I learned this:
I decided to sign up for the RubyConf 5k as I'll be there in November and I wanted a way to motivate myself to run more.
I told a friend yesterday that I was doing it, and I mentioned to him that early on I was having difficulty running long distances, because I'd get really tired out after just a few minutes. But then one day I started out real slow, increasing the pace bit by bit and now I find that I can go on much longer without stopping.
"Paul", he said, "It's called 'Pacing Yourself'"