Running fast is difficult strenuous work at least for me.

[Archaea]

Let me explain, I like hard things. The more difficult the better. But, after a while one finds a comfort zone.

In racing running, to get faster, you must always push yourself outside of the comfort zone. I've never experienced anything that hurts more than high intensity race running.

Jogging forever is easy. Let me run nine minute miles until the cows come home and then some. Ask me to go to seven minutes or below and I blow. We did seven measely miles and I was chunking it. A chick almost caught me. In the tris, chicks have caught me on the lousy run, lots of them. That's why I'm trying to get better.