VO2max training in TR effective? – power vs heart rate

I’ve a question on TrainerRoad VO2max training/workouts – and the effectiveness of the training when heart rate does not go above threshold at all (I am fresh/rested).

In short, to my understanding VO2max training in the sense that it actually increases max. O2 uptake correlates strongly with heart rate above threshold – which is what I do not achieve on the VO2max workouts I get from TR at all.
Should I do more traditional 4 x 4’ type VO2max workouts to get my actual HR > THR?

My threshold heart rate (THR), as determined from a 20 min TT (98 % of that HR), is 167, max HR is 185, rest HR in the range of 40–50 depending on state/rest.
THR is also still reasonable, for instance based on data from a “errants Tempo ride” I did last week, 2 x ~1 h with 40 min break in-between. This is from some near-threshold section at ~20 min into the second hour, with HR = 165 just below THR after ~4:30 min at 90 % FTP:

Now, if I look at my TR VO2max workouts I never get to these HRs… For instance, following a recent FTP bump, and corresponding PL decreases, and an easy weekend, yesterday I did the TR suggested Sleeping Beauty +2 workout, a variant of 30/30s at 125 % – which I marked as hard, leaning toward moderate.

Now, for this VO2max workout my HR never went above 160 < THR = 167.
In fact, for all the TR VO2max (or anaerobic, for that matter) workouts my HR zones never have any contributions in VO2max (independent of using, e.g., Friel or Coggan HR zones).
Here’s the power and HR zone distribution of yesterdays workout:
HR zones from Coggan, Friel looks even “worse”:

Now, are these workouts effective in increasing VO2max despite never getting HR up?
Or should I bite the apple an do more traditional 4 x 4’ type VO2max workouts to improve my VO2max?

SN: Newbie, <2 years of cycling, <1 year with PM, ~8 month of structured training, ~5 month with TR.
(AI) FTP now at 319 W, ~80 kg, >50 years.


Quick answer:

Was it really moderate/hard? My guess (and it’s just a guess) is that you’re capable of completing a much harder workout than that one. I know when I first started doing short/short TR VO2 Max workouts they were too easy. I picked a couple of Stretch alternates and found a better level.

I think everybody has a slightly different power curve. It may well be that 30s at 125% FTP isn’t hard enough to stress your system so that the desirable adaptations occur. This is actually an incredibly effective workout and enables you to accumulate a good amount of time above threshold. However you may need to adjust your settings to make it hard enough.

(This is why FTP isn’t a great metric for everyone)


Well, it wasn’t “easy”…:wink: RPE is still something which I am not really sure about, but – yes – I could likely have done a harder workout. Nevertheless, for all these 30/30, 1 min/1 min type of workouts I get from TR my HR does not go into the VO2max zone (much/at all).

Thus the basic question I have is if “VO2max” training not going into this VO2max HR zone is efficient in increasing VO2max in terms of max. oxygen uptake.

Which then guides my selection of which harder workouts to do…

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Are you suggesting that I should have changed the intensity to 130 or 140 % FTP such that my HR does actually go into the appropriate zone at the end/just after the 30 s?
That would indeed be hard on my legs;-)

In fact, I am a bad sprinter… on crits and fast training rides I realize I am quite good in terms of staying/pushing groups, even riding out front in small groups, but actual sprinting for points/finish or simply the city border sign is not something I am good at at all. Generally, improving that is on my agenda for next winter/season (not everything doable in first season;-)), but maybe the “fact” is relevant with respect to the discussion of HRs?

I think this really gets to the core of what the OP is asking and I have wondered about myself. Is the principal training benefit from VO2 sessions derived from accumulating time spent with power in the VO2 zone, or from accumulating time spent in a state of maximal oxygen uptake?

Because short 30/30 sessions are great for accumulating time in the VO2 power zone, but my experience is similar to the OPs in that I don’t seem to spend much time in a state of maximal oxygen uptake. Based on HR and breathing rate I.e. My HR often stays mostly below threshold and I’m rarely gasping for breath. Even on workouts that I find hard and struggle to complete or even have to quit or dial down, it’s really only towards the end of the later blocks that my HR and breathing have built up towards what I feel is a state of maximal oxygen uptake. 30 seconds is just so short that by the time my HR and breathing are starting to climb towards threshold I hit the next rest interval and they’re dropping again. Same time accumulated in power zone but via 1 minute instead of 30s intervals typically accumulates more time with HR in zone for me, and 2 and 3 minute intervals better still (though more mentally and physically taxing so there is a trade off).

On the podcast they’ve talked quite a bit about that state of maximal oxygen uptake being what is key for the training adaptation. That just doesn’t chime well with my experience of short shorts. I tend to use them when I just want to touch on VO2 max without too much fatigue e.g. During base or off season (I’m in my 40s and figure it’s good to always do some VO2 as research says use it or lose it). When VO2 sessions are a priority e.g. during the build phase I tend to pick alternate workouts with longer intervals.


