Whenever I wear the HRM, I may not like how it forces me to slow down but one thing I know from past experience.
It is the truth.
For 70 minutes I ran the truth. 36 minutes in the morning and another 34 minutes in the afternoon. It was not a cool day. Not for mid November. In fact it was Indian summer with the afternoon temps in the high 70's.
If I want anything from my running outside of the plods and beat up legs I will have to go back to late 1990 when I made it the rule to wear the darn thing every day that I ran. I trained alone or with really, really slow runners because ti forced me all the way down to a 10 pace which seemed catastrophic back in those days. Of course back then I couldn't break 40 minutes for 10K and six months later I was running them in the 35's.