Hard start VO2max intervals

This seems to have worked. Instead of the TR 3x60s gradual increase efforts up to 120%, I went out at ~150% for 3x45s (and high cadence). Took about the same 45s during the first interval to get my HR up to VO2 compared to 90+s w/o the anaerobic warm-up.

The rest of the interval was the same, controlling both power and cadence to keep HR and breathing in the zone.

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@DaveWh got me thinking more about hard-start prescription & individualization a bit more, and I wrote a post with some further reasons why/why not or when/when not to perform them, and how to program hard-start intervals based on our own characteristics or intent of our training block.

More curious to hear about other experiences, especially performing them on trainer in Erg mode vs out on the road?


Yep. The TR builds to 120% warmup intervals weren’t sufficient for me either. In the hard start workouts I created, I go from 130-140-150% in the three warmup intervals. And I could probably do even more to get my HR primed.

I’m a big fan of hard start VO2 intervals…or fast start. Whatever vocabulary you prefer. :smiley: Similar experience to yours…without having a vo2 mask or metabolic cart I started using HRR to estimate % of VO2max per info in the Lounana paper ( Relationship between %HRmax, %HR reserve, %VO2max, and %VO2 reserve in elite cyclists).

Once I was in that frame of mind it was clear that the first interval wasn’t hard enough and the last intervals were probably too hard.

I tried Burnley’s ‘priming’ in the warmup to make the ‘1st interval’ effect go away but it didn’t seem to make too much difference. You’re workout has a much better ‘priming’ warmup than I ever did. Eventually I settled on a much harder initial interval, as you did, but instead of varying the intensity of the hard start just varied the duration…only holding the fast start until my HR would achieve the target I was after & then hold on.


HR response to those two intervals is very similar for me.

Recently I revisited the fast start interval concept based on Ronnestad’s 2019 study " Increasing Oxygen Uptake in Well-Trained Cross-Country Skiers During Work Intervals With a Fast Start". Those intervals are 1.5min @ MAP followed by 3.5min @ what would be 113% of TR FTP. Same experience…first interval is not hard enough & the last couple are too hard.

I like what you’ve done with your workout. Wonder how general/specific it is…

@DaveWh I hasten to add that, although I’ve spent a lot of time doing hard start VO2max stuff, nothing improved my MAP more than Paul Laursen’s MAP interval protocol. This in spite of tiny volume and miniscule time spent @ >90% VO2max (compared to fast start intervals). And in spite of the fact that I was never able to complete even a single Laursen workout.

(Interval training program optimization inhighly trained endurance cyclists)


@DaveWh here is some hard data from the University of Kent’s work on variable VO2max intervals for cyclists that sort of proves your approach. Notice that regardless of whether or not a continuous or variable power interval is used…if >90% VO2max is the goal that first interval is a throw away if you maintain the same intensity across all intervals.


My guess is your approach would achieve > time @ 90% VO2max for the same RPE.

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Do you have any recommended reading on this (other that what the google will tell me!)?

Just the paper. Otherwise I am without guile on this topic…just heard about it on this forum & by word of mouth. My bias was that it wouldn’t work very well. I was wrong about that.

Interval training program optimization inhighly trained endurance cyclistsPAUL B. LAURSEN

Just take the MAP from your last ramp test…ride at that power until you pass out…then twice a week ride at MAP for 60% of TTE@MAP 8 times. Do that for two weeks…retest…do it for another two weeks. Winds up being very little total volume and even not too much time at >90% VO2max. But somehow it works to trigger MAP improvement.


That’s what it sounds like. Yikes. Here’s the paper:


Thx. So to make sure I have this right:

  • MAP from ramp test is highest 1 minute power
  • TR sets FTP at 75% of MAP
  • Hence MAP is 133% of FTP
  • Ride at 133% of FTP for as long as possible. Let’s say that’s 5 minutes
  • Set intervals to 133% of FTP, and 3 minutes long (60% of 5 minutes)
  • Do 8 intervals

Not a chance!! I struggle with Kaiser - which is 6x3 mins at 120%.

Basically, this protocol has you bury yourself for 8 intervals. No wonder it shows an increase in MAP.

I’m too soft to do something like this.

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Same. I never was able to finish a single workout. It’s hard.


Think you probably can’t hold MAP for 5 minutes. And if you can, then 3 mins should be repeatable.

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If I’m reading correctly, there might be a bit more nuance to it. Their ramp test is 15 W per 30 s, instead of a % of FTP per min. Don’t know what effect this has on Trainerroads MAP vs their Peak Power Output (PPO).
But they do not use that figure for the estimate of Tmax, but use Pmax, being

defined as the minimal power output that elicited a V̇O2 reading that was within 2 mL·kg−1·min−1 of the previous reading, despite an increase in workload

Table 2 shows that Pmax is a little lower (3/4%) than PPO.

So if you assume that TR MAP is PPO, you might want to decrease your TR MAP with a few % for the Tmax test. Which will give you a bit higher Tmax, which will contribute to just 60% more time in the workout itself for a lower power.

I tried this calculation for myself, and the result is that the workout I created was very similar to Spencer…except the 8 repeats :hot_face: and a bit more resting time. (1:2). But that’s just my n=1


I do reduce my FTP calculated from the ramp test by 5%. So if I reduce TR MAP by 5%, that would bring it down from the 133% of FTP I calculated above to 126% of FTP. So yeah - getting closer to the likes of Kaiser and Spencer.

I know from experience that if Kaiser was 6x3 at 126% instead of 120%, I’d fail the workout.

I guess the main takeaway from this is whatever VO2MAX protocol you follow, the intervals need to be hard - pushing you to the brink of failure.

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From the paper:

”The present subjects were pushed to exhaustion in nearly every HIT session. Indeed, only 64% of the prescribed number of HIT bouts could be completed.”

The only “fail” is not going all out.


5 minutes would be very good!

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Similar to the original Tabata protocols.


Actually Tmax turned out to be shorter in the study, on av. it’s ~240s = 4min.
So the av. interval duration (G1, G2) is 60% Tmax = 2min 24s.
Seems like a really short duration for VO2max intervals… combined with long rests… Quite a different approach to the “maximize time >90% VO2max” idea with longer intervals and/or hard-starts.

For me that’s still one of the big questions, how great is the advantage of going as hard as possible vs. settling for 8-9/10RPE.


The problem is if you don’t go ‘maximal’ you might not get into VO2max… and then you wasted your time.

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Confirm! Tmax workouts had me >90% VO2max for about 10 minutes per workout. A workout like East Vidette would me >30min. I don’t think I get the same benefit from East Vidette but who knows? Maybe if I just did East Vidette 2x/wk for a month?

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