The Continuous Pulse
The primary selling point of the Apple Watch is its array of health sensors, most notably the optical heart rate monitor pressed against your skin. By default, the watch constantly fires bright green LEDs into your wrist to measure your pulse throughout the day, and continuously during workouts. While useful for fitness tracking, this constant optical measuring is a massive drain on the tiny internal battery. Furthermore, if you wear the watch strictly as a fashion accessory or a notification screen and have absolutely zero interest in logging your biological metrics, you must permanently disable the optical sensor array.
How to Turn Off the Heart Rate Sensor Globally
You can permanently sever power to the optical LEDs via the Privacy settings.
- Open the Settings app directly on your Apple Watch (the grey gear icon).
- Scroll down the main list and tap on Privacy & Security.
- Tap on Health.
- Tap on Heart Rate.
- Locate the master toggle switch labeled Heart Rate.
- Toggle this switch to the Off position.
A Purely Digital Wearable
The change takes effect instantly. The Apple Watch will physically cut all power to the green optical LEDs on the ceramic backplate. The watch will instantly stop logging your background resting heart rate, and it will refuse to measure your pulse even if you manually open the Heart Rate or Workout apps. Your device is now biologically disconnected from your body, transforming it into a purely digital notification screen while significantly extending its battery life.