I have a Forerunner for 2 weeks.
The first week, the heart rate seemed correct varying between 60-100 and higher when excercising.
But a few days ago, the heart rate started to peak from morning to evening (up and down between 60-170), even if I am not excercising.
I checked how to wear the watch correctly and the cleanliness of the sensor.
What could be the problem?
Thanks in advance,