Fenix 5x and hrm problems

New to garmin Fenix 5x and having some hrm issues. The wrist based hrm on the watch is way off. Seems to work okay when resting, and okay at a hard effort, but way off anywhere in between. I’m comparing it to a garmin chest strap connected to my phone while doing trainerroad workouts. My Apple Watch was significantly more accurate and way less lag. In an attempt to really do a comparison I’ve downloaded the data field “auxiliary heart rate monitor” but can’t figure out how to get it on the watch at the same time so I can compare both hrm’s at the same time. Any ideas?

0 bglover11 over 5 years ago

I've always considered wrist-based HR more of a novelty than an actual training tool in terms of accuracy. That said your results will very largely based upon things such as skin tone/thickness, arm hair and especially how tight you wear the strap. In my own personal experience when using solely the wrist-based HR it will show relatively accurate increases and decreases of my heart rate in an exercise/rest interval but the actual heart rate value itself is never much closer than 20-30 beats per minute to an actual chest strap measurement.

0 5244721 over 5 years ago in reply to bglover11

Hmmm.... I expect an Apple Watch hrm to be a novelty. And a dedicated Multisport watch to actually be a viable hrm. But in my experience it’s the complete opposite, my Apple Watch was always within 3 bpm of my chest strap

0 GSAUN over 5 years ago

Unpair the chest strap HRM from your watch. It will try to pair again and when it does select "no." That way it can record bother the wrist and the chest strap. Assuming you've set up the auxiliary heart rate monitor data field correctly, you should by able to scroll between the two readings or, as I've done, create a data screen where you can see both simultaneously.

After you've downloaded the activity through Garmin Connect, you should also be able to see both on the data fields and you can select them to graph together. Be aware that they may graph on different scales. The only times when I get really anomalous readings is when it is cold and my arms get cold or at the very beginning of a run. It can be harder for the LEDs to pick-up the capillary flow to give the HR output. Less of a problem with arm warmers or heavier long sleeve shirts. Within the first couple of minutes, both readings are relatively close together

Yes, there is a lag between the two readings and I find that the wrist-based reading tends to lag and be higher by 1-3 bpm over a long-term average.