Everybody knows it. But everybody conveniently takes their eye off the ball. If you’re not active enough, you’ll do yourself untold damage, specially as you grow older and get more sedentary. But if you happen to be using a recent version of the Apple Watch, you’re at least more likely than most to have become sharply aware of your cardio health. You’ll be noticing your heart rate, taking the occasional ECG if you’re using the Apple Watch Series 5 or Series 6, and in these times of the pandemic, checking how your blood oxygenation is doing. Hopefully you’re taking advantage of the activity tracking to close those circles and keep yourself fit.

And now, make sure you upgrade to iOS 14.3 on your phone and WatchOS 7.2 to also keep track of your cardio fitness on a longer term basis. Cardio fitness is a predicted V02 Max value which is the maximum amount of oxygen your body can consume during exercise. This is measured when you walk or run outside. We have apandemic in the way preventing many of us from being outdoors as much as we would like, but if you do have space to walk outdoors safely, it’s obviously important for cardiorespiratory health. And every little bit counts.

Ordinarily, measuring V02 Max calls for specialised equipment and while the Apple Watch doesn’t purport to replace such tests, it gives an indicative estimate that can help the user make some lifestyle changes and step up fitness. The measure isn’t one that you check on an everyday basis as you would with some of the other parameters so we will only know how useful users find it over time, but Apple does refer to it as a ‘breakthrough’ technology. To make it happen, the Apple Watch uses multiple sensors, including the optical heart sensor, GPS, and the accelerometer and what it does it to estimate lower levels, as well as average and above average and the measurements happen as one walks throughout the day whether involved in a workout or not 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, in fact. Apple Watch Series 3 or later can record an estimate of your VO2 max using the heart and motion sensors during an outdoor walk, run, or hike. It can also estimate your VO2 max if you start an outdoor walk, run, or hike in the Workout app. Apple Watch supports a VO2 max range of 14-60 mL/kg/min that is validated for users 20 years or older.In fact, to estimate your cardio fitness level, the Apple Watch also takes into account your age, sex, weight, height and even medications such as beta blockers. It can take at least 24 hours wearing your Apple Watch, followed by several workouts and passive measurements before you receive an initial estimate.

Apple is referencing a 2016 scientific statement by the American Heart Association that says there’s a growing link between low cardio fitness and a higher risk of significant health issues, such as heart disease, high blood pressure, and obesity specially in later life. Research even suggests cardio fitness is a stronger predictor of mortality risk than common risk factors like smoking, diabetes, and hypertension. Jeff Williams, Apple’s chief operating officer has also said that the Apple Watch now brings insight into how users can improve their long-term health through daily activity.

Watch users can 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. They can also see how their cardio fitness level has changed over the past week, month, or year. If a user’s level falls within the low range, they can receive a notification on Apple Watch, along with guidance on improving it over time and having a conversation with their doctor.