Connecting Strava (and other sources)
Connect Strava under Profile → Data hub → Connect with Strava. Once connected, Runsei imports your runs automatically (new activities arrive within minutes; you can also pull in your history). Every run brings its splits, route and heart rate, which feed your zones, training load and execution scores.
Apple Health and Health Connect are the other way in, in the same Data hub, and they are the only sources that also bring recovery — sleep, HRV and resting heart rate. Once connected, those arrive on their own each morning and Runsei stops asking you to type them in. If a run reached Runsei without its heart rate, open that run and either type the average or upload the original .fit or .tcx file.
Suunto connects directly too, with nothing to wait for; see Connecting Suunto. Garmin has no direct connection: Garmin's partner programme is closed to us for now. Garmin runs reach Runsei today through Apple Health or Health Connect (or Strava). COROS is waiting on COROS's approval and shows as not available in the Data hub until it is.
You can disconnect or reconnect any source at any time from the same screen — every connection is reversible in-app, and all data sources are optional.