Here are some hard start threshold intervals. Taken from mid workout. The yellow numbers annotating different threshold work rate intervals w/in the overall hard start intervals are heart rate expressed as a percentage of heart rate maxima (maximum heart rate from the last few weeks).
So, all of these are well above 90% of max HR. Is this rider at or near VO2max?
Being fairly familiar with this rider I’ll say definitely NOT VO2max. Maybe for a couple minutes the whole time.
1-min above FTP and it looks like 6 or 7 minutes under FTP, is that right? Probably drive my HR to 90% HRmax and make me uncomfortable. But very unlikely that is vo2max. I vote NOT vo2max.
No. You don’t even need the annotations or the power data to tell.
Well since 90% of maximum HR is less than 90% of VO2max, I’ma gonna say no.
What’s your beathing like? I’d think probably not, looks too easy and power too low.
Training status doesn’t really have any significant effect on the offset between %VO2max and %HRmax.
The fitter you are, though, the harder you have to train to drive further improvement.
In any case, the stated question was whether they were close to VO2max, not whether they obtained training benefit.
The horizontal white line is FTP?
If so, either the rider’s FTP is a pretty high % of their VO2max, or the “hard start” shrunk their SV and jacked up their HR.
Shape of the HR curve gives it away.
Here is a pic with zero axis or legend but I’ll tell you that all intervals were executed the same way (to the best of my ability) and this was a VO2max session. Which interval do you think was the best executed one? Why do you think they look different?
In the context of individual differences and variability of HR, a couple of bpm is irrelevant.
Heart rate dropping after an initial increase is the dead giveaway that the person is not driving towards a VO2max stimulus (assuming there aren’t other weird things going on related to large temperature or cooling swings mid workout)
For most efforts that are above threshold where you have eaten through your initial anaerobic contribution and are operating at a high percentage of vo2max, the most obvious metric written to a file is that HR follows a LOG style curve where it increases quickly at first and then continues to climb over the course of the interval.
(correlation not causation. IME high VO2max % creates the HR response, not the reverse)
Here is a good example that is more similar to the OP’s example above, no time scale, but with power.
Was I close to VO2max at the end? Or to something else?
These are not V02 max intervals. Something makes me want to call them hard start threshold intervals for some reason, can’t put my finger on it.
The HR response to the hard start tells me the athlete is probably well conditioned and buffers lactate well. We could really test that if the intervals after the hard start were at FTP rather than slightly below it.
Just to confuse the issue…here is a 20+ minute VO2max interval. Note that for a substantial portion of this interval the rider was at (just a little below?) lactate threshold. No idea what heart rate was.
I actually thought of that study before answering at the top of thread.
So then, with neither power or heart rate data to show whether a particular interval has been effective we are left with presumably just respiration rate and how it feels to actually breathe to judge the effectiveness of the interval. I’ve been playing around with gearing and effort levels and have got to the state where a breathing like a fish out of water is a very good description. Does that, coupled with a deep rasping noise every time I try to gulp in air mean I’m probably close to or at my VO2 max. When I get to that stage though I really only have seconds left before I pop.
Yes! That seems to be the best indicator. Well, next to that VO2 master pro…or whatever they call that tubeless mask that measures gas exchange (which I colloquially refer to as ‘the most unhygienic bit of cycling kit ever’). Just get to the point where you feel like you’re drowning & hold that feeling until the end of the interval. The next day you’ll have DOMS in your intracostals and abs.
It’s part respiratory muscle training, part stroke volume training.
I guess my observation kind of mirrored what @anon20047708 said/linked…traditionally O2 consumption is considered to be roughly linear with heart rate. But these hard start intervals seem to make athletes say they are ‘much easier’ than hard start VO2 intervals…even though HR isn’t all that different. Maybe 1 bpm difference. One of my colleagues suggested the portion of venous blood saturated with oxygen must be higher in the case of the threshold intervals.
But I’ll admit: I don’t know. Just curious what everybody else thinks. If it’s really possible to elicit material VO2 adaptation using these hardstart threshold intervals…holy moly, that’s the way to go. It takes a lot less motivation to bang them out. And you can do a lot more of them. Just seems hard to believe.
As I mentioned, one possibility is that HR is elevated due to plasma volume contraction, due to the hard start.
Another possibility is that HR is elevated due to increased signaling from muscle nocireceptors, again due to the hard start.
In either case, SV (and VO2) might be reduced compared to what you would expect at that same HR without the hard start.
If you go by power you will never overestimate the steady-state VO2 requirement.
From that study (“The sustainability of VO2max: Effect of decreasing the workload” published 2012, Billat et al), you can see they attained and sustained VO2max by doing the following:
where power at VO2max was determined by a ramp test with 3-min step increments.
So going back to this:
So given the results of that study, I answered NO for the following reasons:
In other words, likely not enough time on the hard start, possibly not enough power, and undershooting threshold.
Its why my first questions were:
The 6 or 7 minutes was a curiosity question.
At a given power output, the steady-state VO2 can be higher than expected, due to drift. However, it can’t be lower.
IOW, if you go by power you will never overestimate the VO2 requirement, and hence will never underestimate your actual VO2.
This logic only falls apart when the intervals are too short for VO2 to approach steady-state. However, since longer intervals seem to be more effective, I don’t think that is much of an issue.
