Measuring VO2max on stationary bike

Question

Have collected some data points in measuring VO2max over a few years using two methods: non-exercise and stationary bike (2min warmup + 6min at constant heartrate). The latter is supposed to be more accurate, but a couple things stand out:

1. The variability in the stationary bike method is far higher than what I would expect, even when discounting for the fact that it only returns integer values.
2. Stationary bike method underestimates my VO2max compared to non-exercise method.

The non-exercise method adjusts for age, weight, gender and depends on a self-assessment score and is ultimately more of a marker-in-the-sand value. Now, the true VO2max will depend on many factors, but ceteris paribus (apart from age), is anybody familiar with the poor accuracy of a VO2max measurement using a stationary bike + chest-worn heartrate monitor?

Answer 1

First, it is worth noting that non-exercise tests are especially inaccurate at determining both VO₂max and changes thereto. One study examining a host of different methods, including that described by Jackson (1990), concluded:

"changes to [estimated cardiorespiratory fitness] (eCRF), as determined using non-exercise prediction equations, were significantly associated with changes in directly measured [cardiorespiratory fitness] (CRF). However, changes in eCRF values from most of the prediction equations were significantly different from the changes in directly measured CRF. Furthermore, all of the prediction equations had a low degree of accuracy when identifying even the directional change of CRF. These findings highlight the errors associated with non-exercise prediction equations, especially related to monitoring longitudinal changes, and suggest limited prognostic utility of eCRF within a clinical setting."

Exercise VO₂max tests are therefore more accurate, but without knowledge of the precise method employed by your stationary bicycle, it is impossible to assess its accuracy and/or limitations.

In sporting circles, VO₂max is typically tested directly with a multi-stage maximal test, but this requires specialised equipment and tester expertise. In the field, this can be replaced with a multi-stage submaximal test, such as the YMCA Submaximal Cycle Ergometer Test, which estimates VO₂max through extrapolation from submaximal efforts. Intervals are typically three to five minutes, since a maximal three-minute effort is around 95% aerobic and a four-minute effort around 99% aerobic.

I hope that helps, even though I can not give you more information about your particular stationary bicycle.

Answer 2

The method that I will work with for the time being is VO2max = 190*calories per second when done on a stationary bike for at least 10 minutes. Level of resistance does not matter. Neither is heartrate, age or weight. I am a male.