Originally Posted by
69chevy
The HR training guide I read calls "zone 4" the 80% to 90% zone.
It calls "zone 5" 90-100%
Should I be able to average "Zone 5" for over an hour and never get below "Zone 4" from mile 2 to mile 22?
Well . . . There are many HR zone systems, which don't matter at all because the only thing that matters is how a training plan is structured within that zone system. I've actually gone to a 3 zone system for my training, but don't usually mention it because the US audience is wired for a 5 zone system. In the 3 zone system, zone 1 is below where your breathing rate increases so that you can no longer talk in a normal conversational manner. Zone 3 is panting. Zone 2 is everything in between. The idea is to train as little as possible in that system's zone 2. More easily said than done.
Edit: that system's zone 3 is the same as the conventional US zone 5: panting.