VO2 Max should feel harder than this

From https://www.peakendurancesport.com/endurance-training/high-intensity-training/billat-intervals-magic-bullet-next-pb/

    • 30-30s (version 1) . Soon after developing the 3-minute protocol, Billat developed another one, this time a good deal less intimidating. Instead of running 3 minutes at vVO2max per repeat, she broke the workout into much shorter segments. The result, now known as Billat 30-30s, involves alternating between 30-second surges at vVO2max, and 30-second jog recoveries, and doing it for as long as possible. What’s interesting about this workout is that during the recoveries, your metabolism is still ramped up to VO2max for a significant amount of time. And it’s still high enough at the end of the recovery that it quickly returns to VO2max when you speed back up. With these quick alternations, she found, you can spend nearly 40 percent more time with your metabolism at VO2max than you spend actually running at vVO2max. But it’s not as taxing as it sounds. Billat found this to be an extremely good early-season workout, and also good for relative newcomers to speed training(6,8). Fifteen to twenty minutes of this, is a lot for most people, so luckily it’s also a workout that’s over fairly quickly!
    • 30-30s (version 2). Still later, Billat developed another protocol, this one a (very fast) fartlek session. This workout is the most intense of the three, being suitable mostly for fairly experienced runners, late in the season, rather than early on. After warm-up, you pick up your pace to vVO2max, and hold it for a minute. The reason for 60 seconds, rather than 30, is to not waste time ramping up your metabolism. Also, if you are running on a track, this will also allow you to cover at least 200 meters, a good point at which to take a split to make sure you’re not wildly off pace. After that first fast-paced minute, you cut back not to an easy jog, but to tempo pace (perhaps 45 to 60 sec/mile slower than vVO2max) for 30 seconds. Then you speed back up, repeating tempo-pace recoveries and 30-second surges for as long as you can.

Neither of which are what TR prescribes.


I may be wrong on this but I seem to remember that some of the 30-30 interval workouts used to be described as Billats in the descriptions. This would be three or four years ago.

Is there really that much difference between 40% & 60% when discussing such short recovery intervals? I use a dumb wheel-on trainer and power takes about fifteen seconds to ramp down to that sort of level anyway.

Coggan gives VO2max as 120% of FTP but is that the same as vVO2max which the linked article states is “is simply the pace you run at maximum oxygen consumption” it sort of suggests that the level is close to an all out sprint, i.e. anaerobic but the wording in that article is somewhat confusing to me at least. From https://www.trainingpeaks.com/blog/how-to-use-anaerobic-intervals/ we have:

Billat knew from the outset that an interval format would be best. The typical trained athlete can hold VO2max pace or power for about eight minutes. So a workout that entailed one sustained effort to exhaustion at VO2max pace or power would provide only about eight minutes of exposure to this intensity. But by breaking up the work at VO2max into shorter intervals separated by recovery periods, athletes can do more total work at this intensity.

In the process of testing and comparing different interval formats, Billat learned and took advantage of the fact that there is a lag between the time an athlete slows down from VO2max pace or power and the time his or her rate of oxygen consumption drops below maximum. The end result was a novel interval workout format that became known as Billat’s 30-30, in which 30-second efforts at VO2max pace/power are interspersed with 30-second active recoveries.

Which suggests that the surges should be at 120% FTP (assuming that is your VO2max level) and the recoveries , well low enough to get some benefit.

The next section in that article throws more mud in the water :wink:

Just done with Bluebell and following everyone’s advice, I kept the same intensity. After the first block, my HR was going up to 140 at the end of each 1 minute interval. It started to feel a bit more intense but nowhere close to struggling towards the end of the block, like the workout text was sugesting.

So the second block I did at 102%. HR was now going up to 145, but still well below my sustained HR of 160. Also was not really struggling to complete, the end of each minute felt more like the level of pain during a threshold interval.

For the third block I went to 104%, and the last two intervals at 105% the HR went up to 153, this still felt doable. Next week, with Mills I will start at 105% and take it from there.

Yeah, I think you’re just good at VO2 Max. Dialing up the intensity seems appropriate. This is one of the reasons I like having a dumb trainer. I go by feel at the power I think I can sustain over all the intervals, which often ends up being higher than 120% FTP.

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Bluebell is also relatively easy. I’ve done as much as 110% on Bluebell. Mills is more like it, but it’s kind of still a practice run for Spencer.

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1 minute intervals are not VO2max efforts unless you go a lot harder and keep the rest really short.

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I did Bluebell yesterday, and ramped up the middle set to 102 and the last set to 105, and like you still fell a little short of where my HR would be at VO2 max. I’ve been through this before though, and Mills is a step up - maybe knock off one or two intervals before you hit the + button.

