Your Fitbit fitness tracker might be lying to you • Hacker News Board

Re: Your Fitbit fitness tracker might be lying to you

#31

Post by rconti » Fri, Jan 08, 2016, 2:19 PM UTC

zimpenfish wrote: post #2

(The HN title has "might be" where the page currently has "is".) > However Teresa Black, along with two other claimants, is arguing that her Fitbit reported a heart-rate of 82 bpm while her personal trainer recorded this at 160 bpm. I find it somewhat hard to believe that you can be this oblivious as to your own heart rate, especially at high levels. [Edit for personal anecdata] Also "approaching the maximum recommen…

Yup. It's total crap. You're not going to push your heart rate so high you damage yourself, at least not a normal/sane person. If it was a serious risk, we'd all be wearing heart rate straps 24x7 with alarms sent to remind us to sit down when our HR gets into dangerous territory.

I have a Suunto Ambit (GPS, HR strap, altimeter, barometer, etc) and a Fitbit Surge HR I got for Christmas. Sometimes both work, sometimes neither works. You use it for what it is. Typically when they both get a good signal, they're reporting the same figures.

Let me guess, the claimant wasn't wearing the Fitbit the recommended 2-3" above her wrist bone at the time.

Re: Your Fitbit fitness tracker might be lying to you

#32

Post by rconti » Fri, Jan 08, 2016, 2:22 PM UTC

simi_ wrote: post #12

I had a Charge HR for almost a month, got one for my wife too. I finally returned them this week. They're nice to wear and pleasant to use, but the battery lasts one day and the reported steps/calories/distance is basically science fiction.

The reported distance is basically fiction, of course. It's not a GPS device. It's an estimate based on how many steps it thinks you took, and the average distance an average person goes in that number of steps.

As far as I can tell, steps/calories is roughly accurate (eg, not off by much more than, say, 10%) compared with other devices (my chest strap HRM+GPS device, stationary trainers, bicycle computer). Close enough for consumer use.

I echo the poor battery life. I forget what it's rated at, but I get barely 3 days. My old Nike Fuelband was rated at 7 days but I could push it over 2 weeks.

Re: Your Fitbit fitness tracker might be lying to you

#33

Post by iaskwhy » Fri, Jan 08, 2016, 2:26 PM UTC

lmm wrote: post #7

zimpenfish wrote: post #2

(The HN title has "might be" where the page currently has "is".) > However Teresa Black, along with two other claimants, is arguing that her Fitbit reported a heart-rate of 82 bpm while her personal trainer recorded this at 160 bpm. I find it somewhat hard to believe that you can be this oblivious as to your own heart rate, especially at high levels. [Edit for personal anecdata] Also "approaching the maximum recommen…

> Also "approaching the maximum recommended heart rate for her age [...] may well have exceeded it, thereby jeopardizing her health and safety" seems a bit far-fetched - I'm not a small fellow by any means and I struggle to get my heart rate up to my max (~180bpm), much less over it[1]. Hmm. I'm pretty overweight and can easily go over 180bpm if I'm not watching myself on the treadmill - 5 minutes at 10-11kph will do…

I'm not that overweight (around 77kg for 1.81m). Last week I went for a trial at a gym and tried a treadmill for the first time in my life, I got to 180bpm in around 30secs at 5kph. I don't do much exercise besides walking 5 to 10km almost everyday and the rare (and slow) 10mins run. The bpm were measured by the treadmill itself, not sure how accurate that is.

Re: Your Fitbit fitness tracker might be lying to you

#34

Post by shallowpedantic » Fri, Jan 08, 2016, 2:50 PM UTC

not might be, is. example, walked from my job to the downtown mall. my note 4 said I only walked 3500 steps, yet somehow my fit bit said I walked somewhere in the neighborhood of 6000.

Re: Your Fitbit fitness tracker might be lying to you

#35

Post by zimpenfish » Fri, Jan 08, 2016, 2:51 PM UTC

iaskwhy wrote: post #33

lmm wrote: post #7

Earlier quoted context omitted.

> Also "approaching the maximum recommended heart rate for her age [...] may well have exceeded it, thereby jeopardizing her health and safety" seems a bit far-fetched - I'm not a small fellow by any means and I struggle to get my heart rate up to my max (~180bpm), much less over it[1]. Hmm. I'm pretty overweight and can easily go over 180bpm if I'm not watching myself on the treadmill - 5 minutes at 10-11kph will do…

I'm not that overweight (around 77kg for 1.81m). Last week I went for a trial at a gym and tried a treadmill for the first time in my life, I got to 180bpm in around 30secs at 5kph. I don't do much exercise besides walking 5 to 10km almost everyday and the rare (and slow) 10mins run. The bpm were measured by the treadmill itself, not sure how accurate that is.

5kph is walking pace (a shade over 3mph) and I'd guess that 180bpm was inaccurate - may be a doubled 90bpm?

Anecdata: Last summer I was considerably heavier than 77kg, carrying 5kg of stuff, walking 51km in 10 (hot sunny) hours, and averaged 105bpm (max of 119bpm).

Re: Your Fitbit fitness tracker might be lying to you

#36

Post by iaskwhy » Fri, Jan 08, 2016, 3:06 PM UTC

zimpenfish wrote: post #35

iaskwhy wrote: post #33

Earlier quoted context omitted.

