Inadequate smoothing of GPS data

[benjamings]

Hi everyone, first message here since I got my Membership 🙂

I'm training for a marathon and noticed that Strava consistently reports better pace than my friend I'm running with who's using Nike Run. Upon closer examination we noticed that Nike applies aggressive smoothing to the GPS data, while Strava leaves lots of wiggles in. Compared to a map-based route plan the Strava distance is inflated almost 3% (!) due to the wiggles, while Nike is quite close to the theoretical map distance.

This is explained in https://support.strava.com/hc/en-us/articles/216919487-How-Distance-is-Calculated but the GPS smoothing explained there is either not working or not aggressive enough. The correct value is probably in the middle between "map" and "snake lines all the way", but as it stands, Strava is giving me a better pace than I'm actually running due to this.

My friend told me she actually left Strava due to this and honestly I'm considering the same - a 3% difference is significant when training for a competition.

What do you reckon, or have we got something backwards?

Ben

[Jan_Mantau]

If you're training for competitions you shouldn't use the Strava app for recording. That is only a crutch for starters or if you don't really care about data fields, sensors or exact measurements. And if you do it anyway a smartphone with a good gps reception and wearing it without obstructions to the sky is a must. There are a gazillion devices out there that can record better than the Strava app and can upload the activity to Strava afterwards.