How to Use Heart Rate Zones for Exercise on in watchOS 9
By Rachel Needell
In watchOS 9, the new ability to see and track heart rate zones really takes Apple Watch workouts to the next level. Heart rate zones for exercise are a way to monitor the intensity of your workout. Although this feature won't be available to the public until September, once you have watchOS 9, you can add heart rate zones to any workout. Here's how!