Wrong heart rate while using external heart rate monitor

Hello everyone.

I just bought a Garmin forerunner 965. Yesterday was my first run. It's winter now and I put the Garmin not on my wrist, but on the sleeve of my winter jacket (that is, the heart rate sensor did not touch the skin). I used an external sensor (polar h9) to measure my heart rate. During the first 5 minutes of my run, the watch showed an abnormally low heart rate (about 70 beats per minute - you can see this in the screenshot). I was sure that the heart rate data was not taken from the external sensor. So I took the watch off my wrist. At the same second, the watch began to show the correct heart rate (about 130 beats per minute).

Has anyone encountered the same problem? What needs to be done to make Garmin show the correct heart rate data from the first second of the run? (taking data from the external heart rate sensor)

Top Replies

All Replies

0 expo8282 14 days ago

Try changing the setting to always use the external hrm when connected and not switch between the best source.

support.garmin.com/.../

0 flocsy🤠 14 days ago

A few thoughts: the clothes can also return the LED light (or a desk if you just leave it untouched).

It can even be cadence lock.

You don't need to put the watch on your clothes, you can wear it on your skin. The way you'll know if/when during the activity the hr came from the polar is by looking at the Charts. On the respiratory rate chart, when you have values, then it's from the polar. Where there's no respiratory rate, it's from the optical sensor.

If you want to compare the optical hr sensor with the polar, then try this datafield: ANT+ HRM: https://apps.garmin.com/apps/7c83d402-4b68-4f0a-b167-7139788a19b3

0 Bitti 14 days ago in reply to flocsy🤠

Trust me, there are a lot of places where you have to wear the watch over the clothes during winter if you want to be able to look at the watch while running... I would freeze my wrist otherwise.

0 flocsy🤠 13 days ago in reply to Bitti

Then I misunderstood. I thought they did that in order to "deactivate" the optical sensor to make sure that only the polar is used

0 pxl 13 days ago in reply to expo8282

side note: it is not an option for FR265

0 expo8282 13 days ago in reply to pxl

Missed that you are using a Polar HRM and not a Garmin strap. In that case it should always use the strap since switching isn't supported. You may need to change the priority of the sensor but I don't think so.

0 Vizi 13 days ago

Old problem. Garmin acknowledged it but did not fix it.

forums.garmin.com/.../18-20-19-18-hr-bug-still-here

0 flocsy🤠 13 days ago in reply to expo8282

What? The automatic switch between the strap and the optical sensor doesn't work with polar? Where do you get this from?

0 expo8282 13 days ago in reply to flocsy🤠

It’s in the original link I posted:

Heart rate dynamic source switching aims to provide the most accurate heart rate possible by dynamically selecting the best source of heart rate data when wearing a compatible Garmin heart rate monitor strap with a compatible Garmin watch.

0 flocsy🤠 13 days ago in reply to expo8282

Hmmmm. I think it works with Polar. I am injured now so I won't be able to test, but I think it worked.