2515 Garmin track log file Text (Structured) Gmn files are used within Garmin Forerunner watches, which track GPS and heart rate data when work by the user during exercise. Gmn files store data relating to the exercise session, which can include heart rate, altitude, timestamp and position (latitude and longitude). 1 Digital Preservation Department / The National Archives 28 Apr 2022 28 Apr 2022 fmt/1679 PUID gmn File extension 2012 Garmin track log file BOF Absolute from beginning of file, magic bytes: <@gArMiN@> 1 Absolute from BOF 0 0 3C406741724D694E403E