I have seen the FAQ article: The Heart Rate Sensor on My Garmin Watch Is Not Accurate. My situation looks similar to the run cadence tracking issue shown in that article, but the rates do not match like that case. In my case, the heart rate goes from around 136 bpm to 168 bpm in about 10 seconds and then varies from there like I would expect as my run progressed. Meanwhile, my run cadence stayed pretty close to the 154 spm average throughout. Here is a screenshot of the heart rate overlayed with pace and cadence:
Other than buying a chest strap HRM, is there a way to tell what's really going on? The watch was quite snug, but not overly tight, and the outside temperature was around 50 deg. F. The most concerning thing is that my Venu 3S adjusted the Maximum Heart Rate setting up to 178 bpm based on this run, but it doesn't look reliable. I am 62 yrs old, so I expect my HRMax to be somewhere around 158 - 164 bpm (or perhaps a bit higher from having played tennis for many years before I got out of shape). It has shown similar offsets in several previous runs, sometimes even with a step back down later in the run.
Any help or insight would be greatly appreciated. Thanks,
Ron
