My running shoes, although only five months old, have already logged a fair number of miles.

This past week has seen a significant increase in their mileage, as I find that the only thing that keeps me on a semi-even keel is a regular fix of endorphins. A great drug, that.

But as I run (and more so when I am nursing my various aches and pains afterwards!), I often wonder why it’s such a phenomenon in our culture. Moreover, I wonder why people feel compelled to run when they’re clearly not enjoying it – I guess a lot of people still buy into the “no pain, no gain” concept. The truth is that most people really don’t enjoy it, and force themselves to run because they think they should.

I, however, happen to be one of those crazy people who not only enjoys running, but has developed a serious physical dependency on it. I am truly addicted, and it is a harsh mistress.

My question is: Which attitude towards running is natural? Is it truly against our nature to run, to the point that it causes most people both mental and physical anguish? Or is it ingrained into us at such a basic level that we gain natural chemical stimulation from this physical activity?

In other words, am I a total freak?

For a long time, I thought that running must be unnatural, and that therefore, yes, I am a freak. Running for sport seems like an artificially sustained fight-or-flight reaction, developed to entertain ourselves as we became the lazy and unchallenged lords of the food chain.

Plus I can’t see that running long distances would have served any evolutionary purpose. No one would ever have to run from a predator for five or ten miles, much less 26.2 of them. Either you’d be dead, or you’d be safe. Either way, there’s no point in running any further than absolutely necessary to escape danger.

But I thought wrong. When I started looking into it, this is what I found:

Running has substantially shaped human evolution. Running made us human—at least in an anatomical sense. We think running is one of the most transforming events in human history. We are arguing the emergence of humans is tied to the evolution of running.

No way! Running made us human??? I don’t believe it. (Granted, this article was found at a runner’s website, which may be just slightly biased, but still – the scientific proof is out there.)

Basically, a couple of scientists from Utah have concluded that it was our need to run long distances that made us evolve certain physical characteristics, “literally from head to toe.” They’re not sure exactly why our distant relatives would have needed to run so prolifically, but they theorized that it could have been either to chase down predators or (I like this one) to reach dead animal carcasses more quickly than other scavengers. Mmmm, yummy. Personally, I use the thought of breakfast and my second (OK, third) cup of coffee to motivate myself while running, but to each their own.

I like this theory, but I have a different explanation. Forget the stinky carrion, I think those long-distance running Prefontaine-style australopithecines just liked the endorphins.

Either way, it looks like I am not in fact an evolutionary freak, but instead am hyper-evolved.

I always had my suspicions.