Distance shorter when using watches GPS?

[dj1891]

So this is interesting. The Series 7 uses the phones GPS when you've the phone with you, I usually have phone with me so its never an issue, It matches pretty much identical to my Garmin FR 255 which is a multiband watch, so 5.00k on the Garmin, 5.01K on Apple watch, no problem.

Now leave the phone at home so its using the watch GPS. the same 5.00k run on Garmin comes in at 4.71K on the Apple watch. Even the GPS tracks and everything aren't great, corners are cut short.

Any ideas why this happens?

 

[BlackBun]

Interesting. I had this issue with my 6 but the 7 & 8 have been superb recording every tiny deviation in my run eg roundabouts or running a few metres more if traffic prevents me crossing a road straight away as I don’t want to stop running.
What I do have issues with: always and only the first mile can become in essence 1.1 or even 1.2 miles if a) I use the 3 second run count down time or b) if I haven’t run a particular route for a few weeks. The big problem then is my data giving me excessive time for a mile run.