Any thoughts on the best type of workout? Vo2max or threshold?
you cannot do one type of workout over and over and expect continual gains, polarized or not.
Except ISM Z2!
The best type is the type of work you need!
FWIW, Seiler found that the 4x8min intervals were the best of the ones he studied (4min, 8min, 16min) but they were the best by a statistically insignificant amount. I think the conclusion is that you can pretty much design any progression for similar gains, assuming equivalent time in zone.
Try the 4x8s. If 32 minutes is too much work then start lower 3x8, 3x6, etc. and then work up. Some people do 10s and progress 2x10, 3x10, 4x10, 2x20, etc. You can slice it and dice it a million different ways.
Watched a video on this and these are threshold sessions from what I can see.
Does that mean that if you’re training under a polarised model the best high intensity workout is threshold over VO2 Max?
Unless your TTE at FTP is very, very short 4 × 8 should definitely be supra-threshold work. If so, 32 minutes of work up there is very likely to get you some time at or near VO2 Max.
Does Seiler not prescribe them as max efforts while minimising power loss across all the intervals?
8 minute intervals will be a little bit over threshold.
I can’t answer that because that is on your to design your program and decide what type of intensity to do at different times of the season. VO2max is great but you can’t do VO2max intervals 52 weeks of the year. You could try!
Polarized simply refers to 80/20 (two workouts out of ten being hard workouts). That could be threshold, VO2, sprint intervals, tempo, sweet spot, or a 5 hour hard endurance ride. It’s up to you and your coach (most likely you) to decide.
You can join TR and follow their plans or read books (Friel, Time Crunched, etc) and design your own.
Here’s a great blog post by Jem Arnold that sketches out a basic plan one can rotate through:
Interestingly the polarized base plan that I am following right now as 2x16 minutes at just above threshold twice a week before switching around the interval durations and intensity.
30 second intervals are apparently pretty good
more generally, you should be doing all the zones - vo2, threshold, anarobic, sprints (not in one session, obvz)