Pain Threshold and Fitness Threshold

Someday I'm going to write a well thought out post on this topic. It all seemed so clear during my workout yesterday. Results are definately a combination of pain threshold, fitness threshold, and how willing you are to near each of those points. It seems obvious to me that as I get older, I can worry less and less about the pain tolerance, and simply go at the pace that I know I'm in shape to perform. More to come...