Apple Seeds Second Beta of watchOS 7.2 to Developers
To install the watchOS 7.2 beta, developers need to download the proper configuration profile from the Apple Developer Center. Once the profile is in place, the watchOS 7.2 beta can be downloaded through the dedicated Apple Watch app on the iPhone by going to General > Software Update. To update to the new software, the Apple Watch needs to have 50 percent battery life, it must be placed on the charger, and it must be in range of the iPhone.
watchOS 7.2 introduces a new Cardio Fitness feature for the Apple Watch, and Apple says that the cardio fitness metric are a "strong indicator of overall health." The feature measures VO2 max, or the maximum amount of oxygen that your body is able to consume during exercise. Measurements are done over time, and the Apple Watch and iPhone are able to send notifications to let you know about fluctuations in your VO2 max.
Cardio Fitness can be accessed through a new trend that’s been added to the Activity app, and it can be set up in the Health app on iPhone. Cardio fitness levels are available for users age 20 and above, and are estimated by age.