One of the health features that is buried and hidden on the Apple Watch is the VO2 Max. The measurements can be analyzed by the Apple Watch when recording your workouts but it is not enabled by default. It also goes by a different name.
Let us take a deeper look at how to use the VO2 with your Apple Watch and iPhone and why is it so important.
What Is The VO2 Max?
If you are new to Apple Watches and have never used VO2 Max before, it is a valuable measurement to understand and utilize.

But since VO2 max tracking isn’t turned on by default and Apple uses the name “Cardio Fitness,” it flies under the radar for many.
By measuring the “body’s ability to take in, circulate, and use oxygen” Cardio Fitness via VO2 max is a metric that gives a good indication of overall health and can also predict long-term health. While there’s a correlation between low VO2 max and future health issues, you can raise your levels with consistent aerobic exercise.
Relative VO2 max is expressed as a number between 14 and 60 with Apple Watch/iPhone and represents the number of milliliters of oxygen used in one minute per kilogram of body weight (mL/kg/min).
Two more great resources to track heart health is with HRV on Apple Watch and the Withings “Vascular Age” feature on its latest Body Cardio smart scale.
How To Use It With Your Apple Watch Or iPhone?
1: If you haven’t set VO2 up before, open the Health app on your iPhone
2: Tap Summary and swipe down near the bottom and look for Cardio Fitness Levels (under “Get More From Health”)
3: Choose the blue Set Up button
4: Follow the prompts like confirming your health details (users must be at least 20 years old)
5: You can choose to turn Low Cardio Fitness Notifications on for your Apple Watch
6: Now you’ll see VO2 max/Cardio Fitness show up under the Heart section in the Health app