I was looking at the training plans and noticed that for SSB the MV2 and LV2 options both include V02 max work and some direct threshold work, whereas the HV2 is almost completely Sweet spot work continuing. Just curious why they are so different?
@chad any suggestions?
HV contains ONLY SS workouts because it is HIGH volume. SS is less stressful on the body therefore you can do more of it.
L/MV contain other zone work because they have less volume; the additional training stress comes from higher intensity.
TradBase contains an even higher volume at an even lower intensity level.
If you think about it, you could reach the same level of fitness doing an ultra-low volume ultra-high intensity plan. Not sure you want to do 8 weeks of only VO2max intervals. 
Thanks for the response. I guess I was just thinking there is more room in the MV plan particularly to get rides up to 1.5 hours with some of the longer sweet spot intervals ( Galena, etc.) and drive CTL that way and save the VO2 stuff for Build.