GitHub - mcandocia/fit_processing: Convert Garmin FIT (or GPX) to CSV and censor files
4 Best Free FIT to GPX Converter Online Services
GitHub - MaksVasilev/fit2gpx: Converter Garmin FIT files to GPX, CVS, HR, HRV, SpO2: fit2gpx, fit2csv, fit2sqlite, fit2db. Standalone application, not a shell script to gpsbabel, redy to use (Java).