Originally Posted by
wktmeow
Have you tried 110+ RPM hard starts/positive split for 3-6 min efforts? Those seem to do something for me, but I hate actually doing them.
The tricky thing is that supra-threshold power improvements do not necessarily correlate to vo2max improvements. E.g. if your vo2max actually improves but your anaerobic capacity decreased then your power might be the same for 5 minutes, and vice versa. Not sure how you determine what your 'actual' vo2 power is either, as you can achieve vo2max at a wide range of wattages. Sooner at higher power (e.g. 125-150% FTP) but you can't stay there as long, later at lower power (e.g. 105-110%) but you might be able to hold it longer. There's an important difference between improving your 5 minute power and actually improving vo2max. One is not necessarily indicative of the other. Ideally, for an endurance sport at least, we should probably prioritize improving actual vo2max and not 5 minute power, as this would increase the ceiling for FTP, whereas improving 5 min power via increased anaerobic capacity may not.
I just go off of what WKO4 says it is. It frequently seems to be within a couple of watts (or exactly the same) as 5 minute wattage when my PD curve is robust enough. Could be I just rarely do max 6-8 minute efforts, though. There's also an interesting chart called "Relative VO2 Max Chart" that provides the amount of time at a certain percentage of VO2 max, and it shows pretty well on the graph what you mention above with starting at higher power and getting into vo2 max territory sooner, etc.
But also according to that chart, I have to go really, really hard to build up any significant time at 100% vo2 max, which is where my 128% FTP comes from. In the past my very best workouts for accumulating time at 95-100% have been ~4 x 3:45-4:00 getting up to 9-10 minutes at VO2 max based on that number. At my roughly 340 FTP or whatever it was at that time, I think it was over 430 watts for 100%. It's very, very tough for me to mentally dig in after a couple of those when on my own.
In the past, for race prep/maintenance, I've done intervals like 30 secs very hard, ~110% ftp for 3 minutes, 30 secs hard for a few sets. Sounds pretty similar. But I always felt those were more mental conditioning than physical at that point, since 110% isn't that tough for 3 minutes. I might investigate that a bit more.