Very short threshold intervals?

I’m thinking about doing a threshold progression in my power build phase and looking at Seiler’s 4x8/5x7/5x8 progression. My short power build plan builder however has very short hard start 3-4 minute threshold intervals (“Myrmel”).

I was trying to read up on short vs long threshold and I only saw a limited number of posts here about it. Plenty discussing VO2 and sweet spot, though.

I skimmed through the threshold progression thread, but still not much on relatively short intervals like 3-4 minute range. When it comes to these, is it about trying to accumulate time in zone? Or how effective are these actually in building power? I’m guessing that they would stress lactate clearance more and help with repeatability.

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Seiler’s intervals are over threshold, all out if I remember correctly.

You probably didn’t find much about FTP intervals that short because they are basically useless. You very likely won’t get a stimulus from something that short at FTP even if you do 10 of them.

Hard starts are different of course, but still I’d say they are very short at 3 to 4 minutes.

I would do 10 minutes intervals, starting with something like 3x10. Then take another look at the threshold progression thread which is full of good info.


Just had a look at the workout. They appear to be an over/under variation to help build FTP but not one that would be a go to for me. Too broken up with lack of consistent TiZ but I could see how they could be used to get someone familiarised with over-under work is they are new to it.

If we accept that it is a variation of over-unders, responding to the wider query then yes I find these type of workouts to be beneficial to raise FTP but with the caveat that they would be structured differently to the workout your note. I like high overs, lower unders for mine (eg. 120%/90%) building TiZ (eg. 3x12 > 3x15 > 3x18 - 1m over, 2m under)

What do the follow on workouts in this short power build plan look like? important to not consider one workout in isolation but look at the bigger picture/ progression etc.


Yeah my thought is that these are the equivalent to 30/30 for VO2 max workouts, a far cry from the best use of time but a needed step (for most riders) to just get used to training in the intended zone. It’s basically mental training until the longer intervals are prescribed.


That looks quite a tough session but I wouldn’t call them threshold intervals - 8-15mins@96 - 102% FTP is more like it…that said I TT so they would help me - on short power build they are probably the correct training for the aims of the program :grin:

Unfortunately I’m having a 3 week time off block after next Sunday so I’m looking to restart with a longer suprathreshold block when I get back. Your first comment about inconsistent TiZ was what I was thinking too. I’m questioning the layout of my plan because the next one like it is Whiteleaf in March, and nothing else follows. It’d probably work if it were uninterrupted but the way my time off lands might not work out so well

There are indeed VO2 repeat workouts but I feel like these short over-under threshold workouts can achieve the desired result more efficiently with a different layout.

And definitely I learned a lot in the threshold progression, like the rest of y’all are saying about 3x10 etc—is why I think I’d prefer to do something like longer sustained work, and then sprinkle in VO2 efforts for the short power side of the equation as I get closer to crit and road racing

I too was interested in shorter threshold workouts. Coming from a running background, before turning to biking, I have been intrigued by the excellent results from lactate threshold training done by the Norwegians. My interpretation to adapt this to my bike training has led me to design my own workouts on workout builder. 10 x 6 minute intervals with 1 minute rest between, and another workout consists of 24 x 2 minute intervals with 45 seconds rest between, in addition to a more standard 3 x 20 minute intervals with 3 minutes rest. The speedwork days are not FTP gut busters, but are done more like upper level tempo to low sweetspot efforts, at or just below lactate threshold. As such, I’m able to get a longer time in at a quality effort. Have been at it for a few months and just starting to see some benefits.


If you need to break up threshold into short intervals just to accomplish meaningful TiZ then it’s not the end of the world. But I also suggest that if you can’t get through a 20 min threshold interval, then you’re not riding at threshold, so we get into how is your threshold determined.

When it comes to threshold intervals and below, there is value in being able to handle long intervals without rest. I dabbled with 5x5s on 1 and 4x8 on 2 (true threshold stuff, not 105%) and didn’t find them meaningfully effective. Maybe good for a little threshold stimulus in early season, but not going elicit much change IME.

The shortest intervals at SST or Threshold that I generally prescribe are 10min, and that for athletes that are really new to structured training, but my goal is to get them working 20+ min as soon as reasonably possible. Once they’re there, I rarely go back down. Sustaining sub-threshold power matters.


4x8 on 2 at 105% of how he defines threshold, which seems to be generally “hour power” - like no kidding your 60 min MMP as determined by a test effort.

So depending on your TTE, it might be at FTP if your TTE is shorter, or it might be slightly above FTP if your TTE is longer.

Wasn’t Seiler’s 4x16 at 97% of threshold? That would IMO be closer to what he would suggest, for the 4x8 it was 108-110% IIRC


I think he did the study with 4x4, 4x8 and 4x16s at the various powers and found the 4x8s had the largest impact long term. The problem I run into is the definition of threshold varies so widely in a lot of these cases and that nuance gets lost in casual discussion.

I believe his study was 108-110 but the “Seiler 4x8” prescription is 105. I would have to go back and double check my memory on that.

I’ve seen the 5x5s prescribed at 110% (Kristin Armstrong).

There’s a dramatic difference in 4x8 at 105% of ramp test “FTP” vs. 4x8 at 105% of 60min MMP. And I read and listen to a lot of Seiler stuff and I’m just not convinced any of it is earth-shattering. It’s generally just traditional training methods labeled differently, IMO.

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At the bottom… max sustainable (repeatable) “erg like” effort, whatever that was for each participant.


No, there was no prescription of percentage of ftp, that was calculated later from the results… they were done at maximum repeatable.


Ah just posted similar, that was as I thought.

Yes, that’s right. It was DEscriptive. And i think when he talks on FastTalk about being more PREscriptive I think he says 105%. Thank you.

yes, the percentages were calculated after, but based on the blood lactate data, the 4x16 were near threshold(4mM) and the 4x8 was VO2max efforts(9mM), there was never 4x8 threshold efforts studied

I was basing it on the lactate values from the paper

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Yeah, I meant more as a prescription when people are talking about it casually, not when citing the paper. People throw around the Seiler prescription (e.g. 4x8/2 at 105%)… but 105% of WHAT? He loosely says “threshold” which he means power at MLSS most of the time (as you said here), but then he talks about “hour power” since most people don’t have lactate test data… and then you have TR athletes doing ramp tests and wanting to do 105% of THAT “FTP” which is probably a mistake. That’s more what I was driving at…

Round and round we go with the various definitions of “threshold.” :sweat_smile:


Yea I guess whether its 105 or 108, the intention is for them to be over threshold/VO2max), I don’t think he is suggesting short threshold intervals as OP says. As you’ve said above, 20 mins is generally the minimum effective dose except when first ramping up after a layoff or new athlete. My HR doesn’t even stabilize near LTHR until after 7-10mins

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I’m still debating whether I should give it a go at these supra-thresholds workouts.

From listening to podcast it is also clear there’s no clear consensus either.

Some coaches claim they’re rather pointless whilst others swear they’re essential :thinking: