Weird behaviour Ruunto Run + Polar Verity Sense

[oni0n]

I’m using a Suunto Run paired with a Polar verity sense. On almost every run I get scattered spikes in hr that have nothing to do with reality. Happens every 5-10 minutes on average, but it’s random. These don’t look like the Suunto ohr cadence lock, they are much more instantaneous (one second 140, the next two 180, and then 140 again).

Another thing. maybe related, is that the fit file generated by Suunto contains “R-R intervals”, which are not really measured by the Verity Sense. It says that the R-R intervals are 5 seconds (yes, as in 12 bpm ;)). It’s not always the same value but it’s almost always around 5 sec. The only time it’s not 5 seconds is exactly the moment before a spike in measured hr, and then it’s ~10-15 sec (yes, longer when hr is higher!).

I’m really clueless as to what causes it. on one hand it seems like cadence lock, but on the other hand it has this weird relation with the bogus R-R. I wandered whether it might be some sort of connection failure and then maybe the watch tries to measure hr by itself.

Also, and even if the hr spikes are a problem with the Verity Sense, why does Suunto produce R-R intervals from the Verity Sense data? This is weird.