VO2 max (also maximal oxygen consumption, maximal oxygen uptake or aerobic capacity)
VO2 max refers to the maximum amount of oxygen that an individual can utilize during intense or maximal exercise. In a lab a VO2 max test is generally done with a graded exercise test on a treadmill (for runners), cycling erg (for cyclist), or rowing erg (for rowers) where each stage the workload is increased while ventilation and oxygen (O2) and carbon dioxide (CO2) is measured. VO2 max is reached when oxygen consumption remains at steady state despite an increase in workload.
VO2 max is expressed either as an absolute rate in liters of oxygen per minute (l/min) or as a relative rate in millilitres of oxygen per kilogram of bodyweight per minute (ml/kg/min).
The relative rate is the expression often used to compare the performance of endurance sports athletes.
>75 Olympic caliber endurance athlete
>60 National caliber endurance athlete
>45 Athletic fitness
>38 General health & fitness
If you have a VO2 max over 75 does it mean you can compete as a Olympic caliber endurance athlete? Unfortunately no, there are many other factors to consider. With that being said you may be a very efficient athlete and compete well at the regional or national level with a VO2 max of 57 but competing on the world level (Olympic) your VO2 max may very well be your limiting factor. In the car world it's like showing up with a 6 cylinder engine while everyone else has an 8 cyclinder. They'll have more "horsepower" to play with.