What does a Garmin export bring in?

A great deal. Alongside weight, HRV, sleep and resting heart rate, a Garmin export brings in:

• your activities, with per-activity training effect, training load, VO2max and running dynamics (ground contact, vertical oscillation, stride, power);
• daily wellness: steps, stress, body battery, SpO2, respiration, intensity minutes, floors, calories and sleep stages, plus all-day heart rate read from the export's monitoring files;
• higher-level metrics like endurance score, fitness age and race predictions;
• your personal records, which show on your profile.

If the export includes detailed FIT activity files, those become interactive route maps with elevation and pace charts and lap splits on the activity detail page. Imported activities are matched against what is already synced from Strava, so the same workout does not show up twice; Garmin-only running dynamics attach to the matching Strava run.