Events in an interactive application (e.g., a location-based parallel reality game) are triggered by a user's real-world activity meeting one or more criteria. A background process executing on the user's client device periodically extracts activity data from an activity monitoring application (e.g., a fitness application) and provides it to a server hosting the interactive application. The server determines whether received activity data triggers an event and, if so, sends a notification of the event to the client device.