It depends on what you want. Apple's workout data is pretty much kept in Apple's walled garden. There are limited, unsupported methods of exporting portions of the data, but no way to export all of it. Third party apps will keep your data in their systems, which may be much more flexible, and allow you to export it in standard, supported ways to other sites like Strava or Training Peaks or just download it for your own keeping. There are not any 3rd party apps to my knowledge that can use the watch's GPS at this point, however.