I will just ask one more question:
How many incremental exercise/VO2max/cardiopulmonary exercise/whatever you want to call it tests have you personally done? How many have you administered?
(Sorry, I guess that’s two questions.)
will put my 6yo on some vo2max right now to see if she can improve in the future as I’m not genetically gifted. 
I’ve personally done 3 VO2max tests in my life.
Administered? I don’t know, I’d have to think about it. Not many since COVID - 3? Many more before 2020.
I am not an exercise physiologist, I work in medicine. There are gaps in my knowledge that I’d love to explore and find. However, the insinuation that someone who disagrees with you on minor matters has no idea what they’re talking about is a bit of an unflattering look.
I had enjoyed our conversation otherwise. If you have a problem with me, please take it offline.
Just wondered about your background. For the record, I’ve measured/had measured my own VO2max dozens and dozens of times (last time about a month ago…although being semi-recumbent cycling, I couldn’t actually get to VO2max, only to a VO2peak). I have also administered/helped administer hundreds and hundreds of such tests, to participants ranging from world champion cyclists to ostensibly healthy elderly individuals to patients with heart failure or who had undergone Fontan surgery. (FWIW, I have also built/rebuilt/validated 7 different metabolic carts at 5 different institutions.)
Anyway, back to my point:
VO2max is defined as the highest achievable rate of whole-body oxygen uptake during exercise. Ipso facto, encouragement cannot increase VO2max, because if it it did, the lower value could not have been VO2max, but was simply a VO2peak.
Is there a way in a lab to determine when true VO2max has been achieved, and not just a VO2peak?
Related, how psychologically difficult is it to push yourself to VO2max? Like 1 in every 2 times during a ramp test people typically can get there, or 1 in every 10?
Asking out of curiousity. I don’t think understanding any of this will change my training or make me a faster rider!
Increase in effort (power) without any corresponding increase in VO2.
Basically, you keep increasing the workload while oxygen utilisation plateaus.
I think.
As @Helvellyn stated, the ultimate indication is whether or not VO2 plateaus as a function of demand.
I would cite statistics for how frequently such a plateau is typically achieved, but I don’t think that really means much, since it is so context-specific.
Good to have you here. There are a lot of forum members (including myself) who don’t have any relevant professional training, so it’s nice to have your input.
Here, I’ve thought of a different way to explain how I’m thinking of things. Maybe this will be helpful.
My understanding based on reviewing research and the odd seminar at the conferences I go to (and personal experience from training), is that VO2max is somewhat activity specific. Like, if you put a cyclist through a VO2 max test done on a stationary bike, the plateau typically occurs a bit off (like 5%?) from if you had them do a treadmill test. Assume in both the athlete reached a true plateau so we can simplify the concerns with VO2 peak.
The presence of this exercise-specific component to VO2 max values suggests that cardiovascular capacity is not the rate limiting step on VO2 max; but rather that peripheral demand is playing at least some role in its value. Yes this is an area of controversy in exercise physiology, but I think most people acknowledge these days that peripheral demand plays some role.
If peripheral demand is playing a role in VO2max, why would there not be a small psychological component to it? Given that psychological factors influence peripheral muscle recruitment. (No I don’t want to talk about the central governor hypothesis, I mean independent of that idea). Thats premise A.
Premise B is that multiple studies have shown that psychological factors play a small role in measured VO2max (again there’s maybe 10 altogether; I haven’t counted though). You are correct that many of these studies have some unknown degree of uncertainty in their results due to use of surrogate endpoints for VO2 max in some participants… but this remains a fairly consistent signal regardless of issues with internal validity - and consistency of effect is one of the Bradford Hill criteria for causality (yes there could still be reporting bias). The correct way to think of this is not “this study is wrong” or “this study is right” but rather there is x% probability these results are correct (this is the Bayesian in me coming out).
Premise C is that… well, we know that everywhere else in human physiology, that psychological variables impact and change human physiology. This is what the placebo effect is. I can give you a puffer that has nothing in it… and your odds of developing severe COVID requiring hospitalization drop by a few percent (actual study results from a few years ago).
Altogether, my conclusion based on premises A, B, and C, is that it is highly likely that VO2max is influenced by psychological factors. This is not certain, but no research is.
Sorry, this is as far as I read, because your understanding is clearly incorrect.
NON-cyclists will typically exhibit a cycling VO2peak some 5-7% lower than their true VO2max. Well-trained cyclists, OTOH, can achieve VO2max while cycling (as well as while running uphill on a treadmill). Triathletes tend to fall in between, closing the gap more when cycling more and letting it open more when cycling less.
Along the same lines, Nordic skiers are able to reach VO2max while skiing, but also running uphill while arm poling.
Swimmers are an exception, as they generally can’t achieve VO2max in their chosen sport. This may have to do with innate differences between upper- and lower-body musculature, such that you can’t drive the CV system to its true limits using (mostly) your upper body, no matter how much you have trained it. Still, VO2peak in highly trained swimmers can be >90% of VO2max, vs. the ~70% observed during upper body exercise (e.g., arm cranking) in untrained individuals.
You might find it worth picking up a good exercise physiology textbook, vs. trying to piece things together by, e.g., reading clinical studies, many of which are incorrect.
To give one example of the disconnect in understanding between the fields of exercise physiology and medicine, to this very day the American Heart Association endorses/perpetuates Wasserman’s “anaerobic threshold” hypothesis in their position stand on exercise testing, even the idea was debunked in the core scientific literature over 40 y ago.
As an aside, yes, I have (had) measured my VO2max both running and cycling on multiple occasions, including in the name of research:
(Bob Withers’ study was the very 1st experiment in which I participated…the only prior VO2max I recall doing was in Rick Sharp’s undergraduate exercise physiology class.)
What do you think of this estimation?. Intuitively makes sense to me, when I go to sea level, my RHR drops 15bpm and I have an easier time reaching max HR. I live at 8000ft
Correcting for resting HR helps, but if you know what you’re doing, you can predict VO2max more accurately and precisely from power alone. 
*
*Although I wouldn’t necessarily trust the estimates provided by WKO5 (vs. WKO4), since they (somewhat foolishly) altered my P-D model without considering the “downstream” effects.
Do elaborate on this!…. I’m assuming you are not talking about:
Are you arguing against yourself now?
No, I am not.
WKO4 will estimate VO2max for you, based on the parameters of the P-D model that I developed. The algorithm was validated against direct measurement of VO2max obtained using a metabolic cart.
The model itself wasn’t changed in WKO5, but (as best as I can tell), they altered the weighting assigned to different data points, resulting in different parameter estimates (in particular, a higher mFTP… better to flatter the customer than to provide the absolute “truth”, I guess). This then has knock-on effects of, e.g., estimated VO2max, etc., which the folks at TP either didn’t realize or simply ignored.
Is there anyway to get the original PD model?
No, or at least not from me. I licensed it to TP along with other ideas (although, somewhat ironically, my most original one) for six figures. Some have attempted to reverse engineer it, but have failed.
You don’t have to give us the “secret”, but could you at least share insights about how to look at the PDC in a more scientific way to derive other variables?
You do understand that your argumentation is doing nothing for your claim „max is max“?
You don’t need a posteriori knowledge to show that your claim is true, because it’s an a priori knowable truth.
I know you are not a logician but you are arguing on a wrong level here. The discussion is more about logic than soft/empirical facts.