As part of a broader move towards self-hosting my personal data, I've recently switched all my fitness applications to free and open-source alternatives. In doing so this has offered far more control over how I view and process my fitness data along with offering certainty it isn't being mined without my knowledge/consent.
Strava is one of the few services to offer built-in export functionality, as such I'll link to their guide on how to retrieve your data.
For services that do not offer export options, like Nike Run Club, solutions do exist. It is possible to retrieve your previous runs using Nike+ Exporter, a third-party tool[^1]. Once logged-in to your Nike account, you should be presented with a list of all your previous runs. From here, select the option to export in
GPX format[^2] and save it to a folder on your phone.
[^1]: As stated, this is a third-party tool that requires access to your Nike account, use at your own risk.
[^2]: In my experience
GPX seems to offer the greatest degree of interoperability between applications should you decide to make any changes in the future.
For a greater selection of open-source apps to choose from, install F-Droid - an open-source Play Store alternative.
You may be prompted to allow your browser to install applications from "unknown sources". If so, follow the on-device instructions on how to enable this. Alternatively you can find instructions here.
With you data exported, you'll now need an alternative app to track your runs. For this I'd recommend Open Tracks, it's open-source and offers much of the functionality you'd expect from an app of this kind: distance, pace, time, mapping etc.
With Open Tracks installed from F-Droid or built from source via the projects GitHub repo you can begin re-importing your previous runs. To do this, launch Open Tracks on your device and navigate to the settings menu via the 3-dot menu at the top of the app. From here, scroll to the bottom to the
Tracks section and select
Import All, specifying the folder you saved your previous run data to. After a moment, all your previous runs should be visible in app.
For additional functionality, install OSM Dashboard to display the location data from your runs.
And there you have it, you've just successfully migrated and taken control of your personal fitness data! Why not celebrate by getting out there and recording some new runs?