Samsung's Health app will no longer support older Galaxy smartphones
SamMobile, starting March 23, Samsung Health will no longer be available on Android OS 7.0 Nougat or lower. Those who own old Galaxy phones and tablets will have to upgrade to a new version of Android to keep using Samsung Health or switch to a newer phone.
Bear in mind though that even if you have an old Galaxy device and you're not willing to upgrade to a newer one for just one app, you will still be able to use Samsung Health, it's just that you “will only be able to use limited services and features without further support.”
Samsung also advises Health users to backup their data regularly to prevent any data loss. Of course, it's the data related to the Health app that Samsung is referring to, not your data stored on the phone.