This is my favorite loop in the foothills. I was a bum and didn't get out the door on time so I started just after 6. I wasn't feeling wonderful but the temperature was wonderful and the foothills are gorgeous with spring flowers. In the first 2 minutes my right knee was feeling a bit creaky. I almost stopped and just turned around. Then I thought I would keep going and if things worsened I would just powerhike and enjoy the morning.
I felt pretty good after the first mile and just kept going. The result was I cut nearly five and half minutes off of my fastest time ever! I walked several key uphill spots that always kick my butt and just stayed steady on the downhill. I looked at my watch when the mile splits popped up and didn't have the HR monitor this morning.
One key difference was I took an MP3 player with me which I never do. This was just supposed to be a casual run so I took it with me. I noticed, believe it or not that I was able to pay closer attention to how I FELT as opposed to how my breathing was. I think I hold back a lot based on my breathing without regard to how my body feels. Since I couldn't hear my breathing I tuned into my legs and the music was really just background noise.
I did have a gel around mile 4 which I rarely do too. It was in the zippered pocket of the handheld I was carrying so it just worked out. I didn't have any breakfast before this run so going this fast seemed even more amazing to me.
Anyway, I followed it up with a 2.5 mile cool down lap in the lower military reserve which was wonderful.
My guess on the HR is about 155. Pushing but not race pace OMG I am going to die....
Here are a few other times I have tried it. By myself, with others, in the snow, you name it so they aren't all comparable.