I don’t know if you’ve had your question answered but in sum, you take the FTP test to find out how much output you can create in 20’. That is automatically inputted into your power meter on your screen (each zone correlates to a percentage of your average FTP test wattage regardless of how high or low your score is). In power zone classes you are given a set of work and rest intervals, generally the higher the zone, the shorter the interval (they won’t give you a 20’ interval in Z5 b/c 20’ in Z4 is the best you could do in the FTP test).
A sample 45’ PZ class might look like:
13’ warm-up
4 sets:
4’ Z3
2’ Z4
1’ Z5
Rest 1’ in Z1
1’ cool-down
