When using the Strava and Apple Health integration, some Strava activity data is syncing twice in Apple Health. Troubleshooting this problem is difficult and hard to reproduce. Fixing the Strava and Apple Health integration is planned for 2018. In the meantime, below are steps that may temporarily resolve the duplicates:
- In Health, turn off all sources for each of the data types (Active Calories, Cycling Distance, Walking + Running Distance, Workouts). Close the Health app and the Strava app.
- Start the Health app again and turn all Strava sources back on, including the Workouts option.
- Open the Strava app, go to the "You" feed and pull down to refresh. Then scroll down through that feed to view past activities. This allows your data to be pulled from Strava and passed to the Health app.
- If that doesn't work, delete and reinstall the Strava app (when prompted to remove Health-related data, say yes). Go to settings after reinstalling Strava and enable Health sharing.