I finally got an HRM recently, and thus far I can make it read and record my heart rate. It has told me that my average HR on my usual 2 or 3 mile runs is around 160 (I keep a pace of around an 8-minute mile). I'm pretty comfortable at this pace.

What I'm curious/confused about: is 160 too fast of a heart rate to sustain, for what I consider to be a general endurance-training run? I read a few fitness websites and I've gleaned that 160, for a woman my size, is considered a "performance training" level - one step above "endurance training". I.e., it's more of a rate that I should get if I were doing sprints or intervals. It's not a rate I should maintain for 2-3 miles.

So, on yesterday's run, I ran at a pace that kept my HR at around 150, and for me that meant not only running slower, but running more vertically - i.e., it bothered my knee (I had ACL surgery 10 yrs ago). I really didn't like the slower pace.

I suppose I may find a more accurate prediction of what my endurance training HR should be a) when I finish reading the Polar manual and/or b) if I consult with a fitness trainer, but perhaps you ladies can give me some perspective. What's your average HR for a general endurance run (no intervals/sprints)?