Originally Posted by
Carbonfiberboy
The issue with zone 3, whatever that is, is that it's too easy to do too much work in zone 3, leaving one too tired to effectively work in the upper zones, where the progress really is.
There's a whole lot of effect to be gained from appropriate work in zone 3 and sweetspot. And it's certainly not easy. Building up to an hour+ continuous at sweetspot (with power) is a helluva workout.
