On Monday we have a VO2max test. I've done loads of tests over the years and the improvements are small. The tests we do are not proper VO2max tests. It is not VO2max that we are looking to find, they last about twice as long as a standard test as the increments in power increase are much smaller than the standard test. I did a couple of "standard" VO2max tests in 2006 and scored 530w and 91.8 ml/min/kg.
VO2max is kind of a useless measurement: A bit like the cilinder capacity in a combustion engine; what really matters is the power of the engine, not it's size, hence we look for the power of the "aerobic"engine.
Races are usually won in supra-maximal efforts (4-5km climbs, sprints, short TT's) generally efforts that fall into this range are efforts up to 12 minutes. This accounts for most cycling races.
I am not sure of the exact physiology, but quick people (people with oxidative type II fibres) have amazing stamina and speed combined. This because they "recover" energy from lactic acid in the cori cycle in the muscles and liver.
You are what you are. A test is merely a method of determining training intensities.