VO2 max workouts with long rests

My understanding is that the main point of VO2 max workouts is to spend a lot of time at a high percentage of maxHR (specifically, I’ve seen 90%+ discussed a few times). Given that, I don’t understand the point of VO2 max workouts that have very long rest intervals like Baird-1 Log In to TrainerRoad

The rests are long enough that I don’t come close to 90% of maxHR at all, let alone for any significant duration. Baird-1 is included in a lot of triathlon base plans, so I assume it’s valuable, I just don’t understand the goal. Is it just included in Base plans as an intro to intervals in this power range? Prep work so that actual VO2 max workouts are less of a shock when we start a Build phase?

A couple of things:

There are always two parts of a workout to consider – the work and the worker. VO2max sessions are particularly specific in that to get the most out of them you need to match the work to your specific physiology, i.e. VO2max kinetics. If short intervals don’t get your HR to that magic 90% level, then you might be a slow responder, in which longer sustained intervals would be more beneficial. If those short repeating intervals get you up to 90% then you might be a fast responder. There’s going to be some experimentation/trial and error involved in figuring out what type of VO2max workout is best suited for you.

As for Baird:

Primarily, these efforts are about improving your maximum aerobic power or your ability to repeatedly operate at or near it.

This workout is probably not designed exclusively for improving VO2max capacity but, as the description says, for improving your ability to do higher power repeats (however, 120%FTP is well below your true MAP – maximum aerobic power).

Good luck! :v:


Frankly I think this is one thing TR gets wrong, and you’re right to question it.

A 1 hour workout with 0.82 IF like Baird -1 isn’t a vo2 workout. It just can’t be. But read the text in the “goals” section and it’s exactly the same as it is for Baird +2 which is 0.92 IF:

Primarily, these efforts are about improving your maximum aerobic power or your ability to repeatedly operate at or near it.

Intervals like these can raise your aerobic ceiling and create room for later improvements in your VO2max, and in the process they’ll bring about aerobic adaptations that benefit your performance across the board.

It speaks to a wider problem in the workout library. Sometimes the + and - versions are simply shorter and longer versions of the same workout with similar intensities (which makes most logical sense to me). Whereas with Baird, -1, the original, +1, +2, and +3 are all 1 hour long, just with different rest intervals and therefore intensities. It’s inconsistent and can be confusing when you’re looking for suitable substitutes for your planned workouts.

This is the only explanation that makes any sense to me, though I’m not convinced that doing a few short intervals at 120% with long rests is ever going to prepare you for the horror of a Shortoff or a Spencer.


Keep in mind that 90% HRmax isn’t necessarily 90% VO2max. It’ll vary some up or down based on your physiology. And also VO2 kinetics respond faster than HR, so if you’re doing micro-bursts, HR may stay elevated above 90%, even as VO2 is lower. Conversely, for sustained VO2max efforts, they track much better together.

On Baird -1, I’d think the work effort is so short, and rest so long, you shouldn’t expect to get near VO2max. It takes a while to hit VO2max. On a short effort like that, by the end of the minute, you’re just starting to get up there again, and then you’ve got a long rest.

I’ve seen some plans start with a really easy workout at 120%, to get the rider used to that intensity. But the plan would progress past it quickly. I’m not familiar with the tri plans, so I’m not sure if this is how it’s being used there or not. Otherwise though, if it were my ride, I’d probably extend the intervals out longer till I was just getting enough recovery to repeat. Hold that work interval out another 30-60 seconds, and it’ll be a MUCH stronger VO2max stimulus.

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In 2015 Dr. Andy Coggan* introduced Coggan iLevels to replace Coggan Classic Levels as a result of extensive work showing that power above FTP needs to be individualized (the “i” in iLevels) and is non-linear (i.e. using flat % of FTP for training zones above FTP was no longer appropriate). Simultaneously, he introduced Optimized Intervals where the duration of the interval (a range) and the intensity of the interval (also a range) for intervals above FTP were determined for each person to elicit the appropriate physiological response (e.g. to increase Functional Reserve Capacity, FRC, a measure of how many Kilojoules you have available above FTP).

TR still folllows old school training with the fixed percentage approach. Thus far, Optimized Intervals are only available to users of WK04. If you aren’t a WK04 user, what you can do to compensate is that if you aren’t getting the appropriate training load you feel you need, you can sort of “guess” by increasing the duration and/or intensity via +1, +2, etc or via using Workout Creator to modify your workouts.

btw: The above explanation is why some individuals find TR’s “VO2Max” intervals ridiculously hard at the start (typically those with a phenotype of a TTer) and some find them easy (phenotype of sprinter).

*If you are unfamiliar with Dr. Coggan, he is the developer of virtually every important power metric, including TSS, NP, IF, CTL, ATL, FRC, etc.


The point of VO2max workouts is to spend a lot of time at high % of max aerobic uptake (VO2max) - and knowing for certain requires measuring oxygen consumption. Here is something you can use at home - https://vo2master.com - but it costs $5000. Not practical.

