AW3 HR sensor is quite accurate.

[576316]

There was a recent poll which found the Apple Watch to have the most accurate heart rate sensor of any fitness tracker, but is the least accurate at calorie tracking.

 

[newellj]

Unless I'm missing something, all calorie tracking is mostly guesswork. Heart rate is measurable, though. I have compared Polar, Mio, FitBit and Apple Watch results and have had great results with the AW. Some people's anatomy may make accurate results less likely, and if you wear the watch loosely you're going to get less consistent results.

 

[Pseudo-Fed]

My S3 cellular is very accurate and seems more so than my Garmins. But for what I consider perfection I always pair a Scosche Rythym + during workouts.

 

[iPhysicist]

It’s not a light leak issue rather a physiological one. When the wrist or arm is cold and your just starting a run (or ride) the body is shunting blood to the core and legs. The capillaries in the arms also construct further reducing the hr sensor’s ability to pick up a signal (i.e. blood passing by). Once properly warmed up the sensor can pick up and lock onto and obtain an accurate consistent hr. Not sure what’s up with WatchOS 4 changing the way it reads hr data... I’m on S0 and WatchOS 4 and get great data on my trainer rides.

Yeah I also think that’s the reason.
(After a while) I figured it out being the temperature drop when going for an outside run. During indoor cycling the first minutes I do not get those dropped readings.

 

[PHILIP1193]

I will say mine is fine go static exercise bike work. Infact it’s as accurate as my Garmin HR strap linked to the exercise bike. But any exercise which actively includes arm movement it’s crap.

 

[Maui19]

I don't think my S3 is all that accurate. It shows some peak HRs that are hard to believe, like numbers in the high 180s to around 200 bpm. I'm over 60, and although I'm in good shape, I don't think my HR is getting anywhere near that number. 150-160, maybe, but not 190-200.

 

[montycat]

I compared my AW3 heart rate to a pulse oximeter on an anesthesia machine at work. The AW3 matched the pulse oximeter perfectly. Very impressive!

 

[newellj]

I will say mine is fine go static exercise bike work. Infact it’s as accurate as my Garmin HR strap linked to the exercise bike. But any exercise which actively includes arm movement it’s crap.

I get good results with the watch strap set quite snug. Doesn't bother me, but might annoy some people.

I don't think my S3 is all that accurate. It shows some peak HRs that are hard to believe, like numbers in the high 180s to around 200 bpm. I'm over 60, and although I'm in good shape, I don't think my HR is getting anywhere near that number. 150-160, maybe, but not 190-200.

I compared my AW3 heart rate to a pulse oximeter on an anesthesia machine at work. The AW3 matched the pulse oximeter perfectly. Very impressive!

I speculate that there are differences in how people wear the Watch and in their individual physical configuration that affect accuracy. I get amazing accuracy, but others don't. Some wrists work better than others?

 

[roncron]

The contact area must be moving around on the wrist in your situation.
My 42mm sits snugly on my 6" wrist. I use silicone strap for working out and the watch sensor area is in full contact with my wrist all the time. I use 38mm strap on my 42mm because 42mm bands do not provide good fit on my small wrist.

New Series 3 owner here. I wear a Polar H10 strap while working out and I’ve had mixed results with AW’s heart rate accuracy. During some workouts, AW is very close to the Polar strap, like +/- 3bpm, which I consider great. During others, AW is +/- 20bpm during part of the workout.

Like you, I’d rather not wear the chest strap.

I’d thought I was wearing the watch correctly, but after seeing this reply of yours, which is a great suggestion, I will try tightening the strap by one notch during my next workout.

Thanks for starting this thread and posting your HR monitoring info. It’s helpful for me as a new AW owner.

 

[dypeterc]

New Series 3 owner here. I wear a Polar H10 strap while working out and I’ve had mixed results with AW’s heart rate accuracy. During some workouts, AW is very close to the Polar strap, like +/- 3bpm, which I consider great. During others, AW is +/- 20bpm during part of the workout.

Like you, I’d rather not wear the chest strap.

I’d thought I was wearing the watch correctly, but after seeing this reply of yours, which is a great suggestion, I will try tightening the strap by one notch during my next workout.

Thanks for starting this thread and posting your HR monitoring info. It’s helpful for me as a new AW owner.

Discrepancies in HR could also come from the activity you're doing. Arm swinging sports or sports with a lot of vibration (like mountain biking) can cause errors. I've also found you won't get a locked HR until your warmed up especially if it's cold.

 

[newellj]

Discrepancies in HR could also come from the activity you're doing. Arm swinging sports or sports with a lot of vibration (like mountain biking) can cause errors. I've also found you won't get a locked HR until your warmed up especially if it's cold.

I have found I have to be careful when cycling (something to do with how the wrist is bent?). Some weights activities might have a similar effect. I also found that high-motion activities throw the watch around, so I keep it snug, and am glad I got the special lower-mass version of the Series 3 watch (aka the aluminum Sport) rather than the higher-mass version (the SS watch). Kidding but not...

 

[Anuba]

On average I've found the AW3 sensor to be very accurate. When I got mine, it confirmed some suspicions I'd had about my old 2015 "Series 0" AW. It kept registering lots of HR outliers up there in tachycardia territory (100+), and they were pretty much always 2x my average at the time. E.g. if I had a steady rate around 55-56, the AW was almost guaranteed to stick a pesky 112 in there once an hour or so. Same thing during the night... 44-43-88-44-42 etc.

I've had the AW3 (non-LTE) now for a few weeks, and haven't had a single instance of those outliers I used to get from the AW0 daily, if not hourly. The highest recorded non-workout reading by the AW3 so far is 77 (my averages are, roughly: Sleep 40-45, at my desk 55-60, very brisk walk 85-90, jogging 130-135, running 150-155). Whenever I switch back to the Series 0, I get the random 100+ outliers again.

I can't recall any mention of improvements to the sensor. There's added functionality like HRV etc, but that's another story. Then again, maybe "oh btw, the HR sensor no longer sucks" isn't a message they'd want to put out there...

 

[HiDEF]

I hate to resurrect an old post but figure might as well ask here instead of starting a new thread.

I currently bought the Nike+ on sale from BB (non LTE) and I'm wondering if there is a difference in HR accuracy when it comes to composite or ceramic backing?