Originally Posted by
unterhausen
FIT files are binary whereas the other formats are plain text. So editing a FIT file requires some translation out of binary. Here is a link to the fit sdk which has a document that describes the format.
https://www.thisisant.com/resources/fit/
Binary vs. text explains a lot of the size discrepancy. I'm not sure why they would prefer other, more verbose formats over FIT.
OOOPS! I quoted the wrong person on my last post. Please see my last post for my response.
I don't want to get the SDK because I'm now retired, I no longer have my language compilers on my PC and I don't want to have to write an app in order to do the conversion.