How do I import my activities from Samsung Health?

If you already sync your Samsung data with Strava, those activities load automatically when you sync with Strava. Support for loading past activities directly from Samsung is coming soon.

Ongoing activities: sync via Strava (you can create a free account if you don't have one). In the Strava app go to Settings → Connect an App or Device, then select Samsung. Once set up, your activities track automatically to both Strava and List Hiker.