I'm not that overweight (around 77kg for 1.81m). Last week I went for a trial at a gym and tried a treadmill for the first time in my life, I got to 180bpm in around 30secs at 5kph. I don't do much exercise besides walking 5 to 10km almost everyday and the rare (and slow) 10mins run. The bpm were measured by the treadmill itself, not sure how accurate that is.

5kph is walking pace (a shade over 3mph) and I'd guess that 180bpm was inaccurate - may be a doubled 90bpm? Anecdata: Last summer I was considerably heavier than 77kg, carrying 5kg of stuff, walking 51km in 10 (hot sunny) hours, and averaged 105bpm (max of 119bpm).

Yeah, maybe the reading was incorrect but I do get a spike in bpms whenever I run or climb stairs. I don't get it when walking or weight training. Might need to check this with some exam...

Re: Your Fitbit fitness tracker might be lying to you

#37

Post by PaulHoule » Fri, Jan 08, 2016, 3:32 PM UTC

zimpenfish wrote: post #2

(The HN title has "might be" where the page currently has "is".) > However Teresa Black, along with two other claimants, is arguing that her Fitbit reported a heart-rate of 82 bpm while her personal trainer recorded this at 160 bpm. I find it somewhat hard to believe that you can be this oblivious as to your own heart rate, especially at high levels. [Edit for personal anecdata] Also "approaching the maximum recommen…

I think for most people your maximum heart rate is your maximum heart rate. That is, there is a certain rate you can reach and there is not any problem with that.

If there is a question about your heart you go to the cardiologist and get a stress test where you have an ECG attached and maybe also they look at your heart with ultrasound and if your are healthy nothing untoward happens.

If you are not healthy there is a risk of arrhythmia and other things that can go wrong. The risk of this is certainly higher if you are older, but young people, even teens, sometimes have sudden cardiac death under stress.

Anyway, I have seen the old electrical types of heart rate monitors do something like this, where the heart rate seems to bounce back and forth between the true rate and 1/2 the true rate and probably there are situations where the monitor picks up every other beat for some reason.

Re: Your Fitbit fitness tracker might be lying to you

#38

Post by sgdread » Fri, Jan 08, 2016, 3:37 PM UTC

equalsione wrote: post #21

A really good source of info on this is DC Rainmakers blog. His comments [1] on the lawsuit are worth reading if you're interested. In terms of heart rate accuracy, HR straps aren't always accurate either depending on placement, body and ambient temperature, moisture etc. Certain heart conditions can cause the strap (or maybe more accurately the software processing the data) to significantly underestimate heart rate…

My practical experience: optical trackers almost always lie to me when I do intervals training (though, I haven't tried expensive high-end dual-wavelength devices), while wet chest strap is pretty accurate. As instructions say: just put some water on strap and it will work.

Re: Your Fitbit fitness tracker might be lying to you

#39

Post by sgdread » Fri, Jan 08, 2016, 3:42 PM UTC

iaskwhy wrote: post #33

lmm wrote: post #7

Earlier quoted context omitted.

> Also "approaching the maximum recommended heart rate for her age [...] may well have exceeded it, thereby jeopardizing her health and safety" seems a bit far-fetched - I'm not a small fellow by any means and I struggle to get my heart rate up to my max (~180bpm), much less over it[1]. Hmm. I'm pretty overweight and can easily go over 180bpm if I'm not watching myself on the treadmill - 5 minutes at 10-11kph will do…

I'm not that overweight (around 77kg for 1.81m). Last week I went for a trial at a gym and tried a treadmill for the first time in my life, I got to 180bpm in around 30secs at 5kph. I don't do much exercise besides walking 5 to 10km almost everyday and the rare (and slow) 10mins run. The bpm were measured by the treadmill itself, not sure how accurate that is.

Threadmill lies to me pretty much all the time. In most cases it doesn't even work for me. Unless you have a medical condition, it is very unlikely that you'll get 180bpm from 5km/h walk (mine usually don't go above 150 even going uphill with 20 pounds weight vest on my shoulders). 180bpm is 3 hearbeats every second - pretty easy to check with finger on your wrist.

Re: Your Fitbit fitness tracker might be lying to you

#40

Post by sgdread » Fri, Jan 08, 2016, 4:00 PM UTC

cptskippy wrote: post #24

lmm wrote: post #7

Earlier quoted context omitted.

> Also "approaching the maximum recommended heart rate for her age [...] may well have exceeded it, thereby jeopardizing her health and safety" seems a bit far-fetched - I'm not a small fellow by any means and I struggle to get my heart rate up to my max (~180bpm), much less over it[1]. Hmm. I'm pretty overweight and can easily go over 180bpm if I'm not watching myself on the treadmill - 5 minutes at 10-11kph will do…

So how aware are you of your heart-rate? I'm keenly aware of when my heart-rate rises, I notice it jump if I sprint up a stairwell. When it gets too high I can feel the pressure in my neck and temples. I'm the most out of shape I've ever been at this point in my life and I'm alarmed sometimes at how often my heart-rate stays high after seemingly inconsequential physical exertion so I'm wondering if it's something you…

I can tell when I'm crossing 162bpm (I think it's my personal aerobic threshold). If my HR below that I'm recovering; above that - fatigue starts to build up. Also I can tell when it's above 171 - itchy feeling from lactate start to build up much faster. I did VO2 max test once and went as high as 220. It feels absolutely horrible after 190 (long-time exposure to HR at that level most likely will do permanent damage to heart).