Of all the sports in the world, running is among the most simple. There are no rules except for the ones that I set for myself. I decide the speed, I decide the length, and I decide the time. I decide why I run. However, I am often asked why I run by people who don't understand running. I have quite a few answers to that question.

Running is a natural impulse which I can't fight.

Once I heard someone describe running as "emphatic walking," but I disagree. First of all, there is a definite line between walking and running. There are walkers, and speed-walkers, and joggers - and then there are runners. There is a natural barrier between walking and running, or even jogging and running, which will crumble and fall away as soon as I set into running. It 's the feeling that I've snapped into place with the world and I'm not just living in it, I'm running with it.

I think everyone has the urge to break this barrier. I can see this compulsion in the children playing chase or soccer, and it is evident in every other mammal in the world. I couldn't fight that urge as I've seen other people do - I just run to allay it.

Running is a good way to stay in shape.

Not only do I burn more calories when I run (and even for some time after I run), but I've found that I eat less and drink more water. Water is the essential ingredient in good health, without it all else fails, especially running. I eat less because I eat slowly, and I know when I'm full; I certainly don't want to stuff myself a few hours before a big run. I also eat better, because I know that a banana will provide more energy and nutrients to help me get through a run than a Twinkie will.

Running is my meditation.

At nine miles an hour, I don't have much room for thoughts. All I can think about is the next breath and the next step. It's wonderful to be free from all the troubles in life, at least for twenty minutes or so. I let my mind take a break by forcing it to concentrate on something as simple as breathing and movement.

I have found that conventional meditation never works for me, because my mind is restless and, like the tongue to a sore tooth, it always concerns itself with the painful spots. Running alleviates this problem by sidetracking my thoughts and letting me have some much needed peace and quiet.