Tempo runs.....
I do everything by HR and time (duration). Eventually I guess it's works out to be similar as you'll get to know your pace at different zones. But for me the base gage is always HR and duration. So for example it'll be a 45 minute tempo run, rather than a 5 mile run. This way no matter what the course looks like for the day (flat, rolling, hilly) I stay consistent in my workouts week in and week out.
I know my race pace for everything from 5K to marathons, so, depending on what I am training for, I tempo run at pace for a period of time. I also sometimes combine farlek and tempo runs for a longer distance....that mixes things up and may simluate times during the races when I surge to gain some ground/time.
I use perceived effort as I don't know how to use a HRM :(
My training is by time, i.e., I don't go fixed distances (except for swimming); but rather I bike & run for a set time. If I'm supposed to do x minutes of tempo running, right now I use my pace to guide my speed rather than my HR, but I'm pretty experienced and know my pace parameters. I do wear an HRM, though, and if my HR is shooting the roof for no good reason, then I"ll back off a little. And then use a little of RPE, because if it feels too hard, I'm probably having an off day and would back off also.





HR or pace....I go by HR. What about you and why?
Tim G