Will try to answer all the comments.

Polarized/periodized - seem to mean the same thing? Go easy, or go hard...

I had some metabolic testing done that got me on this type of training. My zones are based on blood lactate response. zone 2 -123-135, 3 -136-144, zone 4 145-154, zone 5 155-166, and zone 6 >166. I'm 45, 175lbs. The new training model I got from a lecture here - http://www.canal-insep.fr/fr/trainin...hen_seiler-mov and from the guy who tested me, (former pro) after going through my results. He basically stated that I was on a dead end street working at the level I had been, and to switch to zone 2, which when I watched that video started ringing bells in my head.

The past 4 years all my rides/races I have been at 150-160 consistently. I am very comfortable in this range. My average HR for my 20 minute FTP test on an indoor trainer with stages power was 164bpm, that was very hard to sustain, and I maxed out the last 45 seconds at 170 (not sustainable).

What I am not sure about is when I am working the 20% hard rides, where do I go with my HR? Curiously, zone 2 (135) for 90 minutes I perceive as being harder than what I am referring to as zone 5 (155). A week of training realistically is under 8-10 hours max, and that would include races during the season, crits and road races.

I am super comfortable at the low end of zone 5, do I push to the upper end zone 5 and into zone 6 for my hard workout? That is what I am not sure about.