I have a Vivo Active 4. The exported data is not easy to work with and to chart. Do you know where to find software that will convert the VivoActive data to a CSV file. Coma Separated Values.
I presume that the files on the Garmin are standardized, <date>.FIT (in upper case). It can be exported in two formats, .gpx and .tcx.
The gpx file has a prefix that claims it is xml version 1.0 Its not a CSV and I am pretty sure Excel will not plot it.
The tcx file is also xml, but a different format. Again, not a CSV file and not directly plottable.
Both are much better than the .FIT file.
I know little about JSON but have looked at some web pages and they are not arranged to be plotted.
I need a CSV file so I can plot in Excel and configure the plot as needed. Do you know of any existing utility to convert any of the Garmin files to a CSV format?
Do you know of any existing utility to convert any of the Garmin files to a CSV format?
Fit File Repair Tool will convert the original FIT, TCX, or GPX into a .CSV file. I've used it for this purpose many times.

Another option is Garmin Online Fit Repair Tool, assuming it is working.