Optical HR reading 100 low during intensity?

While Polar OH1 is way better than the optical HR from wrist, it’s not perfect either. I’ve had a couple of occasions where it didn’t manage to keep up with a rapidly increasing HR. Here’s one example from some outdoor 2min vo2max intervals:

(look at the one interval right in the middle)

Still very happy with it, but no HR measurement is going to be perfect (even chest straps can have false readings).

That’s interesting, I’ve never had that problem with my OH1. Where are you wearing yours? I wear mine on my upper arm above the elbow. I’ve done literally hundreds of workouts with it and never seen anything like that. My Fitbit wrist HRM on the other hand is complete junk for anything other than resting HR.

Upper arm above the elbow, same as you.

The sensor will still have similar struggles as a wrist based OHR sensor. It will have to figure out which of the many signals it detects in the skin reflectivity is the change in blood volume (and not sensor movement, muscle contractions, stray light, etc) and keep tracking it. Moving the sensor to the upper arm from the wrist does reduce the false signals significantly, making the blood volume changes easier to detect and track.

But how detectable the blood volume changes are in the first place, how strong the false signals are and how much the false signals are attenuated by moving the sensor to the upper arm is going to vary from one person to another. For some individuals it may even be possible to get very reliable heart rate measurements from the wrist with a good sensor while cycling. For others it may be hard to get reliable readings even from the upper arm.

In any case, I only see a handful of errors per season with the OH1, and I do well over a hundred workouts per season.

Same here. The verity sense or OH-1 from polar on the upper arm react a bit slower than the wahoo tickr, like 2 or 3 seconds, but then the reading is the same

Scosche RHYTHM for me on the upper arm works exceptionally well for indoor training. I have used the same unit for about 4 years with zero issues. The optical sensor in the Scosche IIRK is also much-adored by @dcrainmaker

Outdoors, it’s too chunky to wear with nice looking euro-length sleeves, so I generally wear a TICKR chest strap. But indoors? Heck yes… 10 out of every 9 rides, I’ll use (and trust) the Scosche RHYTHM.

The HR recording between a Scosche vs my TICKR seems very very close. I only wore the two (and dual recorded) on them when I first got the Scosche. Numbers were exactly the same vs. a TICKR.

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I used a whoop for 6 months, which has an optical hr monitor, and it’s numbers were completely bogus. I’d been wearing a chest strap for years and my max HR has never exceeded 185. Whoop was telling me I was over 200 on a decent… Those things just don’t work and/or are unreliable. I started wearing the chest strap and the whoop simultaneously and they were constantly at odds. If HR data is important to you I would avoid an optical HR monitor.

Same for me - Rhythm 24 on the upper arm for many years with zero problems (apart from remembering to charge it)