Switching from Strava to HealthFit as sync source — how to avoid duplicates with historical import?

1

Hi,

I’m currently syncing all my Apple Watch workouts via
Apple Watch → Strava → intervals.icu.

I want to switch to Apple Watch → HealthFit → intervals.icu
for two reasons:

  1. Strava doesn’t transfer complete swim data (missing SWOLF,
    stroke rate etc.)
  2. HealthFit activities get proper i-prefix IDs in intervals.icu,
    which works better with API/MCP access

I have workout history since 2023 in Apple Health that I’d like
to import fully via HealthFit.

My concern: I don’t want to create duplicates for activities
that are already in intervals.icu via Strava.

My questions:

  • Does intervals.icu detect duplicates automatically when the
    same activity comes in from a different source?
  • What is the recommended order of steps for this switch?
  • Should I disable Strava first before starting the HealthFit
    historical sync?
  • Are there any known issues with this migration path?

Thanks in advance!