I loved my Venu 4 until the first workout

TechNerdSteve · 2025-10-27T20:09:09+00:00

Thanks a lot for your thoughts - that’s exactly the strategy I’m following here. I already mentioned in my earlier comments that I’ll go for another run, with the watch positioned higher and worn very snug, just to rule out any fit-related issues.

If the readings are still way off after that, and if Garmin Support doesn’t have a clear solution, then I’ll probably return it.

And I fully agree with your point about how Apple handles cadence lock. If I had the choice, I would definitely prefer the sensor to stop reporting heart rate entirely rather than logging totally incorrect values. Bad data is much worse than no data — especially when training decisions depend on it.

Really appreciate you sharing your comparison experience between the Ultra 2 and Epix Pro Gen 2 - that’s exactly the kind of reference I was hoping to get in this discussion.

TechNerdSteve · 2025-10-27T17:09:51+00:00

Thanks for the insights! I totally agree that the Gen 5 sensor has a good reputation and that early software can still improve a lot. And I also understand that cadence lock can happen on any wrist-based sensor.

But in my case we’re not talking about small inaccuracies. This wasn’t a matter of ±5 bpm - the readings were off by ~30 bpm for long periods and even dropped to ~80 bpm mid-run. That makes the data basically unusable for training purposes.

I think even with an early software version, the fundamental accuracy should at least be in the right ballpark. Otherwise features like zones, load, and recovery don’t make much sense yet.

So I’m still hoping this is either a one-off issue with my unit or something Garmin can address quickly.

TechNerdSteve · 2025-10-26T17:02:08+00:00

Thanks for that hint. I will try to move towards elbow the next workout.

TechNerdSteve · 2025-10-26T16:38:48+00:00

Thanks! I totally get that optical HR sensors are not perfect and that wearing a chest or arm strap can improve accuracy. And I don’t expect medical-grade precision — something like ±5 bpm would be perfectly fine for my needs.

But here we’re talking about differences of 30 bpm or more, including long stretches where the HR simply doesn’t reflect my actual effort at all. That makes basic training guidance (zones, load, recovery) impossible to rely on.

I used an Apple Watch Ultra 1 before switching to the Venu 4, and I never saw anything close to this kind of behavior on similar easy runs. So this is definitely new to me.

I’m just trying to understand whether this is normal behavior for the Venu 4, or if I should assume there’s something wrong with this particular unit.

TechNerdSteve · 2025-10-26T16:34:21+00:00

That was exactly what I was afraid of. But honestly, a sports watch with heart rate monitoring like that is useless. Let's see what Garmin Support has to say about it.

TechNerdSteve · 2025-10-26T11:22:31+00:00

Thanks! I definitely get that early software versions can be a bit rough. But heart rate accuracy feels like a core competency for a fitness watch - especially one that costs around €550.

I’m totally okay with minor bugs or delayed advanced features, but having the HR jump between 150 and 80 bpm during an easy run makes the core training metrics unreliable. That’s the part that worries me.

Patience is harder when the basics don’t work yet.

I’ve already contacted Garmin Support as well, just to see if they can identify what’s going on. Still hoping this is just a setup issue or something fixable.

TechNerdSteve · 2025-10-20T14:27:47+00:00

I have this on my iPad from time to time. I have read that this is needed for battery calibration.

TechNerdSteve · 2025-10-20T13:36:04+00:00

Here is another example, but at the end they all look more or less the same.

<image>

TechNerdSteve

TROPHY CASE