13/03/2013 09:24 GMT | Updated 12/05/2013 06:12 BST

Why Do We Run?

It was only a couple of weeks ago that I put on a final burst and crossed the finishing line of the Paris half marathon. The steam rose off me into the crisp Parisian climate, as I tried desperately to suck air into my lungs and walk on legs that had suddenly taken on the constitution of a dessert traditionally served at a children's party. As my father and I (30 years older but, slightly gallingly, much fitter) trudged from the finish line to pick up our bags and medals, two main thoughts struck me.

The first was how much more beautiful the French language is than the English one. I could have listened all day to the people handing out bottles of water and fruit, whereas I would have given any English person who said "bravo" to me after the race a funny look and thought they were taking the Michael. Its delivery in the French accent was simply magical. The second point is how odd all this would have looked to an alien.

Seriously, if an alien had asked me why all these people had chosen to get up early on a Sunday morning and run 13.1 miles for fun, I would have appreciated their confusion. So why did over 30,000 of us - many paying for the pleasure - turn up at the same time to run in what was effectively a big circle?

The Guardian recently launched a running blog and, alongside more straightforward pieces about lap times and reviewing running headphones, some of their contributors have posted interesting pieces on the philosophical questions on running, such as this one. The question about running posed by our alien (let's call him Peter - it's always fun to call exotic things mundane names), can be applied to all types of fitness. Once you accept the premise of Peter, it's very easy to imagine him staring aghast at one of the increasing numbers of CrossFit classes up and down the country, and asking them why on earth they are putting themselves through that. Or observing with almost clinical detachment (have you seen Star Trek? Peter's a bit like Spock - he's very logical) those exercisers who can't walk after completing a HIIT (High Intensity Interval Training) class.

Although I do think the exercisers who attended the CrossFit or the HIIT class would have, if not a better argument than all of the runners from the other week, certainly an easier and more straightforward answer for Peter. They could talk about weight loss (every man and his dog have jumped on the HIIT bandwagon recently) and gaining muscle, and how the classes that they were doing were scientifically proven to be good for these goals.

Running burns calories, of course it does. But going for a long run is a really inefficient way to burn calories compared to other exercise options, and it's also not a great way to put on muscle. Not many outlets of the media hold up marathon runners as having a body we should all aspire to. Besides, I think a really small percentage of the people on that Paris start line were there because they wanted to lose weight. People were running for lots of reasons: to try and achieve a certain time; to prove to themselves and others that they could do it; for fun; and because running had somehow wriggled under their skins, burrowed down and stubbornly refused to leave.

I don't think the people at the end of the race would have been able to provide Peter with a good enough reason, or at least one that was easily articulated. They were running, well, just because they were, because they felt an almost inexplicable urge. And that's the best reason of all. The more that running - and other types of exercise - can get under the skin of the general population, then the healthier and fitter we will all be. Which means we'll have more chance of taking on Peter and his mates when things turn ugly ....