Spencer+2 is a different level again…

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I remember before starting this TR plan, I started with the Build me Up program on Zwift, that had VO2 max intervals 5x2min @ 115% and had me totally grasping for air. Now my FTP is higher and at least for 1 minute I can do 120% very easily. Was just expecting the same type of grasping for air feeling from these, but I guess I have to wait for 1 or 2 more weeks then. I see Spencer +2 in 2 weeks time.

IMO you need to be more responsive than this, and know when to can the workout and do something else. If your HR is low, then an extra 1 or 2% for a minute won’t make much difference. No offence but it sounds like you didn’t really get much out of it as a VO2 max workout.

Next time go for some harder 3 , 4 or 5 minute intervals. No idea what your training history or physiology is, but even if you only get 2/3 or 3/4 through your chosen workout, you’ll probably gain more than a cake walk through 1 minute intervals.

For me Spencer +3 is the penultimate VO2 workout - 7 x 3 / 3 @ 120% (three minutes on, three minutes off). I also haven’t been able to do this in a very long time, so still lots of gains to earn.

Yes, might need to keep increasing the intensity until a block of intervals leaves me gasping for air. It is just that the SS and threshold intervals are hard enough at my current FTP setting, feels strange to do these workout adjusted for 110%+.

If VO2 is a strength I’d start at 3 mins. Here are some from the TR catalogue I like. Try and do more work week on week, and up the stimulus (time, %FTP, shorter rest intervals)

3 mins
Spencer +3
Kaiser +2
Morgan (did this last week - was hard)

3.5 mins
Mist +3

4 mins
Mist +1

5 mins
Old Rag +6

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I’m naturally the opposite to @mrpedro, decent on SS and Threshold but poor on VO2max. I didn’t have a HRM the last time I did Bluebell but my notes indicate that I increased intensity of the last set by 2% and still overshot target power by 3%. Due to being on a dumb trainer and doing intervals at the boundary between two zones it’s quite easy to get a lot of time in the “wrong zone”.

My notes also indicate that I found Bluebell easy. As others have noted, it’s an introduction to the intensity required for VO2max work. If the first such workout were Spencer+2 then I’d imagine there’d be very little compliance!

The last designated VO2max workout I did was Bird. I had a HRM for this and my HR got to 167bpm (max is probably 180) with an average of 146bpm.

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The only problem with this topic is the mix of definitions. 30 seconds @ 120% isn’t a VO2max workout even if it is using the VO2max zone. From Friel’s blog description of zones:

Typical intensity of longer (3-8 min) intervals intended to increase VO2max. Strong to severe sensations of leg effort/fatigue, such that completion of more than 30-40 min total training time is difficult at best. Conversation not possible due to often ‘ragged’ breathing. Should generally be attempted only when adequately recovered from prior training – consecutive days of level 5 work not necessarily desirable even if possible. Note: At this level, the average heart rate may not be due to slowness of heart rate response and/or ceiling imposed by maximum heart rate)

See my post from last week: Taylor’s 30s on/30s off regimen is exactly that prescribed by Billat as a VO2max workout. Taylor isn’t one 30 second interval but ten minutes of them in each block and you are going to have pretty ragged breathing after that lot.

Some of the VO2max workouts in the library are more “tasters” or “preparation” for the true VO2max workouts, Bluebell is one such. So while you are working in the VO2max zone they aren’t necessarily a VO2max workout.

If I understand correctly there is no real VO2 max intensity. It is something above threshold that you can maintain for a while and as the anaerobic muscles fatigue you are left with a VO2 max performance.
When I did the 30s intervals it just felt like it was not enough to fatigue the anaerobic system, making it very easy with fairly low HR. But if the intensity would have been higher I could have reached VO2 max towards the end of the blocks.

Same as me. And the “VO2max” workouts with shorter intervals like Taylor, Bluebell and Mills felt easy. It wasn’t until I got to the likes of Kaiser when I realized what a VO2max workout should feel like.

I’m a fast twitch anaerobic athlete - so on the shorter intervals, my anaerobic system does much of the work. On the longer intervals like Kaiser my anaerobic system is insufficient - and that’s where things really start to hurt.

Yes, I had that feeling before, both during climbs outside and doing intervals, it is where you are gasping for air, but just not intense enough that you need to stop because of burn in the muscles.

So do you skip the shorter intervals for VO2max or increase the intensity?

I do 3-5 min intervals. The trick is knowing the right intensity to be hard enough, but not so hard where you can’t do the workout.

I’be dialed in a few VO2max workouts that work for me. See the following thread.

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Didn’t Billat use higher intensities during both the on and especially the off periods?

ETA: Here is a case study of somebody doing 30/30s at 125/85%. That seems hard enough that they were probably tickling VO2max, but I doubt that it provided a major stimulus.