There is no need to start and stop the app between the races. The app operates in “set-it-and-forget-it” mode. You have much more important things to do on the race than think about the phone app. As you got the full track from the race you can segment it in your journal. The segmentation is optional and the course set up will work without it.
Here is the video tutorial on segmentation: https://www.youtube.com/watch?v=aTBJgcjFN3k
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