Vo2Max intervals erg as written or resistance and hammer

Do most folks just follow the vo2max workouts as written and let erg do its thing or are people riding these in resistance mode and going 100% for the interval?
I am asking more so for the shorter stuff 30/15 30/30 etc where I never really feel like i am a fish out of water. The 3-5min stuff kills me just fine on erg and I am counting seconds by the end.

I can only assume I am leaving progress on the table doing the former (erg) as I do today, but what is the cost to the next workout if i try to really get all i can out of each interval?

I prefer to do short sharp VO2max intervals in resistance mode. My Suito seems to take a bit to ramp up then rapidly drops out as it tries to balance things. I feel like I get a better workout in resistance mode with me more consistently pushing into the VO2max zone and not being confined on a good day when I can push that wee bit harder.

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I do them all in erg but you are correct…most trainers have a max slew rate for resistance changes that takes up a material portion of a 30s interval. Or at least I think that’s what you’re saying. When I switch to resistance mode, my problem is controlling my own power. :rofl: I can only describe my power output during resistance mode micro intervals as ‘underdamped’. :crazy_face: It takes me at least 40s of declining under/over shooting target power to settle in.

I went back and found a representative 30s interval from my last Grassy Ridge workout. It looks like the slew rate of the trainer delays target power until about 20% into the interval. On the other hand, it delays the drop in power a similar amount at the end of the interval. In the end, all the 30s micro intervals were 2W to 3W under target power. My only observation is that I’m unable to do better in resistance mode.

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Both of these with Stages power meter…


Intervals.icu approves of these 40/20 second intervals in resistance mode, this was the second set.


TR’s Taylor -3 in Erg with power match, these 30/30 second intervals also have well defined edges but some fighting with erg.

very commendable! :clap:

This is quite separate issue from erg/resistance debate. For example I have poor under 1min power and there’s no way I would feel during intermittent intervals like during long vo2 max intervals. HR is elevated but breathing is not there - even when doing 15min long sets. And this is very common for many people with them. On the other hand, people with huge anaerobic capacity and short power can burry themselves doing 2-3 short bouts.

To stay on topic - always resistance/level. Just hammer as hard as you can, taking interval set into consideration. But I never use ERG mode for anything as I decided to focus more on RPE and I simply like the feeling of Level mode way better than erg.

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just updated that post to also include a pic showing erg/power-match.

Here’s some of Grassy Ridge +2 in erg mode as interpreted by intervals.icu. So, as you can see, either trainer manufacture or intervals.icu setting can make a difference. This data is taken from a low-end trainer (sub $700, purchased 3 years ago) so maybe it’s the case that cheaper is better for these micro intervals? Anyhow, intervals.icu catch micro intervals pretty consistently for me. So that’s interesting. Not sure I understand why the difference but it’s more proof to the assertion: your mileage may vary.

Forget about intervals.icu recognizing them, part of the problem might be that I don’t really use intervals (I think Taylor -3 is >105% and my ftp isn’t set correctly).

The erg ones show a little more power variation, and I often see some overshoot and ringing. Maybe I’m fighting a bit with the Kickr, or maybe its the Kickr. IIRC DCRainmaker posted in a review something about Erg and a feeling of ‘fighting’ with it on TR. It is a minor thing, nothing to get excited over.

In any case, the resistance ones are a bit smoother. Resistance (standard/slope mode in particular) definitely feels more natural to my legs/brain/body. In all cases I was using Stages crank arm power meter.

Can we talk a bit more about this part of it. I see now it was not clear in my question but this was more what I was hoping to understand. If i use erg i am going to be locked into the 120% or whatever. For plenty of workouts that is too easy, but if i turn up the % the rests are not rest. I was trying to get a feel for how many people ignore the % for these types of intervals and just go as hard as they think they can for a given time and number of sets.

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A lot of the intervention studies use this protocol - ask participants to go as hard as they can repeatably do. Part of my own reasoning for why that’s better - because working above threshold can vary quite a bit between people. The same reason why Coggan updated his 7 zone model and introduced iLevels for power zones above threshold.

That is just where my head is. I have little doubt its more effective for that workout. Wondering from those who do it if it just blows you up so badly the next 2 workouts are trash and so overall its a net negative. General feel for how much it seemed to help/hurt, etc. So is it really a net positive and is it worth what is likely quite a lot more miserable workout experience.