Heart rate error - Forerunner 255 Series - Software Version 27.09

Hi
Yesterday, twice during a 1 hour and 23 minute bike ride, my heart rate fluctuated twice. Normally it doesn't go above 180 bpm (I have an alert to notify me when it reaches 180 bpm).

And yesterday it reached 214 bpm, then I stopped the bike and suddenly the heart rate dropped to 135 bpm. This happened twice at different times... See the attached photo.

Forerunner 255 Series - Software Version 27.09

drive.google.com/.../view

Top Replies

ovekvam 2 months ago in reply to 5639340 +1

When you are using a chest strap, the watch gets the heart rate from there, so any issues must be with the strap, not the watch. There is however a setting on the watch that makes the watch use the wrist…
Garmin - KS 2 months ago +1 suggested

5639340 Based on those screenshots, the elevated heart rate readings appear to be very brief spikes that return to the expected values almost immediately afterwards. When cycling, factors such as watch…

All Replies

0 5639340 2 months ago

0 SAMONZEWEB 2 months ago

Same here today. I went for a very easy run, using an HRM200 I've already used multiple times.

Before the run the HR was ok, but when I started to run it went at 80% of my Max HR which was suspect (I should have been around 75%), and went progressively higher. Then it jumped around 95% which was impossible at that slow pace (or I would have a serious health issue). It stayed high until I stopped a few seconds before crossing a road, then dropped around 75%. After that everything was ok, the HR fluctuated accordingly to what I did, and stayed mostly around 75% as expected for one hour.

The strap was wet, I always put some water on my chest before taking the strap on. And as I said above, it behave perfectly until I started to run.

0 5639340 2 months ago in reply to SAMONZEWEB

0 5639340 2 months ago in reply to 5639340

Yesterday I did another ride and everything was normal, and it's the same version of the program. I don't understand what happened that day; the watch was firmly on my wrist.

But I'm wondering if the problem is with the watch or my health... See yesterday's graph.

0 ovekvam 2 months ago in reply to 5639340

When you are using a chest strap, the watch gets the heart rate from there, so any issues must be with the strap, not the watch. There is however a setting on the watch that makes the watch use the wrist sensor if the data from the strap is not okay. Maybe you could try to turn that off.

0 Garmin - KS 2 months ago

5639340 Based on those screenshots, the elevated heart rate readings appear to be very brief spikes that return to the expected values almost immediately afterwards. When cycling, factors such as watch fit/placement and flexing of the wrist while gripping the handlebars can restrict blood flow and affect the wrist-based optical heart rate performance. We recommend reviewing the tips outlined in this article to help ensure the most accurate readings possible: Garmin Watch Optical Heart Rate Accuracy Tips

0 8275105 1 month ago

The same issue with mine 255M on latest firmware. I am 30 years old and my HRMax is 220 ehhhh. On previous versions no issues with heart rate monitor.

0 7157803 25 days ago

Just to add to this thread I have a two years old FR 255, been great up to now. Wrist HR monitor may be less accurate than a strap but at least it has been consistent with itself and allowed me to judge effort especially in longer runs. Eg in Edinburgh marathon in May it was hot, noticed HR was about 10bpm higher than normal and adjusted pace to maintain effort. Since June (?after last update) HR has gone mad. Typically races up (200bpm) at the start of even a gentle run then drops off a cliff to normal levels at around 1.5-2 miles. Playing havoc with my recovery stats, V02 etc. is it time for a new watch or do we need another update from Garmin?

0 ovekvam 25 days ago in reply to 7157803

Mine is still working well like before on steady runs. As always, fast intervals starting from a "low" heart rate is too confusing for the wrist sensor. With a chest strap, it is always spot on.