Heart rate monitor is (almost) always On

Anyone has noticed this? Almost every time I look under my watch the heart rate monitor is glowing green. Is this normal?

The problem with the heart rate sensor after upgrade

Stops working pulse sensor after updating to Android 6.0.1
I downgrade to 5.1.1, everything works.
Put through fastboot 6.0.1, the sensor stops working ..
Who faced with similar?

Best Heart Rate Monitor?

What is your preferred heart rate monitor app? I'm looking for an app that is continuous rather than having to always manually do it.