The article on understanding Heart Rate...

Does anyone remember that article that someone (maybe Banks..?) posted a while back about understanding target heart rate, and working out in the zone, etc.?

I've done a few searches, but can't seem to find it. I can't remember if it was a link or if someone cut and pasted the text of it into the post.

Would love to re-read now that I'm getting acquainted with my new Polar F6!