VO2 Bike/Rower/Watt Calculator

Self-Paced Exercise Test (SPXT) - Stationary Bikes/Rowers/Airbikes/Turbo-Trainers

Warm-up: Begin with a proper warm-up to prepare your body for the exercise.

Starting Level:

For both men and women, start with a moderate workload or resistance level on the stationary bike, rower, air bike, or trainer (technically you could substitute for any machine that measures in watts, it's just that I've tested the formulas on these). Choose a level that allows you to cycle comfortably while still feeling a moderate level of exertion. A suggested starting workload is in the range of 50-100 watts, adjusted based on your fitness level. Your increments should coincide with the perceived rate of exertion as per the Borg scale (see chart), start the test at RPE (ratings of perceived exertion) 11 and incrementally increase RPE to 13, 15, 17, and finally 20 for each stage.

Test Progression:

The test consists of 5 stages, each lasting 2 minutes. Gradually increase the workload or resistance level for each stage to increase the intensity of the exercise. A common approach is to increase the workload by approximately 10-20% for each stage. Adjust the increments based on your perceived exertion and ability to sustain the required intensity. If it feels too challenging, reduce the increment size to 5-10% to ensure a more gradual progression. Monitoring:

Throughout the test, monitor your heart rate, perceived exertion, and signs of fatigue or discomfort. Pay attention to your body's responses and adjust the intensity if needed. If you experience any unusual or concerning symptoms, stop the test and consult with a healthcare professional.

Recording Data:

Record the workload or resistance level (in watts) reached at the point of exhaustion. This is the point in the last 2-minute block where you can no longer sustain the effort Note down your age and gender for accurate VO2 max estimation.

VO2 Max Percentile Values by Age & Gender

Age Group 25th Percentile 50th Percentile 65th Percentile 75th Percentile 90th Percentile
20-29 40.1 48.0 52.9 55.2 61.8
30-39 35.9 42.4 46.6 49.2 56.5
40-49 31.9 37.8 42.3 45.0 52.1
50-59 27.1 32.6 36.8 39.7 45.6
60-69 23.7 28.2 32.1 34.5 40.3
70-79 20.4 24.4 27.8 30.4 36.6
20-29 30.5 37.6 42.3 44.7 51.3
30-39 25.3 30.2 34.0 36.1 41.4
40-49 22.1 26.7 30.2 32.4 38.4
50-59 19.9 23.4 25.8 27.6 32.0
60-69 17.2 20.0 22.2 23.8 27.0
70-79 15.6 18.3 19.8 20.8 23.1

Joe's Borg Scale

If you would like a printable copy of the Borg scale leave your email and you can download it straight away.


This calculator was developed by me from the protocol described by Hogg, James (2018) The use of the self-paced exercise test in assessing cardiorespiratory fitness in runners. Doctor of Philosophy (PhD) thesis, University of Kent,. (KAR id:68563).The Watt based version is my own extrapolation of this thesis and has been tested by myself and my clients and found to be remarkably accurate but is purely anecdotal.

Would love to hear from you so we can keep gathering data and prove my thesis that this is as applicable on Watt based cardio machines of all kinds, as it is to runners, as an alternative to the 20 minute ramp test.