VO2max questions

Yo guys, can someone reply to TTer? He asks the most intelligent and helpful questions on here.

Here's answers from what I can help with. Others please correct if I get something wrong:

[QUOTE]Originally posted by TTer
[B]First, how is VO2max measured? Is this the face mask, measuring gas exchange technique? Where they measure the amount of oxygen taken into the lungs, and the amount breathed out, to calculate the amount 'used'. And when this stablises VO2max has been reached? What units is VO2max expressed in? (isn't it standardised to body weight?)[/quote]

VO2max is measured by measuring the maximal amount of CO2 exhaled versus inhaled - CO2 is the end product of O2 metabolism, so this is tests O2 metabolism. Exhaled O2 hasn't been metabolised, so therefore hasn't been used in oxidative ergogenesis, therefore doesn't make you go faster. Yes, this is the one with the mask.

However: be careful, sometimes ppl use VO2 to refer to VVO2 or PVO2 (velocity @ VO2 or power @ VO2) - I think this is slightly dodgy - the velocity or power at VO2max depends on the methodology of the test (eg increments in which power increases, time over which increments occur), and is therefore not a clear physiological concept, though it may be a helpful training tool. VO2max has a conceptually clear physiological meaning - it is the maximal rate of uptake (including metabolism) of oxygen. You can then get to arguing over how good your test is, and what the predictive capacity of VO2max is...

Units are: ml/kg/minute

Quoted post said:

Next question. Are our lungs ever the limiting factor in VO2max, ie. your body can use all the oxygen your lungs can take in? Or does that never happen, except maybe in people with some lung disfunction? I seem to recall reading somewhere of an athlete who reached VO2max at 135litres per minute, while their max lung capacity was 180litres per minutes. Does that sound feasible, that VO2max is well within lung ability?

My understanding is that VO2 is primarily limited by cardiac output (stroke volumeXmaxHR/%VO2 extracted by muscle). Lung capacity is almost never an isue. Except when I get asthma (heh).

Quoted post said:

Finally, when training to improve VO2max, how does the intensity of exercise affect VO2max. I understand the aim in VO2max intervals is to accumulate as much time as possible at VO2max, such that 8-10 minutes at VO2max can be achieved in, say, 6 x 3mins intervals. Do higher intensities improve VO2max faster, or will a higher intensity just cause the rider to reach VO2max earlier in each interval? I'm thinking that higher intensity just elicits VO2max quicker, which makes the interval harder to complete, yet less intervals are necessary to accumulate the required time at VO2max (e.g. 6x3mins might be enough for 10mins at VO2max, vs. 16x2mins at the same intensity to get 10mins at VO2max)? How much time is needed at VO2max per workout, or per week to improve it? 8-10mins, 15mins per workout?

Now this is the juicy question... I need help on this one... ric, 2LAP, acoggan, are you out there? As princess Leila says, help me obi ric, you're my only hope...

Quoted post said:

I am asking all these questions as I'm trying to picture all this in my mind so I understand what I'm training better. Thanks in advance. [/B]

Glad to see there is at least one other cyclist in the world who thinks kinda like me! Lets hope the big guns get in there and answer the juicy bit.