The Athletic Powerhouse has just started training with heart rate zones.
My coach has analysed the results from my maximum heart rate test to identify target heart rate zones for different sessions. So far I've had heart rates set for long sessions - so the heart rate required is E1. This heart rate isn't too full on - just enough to start puffing a bit and feel like you're actually exercising. It's going OK.
I know it won't always be like this. Just wait for the post about how my heart nearly beat out of my chest when when I start sprint sessions...
Even though I've never trained by heart rate before, I am welcoming the change. I'm excited to see what difference it might make. But apart from that, I like the idea of having something to occupy my mind out on the road. I've always done this with other funny little things, like calculating what time it will be when I reach my turnaround point, watching the time to make sure I eat and drink at the right times, trying to keep track of how long each K is taking. (All much easier since I got my Garmin!)
So, some more structure and more science... using the head AND the heart.