How to View Heart Rate Zones on Apple Watch
Starting with watchOS 9, you can view the Heart Rate Zone information on your Apple Watch to learn about the intensity level of your cardio-focused workout.
App Developers Reveal What ‘Game of Thrones’ Does to Your Heart Rate
It appears that Game of Thrones violence isn't what thrills fans the most.
Apple Watch Can Detect Abnormal Heart Rhythm with 97% Accuracy: Study
Apple Watch's heart rate sensor can aid in the detection of abnormal heart rhythm.
Apple Says Sporadic Apple Watch Heart Rate Tracking is Intentional
Apple says irregular heart rate tracking is a feature, not a bug.