Despite the fact that I didn't eat too well yesterday, the fact remains that at an evening lap around Rockland Lake, I improved my personal best from 31:40 to 31:29. This is for a 3-mile run. According to my HR monitor, my heart rate at the end of this run was 95% of max, at the end of the 31:40 run (a couple weeks ago) it was like 102%. I see this as an improvement. Still, this run was hard on me. I wanted to stop even before the halfway point. Felt like I was running too fast - and that I should at least slow down. I pushed through it and it turns out that I wasn't running that fast.
Judging from every source I can see, I probably shouldn't try to run the loop so fast every time I do it, but trying to break my own record keeps it interesting to me. I am still going to have some sort of celebration when I finally break 30 minutes.
According to Bob Glover, who is an author and coaches people for the New York Road Runner Club, training runs are supposed to be between 70%-80% of max, while interval training runs aren't supposed to exceed 90%.. I can keep a run below 90%, but even a slow jog for me gets the heart rate above 80%..