Just out of curiosity (in the context of 'how to train' like a mere mortal instead of like a TdF rider) I took a look at the "Time Crunched Cyclist" Century Training Plan (New Century rider). I did the following 'Zone Assignments' in the context of the link above.

EM - Zone 1 (Endurance Miles)
SS - Zone 2 (Fairly hard Steady State riding)
Tempo - Zone 2 (Tempo Riding)
CR - Zone 2 (Climbing Repeats)
PI - Zone 3 (Power Intervals)
SEPI - Zone 3 (Steady Effort Power Intervals)
PFPI - Zone 3 (Power and Fade Intervals)
OU - Zone 3 - Over/Under Intervals (alternate moderate/hard with no rest in between)


The results were interesting. It came out roughly 80% in Zone 1 (where my reading of TTCC would put this clearly toward the top end of of Zone 1.

FWIW.

dave