I have updated my fenix5 (Asia edition) to version 6.00. I found the heart rate monitoring become unstable and inaccurate during my trail run activity. Previously my max heart rate can go up to 180 or 190. But now it only hit up to 140 max!
The route and elevation are similar. I strongly unbelieve that my heart rate has been improved that much. is there a bug in version 6.00?
