Originally Posted by
DropDeadFred
I guess its relative to the person, how you handle pain and what really gets to you. I personally feel like I've adapted the feeling of being in that zone as my natural fast and steady zone. I'm not exerting myself to a point that can't be sustained over long distances. Zone 5 however gets into the area that can only be sustained for short distances and leaves me needing to recover for a few second before I can mellow out in my 4 again. I tend to thing my pain tolerance is pretty high but I just don't think that 4 is anything to feel super tired over unless you've steady stayed in that zone for something like 2 hours.
Again, you're overestimating how awesome you are. It's doubtful that you have some incredible pain tolerance such that you can magically tolerate true Zone4 efforts for 2 hours whereas even a top pro would have problems maintaining that effort for more than 60 minutes. The simplest, most obvious explanation that you keep ignoring is that your MaxHR is incorrectly low and thus you're actually sandbagging your efforts compared to what they should be. Go and redo your maxHR testing, and go all out - you clearly haven't by your current numbers. If you've got such a high pain threshold, you should be literally on the verge of blacking out if you hit the final seconds appropriately.