Hi I have a Polar F11 Heart Rate Monitor. Over my last couple of runs, the actual heart rate readout has started reading wrong. It starts out about 15 beats lower than my actual resting heart rate. It only slightly increases during my runs. There is some movement but not much.
I would like to think I am in this good of shape, but the reality is I'm not.
I replaced the batteries in both transmitter and receiver recently.
Does anyone have any advice?
thank you