The archive exported via https://www.garmin.com/en-US/account/datamanagement/exportdata/ includes some JSON files containing daily summary data, but how do you extract intraday step counts (which I believe Garmin tracks at 15 minute resolution throughout the day). There are FIT files, but parsing them even with the latest ANT SDK yields mostly "unknown" fields full of mystery numbers. Before I spend too much time trying to reverse-engineer these files, has anyone figured out how to get at that data?