Inconsistent Vivofit Heart Rate Monitor Readings?

Amedee17

Hi,
Has anyone noticed that their Vivofit doesn't always show an accurate heart rate measurement when they are exercising?

I have tried adjusting the wristband on mine, making sure that I have "run", "cardio", or "other" going, and that I have the latest updates, and yet the heart rate is sometimes off by at least 20-30 beats (showing 80 instead of 100-110). It sometimes even drops to 60 when I am working hard and another monitor shows my heart rate around 130.

Any ideas?
Thanks

VintageFeline

Is this a wrist read HRM in the watch itself? If so, they are known not to be accurate.

CincyNeid

VintageFeline wrote: »

Is this a wrist read HRM in the watch itself? If so, they are known not to be accurate.

I tested mine when I bought it against a chest mounted Wahoo Tickr Run. And I found it off to be a beat or two. Not 20-30. Running, Cycling, Stair machine and general walking. Warm-Up, Cool Down, and during the exercise. I know people and results will vary but I found it to be fairly accurate.

To the OP, are you wearing on your wrist at the joint or just above the ulna like the manual suggest? If you're flexing your wrist, and it's on your wrist... that will throw off the readings.

MeanderingMammal

VintageFeline wrote: »

Is this a wrist read HRM in the watch itself? If so, they are known not to be accurate.

It's fair to say that received wisdom is that they're not accurate in comparison to electrical measurement at the sternum. Usually repeated uncritically without any depth.

In practice the difference in HR measurement accuracy is negligible for most people. Where optical measurement isn't reliable is informing the high end devices that measure recovery periods and advanced performance metrics.

fwiw I've found my VivoSmart HR to be pretty reasonable, but there is a bit of a lag on the display. When I broadcast the HR data to my ForeRunner or Edge and analyse it, I wouldn't consider it as significantly worse than the strap.

If someone was training based on HR I'd agree that a chest strap and sophisticated head end would be needed, but for most people the opticals do the trick.

For the originator of the thread, take a look at the data after the fact in Connect and see if you still think it's wrong. There are a couple of points to look at, sample rates and refresh rates on the display. The Garmin devices do have a reasonably low sample rate, which offsets against battery endurance but I'd be surprised if that makes a material difference to your outcomes.

kendahlj

I have the vivosmart and every once in awhile it won't read my heart rate accurately during an exercise. I haven't been able to figure out why...

dewd2

MeanderingMammal wrote: »

It's fair to say that received wisdom is that they're not accurate in comparison to electrical measurement at the sternum. Usually repeated uncritically without any depth.

It really depends on the wearer. Overall it is correct to say these are not as accurate. For some folks the are really off. Add the aggravation of having to get it 'just right' on your wrist to make it work and I am not interested. YMMV

http://www.wareable.com/fitness-trackers/heart-rate-monitor-accurate-comparison-wrist

http://www.wareable.com/sport/optical-heart-rate-tech-the-experts-speak-9763

MeanderingMammal

dewd2 wrote: »

It really depends on the wearer.

Indeed, skin pigmentation, arm hair, excessive fat or minimal soft tissue will all affect it.

Overall it is correct to say these are not as accurate.

I think we get into the materiality of not as accurate, and whether that's actually important or not. It's fair to say that the GPS on my road bike is not as accurate as the speed sensor, but whether it really matters or not is the key. For road performance training, it is important but for the commute, not so much. For HRM it's the same. For a performance training session I'll use a chest strap, for the commute I'll put the Vivosmart into broadcast mode.

For you and me, as runners, the distinction is useful and we'll make a judgement, when many people on the boards are looking for an HRM to guestimate a calorie count using an aerobic DVD, or a HIIT session, it doesn't really matter that a chest strap is more accurate as the accuracy of the input is irrelevant to the random numbers that'll come out at the end.

I'd add that not all optical monitors have the same level of error. The Schoche devices rival direct electrical measurement, and the FitBit devices seem to land at the other end of the scale.

From a practical perspective, the scarring across my chest from my strap does tend to discourage me from wearing it, so what I'd say is that I'm more consistently collecting HR data now, and I don't have blood on most of my shirts from having an open wound most of the time.