I've recently noticed while on a training run my heart rate is higher than my Max HR. I've used a miniature doctor's HR monitor which is highly accurate and the Garmin 745 watch HR is is out by more than 25 beats.
I've also compared at home hours later and the 2 devices are different. I also started getting tachycardia (high HR) the reason I have the professional doctor's HR monitor, The Doctors HR monitor is high and the watch is low. Sometimes they are in sync but many times not. Could this be a software update issue? I'm using the latest version.
Any thoughts?