A VO2max number, next to age and sex.

What the band is comparing

VO2max is the peak rate of oxygen use during hard exercise, written as milliliters per kilogram per minute. A laboratory measures it with a mask and a gas analyzer and usually reports VO2peak. A watch figure, including Apple Watch cardio fitness, is estimated from heart rate and pace. It can help you follow your own change over months. It is not the same measurement as a lab test.

The bands on this page are percentiles from the FRIEND registry, in the 2022 update by Kaminsky and colleagues in Mayo Clinic Proceedings. The table is treadmill testing in apparently healthy adults in the United States, keeping tests with a respiratory exchange ratio of at least 1.0. Groups are men and women, in 10-year ages from 20–29 through 80–89. A value on the 50th percentile sits at the middle of that group: about half had a lower measured VO2peak, and about half had a higher one.

The same paper has a separate cycle-ergometer table, and those percentiles are lower. A bike test should not be lined up with the treadmill cuts here. Ages under 20 and ages 90 or older are outside the published groups, so the page says the table does not cover them. The authors also note that the sample is from the United States and should be used cautiously for people elsewhere.

A percentile only places a number inside that sample. It is not a medical label and not a training target.

Source: Kaminsky LA et al., Updated Reference Standards for Cardiorespiratory Fitness Measured With Cardiopulmonary Exercise Testing: Data From the FRIEND Registry, Mayo Clinic Proceedings, 2022. Table 3, treadmill CPX, directly measured VO2peak, inclusion RER ≥ 1.0.

General information, not medical advice. Talk to a clinician about health decisions.