How to Turn On / Off Heart Rate Monitor on your Garmin Forerunner 645? In this tutorial, I show you how to turn your heart rate monitor on and off. This can be useful if the heart rate monitor is accidentally turned off, or if you are looking to increase the battery life of your smart watch.
Follow the steps below to turn on and off the heart rate monitor on your Garmin Forerunner 645:
Hold down the Up button until the menu opens.
Scroll down (using Down button) and select (using Start/Stop button) Settings.
Scroll down and select Wrist Heart Rate.
Under Status, you will see the status of your heart rate monitor. If it is off and you’d like it on, then simply select it using the Start/Stop button. It will then say Auto. Auto = on, off = off. If you would like to turn it off, select it again and it will be off.