Zone 2 training with Iñigo San Millán, part 2

I’m definitely toe-ing the line of ‘in over my head’ … if not already there. But …

Why would it have to replace anything? For instance, if they have a long tempo ride they may just do it at a low cadence … not replacing anything, maybe? Just altering the execution?


go for it, I do it all the time. The only dumb question is the one you don’t ask.


Oh I’m not sure why I thought that was published in 2010 or so, might have confused it with one of the other similarly titled books… doesn’t look like that one’s on my shelf, soon to be remedied. Anyway, short explanation here is that almost everyone doing endurance or heavy strength training loses most iix fibers to iia. IIRC the most iix % I’ve seen is around 1-3% for trained cyclists, meaning you’d have to be into 97-99% of your total muscle mass at LT2 which is unlikely. This is why a lot of the literature only breaks it down into just type I/II instead of subtyping fast twitch.

The torque stuff is 4-10min long around 30-50rpm around sweetspot (a stimulating dose for a WT person might be more like 80-120min and this is half that at best), tempo stuff is 3x60min self selected cadence (there is probably no reasonable dose that would be stimulating for WT folks), most frequently. Neither is really sufficient to qualify as progressive middle intensity training themselves which would be necessary for better endurance performances in athletes of that caliber. So where’s it come from?

If it’s leading to better performance, putting it in context of what wasn’t working previously is always where I start. I do a ton of consultations and when I see a shift in training leading to better performance, the question is why so we can discern a potential mechanism and learn from it to inform further progression (and more often vice versa). And it’s apparently associated with better long mountain climbs, meaning middle intensity. Where’s this come from maybe? When you combine motor unit recruitment theory and races with long climbs, you’ve got a decent recipe for progressive overload. Meaning that might be what’s working for WT folks, but why such training might not work too well for average cyclists who don’t smash up mountain passes for 6h a few times a month. It’s a theory anyway, and one without much thought behind it so as research comes out on this stuff we’ll hopefully see what’s really happening.

But it would replace something less effective like… non progressive threshold efforts. If someone’s always doing 2x20 that’s not a good dose to improve performance for a WT rider since at no point will they be getting close to needing to dig into bigger motor units. Anyway, hope that makes sense. Been planning on organizing these thoughts and doing a rambly podcast on it. I’d love to interview someone but nobody really has anything definitive.


Using this as my inspiration :grinning:

I’ve seen two schools of thought on cadence in endurance training:

  1. Higher cadence leads to greater adaptation (I think mitochondrial adaptation is the main goal of long endurance training, so this is the adaptation targeted), due to a greater number of repetitions.
  2. Lower cadence leads to greater adaptation in terms of producing torque, per above.

Do we have any evidence for either/both of these? It feels like they could contradict each other, but there’s also plenty of assumptions built into each one, so maybe they’re not contradictory…

Thanks for opening the door to that dumb question!

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more fuel:

haven’t watched it yet, so no idea if there’s something new in there


Similar to others he’s done, but maybe with slightly more meat on the bones. :+1:t2:

Would have been nice if that guy could finish his Slurpee.

One interesting tidbit (and I’ve heard him mention this in other podcasts but not go too deep): toward the end (maybe 50:00 into the video) you hear his view of lactate thresholds (plural). It is different than the way most of us think of it (them). Other than an “inflection point” for Zone2 (LT1, for lack of a better term for it), his mindset is still fixed lactate values for upper thresholds. And those values are goal or event specific (e.g., “his lactate threshold for 12 mins”, he says…“her lactate threshold when running a marathon”). So it is not a single number or range for an individual like all the derivatives of Jack Daniels** idea of A (singular) lactate threshold. Also the way we were taught in school, by the by.

I’m not pointing it out as a more valid or less valid way of looking at it, it just helped me understand some of the way he has explained things in the past.

**not originally Daniels idea of course but he popularized the use of a lactate threshold to anchor training zones, that’s all I mean by that.

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Well since I’m here I might as well chime in… these are definitely not dumb questions.

With greater cadence comes shorter contraction durations, and also lower motor unit recruitment from lower force requirements. Probably no different for muscular adaptations. If kJ is identical, redox demand is identical, and with shorter contractions elevated calcium time probably identical too.

For aerobic performance (and this is what I think gets missed with torque stuff sometimes) we’re still metabolically limited which means limited by oxygen delivery and sustainable utilization (capillary density, mitochondrial mass, etc). Definitely doesn’t seem like it’d lead to any central benefits (cardiac, plasma volume, etc), and none except maybe in larger motor units, TBD. No solid evidence besides improving performances, as far as anyone’s aware of according to the smartest torque training evangelists on twitter. A bandied about theory is iia->i fiber type conversion by recruiting and training larger motor units. Could certainly happen but if you don’t think evidence supports fiber type being directly related to certain thresholds (I don’t, the R^2 for FTP and type I fiber % is about 0.3) then it doesn’t explain anything.

On that coachcast episode, right in the intro ISM says they published about CPT1 last year… that’s been well established since at least the mid 00s if not earlier.


I feel like none of these interviews ask the difficult questions. You really should get him on the show.

As good a theory as any. Throwing some $10 words around, from henceforth it’s no longer torque training’ it shall be called ‘neuromuscular training’ and because it’s difficult to measure in the field I’ll toss in ‘(maybe) increases efficiency’ :wink:

It depends.

Drink! :grin:


Hmm, let me try… after a big-for-me (9+ hours/week) block of endurance in Nov/Dec, yesterday I set all-time power PRs on PDC from 17-min to 20.3 minutes. Why did I see that in the garage, and immediately put on AC/DC’s It’s a Long Way to the Top (If You Wanna Rock ‘n’ Roll) and turn it up to 11? I’m sixty going on sixteen, seven years training. Long time listener, first time caller. Thanks in advance.

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Thus is how I do them, at the 10 minute end. This week is 4 x 10 mins, in a couple of weeks 7 x 10 min. I’m progressing them.

I’m definitely feeling stronger and able to produce power at lower cadence that would have fatigued my legs quickly before. My natural cadence is much higher and I just see this as another tool in the box.

Just as important I actually enjoy these sessions and can do them outside (my turbo doesn’t like cadence this low).

Bit off topic for this thread though :grinning:

He makes it clear with the following comment regarding MLSS.

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Can I ask some of you who’ve been doing ISM’s Z2 what sort of % HR max you’ve been working at?

(Most of my time has been spent 67- 69%)

Lactate tested LT1 is at ~79.5% for me. Actual heart rate at LT1 has been constant for 30 years. Of course as max HR has gone down with age, % at Lt1 has gone up

However, what is max HR? Max at 1min step ramp test? Chased by fight dogs heart rate?


71-73% for my ‘breakthrough’ 120min ISM day, 65% or so on an easier ‘filler’ Z2 ride.

I’m moving on with one session per week now (Friel Base 2) and doing 120mins Tempo. HR for the first one on Tuesday was 81% but that was almost certainly a bit hard for ISM “talk test”. Decoupling was 7% whereas decoupling on my last ISM ride was only 1.5% so that feels like a necessary step to keep progressing.

Good stuff.

Quite variable then.

I’m thinking i’ve went too hard… but maybe not!

@sryke Max HR for me is, if you held it a 5/10 seconds later you’d be sick…I hit mine a few times last year and I thought it was the end of me… it was worrying at the time. A few mins later and i was off again! :rofl:

ISM say’s 2-3 sessions/week to maintain what you’ve got.

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You think 67-69% might be too hard?