GPX to FIT (Garmin) converter

I recently tried to understand why a gpx file I dropped onto my garmin fenix 3 crashed. I investigated what garmin uses, when trying to navigate on a fenix 3 course.

I found out it was a .fit file that contained the data. I presume when someone drops a .gpx file in the NEWFILES folder on the device, it converts it to a .fit file, but was wondering if this had errors. I therefore created my own gpx to fit converter. I can happily say it works and have done a few routes now using the fit file instead of the gpx one.

This uses the ANT fit SDK https://www.thisisant.com/resources/fit/. I wrote this in C# using .net 4.5, I've also proudly unit tested it.

I came across someone else who sounded like they did a similar thing, but think mine looks a bit better 😆, it was useful to read though http://runningbadger.blogspot.co.uk/2015/08/a-tool-to-help-with-navigation-on.html

You can download the program here: https://drive.google.com/file/d/0B87Dcr-CTz1dZ0I3S0U2dlRqdHc/view?usp=sharing

If anyone wants to know some of the math I may be able to help having been through this already, e.g. altitude calculation or lat long to semicircle values. which is what the fit file requires.