The more informed you are about your health, the more empowered you are to affect it. Advanced health sensors in Apple Watch Series 8 provide insights to help you better understand your health. Understand your cycle like never before. Apple Watch Series 8 has an innovative sensor that tracks your temperature while you sleep, so you can see changes over time. Cycle Tracking uses this data to provide a retrospective estimate of when you likely ovulated, which can be helpful for family planning. When combined with your heart rate and logged cycle data, you’ll get a detailed view of your menstrual cycle. Crash Detection. Help on automatic. Tons of ways to train. For your personal best. Your favorite apps on your wrist. With access to tens of thousands of apps from the App Store right on your wrist, Apple Watch is the perfect personal device for whatever you love to do.