Heart Rate Extremely Inaccurate, Microsoft Says Band is Entry-Level Device

[tangledW]

Yes, I'm sure the Band is quite accurate - when there is no movement.

Yes, I'm sure it's not very accurate - if its so loose on your wrist that it's moving around.

 

[gadgetrants]

Yes, I'm sure it's not very accurate - if its so loose on your wrist that it's moving around.

I think he meant, "when you don't move your body", i.e., "while standing still."

For the record -- and despite my post above about the difficulty of IR-based HR tracking -- count me as one of the owners who is having a reasonably good experience with HR tracking on the Band. Lately I've been doing 2-4 mile runs and based on having used a Garmin watch with a chest strap over the last many years, the HR data from the Band are more or less the same.

It may be worth noting: we've all speculated that the real-time HR data that are collected and displayed while working out are likely reprocessed (i.e., smoothed) when they sync to the phone -- I tend to ignore the occasional spikes/dips on the Band and rely on the Health app and Dashboard. Of course, this comes with three rather dumb drawbacks:

- the Band does not offer HR-zone training
- the Band's default HR zones (in post-workout displays) are not modifiable
- IF the Band did have zone training, it would likely not be very robust (without on-Band correction of HR spikes)

In other words...HR detection on the Band seems better suited for post-workout data summary and analysis than real-time feedback. Of course, the final caveat is that everything I'm proposing applies to things like running, walking, and biking -- that is, movements that are fairly regular or rhythmic over time -- I think all bets are off for "ballistic" movements like weight lifting. :unhappy:

​-Matt

 

[Mohamed Abdul]

having 2nd thought now

 

[DroidUser42]

I think he meant, "when you don't move your body", i.e., "while standing still."

Correct.

 

[tangledW]

I'm sure that's what he meant, but if he'd been less of a smartass he would have gotten less of a smartass reply.

 

[NinerJet9]

I exercise regularly in and outside of the gym. When I'm at the gym I have checked the HR w the various cardio machines. So far most are pretty darn spot on or at least when reason. I also use Tickr X chest strap from Wahoo Fitness. I've tracked work outs simultaneously and those results are very close too. With that said, a lot of hand movement will cause a temporary but significant rise or drop in HR with the MSB. Overall I'm pleased w it. Here is some data from a recent bike ride. Maybe you guys will disagree or agree w my assessment.

 

[kevin shea]

My experience is similar. When the heart rate locks, the accuracy is close enough for me. However, getting a lock is very frustrating sometimes. I'm at about 16% body fact, Caucasian, no tattoos and lightly tanned skin. Essentially.... average. ... except for my blood pressure. I'm pretty low and my hemoglobin (and RBC count, HCT) are on the higher side. Hemaglobin runs 16 to 17.2 depending on my hydration.

The only things have seem to improve getting a lock is wearing the band higher up on my arm, towards my forearm and cleaning the sensor periodically.

Things that made NO improvement were: shaving my arms, switching position from bottom to top, wearing tightly, movement or no movement.

Ha I was thinking about shaving my lower arm.
I am getting happier with the HRM portion. It still freaks out most runs at the start. I am warming up, 12+ minute miles and goes up to 170. Not a true indication of my heart rate. But if I ignore it, then when I am done warming up I stop that run a and start another it has been fairly accurate. Today I did a 3 mile test and it stayed between 114 and 121 which is almost exactly where I wanted it to be.
I have not tried cleaning the sensor, might give that a shot before tomorrow's run.

 

[Shripad Lale]

Hello Kronus24, Sorry for the late reply, but wanted to set the record straight. I did use the 'Run' mode. And BTW, I agree that the Band is quite accurate. I am totally sold! No complaints. What I meant was a 'display' lag.

The screenshot below is a superimposition of the heart rate that the Band measured and that measured by Micoach chest belt (taken from my MyCoach portal screen). (Took me quite some effort to match them up and clean up some background colors so that both could be seen!)



As one can see, the band does a super job, for a device that is so convenient to use! But I still believe that it takes a few seconds to catch up on the display, so I wouldn't make 'real time' decisions based on what my band shows me. For instance, if I do zone/interval training, I want to stay as close as possible to the top of the green (136 bpm for me) and yellow (158 bpm for me) zones. If I run till the displayed heart rate is 156 bpm, and then just stop, and keep looking at my band, I can see the HR going to 160..162.. 167.. 170, all well within my Red Zone, and then dropping off, all while I am standing still. This never happens with my chest belt. So, I am assuming that when I stopped, the HR was much higher, and the band display just caught up with it.

So, either there is a lag between the level of my effort and the way my heart responds, or between level of my HR and the way the band responds. I pray to God that it is the latter!! Cheers!

 

[DroidUser42]

so I wouldn't make 'real time' decisions based on what my band shows me.

And there's the problem. Why can't it? Why should we haul something else for "real time"? That's a major issue that I hope gets fixed in the next gen.

 

[Nate Silver]

And there's the problem. Why can't it? Why should we haul something else for "real time"? That's a major issue that I hope gets fixed in the next gen.

