You might have noticed that there is a difference in the distance/elevation data while you were recording vs. once your recording is saved and the data has synced with our servers. The reason is that GPS data from your phone is notoriously noisy. We are able to do moderate filtering within the app during the recording of your activity to keep your data somewhat clean, but a good chunk of data smoothing and cleanup occurs during sync.
Once your recording is complete and you choose to save your file, it will automatically be queued up for syncing the next time you have a stable data connection. During sync, our web servers are able to smooth out the data and recompute your stats to be much more accurate.