Accuracy of GPS tracked runs

[ao1]

I occasionally do a 5k Parkrun, which is event timed. The GPS tracked time on my watch is always longer than the event time, but the distance is correct on the both. As an example my last Parkrun time was 23.26. Ionic recorded it as 23.53. The Ionic consistently has slower times. Question is which one is right. Parkrun is stopwatch timed so it's hard to see how it could consistently be wrong.

[JohnnyRow]

Are you manually starting and stopping the run from your Ionic, or having it auto-recognize the run?  If letting it take care of it all by itself, I suspect it is not detecting the end of the race, perhaps including just walking around for a few seconds after the finish line.

If this is the case, I recommend using the exercise app to manually start and stop it.  See: How do I track my workouts with my Fitbit device?

[ao1]

Thanks for the reply. I've tried auto track and manual and both come back slower than the event time, although manual is closer. I'll try a stop watch next run to see how the time compares with Ionic.

[ao1]

Hmmm, so splits come out on an untimed event as: 4.27 4.41 4.51 4.48 4.48 Plus 4.17 for 0.04 km. Pace total for the 5k comes to 23.35 plus the 4.17 pace for 0.4km. The map summary page states 23.48 I'm struggling to see how that can add up. Timed event at 23.26 4.32 4.46 4.35 4.53 4.59 Plus 13.31 for 0.01km. Pace total for 5k = 23.45 plus 13.31 pace for 0.1km. The map summary page states 23.53.

[sfringer]

While the map may show the proper course; the distance reported by the Ionic is not strictly the GPS calculated distance, but a combination of stride-length x cadence. So, it tends to fluctuate across runs for even the same route.