Well, I think that's mostly down to optical HR monitors in general, not just the Band. My Mio Fuse reacts slightly faster than the Band, but not by much. There is always going to be a slight delay with optical, because you are reading from capillary action on an extremity, rather than electrical impulse via a sensor located directly over the heart. As I understand the tech, there is also some software wizardry involved in decoding the information from an optical sensor, in order to try to distinguish what is an actual heart rate as opposed to 'noise'.

 

[Snoke]

I will gladly take these so called lags in info. for the freedom of not having to wear the chest strap. The beauty of the band is that it is very accurate, based on many articles and peoples feedback on this site, and you have it with you at all times. Its a single tool. It doesn't need a strap or even your phone. You can be in the mood and just go for a run/hike/ride whatever and still capture your GPS route along with your HR. Great tool if you ask me.

 

[DroidUser42]

Well, I think that's mostly down to optical HR monitors in general, not just the Band.

I beg to differ. I found that by wearing my Band in a strange way, I could get accurate spot readings. Contrast that to my prior test on the previous page. The key seems to be to locate the right spot on the arm. If I had a way to move my HR sensor to a different location on the strap, I probably could solve my problem.

 

[gadgetrants]

I will gladly take these so called lags in info. for the freedom of not having to wear the chest strap. The beauty of the band is that it is very accurate, based on many articles and peoples feedback on this site, and you have it with you at all times. Its a single tool. It doesn't need a strap or even your phone. You can be in the mood and just go for a run/hike/ride whatever and still capture your GPS route along with your HR. Great tool if you ask me.

I can't say for sure if this ^^^ reflects the average user's experience, but it's what I see on a daily basis. I also agree 100%.

I know I've already said it a thousand times, but if we remember that it's a very young technology and this is a first-effort, it's a damn good device. The health/activity/wearables sector will only get better in the next 5 years.

-Matt

 

[DroidUser42]

The health/activity/wearables sector will only get better in the next 5 years.

What did they say about MS software? Wait for version 3? (As in Windows 3, DOS 3, ....)

 

[gadgetrants]

What did they say about MS software? Wait for version 3? (As in Windows 3, DOS 3, ....)

And maybe the Surface too? Third time?s the charm with Microsoft?s Surface

-Matt

 

[hagjohn]

I tested my heart rate when I was at the doctors office. My band was one number off of their reading.

 

[DroidUser42]

I tested my heart rate when I was at the doctors office. My band was one number off of their reading.

Yes, "at rest" it's fine. But for some, it all goes haywire when trying to take readings while walking/moving/exercising.

 

[Will Gilliland]

Well, I think that's mostly down to optical HR monitors in general, not just the Band... There is always going to be a slight delay with optical, because you are reading from capillary action on an extremity, rather than electrical impulse via a sensor located directly over the heart. As I understand the tech, there is also some software wizardry involved in decoding the information from an optical sensor, in order to try to distinguish what is an actual heart rate as opposed to 'noise'.

I think I understand what is going on with this perceived inaccuracy of the Band. For a quick background, I'm an electronic engineer with 26 years in the biomedical diagnostics industry mainly focused on hematology. However, my studies are more in blood cell categorization and quantization rather than pulse detection.

There is negligible delay between optical and electronic pulse detection. The difference (delay) stems from the clarity of signal from the transducers and time to interpret. Chest straps provide a pretty consistent electronic pulse to do measurements on. The optical sensor has many more variables that lead to inconsistent pulses. Arm hair, tattoos, skin pigment, hemoglobin level (sort of the "redness" of your blood), vessel size and placement, body fat %, proximity to skin.. I'm sure you can think of several more.

The digital signal processor for the optic sensor must interpret these pulses and set baselines and discriminators to weed out noise and compare it to a table of probability. When you see the Band searching for a lock, I'm pretty sure it's adjusting the discriminators to weed out the noise and set baselines. After you get a lock.... I agree, the Band is accurate.

 

[DroidUser42]

The optical sensor has many more variables that lead to inconsistent pulses.

I've always believed it was mostly due to motion. I think movement of the arm leads to changes. For example, I can get a solid lock while walking if I hold on to my shirt with my band arm (effectively immobilizing that arm as if it were in a sling).

 

[Nate Silver]

I've had very good results with running, hiking, walking outdoors, cycling, even strength training (except push-ups, which not surprisingly always seem to throw it off a bit). The worst problem for me has been treadmill walking. It usually takes several minutes of moving the band around, fiddling between loose and tight etc., before it will begin to catch up with what my chest strap is reading. Then periodically through the activity, it'll start to drop down into the 80 to 90 range, while the strap continues to show high 120's to low 130's. Then I have to fiddle with it again until it starts to behave. Doesn't seem to be any consistency as to what will work. One time its face in, another time it has to be face out. One time it has to be as tight as I can get it, another time it has to be quite loose. But this is only while walking (4.5 mph pace, 12 percent incline) on the treadmill. Its weird, and can get quite frustrating. But, it works fine for everything else, so I put up with it.