Authorizing API access will allow third parties to pull your full activity data. This includes data within any portions of the map you have hidden using your privacy controls.
View certain data about your profile will allow the app to view:
Name
Athlete ID
Segment leaderboards visible to Everyone
Public routes
Gear
Clubs you belong to
View your complete profile will allow the app to read all profile information even if the user has set their profile visibility to Followers or Only You, including:
Location
Gender
Weight
Functional Threshold Power (FTP)
View your private non-activity data such as segments and routes will allow the app to view private non-activity data:
Routes
Segments
Edit certain data on your profile will allow the app to upload and modify:
Weight (e.g., from a smart scale)
Functional Threshold Power (FTP)
Star or unstar segments on your behalf
Viewing data about your activities will allow the app to read your activity data for activities that are visible to Everyone and Followers. In addition, this will include access to data within any hidden portions of the map on those activities.
Viewing data about your private activities will allow the app to read all of your activity details, including activities set to Only You visibility. This will include access to data within any hidden portions of the map on those activities.
Upload your activities from the app to Strava will allow the app to create manual activities and uploads, and access to edit any activities that are visible to the app, based on activity read access level.