Seiler’s 8-minute intervals (Polarized)

I think that’s a fair observation, and as it is, I haven’t worked up to the full 4 x 8 minutes yet, and it’s been a while since my last test…

To complete the picture around the different FTP tests:

The 8 minute test is 2 x 8 minutes at 111.1% FTP (100/90) with 10 minutes of rest between. The IF for this is 0.99 for 26 minutes.

The 20 minute test is 1 x 20 minutes at 105.3% FTP (100/95) with a 110% 5 minute effort before that to reduce the anaerobic contribution. The IF for this is 1.01 for 30 minutes.

On reflection I could see the intensity being reduced back a little to get to the full 4 x 8 minutes.


Although many people believe that 95% of 20 minute test overestimates most people’s FTP. Which would - if the ramp test is a better test for FTP - tilt things back towards 1.03 intensity for 38 minutes being just about possible.

Just adding my 2 cents. I was going to try a polarised plan this year but have since changed my mind. However I did try a scaled down version of the 8min intervals, 3 x 8, using Seilers method of let the athlete figure it out. I’m no athlete but I soon figured out I went too hard on the first interval when the 2nd kicked in!

1st was just a smidge under 110% ftp. 2nd was 106% and third 105%. Had I not gone as hard on the 1st interval, I’m fairly sure I could have ridden all three at 107% or just under.

One thing to note, the 2 min recovery intervals are not set in stone. Seiler said that he found most athletes only needed 2 mins before going again. If I were to do these again, I would increase them from 2 mins to 3.

Try Raymond +7 first and see how it goes.

I modified that workout and reduced the intervals to 2 minutes and completed it. Not sure I was hitting the 108% though with my naff trainer.

Yes, that’s correct. If I remember correctly there was a study into self selected rest periods and the result was that 2 minutes was perceived to be enough. Seiler has said himself that it isn’t crucial.

Maybe like with most of this it’s very easy for people to latch onto the result of a study and decide that it means something it was never intended to show.



Then why assume extended rest would be critical to total time in zone?

You have taken my quote out of context. That was specifically referring to the number of rest periods not the length of them.

However, I was thinking about how extended rest periods could change the amount of time in zone. By starting at a lower heart rate after 3 minutes rest compared to 2 minutes rest you would have to work for longer to get to the desired zone.


Forgot it was 2x8, thanks for the clarification. So it’s actually 4x8 at 3% lower than 2x8 power, tough but might be doable!

It’s all dependant on fitness. Seiler was looking at highly trained athletes. For them, 2 mins was probably enough time for their heart rate to drop low enough for them to want to go again. For me, I needed longer. I’m sure he has said that it doesn’t matter if your rest interval is longer.

No he wasn’t.

His test subjects were “recreational cyclists” doing “4-10h/wk training volume”.


The rest interval is irrelevant. You should take the amount of time you need before you feel like you can go again. That may be 2 mins or 5 mins. It doesn’t matter.


So I decided to be stupid and just jump right in and do it. Calves started cramping in last effort so turned the intensity down by 2%. As such I rate this RPE 10/10.

Ill do it again soon, but will put a bit more periodization in, I only chucked myself under the bus as I have an ITT this weekend.


That’s right on the money for you. Great effort.



Sorry, that was incorrect. 19+ was for the ramps tests that they carried out.

I recently spent some time analyzing TR results for the Raymond +7 workout. This workout is 32 minutes at 108%. 4 intervals of 8 minutes each. I would say the results of that analysis only confirm your assertion: 32 minutes at 108% is a tall order. Less than 60% of users are able to complete this workout. (just looking at the most recent 100 workouts)

Same story with the Elephants +4 workout. That’s 36 minutes at 108% distributed as 6 intervals of 6 minutes each. Again, compliance is only about 55% & that is generously allowing for substantial backpedalling during the later intervals. (again, most recent 100 workouts)

Bottom line: these are tough workouts & while it’s still correct to say ‘most users can do them’…it’s only BARELY JUST correct to say that! Better get your rest and recovery in the days leading up to a workout like that.



When I think of the sustained power build workouts I think of 105%-108% workouts and Over/Unders. When you say you are done with 80% to 100% FTP work, do you mean that you feel like the 105%-108% work in sustained power build just produced superior results & so that’s the way you want to focus going forward?

Curious - where do I go to get this data?

@DaveWh You could get a SWAG of the last 100 rides under “All Rides” within a specific workout.

(or if you believe that list is random enough, you could pick any 30)

1 Like

Thanks. That’s interesting stuff. It makes me feel better when I look at Kaiser and see about half of the people dial down the intensity or bail!

@DaveWh yeah, compliance is a lot lower than I thought it would be for most workouts.

If you want to be truly elite among TR users, don’t shoot for a 4 w/kg bogey…aim to complete your next Elephant +4 workout…complete EFI, no backpedalling, no pausing…then hit the ‘+’ button on the last interval. I’ll bet not many TR users ever accomplish that.

1 Like