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Understanding VO2 max: why is it useful?

VO2 max represents the maximum oxygen flow that the body can consume during an effort. In other words, it is the maximum amount of oxygen that the body is able to extract from the air and then transport to the muscle fibres during exercise. It is often cited as a reference value in endurance sports.

VO2 max can be considered as a criterion for evaluating physical performance. It gives an indication of the level of fitness and endurance. The higher its value, the more it is easy to maintain an effort of a certain intensity over time. If you increase your VO2 max with training, you will be able to run either faster for the same distance or longer at the same intensity.

The VO2 max can thus be seen as an impassable limit in terms of oxygen flow. The volume of oxygen supplied to the body increases with effort but beyond the VO2 max, it can no longer increase. This does not mean, however, that the maximum power or maximum speed is reached. It can go beyond that but for a very short time (a few seconds or minutes at most).

As an indication, here are some figures indicating the time during which a trained athlete can sustain an effort depending on the percentage of VO2 max applied:

  • 100% of VO2max : 7 to 8 minutes
  • 85% of VO2max : 1 hour
  • 75% of VO2max : 2 hours 30


But for you to understand, two athletes of the same VO2 max do not necessarily have the same performances and will not finish the same race at the same time.

VO2 max varies from one individual to another. It depends on gender, age and the level of training. Its value varies from 25 to 70 ml/kg/min women and from 30 to 90 ml/kg/min in men.


Average VO2 Circular


Circular gives you an estimate of your daily VO2 max in the daily metrics section of the “Activity analysis” circle. It will soon be possible to complete a physical test within the app to know your real VO2 max thanks to a future update of the app. 

VO2 Max Circular

We remind you that the Circular™ ring is not a medical device and should not be used to diagnose or monitor a pathology.


Scientific sources:

  • The effects of weekly exercise time on VO2max and resting metabolic rate in normal adults. J Phys Ther Sci. Mi-Na Gim, and Jung-Hyun Choi. 2016
  • Usefulness of Pulse Oximeter That Can Measure SpO2 to One Digit After Decimal Point. Yonago Acta Med. Jun. Akihiro Yamamoto, Naoto Burioka, Aritoshi Eto, Takashi Amisaki, and Eiji Shimizu. 2017 

Amaury Kosman

CEO of Circular, Amaury is passionate about technology and improving human capabilities. He is an avid marathon runner who likes to optimize his training.

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