This is a simple practice project, where I convert a .FIT file to geojson and visualize it in a webbrowser with D3.js and Leaflet.js.
I'm using Python3 to convert the .FIT file to geojson. To read the .FIT file I installed the fitparse python lib from https://github.com/dtcooper/python-fitparse - Thanks!
Having created the GeoJson file, I'm creating a map with transitions based on this tutorial: