Distance way off if you walk during run

Discussion in 'Apple Watch' started by MoodyM, Jun 19, 2015.

  1. MoodyM macrumors 6502a

    MoodyM

    Joined:
    Aug 14, 2008
    #1
    This is probably a stupid question, but does it make sense that if you walk during a run without, the distance is way off? I did an Outdoor Run and ended up walking most of it because I didn't feel great. I had my phone in my pocket and the end result was 2.76 miles. I assumed this would be accurate, even though I walked, because I assumed it would use GPS.

    I did the exact same route next day, and ran the whole way. This time I didn't have my phone, but the Watch has been calibrated with the phone for several runs and walks. This time it reported 3.5 miles.

    I'm thinking maybe walking during a Run workout with phone in pocket has re-calibrated incorrectly?
     
  2. Julien, Jun 20, 2015
    Last edited: Jun 20, 2015

    Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #2
    The :apple:Watch uses an accelerometer to estimate distance. It only uses the Phones GPS to calibrate the accelerometer. Accelerometers estimate distances by stride length X cadence. When you walk your stride length is reduced by over 50% so it takes more steps (cadence) to cover the same distance. :apple:Watch is still assuming you are running and counts the 'extra' steps need as 'extra' distance traveled. Also it will be calibrating while you are walking and when you start back running the opposite will happen.

    For steady pace (stride and cadence) runners an accelerometer can be quite accurate. However in your situation it will be all over the map (literally and figuratively:)).

    I wish Apple would go with true GPS mapping (when available). Of course with wOS 2.0 you will be able to use 3ed party Apps like Nike+ that offer true GPS mapping.
     
  3. MoodyM thread starter macrumors 6502a

    MoodyM

    Joined:
    Aug 14, 2008
    #3
    Thanks, but shouldn't the distance shown when I walked during a "Run" show as MORE distance than the actual run next day, not less?
     
  4. Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #4
    Reread the 2 highlighted sentences in my previous post.
     
  5. Newtons Apple macrumors G5

    Newtons Apple

    Joined:
    Mar 12, 2014
    Location:
    Jacksonville, Florida
    #5
    I think it is crazy if you are carrying both your phone and watch and the watch does not use the phones GPS info for distance. The GPS is accurate within few feet on the phone so what is the problem with using it if it is there?
     
  6. exxxviii macrumors 65816

    exxxviii

    Joined:
    May 20, 2015
    #6
    The watch should be smart enough to recognize this and adapt. My $50 Fitbit Zip handles this correctly. Fitbit has two stride length entries: one for walking and one for running. When you run, you have a cadence in the 160 - 190 steps per minute range. Walkers have a cadence below 130 steps per minute. Fitbit looks at cadence to decide which factor to use. My zip has always been very close to my Garmin 910XT for distances.

    Your observation may reveal that the AW is not using cadence to help calibrate the stride data. So, it will always be jacked-up if you mix walking and running, which a lot of people do. If this is true, it is kind of a ridiculous fail. My hunch is that Apple will catch the clue and fix this in a future update.
     
  7. mistertomlinson macrumors 6502

    Joined:
    Dec 22, 2007
    #7
    I actually went for a run yesterday where I did entirely TOO MUCH walking and found it was more accurate. Traveled 5 miles exactly (according to trail markers) and the watch said 4.94, my most accurate reading yet (without phone).
     

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