When you build VO2 Max you are building your FTP.

You work all energy systems and the contribute to your FTP.

If you are asking when you should be doing VO2 max work then that depends on what you are trying to accomplish and whether you are following a periodization or reverse periodization approach.

Long way of saying ride a lot and ride at different intensities.

There is a famous ST thread called Flanagan. This isn’t the thread, but it’s the first thing that came up:

https://forum.slowtwitch.com/...flanagan%20#p3912451

Original....

https://forum.slowtwitch.com/...ost=2932446#p2932446

I assume you mean "Power @ VO2 Max" not just "VO2 Max." Because it makes more sense to compare a power to power - FTP to Power@VO2. Than a power to a volume of oxygen.

(cycling) Unless all your events are very short, sub 1hr, its probably best to always focus on your aerobic system.

One specific vo2 workout a week during the racing season is probably more than enough for most, probably one a fortnight if you are racing once a week. vo2 workout being something in the 120-140ftp range for min on 1min off. Don't try and push more power try and cut the off to 50sec then 40 sec then 30sec with each workout.

As I remember for cycling before your prep period; If your Power at VO2max is more than 120% of your FTP then you should work on raising FTP. If it is less than 110% then you may get some benefit from training your power at VO2max if your race demands require it.

Raising FTP normally raises Power at VO2max and raising Power at VO2max normally raises FTP.

If you’re into geeking out have a listen to jan olbrecht on that triathlon show podcast

https://thattriathlonshow.libsyn.com/...n-olbrecht-phd-ep198

I have used this advise/method this year to great results ... n=1 I know... but I’m happy.

Thanks to everyone for some great info, still trying to digest it all!