I can and generally do put in 10-14 hrs a week on the bike and after a year of trying to adhere to an 80/20 schedule and getting my blood lactate curve measured to anchor my zones, it hasn't worked out very for me. All my numbers were worse except for very short duration power, which gains I attribute to resistance training and I'm also just slow. I don't know if it's my age (66), my "crunched" time, or the fact that I'm just a guy who needs more stimulus to develop fitness. This season, I'm still trying for long, LT1-ish rides on the trainer (per my post above) and keep it polarized, but I am going to mix in more intervals and have more fun on group rides this spring. Yes, I know Couzens (a bit of a polemicist, IMO) and San-Millan (a legit scientist, but a bit obsessed with lactate metabolism and whose opinions are colored by his own considerable athletic talents and world tour experience) would say I need to give it another five years, but that's not altogether helpful advice for those whose years are limited. I am also influenced by authorities, such as Coggan, who say that stimulus is pretty much just stimulus, viz. that just because you use the aerobic energy system a lot below LT1 doesn't mean it gets any more efficient, and that the reason to load up on the low intensities is to limit fatigue.
Last edited by MoAlpha; 02-02-23 at 08:36 AM.