Is it possible to export the S-Health data from a Samsung S6 into a usable data format? Is it possible to export the S-Health data from a Samsung S6 into a usable data format?

For example, to CSV or similar, so I can import into Excel
There are few ways that you can export it.
it won't work on Settings>About Device and confirm you have an SM-G900?

1:Go to developer.samsung.com/health and download the Samsung Digital Health SDK
Extract the files and read the ProgrammingGuide_SHealthService.pdf to find out how to put S Health into "Developer Mode"
From the Health Data / tools install the DataViewer-1.2.0.apk to get the data viewing app which can export to CSV.
Once its all set up reboot the phone and all exports fine.

2:You need to install dataviewer.apk to your phone and not your computer. Make sure your turn on the developer mode in S Heath. 
Go to S Health-more settings-about S health. Right above "check for updates" tap 10 times on the version. If it works then it will turn to developer
mode. 
Go to your web browser on your phone and go to developer samsung com/health and download. You will need to extract the zip file once downloaded find the dataviewer.apk and install it. Reboot your phone.

Read the programming guide because your need to turn on the permission to sync the data between the dataviewer and S Health for each item you want to view.

To Export the data, go to the main screen of dataviewer and on more is where you export the data. Once you export the data, you need to use a file manager like file commander to find the file and email it to yourself. It should be under the health data folder. It is located under storage/emulated/oN health/com.samsung.health.blood pressure.201601310420.csv for example
link to actual site.