Iñigo San Millán training model

Does ISM recommend a talk test for zones?

From my understanding and his PDF, Zone 2 goes from fatmax to fat-carb crossover, which can only be done with a metabolic cart.

The whole thing relies on using metabolic data to define zones.

He’s said over and over in podcasts that he recommends the talk test for those without lab testing.

I guess I always thought ISM “zone 2” was more similar to coggan zone 2. But if ISM’s Z2 is more like tempo then that is new to me. (Not that it makes much practical difference to me.)

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100%, I would definitely bin the LT1 work during a race build.

Possibly, leaving one day of it, depending on fatigue etc.

It’s rider specific. That’s the magic.

He tests his riders, then sets their zones.

Usually, he has his riders pinging right on the edge of Z2. Which, importantly, is his zone 2. Not Coggan’s and not based backwards as a one size fits all percentage of FTP. Doing it that way can be correct, if you test properly and are right on the bell curve.

I’m a good example of it not working perfectly. I’m definitely in Z3 tempo Coggan when I’m at LT1.

Everyone will be different.

I think it’s worth the small time investment to get some precision, if you do a majority of this style of training. Which in the professional ranks, is basically everyone.

I wish I’d done it sooner.


I’ve been doing this type of training for years. It’s very effective for building long sustainable power. I use 83% of max heart rate and begin to push out the intervals.

An example of starting a training block would have me around 270-280w, I will push it out to 60 mins or more. Usually within a couple of weeks my power is 300w. Over the years I’ve pushed that out to around 2hrs in a single interval at the same 83% hear rate.

The problem with this training is that it will make you flat. Being able to hold 300+ for hours isn’t efficient for racing in my area. The surges will take a toll and also the accumulation of fatigue.



Just finished an indoor LT1 ride (ISM Z2). Few months ago did my own lactate test. LT1 around 220w.
So today avg 214wNP (207w) for 110min. PWhr 0.2% so that is ok. Average bpm was 136 (treshold heartrate about 165, max 180 (very rare).

My goal is to bump the duration up at this intensity. I don’t race, only gran fondo.


I have, but it is rare and indicates phycological weakness for the rider not being able to push to potential. Without lactate data you would not see this nor identify the potential to improve because the rider legitimately feels that they are at a high RPE when doing their FtP or MLSS test.

Similarly the currently in vogue “performance is the best indication of performance” doesn’t work for these riders. Because performance, and things like FTP tests, are both physiologic and psychologic. IMO, If you have tools available to isolate the variables of a system you can use them to improve the system and that is the goal.

Lactate data, for all its flaws, remains a quantitative measurement which if used well can add substantially to a training program.

Your post is spot on in so many important ways. It should be pinned.


  • About 600 posts are ppl getting Zone 2 confused with (surprise) the other Zone 2. It is individual but not as variable as (for example) anaerobic capacity, which can vary widely among riders. Most ppl eventually come around to the reality that it is a “tempo” level of intensity (meaning, there is a level of intensity below this one…namely basic endurance riding). Lots of ppl still hate the term “tempo”. :man_shrugging: so they find other equally useless but colorful ways of labeling it
  • It is not a range. Please, please. If we take nothing else from this: it’s not a range. He pinpoints it at a point during a ramped test. You can derive a range from that (and since it’s lactate, you sort of have to…lactate is not that precise, and power alone is a false precision).
  • There are indirect ways of getting at this crossover point (and many, many labels), but ISM uses a metabolic cart and some posters use a portable lactate meter. Depends on the precision you think you need. He discusses a talk test with Attia.
  • Random and somewhat arbitrary criticisms of podcast appearances (welcome to the internet)
  • Not many ppl had tried this training in Sept 2020. A prominent poster (the OP of this thread) was intrigued by these ideas and started to ride this way. The approach most similar at the time (that anyone who posted could find) was a coach named Steve Neal. That’s why his name comes up in these discussions. Lots of coaches and athletes piped up with “we do that too!” but after closer inspection you see they just do sweetspot/threshold stuff. The bandwagon had formed.
  • Lots of obligatory if that works for you great, this work for me (we need that in every thread LOL)
  • But is it polarized? Pyramidal? That took up a fair bit of wasted time
  • Yes, much of what he saying is not new, but he’s Pog’s coach so ppl paid attention, particularly since it went against the grain of the wood in terms of current, popular training approaches
  • He provides general prescriptions via TrainingPeaks article and in his podcast appearances. Refer to the TP article for quick overview. That TP article was largely ignored until the wider realization that he wasn’t talking about general endurance riding (Coggan Zone 2). When you realize he’s talking about a sort of low tempo / high endurance, that article gets more eyes on it
  • He has addressed intensity a little. He is an advocate of “end of ride intervals”, but don’t expect a “sample build week” from him

