My FTP is currently set at 262w and am on the (experimental) polarised training plane which has me doing z2 most days, with one day of VO2 efforts and one day at threshold. I try to do most riding outdoors (weather permitting).
The threshold days feel about right in difficulty. The last one prescribed 2x16min @266w and I averaged 270w for each effort.
However, I feel like I can go much harder in the VO2 max efforts. Today the prescribed workout was 6x2min @324w and I went much harder than prescribed with 5x2min @370w and the final effort @400w.
Should I continue to push myself beyond prescribed at the VO2 range or is that actually harmful to my training?
Inside vs outside efforts feel quite different. VO2max efforts should be as hard as you can for the duration of the interval. When doing VO2max efforts outside I try and find a power that I think I can sustain over that interval and for the whole set. That’s a bit of a “chicken and egg” situation: you need to know how hard you can go before you can go as hard as you can! With a bit of practice you can get close pretty easily.
I do my VO2max intervals on a slight grade on a quiet road, the longer intervals with corresponding longer rests I’ll ride back to the start and do the same bit of road again. I’m usually within a bike length or two of the distance each time.
VO2 max isn’t really a power zone but an oxygen based zone and its its normal for some folk to find power zones to low for it but ideal for other zones like Threshold. Kolie Moore in his Watts doc podcast does a good peice on it. Switch off ERG and spin/power to your true max on VO2max sessions would be my tip based on listening to him.
6x2min at 124% sounds like Nacimiento (PL 6.2) or Ancohuma (PL 6.5). You pushed it higher, into PL 8 ballpark a la Queva (PL 7.7) or Alma Negra (PL 8.2).
For your next VO2max workout simply choose alternative workout roughly at this progression level (more intervals and/or less rest between them). It will set appropriate level for you in AT. From that point forward, it will suggest you more suitable workouts hopefully.
The highest average you can across the reps and they should ideally have next to no variation between reps. Pick a workouts with longer reps if you can put out power that would traditionally be getting towards mid Anaerobic powers.