Why does it take a few seconds for my Apple Watch to display my current heart rate?

If the heart rate measuring app on your Apple Watch takes more than 10 seconds to load, it is likely that dirt or oil is interfering with the heart rate sensor, which is indicated by the green light. To fix this issue, try cleaning the back of your watch and ensure that it is fitting properly on your wrist.

If the problem persists, please restart both your Apple Watch and iPhone.