I think you’re all caught up.


Lanta. Thanks for sparing me :joy:

So if I just overestimate my FTP and ride at the top of z2. That means I get all of the ISM gains right?

Brilliant, well done, you saved me hours. Can you do this for every thread that has 1000+ posts?


I can measure lactate but never done An MLSS test. It is a good idea to take lactate values every 5min at a constant wattage? Around 250 for me wath could be my MLSS. If it stays stable…

LT1 is around 80%FTP for me.

I usually use around 10 min time points. There are some protocols and data examples from different TR Forum participants over in the lactate testing thread.


You could try Protocol 2 from this pdf from High North. I don’t know how accurate it is but the guy there appears to know what he’s talking about


I don’t follow anyone’s protocol. I just take more measurements in the beginning of the test and and increase the time between measurements as the test progresses. I start without a warmup since I want to see lactate response as it evolves.

I started doing my profile a few weeks ago, but I got sidetracked by work and life. I would have added 170, 190, 210, and 230 watts. 230 watts would have been over MLSS for sure.

Nice write up. I’d also point out that within TR there have always been the traditional plans which to me seem to narrate a similar story to the ISM z2 world and might be a good starting point to look at, for example

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To my eyes TR Traditional base 1, 2, and 3 look like a nod to Friel.

Nice summary, somebody should feed the thread into ChatGPT and see what we get. I know you realize pinpointing something from a single test is false precision, and you back down from it, but some will walk away with pinpointing stuck in their mind.

The talk test subthread, or perhaps cross thread, is an interesting point of summary. It’s not saying the alphabet, or talking on the phone without having to take mid sentence breaths that giveaway you aren’t sitting in an office.

What is it?

Dunno, I find it hard to talk to myself on training rides :rofl: Out here in flatland I find it easier to get in the zone, listen to my body, and find the tipping point in breathing and note my HR. Ride after ride, season after season, its not so surprisingly in a rather narrow range of HR. But not everyone can do that.

Pace by power, informed by HR, and track fitness increases by changes in power @ that narrow HR range. My coach has supported me and pushes me to really listen to my body and during certain times of the year really challenge my ability to push out duration on those steady negative split endurance rides. It took me some time to really listen to my recovery needs, and balancing challenging endurance rides with recovery and not impacting my hard intervals.

Recently subscribed to Evoq channel on YouTube and yesterday at lunch listened to the first 12 minutes of this HR vs Power, VO2Max Intervals, Strength Training: Coaching Podcast with Landry Bobo - YouTube and really enjoyed listening to Landry Bobo talk about use of power and HR and perception. Landry also has some good blog posts on Evoq and TrainingPeaks.


Even more confusing to me has been that in running “tempo” is basically threshold or MLSS. I’m still wondering how cycling adopted tempo as the intensity below threshold.

Steve seems to be using NIRS (Moxy, etc) these days for intensity control. I’m still fascinated and want a NIRS device but I’ve been too cheap to spend $900 on one.

BTW, Steven Henderson mentioned NIRS two or three times in the last FastTalk podcast. They should have had Steve on that episode.

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