A new feature on Apple Watch will give you a review on your fitness levels. When you update your watch’s software to watchOS 7.2, it will bring a new cardio fitness score that uses your VO2 max to measure your cardiorespiratory health, or aerobic endurance. Cardiorespiratory fitness, as measured by VO2 max, is the maximum amount of oxygen the body can use during exercise, and it can be increased through physical activity. Apple Watch already estimates average and higher levels of VO2 max during vigorous outdoor walks, runs, or hikes, which many runners and other athletes monitor to improve performance.

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Now, with watchOS 7, Apple Watch uses multiple sensors, including the optical heart sensor, GPS, and the accelerometer, to estimate lower levels, too. This is significant because direct measurement of VO2 max typically requires a rigorous clinical test with specialized equipment that is not readily accessible to most people. watchOS 7 also allows Apple Watch to take cardio fitness measurements as users walk throughout the day, whether or not they are tracking a workout. With this innovation, Apple Watch is better able to measure VO2 max for users with low cardio fitness, who may not complete high-intensity workouts, reports Apple.

“Cardio fitness is increasingly recognized as a powerful predictor of overall health, and with today’s update to watchOS 7, we are making it even more accessible to more people,” said Jeff Williams, Apple’s chief operating officer. “Using its advanced sensors, Apple Watch now brings estimation of low cardio fitness levels from clinics directly to a user’s wrist, so people have more insight into how they can improve their long-term health through daily activity.”

iOS 14.3 and watchOS 7.2 enable Apple Watch users to visit the Cardio Fitness category in the Health app on iPhone to review whether their cardio fitness level is classified as high, above average, below average, or low, relative to people in their same age group and of the same sex, according to data from the Fitness Registry and Importance of Exercise National Database (FRIEND).

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Here’s How to Set Up Cardio Fitness

1. From the Health app on your iPhone, tap the Summary tab.
2. Tap Set Up under Cardio Fitness, then tap Next.
3. Confirm your details. Any changes you make here will be saved to your Health Details in Settings.
4. Tap Next.
5. Follow the onscreen prompts to learn about other factors that can lower your cardio fitness, as well as the cardio fitness levels for your age and sex.
6. Tap Next.
7. Tap Turn on Notifications to receive a notification if your Apple Watch detects that your cardio fitness level is low. You must be at least 20 years old to turn on notifications.
8. Tap Done.