Post contributed by:

Selina Campbell PhD
Senior Coach and Programs Manager, TCR


Why do a VO2 test?

Let’s face it… We all want to improve our fitness and functional threshold power (FTP). This is the power which you can hold for approximately 45 minutes to an hour. At this level your body is pretty much in equilibrium meaning you are producing lactic acid at the same rate that your body can remove it. Tip over this point and the body can no longer keep up with the rate of removal required and the time you can hold power drops exponentially! The fastest and safest way to improve this tipping point is to train where we are now, in order to get where we want to be.

If you want to get your threshold to “x” watts, doing all your training as if your FTP is already “x” will lead to you doing your intervals in the wrong zone. The result is that you will be working the wrong physiological systems for the wrong time period to elicit the gains you are looking for. If you know accurately where your current threshold is, you know precisely what level you need to bike at to develop your aerobic system. You also know where to hold your intervals to improve your lactate tolerance AND what power to pitch your VO2 max intervals at to pull up your top-end. Knowing your zones and training accurately in them will work in harmony to increase your FTP. The result: you will be able to hold higher watts come race day.

Don’t be afraid!

Many people are afraid of doing a VO2 test. I think they are put off by the word ‘test’. But, I encourage my athletes to look at it as a training tool – a snapshot of where you are today so you can work with your coach to draw out a road map of how to get to where you want to be tomorrow. Having a VO2 assessment done in the TCR Lab relies on physiological outputs that are not influenced by your mind. The data we see (heart rate, respiration rate, % of O2 and C02 that you are breathing out) are totally independent of any thoughts – they are physiological reactions to the workload your body is being subjected to. They can’t be faked. From those data points we can calculate a ton of useful information for you.

A VO2 assessment can be done while running or biking. For triathletes I ALWAYS recommend testing on the bike. That is the discipline where zones need to be nailed down. One can be the best runner in the world, but if they can’t get to T2 in decent shape, it is all for naught.

What to expect from a VO2 assessment:

We ask folks to allow about 90 min from start to finish. You don’t need to bring your bike – we use a velotron spin bike which will be fitted with the pedals you normally use. All you have to bring are your bike shoes, clothes, water bottle and a positive attitude. 😊

We get you warming up on the bike. The fit will be adjusted so you are in the correct position. When you are ready to go, we fit a mask to you that allows you to breathe in normally, but directs all the expired gases down a tube to be analysed. We start you out super easy and then ramp you up in 20w or 25w increments. The ramp we do depends on where we estimate your threshold will be. We hold you at each level for two minutes which allows the expired CO2/O2 ratio, HR, and ventilation rate to settle out.






Once you reach your threshold (we can see from the data being collected when you reach that ‘tipping point’ I talked about) we then switch you to one minute jumps until you decide you have had enough! Typically the entire test takes around 15 minutes of which only the last three are very hard. After, we let you cool down with a nice easy spin and then we crunch the numbers for you. Finally, once you are off the bike we go over your results with you and answer any questions.


Not only can we accurately assess where your FTP is and calculate your training zones, we can also see your oxygen carrying capacity, if you are a fat or a sugar burner, and your lactate tolerance. This information helps your coach know if it’s your top end power or aerobic capacity you need to work on, to improve overall.

For more information on physiology assessments or to set up an appointment contact TCR.