Polarized Training with Stephen Seiler, PhD | EP#177 That Triathlon Show

Original thread used to identify questions for the interview above:


Thanks @Mikael_Eriksson, another good listen :+1:

Interesting point about keeping the high intensity around 90%. As @sryke said in the Q’s thread, POL is often referenced as making the hard days really hard, so this is quite a contrast from that.

In the TR speciality triathlon plans I’ve found some of the workouts, such as Owens, to be too much intensity in the past. They’re do-able on a good day, but I think they edge towards being too much of a risk, especially close to a race. In the last few months I’ve felt my training has gone better by substituting workouts like Owens for workouts with slightly less intensity.


Just finished this, was nice to hear the fundamentals reiterated.

I’m trying to work out my zones. Can anyone give an example of some FTP values and what the zones are for those? Eg 250 watts, 300watts etc?

Or do you need to use that paired with HR? Is there a calculator for his zones? Just want to try and work out the and watts/HR I can do at the low end.

250w FTP:

275w FTP:

300w FTP:

If you really want to adjust everything, follow the instructions on my sheet to make your own copy. Then you can enter all your power and heart rate info to get your specific info.

  • This sheet is from deep review of the prior Fast Talk, and Faster podcasts with Dr. Seiler. It is based on FTP and Lactate Threshold Heart Rate and attempts to capture the zones he defined.
  • It also allows general comparison to the Threshold model from Dr. Coggan.

Once again, a very good interview @Mikael_Eriksson!

Brilliant thanks! If I’m reading it right then a rider with 300w FTP would be allowed to spend a lot of time riding at 240w? That’s fast! I consider that low end tempo. If true then polarised training isn’t really as dull as I thought…

On Fast Talk episode 54, Dr Seiler said (loosely transcribed, not direct quotes):

  • roughly 80% of 60 min for zone 2 bottom / zone 1 top. That gets you in the ballpark, if its too high adjust down. Most of the rides will be 60% or 70% so there is a margin of error. Be conservative and don’t overestimate your ftp.
  • most people over estimate their ftp
  • get off your a** and really do a 60 min power test

For myself, it is roughly 60-70% ftp (and ~72% of HRmax) and the “talk test” or “first deep breath test” are likely better ways of determining your LT1/VT1 (and then riding under it).

  • Kinda. The point of the zones in general is to set the lines. I would not generally consider spending significant time “on the line” between zones.
  1. Our bodies aren’t that discrete in their transitions.
  2. All these zones are estimations and should not be taken for hard transition points.
  3. Overall, it seems best to shoot for somewhere in the middle of the Z1 and Z3 when you are training. Most seem to recommend staying away from the split lines, for many reasons (including #1 & #2 above).
  4. As such, I would say that 300w rider would want to be spending more time in Z1 around 200-230w. Keep in mind that is also depends on the specific duration of each workout. The longer you go, the lower you want to be in Z1.
  5. There are many people who feel the Z1 training is better served with HR as a guide instead of power. As such, you would likely find you need lower power, especially in the longer rides as aerobic decoupling occurs.

You may be interested in reading some long discussions that cover this and so much more about the POL world in great detail. There is some deep info, but I think we have hit just about every angle to some extent.


Based on listening to 3 podcasts with Dr Seiler, the simple answer is “no” and you should be lower and focused on LT1/VT1.

In this EP#177 podcast, he said as a guess for top of zone1 keep it BELOW 75% of HRpeak. It doesn’t mean ride at 75% HRpeak/HRmax, it means riding below that. My cycling HRpeak/HRmax is 175bpm, so that means keeping it below 131bpm which from TR aerobic endurance rides is roughly 60% ftp.

So if I had a 300W ftp, that means doing long aerobic rides BELOW 180W and being disciplined enough to keep it at or below by cross checking against the HR on my bike computer (keeping below 131bpm).


Great podcast. You can tell the difference from earlier Seiler podcasts in terms of how clear he is in defining the zones, etc.


Everyone is different… I can ride at about 75% of what my FTP is set to keep my HR below 130. AT least on my rollers so same PM. Keeping HR below 130 outside results in a lower power number since the output is far more variable, uphill downhill etc… But I’ve been trying to keep 130 as my main HR cap during my endurance rides, so that ends up with an average HR in the low 120’s.

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sure, those are my numbers and yours will be different.

If you haven’t had lactate measured then Dr Seiler gives estimates based on HRmax / HRpeak, from the podcast notes:

  • If you want to find the first lactate turn point, you ideally need to measure lactate.
    As a reasonable educated guess, keep it below 75% heart rate peak for zone 1.
  • If you really are in zone 1, you should not see a big drift in the heart rate. The HR you have after 15 minutes should be the same as at 60 minutes.
    If you’re drifting up a lot there’s a good chance you’re working at a higher intensity than you think you are.

He didn’t give any power based estimates for zone 1.

Personally I’ve used a target of 135bpm as my “ride all day in the mountains” pace, but that is definitely ABOVE my first lactate threshold (LT1). And in last 2 years I’ve obtained very good gains from aerobic riding on the flats using 135bpm target. However I haven’t tried dialing it back to 120-125bpm which is likely my actual HR at LT1 (my best guess using talk test / breath test and 71% HRmax).

Would I see more gains doing long 3-5 hour rides at 125bpm rather than 135bpm? My current aerobic rides are very low end of zone 2, and above Seiler’s recommendations. I’m not aware of any studies comparing vo2max improvements or fast recovery (the two reasons given for all the zone 1 work) when riding near top of zone 1 versus riding near bottom of zone 2.

This is a very similar position to myself. When running, I tend to train around 150BPM (~79%HRmax) for my base runs. Based on the 75% he mentions, I should be closer to 144 as my high end. He did seem to say it in a conservative tone such that he was playing it safe, but curious how much different training 5-10BPM slower would affect everything. I’m just under 2 months out from my A-race, maybe I’ll give it a go on my easy runs and make them even easier.

FWIW my HRmax was highest HR I achieved doing micro intervals 30s/30s

Maybe I missed it in the podcast but I didn’t hear any mention of what sort of intervals to do on the bike for the high intensity intervals.

Are there recommendations such as 15x1min, 3x5min etc…

The podcast was focused on fundamentals, and Seiler has agreed to return for a second podcast.

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Ah okay thanks

What happens if your HR goes above LT1 occasionally during the long flow rides? Does something reset or happen to ruin the effect or do you just get a bit more fatigue that you should be avoiding?

Great podcast. What haunts me the most is Seiler’s recommendation to perform an hour of power for determining ftp. My yesterdays ramp test resulted in an ftp of 343 Watt. I can’t do that for an hour, that’s for sure. But i did sustained power build mid volume with my previous ftp setting of 337 Watt and that worked pretty good. I am pretty sure i would end up with an ftp between 315 - 325 Watt after a 60 Min test. So what does this mean for the intervall intensities/trainingzones? In Seilers model i would do my zone 3 training arround 315 -325 W, maybe slightly higher, right? That would be arround sweet spot in the TR model and has been said here before. With the ftp from the ramp test the intensities would be higher but nevertheless doable.

Has anyone trained with an ftp from an hour of power? How did it feel compared to the Tr model?

The FTP Challenge is a good thread showing a few attempts at this.

It’s likely that in most cases TR workouts would feel too easy using an FTP from an hour of power. I think the TR workouts have been scaled to make allowances for most people using an inflated FTP.


He didn’t say what kind, but did mention that the end result is around 90% hr max, probably capping it a few bpm above that. He did say the athletes tended to stay out of zone 5 which is around 92% of max when using the Norwegian 5 zone model.

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