Heart Rate Monitor - Thoughts on Accuracy?

Discussion in 'Apple Watch' started by Docsteel, May 6, 2015.

  1. Docsteel macrumors member

    Apr 29, 2015
    Been doing some reading and apparently at least among aficionados of devices monitoring heart beat rates the wrist is considered pretty poor compared to say a chest strap.

    I have been watching my heart rate because ironically I have recently had problems with a racing heart (I hope just due to stress at work). Curious if anyone has read a comparo or knows of one on the ability of the Watch to get an accurate reading, and what the limits are.

    My impression is: it's fairly accurate for most people for resting rates and light activity, less so the more intense and irregular the activity is.

  2. NavySEAL6 macrumors 6502a

    Dec 13, 2006
    I wouldn't doubt a chest strap is better but I think the watch is fairly accurate

    When working out on the nice precor machines at the gym those heart rates matched my watch so I feel it's pretty on point
  3. e²Studios macrumors 68020


    Apr 12, 2005
    My resting is 48-52 its been spot on for my resting HR. I haven't really done much activity with it but if it works like the MIO Link Optical HRM I run with I would bet its fairly accurate. With running sometimes sweat and moving around can get false reports, I see that with my Mio but it sure beats wearing a strap around your chest!

    Attached Files:

  4. Denmac1, May 6, 2015
    Last edited: May 6, 2015

    Denmac1 macrumors 6502a


    Apr 22, 2007
    Lost in Space
    I had an issue some time back with an irregular heartbeat and the situation required hospitalization. (won't go into details). Have used a finger pulse oxymeter to monitor my heart rate and I have found that now, the watch reading that also sends to my Health app on my phone gives me the opportunity to keep a constant watch (no pun intended) on my HR. I find it to be almost spot on with my other device and I don't have to be concerned with carrying the other device or check it frequently.
  5. furam90 macrumors regular

    Jun 15, 2010
    Not the best. Mine seems to have an issue where it halves my heart rate sometimes when resting, but mostly when exercising. For example if I have a heart rate of 130 during a jog, it'll show up as 65. Pretty annoying... and yeah its as tight as can be.
  6. MartyCan macrumors 65816


    Oct 31, 2012
    Near Toronto, ON
    I've had very comparable numbers from the watch and various different gym equipment so far.
  7. FrankieG889D macrumors member

    Jun 21, 2009
    I honestly think its horrible. I have a Microsoft Band (got it in December) which i haven't used since my 38mm Apple Watch came in and my typical 700-900 calories per hour with the Microsoft Band is now a 300-500 in that same hour with my Apple Watch.
  8. rhyme macrumors regular


    Sep 22, 2013
    I've tested my watch against my Garmin chest strap and it constently agrees to within a few beats.
  9. MartyCan macrumors 65816


    Oct 31, 2012
    Near Toronto, ON
    Different apps tell different stories to stroke your ego. Even in iOS i had conflicting results. Why? Because some apps reprt total calories but other reprt incremental calories.

    Apple Watch clearly reports exercise only calories (or incremental). The extra you burn versus laying on the sofa.

    Wahoo Fitness records total calories. I ride my bike a few hours and burn 1500 or so according to that app. Then I upload the results to Strava and it says 900 for the same workout. Total vs. incremental.

    Leave it to MickeySoft to exagerate your results.
  10. rhyme macrumors regular


    Sep 22, 2013
    How do they compare wrt actual heart beats? If it's that different, I suspect they are using different formulae to estimate calories burned from heart-beat and whatever other info they have about you and your movements.
  11. The Tuck macrumors 6502

    The Tuck

    Jun 8, 2003
    The Microsoft Band may be incorporating resting calories as well as active calories. It appears that the Apple Watch ONLY calculates active calories through movement.

  12. FrankieG889D macrumors member

    Jun 21, 2009
    I'm not sure what you mean by this...I'm saying that the same workout that i would do with the Microsoft Band yields 50% more calories than on the Apple Watch, something is not right and it's the Apple Watch.

    I mainly do heart-rate excersizes, and am usually drenched from sweat by the first 10 minutes being there until i leave.

    The Microsoft Band has it right, and thinking back I had the Under Armor chest strap that was much closer to the calories burned and heart-rates in line with the Microsoft Band

    Maybe mine is defective?
  13. Knowimagination macrumors 68000


    Apr 6, 2010
    Part of the problem is that to some extent the accuracy depends on the placement on your wrist, from what I can tell from reviews it is more accurate the higher up your wrist you wear it. Get closer to your hand and it becomes more prone to make mistakes apparently.
  14. Armen macrumors 604


    Apr 30, 2013

    Consumer Reports tested the HR monitor against a Polar chest strap.
  15. MartyCan macrumors 65816


    Oct 31, 2012
    Near Toronto, ON
    Your body burns around 2200 calories a day breathing and keeping your heart beating. Adding exercise increases that.

    The 2200 calories are the "base" calories. You don't even need to get out of bed.

    The incremental calories are the extra calories you burn from activity. The Apple watch measures your target calories S the ones when your HR is in an exercise zone. It only reports the diference between resting and active or in another word the "incremental". Not all apps/devicea do that. Some of them decided to tell you how great you were doing and tell you total calories.

    It even happens within iOS apps as I said.
  16. bjdraw macrumors 6502a

    Jan 24, 2008
    Tampa FL
    I love this topic so much, it is definitely worth the 5 thread dedicated to the same thing.


    I'll summarize them for you.
    The heart rate monitor can be very accurate if worn tight enough on the right part of your wrist without tattoos, etc, in the way.

    You may want to pair a different BT HR monitor to your Watch to save battery, sample more frequently (the AW only samples every 5 seconds when the workout app is running, vs every second like other BT HR monitors) or to work around the problems described above.

    PS, the authority on fitness gadgets (dcrainmaker.com) has yet to publish his review of the Watch, but he has published very positive reviews of other wrist based optical BT HR monitors, like the Mio Link.
  17. AtheistP3ace macrumors 6502a


    Sep 17, 2014
    Pretty accurate for me so far. except one time it told me 33 which seemed really low. lol. But that was only time I saw anything that seemed off.
  18. BD1 macrumors 6502

    Jun 27, 2007

    The forum could use a sticky/faq or even a sub forum on workout/activity/and HRM.

    And for me, very accurate compared to chest rate strap running, biking, and indoor cardio. Better than I expected.
  19. gCloud macrumors 6502a

    Mar 9, 2012
    United Federation of Planets
    I used to do an hour workout to burn 800 calories, with apple watch i am now doing 80 mins to hit my 800 target. Been 20 mins late for work everyday since i got the watch #, feel fitter thou.
  20. ipaine macrumors member

    Apr 21, 2015
    The heart on the Apple Watch Heart Rate Glance pulses in line with its heart rate reading for you at that point in time. I've tested this against my own pulse (not by comparing it to a heart rate strap, but by simply checking my pulse on my wrist or neck) and my pulse corresponds exactly with the Apple Watch in most circumstances, and in those circumstances where it doesn't, it catches up a second or two later. Very impressed.
  21. gdeputy macrumors 6502a


    Jul 23, 2008
    New York
    Consumer reports was very pleased with it's performance when comparing it to a chest strap. (the leading chest strap)
  22. tivoboy macrumors 68040

    May 15, 2005

    I find it quite accurate, comparing within a couple of beats to a polar fitness band, my forerunner HR strap and the polar equipped machines at the gym.

    I will say that one DOES have to use the HR GLANCE to get the best readings since within the workout app, I don't find THAT reading to be as real-time or accurate. I think it is doing some form of "recent" analysis or average and not all the time doing the current MAX.

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