Hi
Health data (including Activity app data) can be exported from the Health app on your iPhone in the form of XML files, which are perhaps most useful when importing and exporting data between apps (a health record received as an XML file can be imported into the Health app, for example).
You may find it more convenient to use a third-party app to access, analyse and export Health data to a computer in a more user-friendly format.
For example:
QS Access
- "Access your data from HealthKit in a table so you can explore it using Numbers, Excel, R, or any other CSV compatible tool."
- https://itunes.apple.com/gb/app/qs-access/id920297614?mt=8
SpectaRun Workouts
- "Visualize running, cycling, swimming or walking workouts from your Apple Watch".
- https://itunes.apple.com/gb/app/spectarun-workouts/id991723862?mt=8
Check the descriptions and support resources for third-party apps for details of any supported data import / export and analysis features.