Recent HR issues on Forerunner 235

I got a Forerunner 235 last summer and it was working pretty much perfectly up until a couple weeks ago. I took a couple weeks off of running because of a minor injury, and ever since I started running again I've found my heart rate to be much higher than before, despite the runs being just as easy if not easier.

What I've noticed is that the heart rate measured by the watch shoots up almost immediately after I start a run. For example, on my run yesterday, the heart rate went from about 80 to 150 within the first 20 seconds of the run. Sometimes, even before I start my run my watch will randomly tell me I have a heart rate of 130 despite me not moving, and just by feeling my heartbeat I can tell it's very off.

I know the wrist heart rate monitor isn't reliable, but it was working perfectly before so I don't see why it shouldn't work now. I'm kinda bummed out because it's caused my VO2 max to drop down from 67 to 63...

Anyone else experiencing this issue or know what might be causing it or how to fix it?

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0 1947503 over 2 years ago

Yes my HR has given me very strange readings the last 2 runs. Last Monday it gave me an average HR of 112bpm and was below 100 for a long time when I know I was definitely working harder than that! And today was steady at 130bpm for 5.5km of a 6.5km run then jumped instantly to around 160-170bpm for the last 1km. From what I have read online, 4-5 years ago Garmin Forerunner 235s had an issue called cadence lock, where movements mean your HR monitor logs your running cadence and not your HR. I wonder if a recent update has caused this issue to come back as I've not had it before and like you have had my 235 for nearly 2 years.

0 4202359 over 2 years ago

Same here! It's very high when I start. Today I ran an easy run and it never measured me below 185 BPM. I got up to 191 BMP and stopped to makes sure I was not having a heart attack. I could talk in full sentences so the problem is the watch. My max HR is about 180 BPM.

0 vypermusic over 2 years ago in reply to 1947503

Yeah, I've read about the cadence lock, that might be it, hopefully we get an update soon that can fix this!

0 vypermusic over 2 years ago in reply to 4202359

Wow that's even higher than what I get! Funnily enough, on my run yesterday it gave me an average of 116, with most of my run around the 100 BPM mark. I know that was definitely working harder than that...

0 953fa3aeed2243c8a7d338983ec2436d 4 months ago

Any solution to this? Still exists today 2023