You should try Vo2Max on feel instead on ERG mode targets…

I often up the percentage quite a bit on 1 minute efforts indoor / on ERG, e.g.:

on the very last interval (upped twice…) I still only get to 160 avg HR for the last minute… let alone the earlier intervals…

I got a PM recently and starting to do some outdoor workouts, eg

The main intervals are more “hard start” which causes the HR to get a jump start, and the avg power is more on feel ~ 400+ watt instead of the stated target of 360-380.
HR is closer to 170, even for the intervals where I “just” hit 370-380.

I got a lot of power PR’s on that ride, even while I’m more “maintaining” then training currently,
(conclusion, planned 1 minute vo2 is often way to easy for me, I need a higher target or longer intervals)

Even the MTB rides without power, it’s easy to hit 170+ on for example a nice 2 minute vo2 segment:

Personally i don’t bother doing any VO2 workout under PL5. For the same reason as the OP is doubting if these work. My breathing doesn’t go up, my heart rate stays below 85% of max and i generally feel that they are too easy.

The short/short VO2 session that i do find push me, are the ones where the VO2 part is double the time of the rest period. Something like Gendarme +9 or Baird +1. “Classic” VO2 workouts like 5x5 also work great. Float sets like Richardson -1 also get the heart rate going.

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It may well be that if you find that the sessions like Sleeping Beauty are too easy, then you’re maybe not hitting the right spot. I’ve found understanding my individual power curve with something like a 4DP test gives a much better idea of what numbers are needed to produce the desired adaptations.

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Oh well;-) So you are saying the TR-prescribed VO2max trainings are not good for me? :wink:

Regarding the PDC – I’ve, for instance, a 6 min best/“max effort” from a road race (first hill ~40 min into a 3:15 h race) end of May that, according to i.icu/Morton&Scherer, matches my FTP quite well – it gave FTP = 314 W then and the 5 W increase seems reasonable considering what I did and how I feel since then (declined a bit first due to 2 partly work-related rest/recovery weeks, is up to 320 W now).

Would AT not adapt them up, if you rated them as easy or moderate? I’m the opposite, and AT drops me back to 120% rather than 125%, 30/30’s instead of 30/20’s etc.

Yes, AT does ramp up and I also accepted the adaptions.

However, this does not solve the general problem I have with short/short-type VO2max workouts – HR does not go above threshold…

Here’s a training from a previous build up cycle with PL = 6.6: San Joaquin-1 (3x11 50” 130%, 40” recovery):
And the HR stays in threshold or (mostly) below…

And thus my question remains – should we have significant times with HR > THR?

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Given that this effort was 40 mins into a 3:15 hr race, you could argue that although it’s a power PB, not a all out, best effort.

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Listen to the empirical cycling podcast about vO2 for a better explanation than anyone can give here.

Also you basically answered your own question in your original question.

Do the 4x4s in resistance mode, go as hard as you can keeping cadence as high as you can in order to bring your heart rate up as much as you can for the time block. If you’re not gasping for air it’s not hard enough.

TR uses %FTP because their plans are all based off of %ftp (for inside training) rather than RPE (I know this is an option outdoors, and an effective one).

Every workout designed to target above FTP should be done on resistance mode and not ERG to target the correct symptoms.


True – but AI FTPd after that race wanted to keep my FTP even (8 or 10 W, IIRC) lower than my manual invention that I put in based on this PDC value…

VO2Max relative to threshold is different for everyone. TR has a middle ground of around 120% that is I guess meant to be a norm, but for you it may be 125%, 130%, or even higher. Also, 1:1 work to rest is usually pretty tame on shorter intervals. You should try both increasing the intensity percentage to something greater than what TR is giving you and you should try higher progression levels than what TR is giving you. I’m guessing you’ll find something hard enough soon.

I’m surprised nobody mentioned this before but: HR as an indicator is pretty well known to lag actual effort, so it makes sense that for short intervals it doesn’t go to the target value. That’s why we train with power…

See VO2max training in TR effective? – power vs heart rate - #6 by cartsman

Depends on the effort. For short bursts yes, heart rate lag will never catch up. But for longer intervals it’s a good indicator.

And power shouldn’t be the target, going as hard as you can and keeping heart rate high on longer intervals is more effective

Well - it does, but the point of VO2 short/shorts is that its supposed to allow you to spend more time at elevated O2 transport which correlates pretty well with HR. I.e., over the duration of the workout you would ultimately spend more time working close to your maximum level of O2 uptake.

VO2 max isn’t a power level, it’s the physiological state of maximum oxygen uptake. The power zone we define as VO2 max is just the power level which should elicit that state of maximum oxygen uptake and can vary pretty widely around that approx 120% FTP. And different again with interval length - obviously 4 minutes at 120% is a lot different proposition to 8 mins of 30/30s at 120%.

I also find 30s at 125% doesnt do much for me - I would suggest picking a Stretch alternative until you find your level. Theres no reason why the shorts need to be in the VO2 max pwer zone either, a lot of them are going up into anaerobic. As above, the point is to elicit maximum oxygen uptake and the exact power figure is not super important.