleak, beautiful and flat Norfolk coastline may not be as hard on the legs as the Alps or Hard Rock 100 – but it was further than I had ever run before. The race pounded me almost into submission before I broke through and was lifted on a wave of euphoria unlike anything I've ever experienced…

Using the 'dark side' had felt cathartic – as if I was performing some kind of alchemy in transforming messed-up emotional crap into endurance running gold (I wish). But as I crunched over the final shingle stretch of Kelling beach and headed up the hill towards the finish, I conjured up an image of my six-year-old running alongside me – laughing and joking as we often do on our Sunday morning jogs around the local park.

It was presumed that this common feeling of elation was produced by endorphins, naturally produced opiates released during prolonged exertion or pronounced stress. Current research is looking at the possible effect of what are called endocannabinoids. It’s all very fascinating, but what’s the angle? Well, nature is the most astonishing chemical and engineering workshop. The HIV virus evolved in West Africa, immunity will have developed there also. This is just an example. 

Is it possible to copyright a gene? Well pharmaceutical companies certainly think so. In a world dominated by commodity economy what’s to stop them enclosing this precious commons?