What is the meaning of the 'Continuous recording' option on the Apple Watch?
The Cardiogram companion app for the Apple Watch requires WatchOS 6.2. and above. If you no longer see the app on your Apple Watch, please download the latest version of WatchOS. - How To Update your Apple Watch
Enabling 'Continuous Recording' on your Apple Watch allows it to collect your heart rate data every 5 seconds, similar to when you start a workout on your watch. To use this feature, simply launch the Cardiogram app on your Apple Watch and swipe left on the screen.
The Apple Watch can take background measurements throughout the day based on your activity, which usually takes about 5-15 minutes on average. This feature is useful for people who want to monitor their heart rate during certain conditions, workouts, or even throughout the day to see which co-workers stress them out the most!
However, if you choose to start "Continuous recording," the optical sensor will take more frequent readings, which will use more power and impact battery life. Additionally, since the continuous mode is recognized by your watch and iPhone's software as a workout, your activity rings on your watch will fill in even when you're not actually working out.
It's important to note that Cardiogram may not display new results until you end continuous mode.