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TxWatch

macrumors 6502
Original poster
Nov 30, 2015
439
107
Texas
As some of you may recall, I was not able to calibrate the stride length of my original Watch Sport. I tried to calibrate my Watch more than ten times over the last 11 months using each new version of WOS2. I always followed the instructions on the Apple Web site as listed below.

https://support.apple.com/en-us/HT204516

I reset the calibration data after installing the new WOS2 and then, did two calibrations runs of 60 minutes and 7 miles with my phone. However, as soon as I ran without my phone, my Watch would revert back to an "average stride" length that was much longer than mine. (i.e. I have a "shorter stride" than the average Apple was using) My Watch would record 9+ miles for every 7 mile run, so it was off by more than just a little. The total distance recorded each time was different for the same course and it seemed to be temperature related. It was so far off and inconsistent, that I could not use my Watch for anything more than a step counter and time tracker. (i.e. I ran for 60 minutes with 11,000+ steps, ran for 70 minutes, etc.)

With all of that said, I am happy to report my AW Sport SO with WOS3 is finally calibrated! I used the same technique listed above to calibrate my Watch two weeks ago and after six runs without my phone, I can say it is definitely working for my shorter stride length! :D

For my usual 7 mile runs, the Watch has been within 1/100 for each mile. On several days, it recorded the exact mileage as my Garmin Forerunner. On other days, it was off by less than 1/10 of a mile for my total run, which is well within the acceptable range of a GPS Watch.

I am debating on whether to buy the S2 Nike+ version once the hype wears off, but with the latest calibration results the urgency to have an on-board GPS has somewhat diminished. I am not getting the nice GPS maps I saw with my two calibration runs, but the distance is right on.

TxWatch
 
Last edited:

BarracksSi

Suspended
Jul 14, 2015
3,902
2,663
Good to hear. The main reason I've taken my phone on runs has been to get a good calibration for the AW. I haven't really bothered to check whether it's accurate, but at least if my wife ever gets one, it should be pretty good.
 

TxWatch

macrumors 6502
Original poster
Nov 30, 2015
439
107
Texas
Yes, if she is using WOS3, the accuracy is vastly improved after a couple of calibration runs.

TxWatch
 

TxWatch

macrumors 6502
Original poster
Nov 30, 2015
439
107
Texas
After upgrading to WOS3.1, the distance was off by more than 1/10 of a mile (.17 miles) at the end of my 7 mile run today. This is not horrible, but I will try calibrating again to see if I can get it back in sync with my stride.

TxWatch
 

TxWatch

macrumors 6502
Original poster
Nov 30, 2015
439
107
Texas
I decided NOT to calibrate the Watch again and the results have been much better. Two of my run distances since upgrading to WOS3.1 have been the exact same as my Garmin, while the third run today was only off by .08 of a mile over 7 miles. I have not been able to determine why the distance is accurate most of the time, yet off on other days, but I will keep testing to see if I can come up with an explanation. It could be the outdoor temperature or my run pace which is affecting the accuracy.

However, I can say for sure the stride length calculation survived an iOS and WOS upgrade, so a second set of calibration runs was not needed.

TxWatch
 

TxWatch

macrumors 6502
Original poster
Nov 30, 2015
439
107
Texas
I have determined the measured distance is related to my average pace. The closer I run to my calibrated pace, the more accurate the Watch records the overall distance. At first I thought it was temperature related, but since I always run faster when it is cooler, the weather is just a factor that affects my pace.

If I run slower than my calibrated pace, the distance recorded is lower and if I run faster, the distance recorded is longer for the same 7 mile course.

TxWatch
 

Julien

macrumors G4
Jun 30, 2007
11,835
5,432
Atlanta
Just a little funny side note. Yesterday I ran on the treadmill for the first time in 10 weeks (plantar fasciitis) [not the funny part] and had re-paired and lost my calibration. Oddly for the first time I got fairly accurate treadmill results.:D
 
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