Convert a JSON-file downloaded from Runtastic.com into a GPX-file

Runtastic is now owned by ADIDAS who have stoped development of the Internet version.
You are expected to download an app to your phone and use it for viewing your activity.
All functions in the retired Internet version are in the app and future features will
only be available in the app.

There is no way to extract a GPS route from runtastic.com. The only way to download
your syncronised activity is as a ZIP-file not more frequently than every 7 days.
Connect your Runtastic watch to a USB port on your computer.
Start the Runtastic Connect application which will detect the watch and
syncronise your activety with runtastic.com.

Click on the runtastic.com button in the Runtastic Connect app. and Log in.
Click on the Home tab, then Export menu and finally the Export button.
Wait for the email confirming that the ZIP-file is ready for download (This can
take a couple of minutes).

Open the mail and click on the Download button. Back on the runtastic.com page where the
download was requested the status will have changed from In progress to Not available.
Ignore the status and click on the download button.

The ZIP file will appear in your download folder and has the following contents:

Name: export-YYYYMMDD-000.zip.
Folders: Comments, Purchases, Sport-sessions, User and Weight.
The folder Sport-sessions contains:
Folders: Elevation-data, GPS-data and a number of JSON files.
The folder GPS-data contains a JSON file for each activity with names like:
e62b7556-3057-4797-9b30-ded82b558204.json.

It is the JSON files in folder GPS-data that must be converted to GPX files for interchange
with other apps. Once downloaded and converted to GPX the activity can be removed.

Date and time are converted to YY-MM-DDTHH:MM:SS with decimals and timezone dropped.
Have problems, mail me at martyn@datacompass.se and I will see what I can do.

Local input .JSON file including path:

Local ouput .GPX file including path: