Understanding VO2 Max

If, like many, you spent three weeks in July enthralled watching the Tour de France, you will have heard the metric VO2 Max referred to numerous times when discussing the performances of the top riders. If you weren’t watching, what exactly were you doing? Tour runner-up, Jonas Vingegaard is reported to have recorded a VO2 Max of 97 mL/kg/min at the tender age of seventeen, which is one of the highest ever recorded. Is this number an absolute determinant of athletic potential? If so, what must Tadej Pogacar’s be, because he put more than five minutes into the Dane over the three weeks of the Tour de France?

What is VO2 Max?

VO2 Max is a measurement of the maximum (max) volume (V) of oxygen (O2) our bodies can take in and utilise during exercise. It is measured in millilitres of oxygen consumed in a minute per kilogram of body weight and expressed as ‘mL/kg/min’.

The higher our VO2 Max, the more efficiently our muscles utilize oxygen and convert it to energy. Oxygen is used to create adenosine triphosphate (ATP), the fuel that powers the muscles on a cellular level. The more oxygen we are able to use for ATP production, the more energy we will have for putting force through our pedals.

Keep in mind, though, that just because we have a high VO2 Max doesn’t mean we’ll automatically be the a brilliant cyclist. There are other factors that go into performance, such as training, nutrition and the all important mindset or psychology of the athlete. All that taken into account though, we definitely want a higher VO2 Max rather than a lower one if we have any athletic aspirations. VO2 Max is the size of our engine. How we fine tune and maintain that engine through our day-to-day training and lifestyle, will determine how much of its potential we can realise.

As an added bonus, recent research also suggests that higher VO2 Max levels are associated with greater longevity, so it’s not just our performance on the bicycle that gets better with a higher VO2 Max.

How is VO2 Max measured?

The most accurate method of measuring this metric is in a lab. The test is considered the gold-standard measurement of endurance. The test generally lasts no more than fifteen minutes and involves cycling while breathing into a mouthpiece that collects our exhaled air and sends it into a machine through connected tubes where it is analysed, and how much oxygen we are using is recorded. The test starts off at easy efforts but the effort and necessary power is gradually increased until we reach failure. The testing is done on a bicycle or running on a treadmill but a cyclist should definitely perform it on a bike and preferably their own, because our muscles will be trained to perform at their best on our own machine. This will provide the most accurate results.

Obviously very few us have access to a lab with this sort of equipment and most of us are not that serious about things that we would want to go to the expense of hiring one. So, are there are easier methods of calculating this metric? We could use our wearable devices calculation to determine our VO2 Max but these are not super-accurate as they are estimates based on heart rate and gender and age norms, which can be widely inaccurate, especially in well-trained individuals.

Is there a practical application to knowing our VO2 Max?

The reality is, knowing our VO2 Max is more of a novelty than anything else and it isn’t really useful as a training metric on its own because we can’t measure percentages of VO2 Max while training with a power meter or heart monitor. What we need for training is the power numbers that correspond with our VO2 Max effort level and this we can estimate fairly accurately using a test for a different fitness metric, our Functional Power Threshold (FTP). FTP is the maximum power that we can sustain for an hour. There are a number of fairly simple ways to test them but none of them are physically that easy. The simplest is to do a 20-30 minute flat out time trial effort on an indoor trainer and record the average power from that effort. We then take 95% of that (to extrapolate out to an hour’s effort) and that is a pretty accurate measure of our FTP. VO2 Max power is estimated to be 120% of our FTP and doing intervals and training efforts at this, very hard effort level, over time, will result in improvements in VO2 Max.

As a result of the extremely high intensity of a VO2 effort, we should not be doing more than about 20 minutes in total in a session. If we find that we can do more than that, we probably have not been going hard enough. The recovery periods in between VO2 efforts are also longer in relation to the interval than they would be if we were working on our anaerobic threshold (FTP). During those interval sets we do not allow full recovery between efforts so that the lactate builds up in the muscles and our body is forced to learn how to deal with that. In a VO2 session, the recoveries are considerably longer, often more than twice the length of the interval so that the muscles can recover well in order to be able to produce the high level effort in the next repetition.

After a good period of training our VO2 we should see improvement in our one to five minute power on the bike. These are the kinds of efforts that allow us to break away explosively and create a gap between ourselves and our competition or friends… aren’t they one and the same really?