So people do power based workouts - 106-120% of ftp (Coggan/Allen defined vo2max level in Training and Racing with a Power Meter). Some people try using HR. Or RPE. Or combine all three - power, HR, RPE.

Complicating matters is that working above ftp is far more individualized than working below ftp.

The TR library is categorized by power levels, to @martinheadon 's point. There are some workouts that are focused on raising vo2max but labeled as anaerobic because they use work intervals above 120% ftp.

With all that said, I agree that Baird-1 is unlikely to elicit much time at high percentage of max aerobic uptake (vo2max) unless your vo2 is detrained (for various reasons). When I pull up Baird -1 the first plan its listed in is Sprint Tri Base, and its the first workout in week 2. The weekly tips have this to say:

Tuesday Baird -1 Time to work on developing some high-end power as you target both leg speed and leg strength for one intense minute at a time. Think of VO2max work as pulling your power up from the top while the later Sweet Spot workouts push your endurance up from the bottom.

So yeah, it looks like prep work for real vo2max workouts.


Agreed. It’s partly why I asked for the option to have an extra option under the ‘workout variants’ to also have a ‘similar workouts’ button. Easier to see what’s what.

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Xert has similar optimized intervals that , if you are a premium user, you can export for use on a smart trainer.

Also, there are VO2 max workouts with 4x 8/2min shorter rest intervals here: Log In to TrainerRoad.

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Yes. In fact, in Allen/Coggan/McGregor’s recent edition of Training and Racing with Power, they [compliment Xert and] discuss how Xert has the possibility of taking the optimal interval concept further by using their [continuously] calculated “Maximum Power Available” (MPA) and dynamically adjusting the length of both the work and rest in real time during the set of intervals themselves, including during microbursts workouts.

The “issue” I have with Xert is that they are inventing new metrics, such as MPA, that [seem to be] already available from Dr. Coggan (e.g. MPA is strikingly similar (identical to?) Functional Reserve Capacity (FRC)). However, in fairness to Xert, I don’t know what the licensing issues are/might be. Of course, the real solution to this issue is industry standardization such as took place in the internet world (IETF).

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I think there is a little misconception of what purpose of the VO2max workouts is.
The purpose is to generate a high stimulus on the aerobic system, in order to develop a higher VO2max. The workout text often states the goal to focus and maximize breathing. @mcsenn I think the workouts you have in mind are are the typical e.g. 4*8min @ 106% style efforts. Those realy train your capability of holding and repeating “VO2max efforts”, i.e. super threshold full gas of however you call it.

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Agree. The VO2 max workouts at 3 min intervals are brutal and worse that a similar IF shorter interval workout - for me anyway. I have this beast on tap for this evening:

I’ll likely need to dial the intensity down, as I barely finished Spencer +2 several weeks back.

Also agree on the workout naming convention. I think an alternative approach might be to add the duration of the workouts, and the IF:

Eg Kaiser +2 becomes Kaiser 75 0.92
Kaiser +4 becomes Kaiser 90 0.85
Kaiser +5 becomes Kaiser 90 0.90

This is weird - I was thinking the exact same thing and was going to start a thread on it. I may still do if I can organise my thoughts.
(I’m not sure you need IF in the workout title btw, my feeling is that workouts of the same name should be a comparable intensity whatever the length of workout.)

not sure how putting the duration into the title helps, the variants differ in several ways:

  • duration of work interval (e.g. all Kaiser variants use 3-min intervals)
  • number of intervals
  • rest between intervals
  • % FTP power in work interval
  • existence of 65% endurance interval at end

and I’m ignoring vo2 workouts often are organized by sets.

For vo2 work we are after time at high % of max aerobic uptake, and an approximation of that duration is what I want to see. For example Kaiser is 6x3-min, and if you take of 60-sec off “aerobic ramping” at start of each interval that workout gives you 6x2-min = 12 minutes of high aerobic uptake. And its that 12 minutes of work that I’m interested in.

The challenge with any estimate is everyone has different vo2 kinetics, meaning that 60-sec “aerobic ramp” varies by individual, and will change with training.

The nice thing about sweet spot work is that Tallac’s 3x15-min is 45 minutes of sweet spot for everyone. So I like to embed that into workout titles “Tallac 3x15/3” and “Tallac+1 3x15/6” so that I can see that Tallac +1 is “easier” with 6-min recovery valleys versus Tallac’s 3-min recovery valleys. That makes its easy to review my calendar and see progressions.

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These are interesting points. As I say I may start a thread on this more general topic - as I fear we’re leading this thread down a bit of a diversion from the original poster’s query…

Yes, we should start another thread. I’ve put a lot of thought into this subject, and my conclusion for vo2max workout is that I want a better search function (which likely requires TR storing more meta data for each workout).

lots of rest is good to improve your max wattage within vo2max.
small rest intervals are better for improving your repeatability of the wattages that you can already produce within the v02max energy system.
use whichever helps you get to your goals faster; working both in sync is ideal