SmartScaleSync.com is a great solution if you are looking to sync Wi-Fi scale weight between various health & training platforms.
As of 2022 the platform can take weight data from one these sources:
- Garmin Connect
And sync it daily to:
- Concept 2 (Rowing platform)Fitbit (if not set as the source)
- Garmin Connect (if not set as the source)
Personally I use a Withings smart scale, synced to:
- Apple Healthkit via the Withings app
- TrainerRoad, Strava, and Garmin Connect (connected directly via SmartScaleSync.com)
- Garmin Connect then passes data on to Training Peaks
- Zwift directly via the Withings platform (you can set up this sync in the Zwift Companion App on your smartphone)
It took a few minutes to set up SmartScaleSync a few months ago and since then it has ran flawlessly, steadily checking my Withings account for new weight data and syncing it daily. It costs $15 per year but saves the fiddling and hassle of keeping the weight data updated across multiple platforms.