Seiler’s 8-minute intervals (Polarized)

Bit of an ambiguous question but who has done the 8 mins @ 108% - 2 mins reco - repeat *4?

How would you rate it in terms of RPE?

I’m wondering if I should start with the 4 min intervals and work up over a few weeks or just jump in the deep end.

Cheers in advance.

I tried this yesterday. I had set the intervals to 110% - seem to be various ideas out there - and after the first 2 intervals I knocked 3% off, but still had to bail part way therough the last one. So I would say the rpe is really high. According to a podcast with Seiler recently you can increase the rest periods, within reason, without affecting the usefulness of the session, so that may be the way to go.

I had previously completed the 4 minute version without any problem so I was surprised at how tough this was.


Found this:

It has some relevant tips.





Just having a look at the paper and the maximum RPE was 19+… It should be really hard by the end.

(Correction 26/11/2018). This is in relation to the ramp tests carried out not the intervals.

4 x 8 min intervals at 108% with 2 mins rest would be brutal.

Start with the workout Jobs (4 x 6 min intervals at 105% with 2 mins rest), or Jobs-1, and then adjust up from there over time.


Gross, most likely.

Especially if you are not conditioned for, or weak at, VO2 max work.

Personally I would find completing the same time at intensity, in more bouts (i.e 8 x 4 or 6 x 6) and gradually progressing more rewarding and encouraging than falling to bits on 4 x 8.

Granted the initial adaption isn’t going to be quite the same but productivity from blowing up 4 times on the trot has to be evaluated too.

That said I have a reasonable VO2 Max performance and having done mostly SweetSpot work the last 6-8 weeks I found Elwell (one of my favourite go-to’s of the past) to be challenging but managable.

Might be a good place to start and then modify the workout.

Here’s my personal experience with trying to find the best set for me.

  • I started with 5 x 4 minutes with 2 minutes rest at 111% FTP and started failing in the 4th interval. This was too hard.

  • Next time I stepped up the length of the interval to 5 minutes, increased the length and dropped the intensity a little: 4 x 5 minutes with 3 minutes rest at 108% FTP and I got within 1 minute of the end before failing.

  • My third attempt was 4 x 6 minutes with 3 minute rests at 108% FTP which I completed successfully but the last few minutes was hellish.

Between the second and third sessions I had a week where I did a couple of 30/15 intervals.

Here’s what that 3 week period looked like.

Resting up this week but my plan is to continue to combine the two types of intervals and work my way up to the full 4 x 8 minutes duration. It’ll be interesting to see what happens when I re-test my FTP. Good chance I’ll start with 4 minute intervals again an see how many I can do with 3 minute rests.



Two observations.

  1. Putting numbers into Workout Creator and getting an intensity factor reading across the 4 intervals, I don’t believe anyone should be able to do these at more than 105% of threshold.
    This workout expects you to do 32 minutes of work with only 3 2min rests. If you can do that at “108%”, then you probably need to re-test your FTP.
  2. The stated purpose of the Seiler intervals is not to hit a particular power, but to accumulate the maximum time at vo2 max. It’s on another thread but it’s somewhere around 90-92% of max HR you’re shooting for (maybe up towards 95% in the final interval but not before or else you’ll probably blow up soon after).

Edit: I might have got mixed up with my Workout Creator numbers (see below) - I’d now revise this to say that 108% is just about do-able, but completing it at anything above that would suggest a re-test is in order.


I do these from time to time and I find they are doable but very challenging. However, I execute them the way Seiler (and almost every running coach I ever had) specifies, not the “hit the power ERG mode TR approach”. I go anywhere from 102% to 108%. I only know I hit that %FTP after the fact.

Not knocking the TR way of doing intervals. But I find it trying to fit a square peg into a round hole. A nice side effect is that you are learning pacing by feel, maybe less important for cycling than running? Not sure.


My take (from a different thread):

Conclusion: 4 min intervals rock! :metal:


Lols, I struggled with Mount Hope-2 a few days ago which is 4x10mins at 95-99% FTP and 6min recoveries! I was a little fatigued from the weekend of training, but still…I did however really enjoy the workout.

I previously did sustained power build and I am DONE with anything 80-100% FTP. How I even thought that would be of benefit I do not know (I have a Masters Degree in Sport Science). Sweet spot is nothing more than a no-mans-zone intensity that’s too low to create adaptation but high enough to create fatigue.


Sweet spot and threshold have worked for me. So have VO2max and sprint work. Not everyone responds the same.

1 Like

Didn’t think the sustained power had that much sweetspot work. Thought it was more threshold, U/O’s and VO2. My experience with sweetspot (90% ftp) is that it’s hard enough to bring about adaptations but not so hard that you can’t do back to back days. Think it works well for building a base early on in the season. Horses for courses and all that!

1 Like

Sounds like the Polarised training thread is where you need to be

1 Like

The intensity factor is 1.03 but the workout length is only 38 minutes. I don’t understand why you think that a rider shouldn’t be able to complete that.


1 Like

Well, yes, but the subjects were asked to do even pacing across all four of the intervals, so it makes sense that the intervals should all be at the same power. The trick is to decide what power that need to be at to get to the end only just able to complete the last interval. This is were it becomes very individualised.



Maybe you’re right. I think I was mixing up the numbers I put in for 105 and 108.

Though by the time you get past 30 minutes, the power curve is pretty flat. 38 minutes at 103% is a seriously tall order. TT race pace territory.

These intervals are very hard.

It will depend on the specific rider too. My numbers are a percentage of my FTP taken from a ramp test, which I’m pretty sure overestimates my LT2 so the actual percentages could be a little higher.

I’ll be interested to see what happens after my next FTP test.