Bizarrely variable heart rate

[H2O]

I notice a bizarre phenomenon: at easy pace my heart rate jumps around bizarrely, like e.g. here:
https://log.concept2.com/profile/2423512/log/95088330,
while under high stress it doesn't, like e.g. here:
https://log.concept2.com/profile/2423512/log/95158339
is this normal?

My monitor complains that it has trouble connecting with Ergdata (on Iphone 8).
Could this be a reason?

[Sakly]

The first log seems to show connection issues, or at least reception errors, as there are many plateaus as well. Second one seems to be ok.
Recently my H10 started to pass out in the middle of the rows for no reason. It needs a reset before it connects to the PM5 (or any other device) again. Little bit annoying, when the tech stuff not working as expected...

[p_b82]

I'd second the fact it looks like it's a connection issue in the top log

[MPx]

Could it be that you're not sweating enough on the easy row to keep the pick ups moist but are on the harder session? Do you "wet" the chest belt before starting?

[H2O]

Do you "wet" the chest belt before starting?

I wet both the belt and myself and the belt has a patch of fabric where the moisture is held (which is better than plastic).
But maybe it's not enough.
I have noticed that the measured heart rate seems to have some sort of "memory": often I go on and I know that I am below HR 100 but it shows 130, the heart rate I stopped at on the last row. It then takes a little to go down.

[Dangerscouse]

How long have you had it? It might be near there the end of its life due to sweat. Have you got a spare belt to use? I've found that can be an issue sometimes too, especially if you don't at least occasionally wash it.

[nick rockliff]

My H9 used to do exactly the same thing. Ended up in the bin and got a Garmin Dual, not had a problem since but have noticed the Garmin strap has started to fall apart.

[Ombrax]

DIY (Google "diy electode gel")

Or get the real thing:

https://www.amazon.com/s?k=spectra+360+ ... yfezkoz3_e

[H2O]

Thanks for all replies. I am a cheap skate and maybe this is not the best approach with a heart rate monitor.
I am going to make my own electrode gel, which seems to be easy enough, see https://www.wikihow.com/Make-Electrical-Gel.
If that doesn't work, I'll have to get the professional solution.

[jamesg]

On a Polar watch I started to see occasional extra electric impulses from the belt, at about age 75.

These caused the watch and PM readings to lock at an arbitrary number between 160 and 240, while seeing 90-120 on a finger oxymeter.

Such additional pulses (extrasystoles) always appear in an ecg.

Then a month or so ago, the extra electric impulses disappeared (from PM and watch), and now pressure and electric impulses coincide again.

However I now get some oppressive/pressure chest feelings suggesting, but not actually causing, sudden death. This has reduced me to max 10x1'+1'R intervals at <100W.

This coming Monday I'll know what a cardiologist thinks about it.

[H2O]

For context: I have 2 HR monitors, one from decathlon, the other from Amazon (Moffit), each below 30 EUR. The one from Decathlon has a belt where the electrodes are fabric. This is supposed to be superior, as it retains the humidity better. The Moffit HR has plastic electrodes.

Now I manufactured some electrode gel. With this I got a reasonable reading out of the Moffit and inconsistently also out of the Decathlon HR.
With electrode gel the belt with plastic electrodes seems to be superior, since one can clean the gel off more easily.
Electrode gel is definitely a good idea.

[Tsnor]

...
However I now get some oppressive/pressure chest feelings suggesting, but not actually causing, sudden death. This has reduced me to max 10x1'+1'R intervals at <100W.

This coming Monday I'll know what a cardiologist thinks about it.

Scary. Very glad you're seeing your cardiologist. When you get good news let us know.

[H2O]

However I now get some oppressive/pressure chest feelings suggesting, but not actually causing, sudden death. This has reduced me to max 10x1'+1'R intervals at <100W.

I missed this. Best wishes, I hope you are OK!