False abnormal heart rate alerts from Forerunner during Edge 1040 bike climbs

Sorry to say: forgot it. Looks like this is existing on all modern garmin watches.
I assume that this problem is introduced as kind of "energy saving" to have some marketing material to sell longer battery lifetime without mentioning the impact on accuracy... I would be happy if I'm wrong and this bug would finally be adressed and fixed.
I could also live with slightly less battery in order to get rid of those false positives.

See here: https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/fenix-7-series/350539/fenix-7-x-pro-abnormal-heart-rate-detection-during-cycling-activities-with-edge-devices---works-fine-on-fenix-5

And here: https://forums.garmin.com/sports-fitness/cycling/f/edge-530/351911/abnormal-high-heart-rate-alert-while-working-out-on-edge-and-hrm-pro

The watch vibrates continuously for minutes, and it often takes a while to even realize it's buzzing — usually only once the road surface smooths out. Then you have to wait for a safe moment to glance at the screen to figure out why it’s vibrating in the first place. After that, you still need to find another moment to actually dismiss the alert. These prolonged vibrations are extremely distracting, especially during technical sections, heavy traffic, or fast descents.

If the intention behind this behavior is battery optimization, it's quite ironic — because constant, unnecessary vibrations certainly don’t help conserve battery.

What if you start some other activity, like cardio or something, that you just discard in the end (not save it), does that activate lights etc as well?

That's a whole different can of worms  sir:
For example, when I go out for a run, everything is already set — route, training plan, alerts. But if I pass by my bike, the smart lights start flashing just because the watch gets close enough to detect them. So now I have to walk away from home before setting anything up, just to avoid triggering sensors I won't use.

Worst of all, if I don’t realize that the lights were unintentionally activated (e.g., when passing by the bike during a run), then when I actually go out for a ride, I might end up with dead lights.

There are workarounds, but they all come with downsides:

1. You can enable Heart Rate Broadcast on the watch, but this drains the battery faster — and let’s be honest, I’ll forget to turn it off. I’ll only notice when the battery warning pops up hours later.

2. You can leave the watch at home, but that penalizes your data — no HRV, no Body Battery, no recovery tracking, since it’s declared as your primary wearable.

3. You can manually unpair sensors from the watch while doing dummy activities, but that’s a hassle and easy to mess up.

I'm sharing this here because I didn't buy these devices from some $5 discount site in Asia. I bought them expecting long-term support after the money changed hands. This deserves a real solutions, not workarounds.
I’ve bought all these devices at launch and have been hoping with every firmware update that this would get fixed — but so far, no luck. And now we’re probably getting close to end of support, which makes it even more frustrating.

Are you using the Forerunner passively whilst recording a ride with the EDGE?

Are you using an external HRM to record the the ride activity?

If so, why not just turn off the global Abnormal HR Alerts, you can enable them in the activity and the will then only be triggered by the external HRM.

This is no bug. The watch is working as intended:
It measures your HR, compares it to the set threshold and looks for movement.
If you ride steep climbs seated, there is almost no movement to sense for the watch. The watch now sees: I’m not moving but my HR is above the upper threshold. It will sound an alarm until you dismiss this. 
It’s only done by the watch and has nothing to do with your Edge, your HRM or your phone.
Without you telling us wich forerunner exactly you have: Just turn the upper alarm off in settings.

For the Lights: I have mine paired to the watch but then i switched them off. I only turn the lights on under sensors when I don’t use an Edge but one of the lights from the dropbar bikes. This is almost never. You don’t need to unpair and repair them, only turn the sensor off.

Thank you for your interest and for the solutions you're trying to offer.

You guessed correctly: yes, I’m using the Forerunner passively while recording the ride with the Edge 1040, and I wear an external HRM paired to the Edge only.

As for disabling the global Abnormal Heart Rate alerts:

– I’m wearing a watch that claims to detect abnormal heart rate. But since my heart rate is perfectly normal at that point, that’s simply a failure of the detection algorithm.

– Disabling a feature because you know it fails, and enabling it only when you hope it might work — that’s the kind of logic you apply in DIY projects, not in a commercial “fully integrated” ecosystem.

– Good luck remembering to turn it back on afterwards. (Yes, I’m that old — I actually care about long-term heart rate data.)

Let’s be honest — many of us bought into this ecosystem because it promised smart integration, reliability, and long-term value. And we paid full price, not AliExpress discounts.

It’s not about “wanting too much.” It’s about expecting what was advertised and still advertised to actually work.

We shouldn’t have to disable features, jump through hoops.

As for BeneGi: I’m sorry to say, but if it’s not a bug, then it’s just bad design. What you’re describing isn’t a justification it’s an admission that the watch doesn’t perform well in real-world scenarios.

It’s not our job, as users, to help a flawed algorithm produce acceptable results just so we don’t feel bad about the money we spent. If a fitness watch can’t tell the difference between a seated climb and a cardiac emergency, then something is fundamentally broken, regardless of how “intended” that behavior might be.

Not to mention It;s not hard: I have my phone with me. Both the Edge and the Forerunner are connected to it. The data is there and could be shared for free, yet the system remains blind.

As for manually enabling or disabling sensors before every ride... either you’re joking, or you have a very limited use of the ecosystem. I have multiple bikes, each with their own lights, speed and cadence sensors, some with power meters, some with temperature sensors, others with Di2. It’s a nightmare every time I lend one to a friend just so we can ride together. Identifying and selecting the right configuration before every single ride is exhausting not to mention the fact that some accessories can’t even be renamed, so you end up recognizing them only by their ANT+ ID.

The saddest part?

The watch on my other wrist ... whose brand I won’t mention ... has never flagged those heart rate values as abnormal, even though it wasn’t told there was any activity in progress. It’s old, the battery barely lasts 4–5 hours, but it successfully detected all three episodes of tachycardia and two of bradycardia I’ve experienced over the years.

Meanwhile, after two years of wearing the Forerunner, it still hasn’t had a chance to prove it can do the same but the way it behaves in everyday use doesn’t inspire confidence to leave the old one at home.

5155879 said:

– Disabling a feature because you know it fails, and enabling it only when you hope it might work — that’s the kind of logic you apply in DIY projects, not in a commercial “fully integrated” ecosystem.

I actually have the global level HR enabled all the time because I have no issue with the OHR on my watch it is always within a beat or 2 of my HRM and I do not trigger the HR alerts. I have always used a Garmin watch passively along with an EDGE and have never triggered a global alarm.

The reason That I suggested the workaround is that there are a number of posters on this forum who continually have problems with the reliability of the OHR on the watches. Many posters suggest that their OHR reading either is either way too low, too high or varies between the 2..

We all strive for accurate long term data, but at the end of the day we have to make the best of the equipment have.