VO2 Max: Short vs Long Intervals

Got a bit of a (perhaps) dumb question. I did a little block of VO2 max work over the last 2 weeks. Last week I was able to finish Spencer +2 and a custom version of Monadnock with 6x3 @ 122%. I started General Build Low Volume this week and have Spanish Needle (15/15s @ 150%) coming up. Because of my schedule, I didn’t do a ramp test to start off because I only had 2 days to get a decent workout this week. So my FTP is the same that I completed Spencer +2.

My question is: what would provide the bigger benefit? Should I “go back” to Spanish Needle, or do longer intervals like Spencer again? I say “go back” because it’s 15/15s, already knowing I can do 3min @ 122%. I know Spanish Needle is @150%, but next week is Baird, which is 1 min @ 120%. I can do 3 min intervals, does it make sense to go back to 1 min intervals? Maybe do Spanish Needle because it’s higher %, but then do a version of Spencer for the next 2 weeks after that? I guess my question is: is 3min @122% better than 15/15s @150%?

My subjective view of VO2Max is that the floating/pyramid workouts are good for fitness improvement. Try Bear and pat yourself on the back if you make it.


Scientifc literature says 3+ minute intervals are more effective.


Do whatever feels awful.

For me, “awful” is anything approaching the 3 minute mark. If I got to a point where Spencer was manageable, I’d keep trying to push out the duration of each work interval and/or add more reps.

And you can pretty much ignore any change in FTP; the correlation to what power target you can productively repeat as 2-5 minute intervals is pretty limited, so you’ll be finding your target for these types of efforts largely by trial and error.


For me, the best physiological adaptations seem to come from longer intervals, whereas short shorts train repeatability. I don’t get anywhere close to VO2max from Brasted, Rattlesnake, etc., and I’ve grown to prefer longer intervals - from 3 to 6 min. If I’m training for VO2max, I don’t go shorter than 3 anymore. If I’m training repeatability, that’s different.


This podcast is worth a listen

“There were no significant difference between the HIIT and SIT group when looking at time trial performance.

However, if one would only look at those in the HIIT group that performed longer intervals (> 4min), then a significant increase in time trial performance of about 2 % could be seen compared to the SIT group.”


I both love this and am scared by it. But I know it’s right.

So maybe I keep Spanish Needle this week, but swap the upcoming weeks (Baird, Bashful) for Spencer variations or the like.

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I see your podcast and raise you a peer-reviewed meta-analysis. :wink:


I haven’t read or listened to either - but it looks like the podcast is with the author of a peer reviewed meta-analysis? It’s mentioned in the link-preview above and linked in the show notes.

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Perhaps scientific literature is focusing on VO2max improvements. My subjective view is influenced by recognition that on/off type intervals such as Spencer +2 are not the way we ride bikes. We normally need to punch it to get ahead of someone, or make a technical MTB climb, and then let off power but stay at sweet spot or sub-threshold. Practicing and repeating such intervals I believe has a lot of merit according to my non-scientific and subjective assessment of how my own body responds. Probably does not apply to many others, but give yourself a chance and test it out. Sprinkle your calendar with those floating workouts and see how it affects your riding.

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I’d much rather read an original paper than to listen to someone’s opinion of it. That’s especially true of meta-analyses, since the authors have really only proven that they’re capable of looking things up on PubMed.

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Fair enough. Just thought it was a funny coincidence. Do you have any thoughts on the meta-analysis itself?

My primary thought is that 6 studies is hardly enough to form any firm conclusions.


Just one man’s opinion without turning the thread too dogmatic:

  • Base/early season: train long VO2max intervals (at least 3 min, preferably 5 or longer IMO). Gain the physiological benefits.
  • Build/Race season: train your repeatability with the floating intervals if appropriate to your racing (MTB, crits…). If you’re a TTer or other long endurance athlete, stick with the longer stuff.

I’d even push longer than Spencer, personally. I just wrapped up a VO2max block where the shortest intervals I did were 3:30 (6 times). If you need to scale up to longer stuff, sure. But (again just IMO), if you’ve survived the 3-min intervals in the past, it’s time to push yourself beyond that range. SSB2MV’s VO2max progression is just too easy for previously well-trained athletes, again, IMO.


When doing Taylor -2 my HR doesn’t even get into Threshold zone, and that’s a total of 21 minutes of 120% work. Meanwhile I’m living in Z4 now when doing Matthes -1 or Kaiser +2.

Judging by the feel, I would think there’s more benefit to be gained from the latter than the former. Taylor makes my legs tingle a bit, but doesn’t really get me into that “when is this going to be over?!” mindset


This was in the back of my mind as well. I thought Spencer was certainly hard, but doable. Which to me indicates I need to go up on the power or extend. The custom version of Monadnock was 3min @ 122%, which was killer for 3 minutes. So if I’m doing 120, I need to go to 3:30 or beyond. Maybe that can be my progression for this 3-week build, either 3:30/4/4:30 at 120% or 3:30/4 at 120 and 3:30 at 122%.

Keep the TiZ consistent, push the intervals longer with at least 1:1 rest. This assumes you’re doing a pyramidal approach and not a specific VO2max block, where you might start at 5 or 6 min intervals and decrease interval length at max power so the workouts are achievable in succession.

For what you’re discussing, 6 or 7x3:00 → 6x3:30 → 5x4 → 4x5 → 3x6:30 or 7… something like that. Power should be what’s sustainable for that period rather than pushing a % of FTP in erg mode. You might do all of these intervals around your 5-min power, as they go longer it might push closer to your 8-min power, as an example. But as the interval lengthens, you should be targeting a somewhat lower power. The goal is maximal oxygen uptake, not blowing your legs up (unless you just want to train your sustainable/repeatable 3-min+ power for your events).

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I like the floaters, too, but I’m not saying they are the best VO2max workouts. They’re just good hard, fun workouts. Here is a list for those interested in exploring the possibilities. Try to catch 'em all!

apple orchard
grassy ridge
hawk’s bill
megantic → HARD START
Richardson → HARD START
the needles


I’m reading this and thinking “why would anyone do 4x4’@120% FTP or anything longer than 3’?” haha…I did Matthes +1 last week (9x3’ @ 115% FTP), I was able to finish but it was real tough. Having said that I do think VO2 max is one of my weaknesses, maybe because I do not like doing this kind of workout.