New study compares Time@VO2max of Varied- and Constant-Intensity Intervals

Pinched from another forum:


I don’t think this has as much to do with ERG mode but to me it just says doing shorter v02 max intervals is more effective than doing longer v02 max intervals.

There was one company or person or whatever that was saying something similar about ERG mode, while pitching their own services, so I read it as more of an ad than research. I think this was on a FB group

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  1. I am far from an expert at reading these reports, but what I read in the Abstract seems to be focused on steady-state work vs interval work in the HIIT.

    • Is that correct?
  2. I see no mention of ERG mode vs Resistance mode info, and question if that is even part of the testing.

    • Where is the “ERG mode” association in the title of this thread?
  3. I am wondering if the “varied- or constant-intensity work intervals” is being misinterpreted?

Maybe the thread title was wrong, I pinched that too!

Can you add a link to the origin?

I’d like to read it and the associated info, to see if it adds clarity.

I will correct the thread title if appropriate.

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Interestingly enough, most research labs use Ergometers, so they probably were in Erg mode!

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TrainerRoad has both varied-intensity and constant-intensity intervals for vo2max work. Erg mode supports both, it seems the title of this thread is misleading.

If reading the abstract correctly, what I see is:

  • 14 cyclists in study
  • compared varied-intensity and constant-intensity work intervals
  • HR and RPE was the same for both types
  • measured vo2 was higher for varied-intensity
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Discussing abstracts? Really?

Here’s the full text


thanks! I did a quick search but have been in meetings since 5am and must have fumbled the search

Interesting setup:

  • Kickr
  • SRAM power meter
  • TrainerRoad
  • lactate draws from fingertip
  • vo2 measurement using metabolic cart
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Based on that, I think I am safe to change the thread title (mainly remove the bad ERG reference).

Any suggestions for a more appropriate title from the study experts?

Edit to add one thought:

Benefits of Varied-Intensity Work Intervals vs Constant-Intensity Work Intervals?

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a better title in my opinion is “hard start vo2 intervals deliver higher time at >90% vo2max than constant intervals” or something like that… the problem is that its both a hard 30-sec start, and then it repeats twice during the 5-min intervals


Done. Thanks for this and the related review by everyone.

New study on intermittent intervals vs steady intervals (time@VO2max)


Part of me likes using the actual study terms “Varied-Intensity Work Intervals” and “Constant-Intensity Work Intervals” for consistency. But any of these definitions are somewhat elusive. The actual picture shared above really helps me see the differences in the test groups best.

“Hard start” ignores the intermittent (Billat style) nature of the protocol

but honestly, who cares.


“New study compares time@vo2max of varied- and constant-intensity intervals”

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OK, with a proper title issue out of the way, does this mean we should be picking different VO2 intervals for some/most of our work in that zone?

Interesting. It’s pretty obvious that session b) is going to be more productive when there are multiple surges to 100% of MAP versus none in session c). It would have been more interesting if they tested a session that had say longer work intervals (2-3min) at 100% of MAP (TR equivalent to something like Dade or Kaiser) with equal rest at 30% of MAP against session b).

Cool test though, thanks. I think it’s pretty clear that going to max MAP and then recovering at a still high percentage (essentially over/unders) is going to derive more benefit than sustained efforts at a lower MAP.

I’ve just plugged in the % MAP prescriptions into a zone calculator. I’m not “fluent” in MAPish.

b) basically threshold/vo2max over unders. The surges are not max efforts or so. More controlled.
c) 105-110% FTP. They did 6 intervals of these, with only 2.5’ rest. Could not have been too hard

So basically what this study reveals is that doing a 5min effort at a work rate that will only elicit VO2 max after maybe 50-60min gives you less time near VO2 max than a 5 min effort at the same work rate, but with spikes to work rates that are known to elicit VO2max after maybe 4min.

nothing new here…