1.75hr. (zone 2)
Yes, it is treadmill territory - it was very good, too - I naturally prefer counting by distance, but I think that to make the best of the necessity for indoor running, one really must do it by time and HR. I am going to try and be very disciplined about it, which means swallowing my pride and admitting that I have to set the speeds pretty slow if I want to keep my HR down!
It was actually FASCINATING - I have been reading all this Friel and other stuff, and thinking quite a bit about things I can work on - and one real place for improvement concerns running economy. My stride naturally falls out longer and slower than is ideal, but I have been strongly suspecting I would benefit from consciously shifting to a quicker shorter stride, and I now have the striking visual evidence of it.
I was wearing my HR monitor - for those who are not in the way of doing these things, it usually transmits HR from the little unit on your chest strap to the wristwatch, but most gym treadmills also receive the data and display it in large numbers next to the other pace etc. info. So when I consciously ran with quicker/shorter strides, my HR literally went down 4-5 beats - I could get it to go from 148 or 149 to 143 or 144 just by picking up the foot turnover, with the treadmill running at the exact same speed. It was ENTHRALLING...
In the second hour, my HR really was starting to drift up - I was solidly in the 140s for the whole first hour, but mostly 150s for the rest. I am not heat-acclimated. I should just stay at this speed until I can do the whole two hours in the 140s...
1.75hr. (zone 2)
5.4mph, 0.5 incline, avg HR 147
c. 9 miles