VO2 max is the measure of the peak volume of Oxygen (VO2) you can consume and use in a minute and is a popular measure of an athletes aerobic fitness. It is measured in ml/kg/min. The per kilogram part means that an athletes bodyweight is taken into account.
Oxygen is needed to produce energy and the harder you exercise the more Oxygen you use in order to produce sufficient energy. However, everybody has a maximum level (their VO2 Max), where Oxygen utilisation is at its peak.
If exercise intensity increases beyond this point then the anaerobic energy systems must be used to supply the additional energy. However, anaerobic metabolism produces lactic acid which causes fatigue and also results in oxygen debt which means eventually you will get out of breath and tired and will have to stop.
How do I measure my VO2 max?
There are a number of ways of testing your VO2 max. The most accurate is in a laboratory, where exhaled Oxygen and Carbon Dioxide levels are measured whilst running on a treadmill. This allows us to see how much of the Oxygen inhale is used for energy production.
We know 21% of the air we inhaled is oxygen so by measuring the volume breathed and the difference between this and the air we breathe out we can get a pretty good measure of how much oxygen has been used.
VO2 max can also be estimated using tests such as a bleep test, step test or Balke test. The bleep test involves running shuttles between two cones keeping in time with an ever-increasing pace of ‘bleeps’. Once you are unable to keep up than the level you reached will correspond with an estimate of VO2 max. This estimate will have been deduced from measuring a large number of athletes accurately in a laboratory and then seeing how high they achieve on a bleep test.
It is important that whatever test you do it is relevant to your sport or activity. For example, if you are a middle distance runner then doing a VO2 max test on an exercise bike will not be as relevant for you as doing it on a treadmill. Or if you are a rower then performing it on a treadmill will not be relevant.
How can I improve my VO2 max?
Your VO2 max can be increased through aerobic training, for example, running at a sustained steady pace if you are a runner. If you cycle then cycle for longer periods of time. This causes adaptations within the cardiovascular, respiratory and muscular systems which make the processes of gas exchange, Oxygen transport and aerobic metabolism more efficient. Read more about the principles of training.
Results vary depending on fitness level, sex, age, and genetics. The older you are the lower your VO2 Max is estimated to be. An average score for a twenty-something male would be 40 ml/kg/min with an excellent score being 52 ml/kg/min. An average score for a female of the same age would be 30 ml/kg/min and an excellent score would be 41 ml/kg/min. Some professional sportspeople (involved in endurance activities) have scored in the ’80s!