Hermes, Cleave, Alleghany, AZ - thanks to all for your replies. Yeah, maybe my training is too much higher intensity right now, I'll cut some of the LT and over stuff back in favor of more aerobic time and cycling specific weight training. My interval session each week always has high cadence spinning (120+) and often one leg drills, but that's about it for technique drills.
So I can better interpret all your workouts would you mind providing a brief "key" as to your HR zone designations, there seem to be a lot of different conventions out there. For example, I use a 7 zone system which designates zones 1 to 4 and 5a, 5b and 5c. LT is the bottom of z5a in this system but for Cleave's it's the bottom of z4. Here's the rest of the system I use:
z1/z2 - below .88 LT HR
z3 - .89 to .93
z4 - .94 to .99
z5b - 1.03 to 1.05
z5c - anything higher
Haven't been to lab to determine LT HR but I've used 4 different methods of estimating it based on various timed efforts and they all point to the range of 156 to 158.