Good morning all,
I have recently noticed on a couple of long runs my 735XT decides to stop using my external HRM-Tri, and switch to its internal optical HRM, and hence as well as losing the additional data collected by the external HRM, i get some dodgy mid-run HR readings (e.g. jumping up c. 20bpm or so, then falling back down, without any change in exertion).
It only seems to happen at the 1hr15+ mark, so my midweek <1hr runs are unaffected, and seem to be fine. I thought it must be the battery running down in the HRM, but changing it seemed to make no difference.
I have a marathon coming up, and hence would like to be able to rely on my HRM data once i'm over 1hr in to it.M ight anyone have any idea as to what might be happening?
I attach a couple of example activities. In TrainingPeaks, the data looks even stranger, with what look like long (1/2hr+) stops in the early stages, that certainly didn't happen.
https://connect.garmin.com/modern/activity/3072294561
https://connect.garmin.com/modern/activity/3086657096
Is it a 735XT problem or a HRM-Tri problem..?
Many thanks for any thoughts.
John
