Hi all, hoping for some advice here.
I’ve been using a Garmin HRM-Dual for all of my cycling since January 2020, probably averaging around 5 hours/week, with absolutely no problems at all. I always track my SUF sessions on my Garmin Edge as well as in SUF.
A couple of rides ago I noticed that the HR showing in SUF was a lot different from what was showing on the Edge - at the start of each recovery the SUF HR would go UP while the Edge HR was going down, then they’d swap, and eventually converge.
Today I did Nine Hammers but just after the 8th Hammer the HR dropped steadily to 124 and then got stuck there for a few minutes. I eventually pulled off the HRM because it was distracting me and I wanted to push through Hammer 9 (!). When you look at the trace (picture below) you can see there are also a LOT of dropouts, but no dropouts during the steady alleged drop in HR.
After the session I tried reconnecting it, making sure the strap was tight and correctly positioned etc, and it reported a HR of 74 which was about 40 too low according to a manual check and also my Garmin Forerunner watch.
So… I have checked the Garmin FAQ which doesn’t seem too helpful (eg I definitely had enough holy water!)
Could this just be a battery issue? There hasn’t been any low battery warning. Or something more serious? Has anyone had a similar problem?