Why is pace showing wrong number in the dashboard?

[rogerganga]

I went for a run today. My avg pace is 8'22".

But if you look at the chart above. Although the y axis is showing the pace is in between range of 1'53" - 10'15", it shows an actual value of 36'26".

How could this be? Am I reading something wrong?

Am pretty sure I did not run at this pace.

[charleskn]

I see the same thing from time to time, and I believe it's just a glitch in the GPS data. My guess is that the GPS briefly lost sync. If your watches loses sync for too long, it stops trying to re-connect.

[t.parker]

@charleskn it may be the case but the resolution of the chart in the Dashboard makes it totally useless. No zooming and panning so no way to change the granularity of data.

@rogergangawwhen you see this weird pace look at the map and see whether you can see the location or endpoint. If you see the endpoint of your run on the map then you have lost GPS. You can switch to duration mode (little grey clock icon, right-hand side of bottom of the map) then scroll through the chart and find the same point (by looking at a distance). I usually see pace -:-- in the duration view but the valid pace in the distance view (which makes no sense but hey, what makes any sense here). Not sure if my explanation is clear so here's a visual help:

In general, Dashboard is incredibly poor as a tool for run analysis (not to say one of the worst I've ever seen) and I recommend exporting your runs to third-party services providing much better insight into your data (like TrainingPeaks).

[charleskn]

You learn something new everyday. I never noticed the GPS/duration mode for the display, before.

Yes, if GPS is totally lost, the endpoint is your map/route indication, but sometimes I find the GPS glitches briefly, and then quickly syncs back up (I see this on my Fitbit and my Polar monitor using my phone's GPS). In my screenshot, the first mark is, I believe, a GPS glitch. The second is where I stopped to tie my shoe. The third is where I slowed down to walk, for a minute, due to AFib. In the second screen shot (from Strava), you can see where I slowed down, but it doesn't even show where I stopped to tie my shoe.

[t.parker]

@charleskn it's very rarely a GPS glitch because Fitbit uses sensors to compute pace and that pace and distance. It may use GPS to correct it (maybe it does, I know Garmin and Polar do such real-time correction, Fitbit is quiet about methodology and algorithms) but mainly it uses an accelerometer (and maybe gyro on devices that use it, again - not enough data). The pace may drop like that for several reasons (for example when you do a sharp turn). If you look into the TCX file, the distance tag is independent of the GPS data. Since the sensors are on the wrist then any unusual motion of the wrist will affect the sensor data and may confuse it. However, relying only on the GPS would result in a very erratic pace. Without better data analysis it's hard to tell what could cause the first drop but if you could get the TCX exported, upload it to better software than Fitbit's Dashboard you could probably figure out what really happened 🙂 In the case of @rogerganga notice that there is no drop on the chart at all yet the value is kind of crazy. Again, without actual TCX I can be only guessing 🙂 Anyway, Dashboard doesn't seem to receive any attention anymore (all new features go into the app, Dashboard bugs are not getting fixed, no new features added for ages and it still requires Flash in one place!) so I wouldn't bother using it for any kind of analysis.