About 4-5 years ago Dr. Coggan updated the training zones above FTP, removing the VO2max and Anaerobic zones and replacing with Individualized Zones. The reasoning behind it is classic zones having a limitation when using a fixed % for zones above FTP. One relevant quote from that article:
“As shown in Figure 3 below, their relative power was generally similar at durations more than about 10 minutes. However, there is obviously a very large (approximately fourfold) difference in the extent to which they can elevate their power above FTP at very short durations. As a result, the one athlete can maintain a power of, for example, 150 percent of FTP for about 4 minutes, while the other athlete can do so for only about one minute.”
The classic 3, 4, and 5-min vo2max intervals are meant to be done at max repeatable power for YOU.