VO2 max is a measure of the maximum (max) volume (V) of oxygen (O2) that your body can process in a given time.
To understand VO2 max you first need to understand the distinction between aerobic and anaerobic exercise.
It is all to do with oxygen. Our bodies prefer to metabolise energy using oxygen. If you have sufficient oxygen (and energy supply) your muscles work without undue fatigue. This is an aerobic state and you can sustain this level of activity for several minutes or longer.
If you push your body to the point beyond which it can supply enough oxygen then the muscle cells must rely on other reactions to fuel muscle contraction. This is an anaerobic state which produces waste molecules that impair muscle contraction and cause a deterioration in performance. The muscles become fatigued – they are in a weakened state and they hurt.
VO2 max is a measure that indicates the point where your body switches between an aerobic state to an anaerobic one. It defines the maximum effort you can sustain for a few minutes right on the edge of an anaerobic state.
The fitter you get the more oxygen you can process and the higher your VO2 max.
Where to next?
Back to interval training for cycling Lands End to John O’Groats, look at endurance training or visit one the most popular pages on the site, which concern planning your End to End, thinking about the cycling equipment you will need, what you should be eating and drinking whilst cycling and how to create a route for Lands End to John O Groats. Or you can read my own account of cycling End to End to get some idea of what to expect.