Catch 22 on VO2 work

Thank you for the quick and detailed reply.

I am fearful that my ‘failure points’ were accompanied by a lot of disappointment, and so my HR likely fell too much. Nonetheless, I’m now armed with the information necessary to move forward and attack it again. Grazie!


Why would this be? Perhaps I have a misunderstanding of the science, but if both formats are completed at 100%, wouldn’t the 3x3 give more time @VO2max, or at the very least equal?

I’ll wait until after the podcast knowledge bomb before I bug you again!

Think this has been fairly comprehensively covered but I would add that VO2s are hard and are supposed to be hard. If you get through and feel fine then maybe you need to retest as you have already adapted, which is all positive! Not completing is not a negative just shows rooms for growth and a goal for next time.

Also what I don’t think has been mentioned is that for a particularly harsh VO2 sessions make sure you’re rested and ready for it. Going into of the back of only a days rest and fatigued might be too much. Listen to your body. I found that after a heavy weekend of riding just Monday off probably wasn’t enough, also make you’ve restocked those glycogen stores. Going into it depleted of dehydrated will wreck havoc especially with the longer 1hour/1hour 30 mins sessions.

Hope this helps, my experience was a bit depressing but got great learning point from it to make future session productive. (Main one being don’t do VO2 on a hangover :joy:)

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@chad +1 for really eager for a deep dive in this. I find that when I’m very close to my all-time high FTP, the percentage of repeatable VO2 intervals drops a bit. For instance, if I’m on an upward (base) swing of FTP I may be able to do 120% VO2 efforts pretty well. But when my FTP is as high as I’ve ever gotten it, my VO2 work may only be possible at 113-115%. I’ve noticed this over several training cycles with TR.

I conclude from this that I may benefit from trying to raise that VO2 “roof” rather than the FTP “ceiling”, especially when I’m at personally high historical FTP. If you think the 2 week VO2 focus camp is advisable, any additional guidance would be great. (If it’s relevant, I’m 54, 3.7 w/kg at 291 FTP) Thanks, as always!


It’s because with the 3min intervals, it probably takes you 1.5-2 mins to reach v02 max state so only last 60-90secs of first interval will actually be v02. Then in 2nd and 3rd intervals you’ll hit v02 state quicker (after say 60 seconds). So out of total 9 mins you probably actually at v02 max for (say) 5 mins.

With short sharp intervals the rest period is so short that once you get into v02 max state (again say after 1.5-2 mins…Maybe slightly later due to mini rests - so let’s say 3 mins) then never come out of the v02 max state. So out of the 9 mins likely to get say 6-6.5 mins actually at v02 max.

Hope that makes sense (sure @chad will correctly me if wrong) but that is my understanding.

I did a little analysis of various hard sessions on my own HR here: Time accumulated at vo2 max (or +90% maxHR)

The eventual upshot (with disclaimers for it being in no way scientifically rigorous) was that I got the most time at an elevated heart rate while doing longer 3-5 minute intervals. But your mileage may vary, of course.

In response to the original post, I’ve always found that the TR ramp test tracks pretty well to my vo2 capabilities - because that’s where the ramp test takes you.

I’d observe that in your ramp test, in order to achieve 291 FTP, you did a whole minute at 388 watts, after several minutes of ramping up. In fact, looking at other ramp tests, the last 3 minutes of the test would have been done at an average of 127% of FTP - and that’s after ramping up beyond threshold already. Which should make the prospect of 3 minutes at 120% from fresh seem easy…

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Can’t disagree with your analysis…which shows that partly must be mental (and that I had a superb day I did ramp test and was caffeinated up to my eyeballs!!!)

May be me, or my trainer, or something else, but I can’t do VO2 workouts in ERG mode. Just can’t finish them. I get the death spiral a few intervals in. Resistance mode I can though. I have many theories why but long story short anything harder than sweet spot and I’m doing resistance.

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I’ve only got dumb trainer (Kinetic road machine) anyway so ERG mode not an option

but what about intervals 3, 4, 5 and 6 :open_mouth:

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I’ll need to see the science on this.

Interesting. I wonder if you should be hitting max HR on those intervals. I’m erging for the winter but the power and HR numbers are similar to cycling. So I figure that my threshold on the erg is 260 watts based on one hour erg TT. I am currently doing 4 x 5 min VO2 max sessions and 3 x 12 x 30s/15s session once a week.

On the 4 x 5 session I average 280 watts (108% of ftp) and my HR gets up to 152 bpm versus 165 bpm max (92% of max). On the 30s/15s session I average 315 watts for the 30s on interval (121% of ftp) and my HR peaks at 155 bpm (94% of max). I don’t feel like I can do any further efforts when I am done these intervals. If your HR is maxing out, or within a few beats, I would think you are going too hard. I can only come close to max HR on a race up a climb (in a group ride) knowing that I can afford to blow up because the group will slow after the effort and recover completely before the next all out effort.

There is science to support many different conclusions, but the most common ones cited are Billat’s research on 30/30 interval duration and Ronnestad’s on 30/15 to support short on/off interval durations.

There are also a few amateur folks out in the field validating some of these numbers with portable VO2 meters that I’m tracking. I won’t mention their names so they don’t get inundated with people asking questions but the numbers are pretty compelling.

Excited to here @chad talk more about this topic tomorrow

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@apond58 - strong reply – much appreciated! When I get back to my computer this evening I’ll dig into the WKO4+ data from Julius Caesar and Stanislaus. My dashboard on WKO4 has a specific VO2 panel which shows my percentages based on my known VO2 from lab testing.

I think in Julius Caesar near the 1:00 mark, my HR would have been about the same as where it was on Stanislaus intervals… but (and this is a big BUT), the Stanislaus intervals this morning were only :40 so I doubt my total time in VO2 territory was equal to what Julius Caesar could have provided. Also, Julius Caesar is 120% and Stanislaus is 127%.

I have already created a custom Stanislaus (mod) workout that I’ll do tomorrow – it moves the duration to :45 but keeps the rest interval the same. If that goes swimmingly, I’ll modify it again gently to :50 and so on and so on.

Yes, it’s possible you just go really deep in the ramp test in a way that isn’t possible more than once every few weeks. But perhaps it is just a mental adjustment; imagine each vo2 session is going to be a 100% effort. Treat them like a race. Energy gel, caffeine… whatever it takes to get through it and get those gains.


Is there a scientifically/biologically defined VO2max recovery period, as in, how soon after hitting VO2max will you phase out of it once work has stopped?

Roughly 10-25 seconds based on the research I linked. Probably depends on the severity of the workload.

Speculation on my part, but I would think that energy costs of repeatedly accelerating your body in the short interval bursts demands more oxygen/energy from the body versus someone maintaining their momentum in longer VO2max intervals.

Thanks for helpful replies to original question, and for reposting Coach Chad’s remedy. The whole thread has been fascinating and a good example of the gold in this forum. Besides being ancient and slower, I actually have an easier time with shorter VO2max intervals than the longer SS and threshold intervals, don’t know why. But still interesting stuff that I can actually experiment with. By coincidence, Spencer was up next for me, but when I saw that even Chad had called it “something awful”, I opted for starting with Stanislaus -4 instead, and called myself “sensible” (instead of just lazy) and did in fact almost enjoy it.

Maybe I should have posted this in that thread on “Best Excuses” for wussing out on a hard workout “Coach Chad told me to.” :slightly_smiling_face: