Quote from: ArsLoginName on December 02, 2023, 01:22:51Thanks for the wonderful information. Please post back ASAP as I currently use an arm based optical sensor for when I exercise (biking) but have always wondered how accurate it is - which I still can't decipher from the charts other than I get the closer all of the data points get to being a flat horizontal line, the more accurate it is. But I can't decipher how in-accurate the others are. Are data points outside the dashed horizontal lines (which represent some statistical level of accuracy) off by 0.25% (not significant to me), 5%, 10% (a bit more important when trying to keep heart rate under 140 or 130 etc).

Glad I could help! The dashed lines represent 1.96 x standard deviation, or the 95% confidence interval.

My forerunner 245 and my polar strap give me the same reading over a 5k within 1 or 2bpm. Now sleep tracking, that's the real joke. Overestimates by hours and hours!

I think it's obvious that you use chest strap sensor for any activity (maybe excluding walking 😂 )

Quote from: ArsLoginName on December 02, 2023, 01:22:51Thanks for the wonderful information. Please post back ASAP as I currently use an arm based optical sensor for when I exercise (biking) but have always wondered how accurate it is - which I still can't decipher from the charts other than I get the closer all of the data points get to being a flat horizontal line, the more accurate it is. But I can't decipher how in-accurate the others are. Are data points outside the dashed horizontal lines (which represent some statistical level of accuracy) off by 0.25% (not significant to me), 5%, 10% (a bit more important when trying to keep heart rate under 140 or 130 etc).

Look for the Garmin watches that have the Elevate5 sensor. There are only a few, because it's new.
The Elevate5 has been tested alongside  a Polar H10 strap and it's amazingly accurate.

Quote from: David99999 on December 02, 2023, 02:04:31Not sure want's the point using data from the Fenix 6 which is obsolete,last-gen tech as a reference.

Exactly! This is a hit piece. The Garmin 6 uses the Elevate3 monitor, and Garmin has already released v5, which has been compared to a Polar H10 strap and it's amazingly accurate.

Not sure want's the point using data from the Fenix 6 which is obsolete,last-gen tech as a reference.

Thanks for the wonderful information. Please post back ASAP as I currently use an arm based optical sensor for when I exercise (biking) but have always wondered how accurate it is - which I still can't decipher from the charts other than I get the closer all of the data points get to being a flat horizontal line, the more accurate it is. But I can't decipher how in-accurate the others are. Are data points outside the dashed horizontal lines (which represent some statistical level of accuracy) off by 0.25% (not significant to me), 5%, 10% (a bit more important when trying to keep heart rate under 140 or 130 etc).

I have ample Strava data to support this, and even wore my Fenix 6X during a stress test with 12-lead Siemens ECG. Its HR readings during sleep are adequate for trend tracking, but use the Polar for activities (despite being frustrated with their crappy apps and buggy wireless firmware updates). With the Fenix 7 Pro, Garmin redesigned their optical sensors, and I'll start testing it when it arrives next week.

Also note, someone wrote a really cool free ECG Android app for the HRM10.