Best answer by tfarabaugh
A factory reset will not cause you to lose any data, the watch syncs when you first plug it in so everything is saved on MySports and your settings are reset afterwards. All you lose is the wheel size in cycling and turning splits on & off in running, as these are watch settings, not user settings. The history is erased from the watch but this clears itself every 10 activities anyway. The music is on a different drive that is untouched during a reset and MySports is not affected. The reset itself takes less than 5 minutes.
I hope this helped answer your question. If so, please mark it as a solution so others can look for it if they have the same question.