Does a VO2 max test have a mental discipline component?

Question

I've often wondered about the "Max" portion of a VO2Max test?

Is there a component of the test that is dependent not on how far you can push your body, but on how far you are willing to push your body?

For comparison, the instruction "how your breath for as long as you can" might seem very simple, and a test of your lung capacity ... except if I choose to do so, I can hold my breath up to a much more aggressive limit than I think most people contemplate. I can hold my breath 10-20 seconds beyond the point of "my sub-conscious nervous system is has capitulated and is desperately trying to breathe": my chest and diaphragm are physically heaving to breathe (clearly visible to others), I can feel panic chemicals affecting me, and the only reason I'm not breathing is that I still have conscious control of my lips and throat and am sealing them shut. When my mind finally capitulates, I gasp explosively and am "gasping for life" for 10+ seconds, and it takes me over a minute to recover. When doing casual "hold your breath tests" ... no-one else ever seems to do this. (Though I imagine there are actual competitions, and that the competitors do)

This isn't a reflection of my lung capacity or my body's consumption of O2 ... it's a reflection of my mental stubborn-ness (or stupidity, take your pick) in overriding my body's physical demands.

In the same way, does a VO2Max test measure/depend upon how far you can push yourself, or how far you will push yourself?

To put it another way:

• Does the test depend on/look at "How long you can hold yourself at some limit?"/"What ever-increasing value you give up at"?
• Or do you just need to push yourself "very hard" to the point at which you've hit an internal consumption limit, and hold yourself there for "a while" in order to get a stable reading.

Answer 1

TL;DR

A well-done lab test shows when you are not going all out. Will-power is more about where the power goes (and how much of your max power output of your individual muscles you are able to use), while this variable determines your systemic max power output.

Long answer

VO2Max is, essentially, the maximum amount of oxygen (in litres) your body can absorb via the lungs (per minute, per kg body weight), which depends on how much can be transported through your body and how much is consumed due to the relative gas pressure necessary for oxygen to get from the air into the blood in the first place (source).

As such, it is an objective measure that almost exclusively is determined by how much blood volume your heart can transport per stroke and the concentration of haemoglobin in your blood, as I explain in this answer of mine over on MedicalSciences.SE.

You cannot really not go all out in these lab tests since your heart rate is monitored and the max heart rate is pretty consistent over populations given the same age. Outliers are identified in baseline measurements. Additionally, since CO2 going out and O2 going in are measured, they take your so-called respiratory exchange ratio, which, when going above 1.0 (CO2 out vs. O2 in), shows that your body taps into acid buffer systems because there is not enough O2 to fully metabolise energy sources and lactate is building up. Therefore, if you stay significantly below what you are able to do, they'll notice. Going significantly above that by sheer will power is impossible as well since the heart becomes arythmic above a certain rate, which then again evens out over the course of a minute, and too much acid slows down metabolic processes needed to produce the energy for your muscles.

Also, they just ask you (with the help of a Borg scale) how much effort you put in. You may cheat that but your measurements will still tell the truth.

Now, where does your "mental discipline" come into play? Basically, every time you do not measure in a laboratory (where actual O2 consumption is measured over a mask), but use any approximation by exercise output instead. Of course, the tests all say "as fast as you can" but that is very much relative to several factors that do not depend on the real VO2Max at all, e.g. breathing technique: When you have a bad technique in breathing, a significant amount of your VO2Max is consumed by the muscles that do the breathing itself, leaving less to be used for actual exercise output.

The same can be said about overcoming muscle and mental fatigue: With the ability to keep your focus and push further, you may reach better test outcomes in terms of athletic feats although your maximum systemic consumption may be lower.