To measure your heart rate, make sure your device is comfortably fitted against your wrist and not loose. The heart rate sensor on the underside of the Fusion Bio needs to be in direct contact with your skin. 

On your device, swipe to the right of the time/date and step count screens until you see the heart icon. Tap it to initiate the heart rate monitor. Make sure you are sitting or standing as still and quiet as possible while the device is measuring. The less you move, the more accurate and speedy the heart rate measurement will be. The device will buzz slightly when your measurement is complete and then briefly flash your resting heart rate. (Please note that this measurement data is currently not stored on your device or within the app)

In addition, your device is regularly measuring and capturing your heart rate (approximately every 15-20 minutes). Your average heart rate information can be viewed in the Striiv app by selecting the heart rate tile on the app home screen.