I’ve been frustrated for a while because Garmin’s biometrics are great, but their strength tracking is essentially useless for detail. Hevy is perfect for logging, but the two just don't talk to each other.
I spent the last few weeks building StrengthSync. It’s a local web app that stitches your Hevy data into your Garmin files so you get the best of both worlds.
It's free and open source: github.com/Exclad/StrengthSync
Why I built this:
- Actual exercise names: No more generic "Strength" logs. You see your actual sets, reps, and weights in Garmin.
- Privacy: It’s a local app. Your fitness data never leaves your computer and isn't stored on any server I own.
- Efficiency: It uses fuzzy matching. Once you map "Hevy Bench" to "Garmin Bench" once, you never have to do it again.
Features:
- Direct Zip support: You can now upload the full export Zip from Garmin without unzipping it first.
- Batch processing: You can drop a whole week's worth of activities in at once. The app will walk you through them one by one.
- Intensity Minutes: Contrary to what I thought before, my recent tests show that Intensity Minutes are actually staying intact after the merge.
- All processing is local: Your files never leave your machine. I like my privacy, and I'm sure you do too!
- History tab: Shows all your merged files, re-downloadable any time
- Saved Mappings: Sometimes, the fuzzy matching may give you a wrong mapping. You can change it and find the closest match exercise, and it will save it as your preference. Future workouts will take your preference instead of fuzzy mapping.
- Multiple OS: Works on Windows, Mac, Linux — single command to launch
- Docker: Docker support if you want it running permanently on a NAS or home server
How to use it:
- Export your Original .fit or .zip from Garmin.
- Export your Hevy data (CSV or use the API key in the app settings).
- Run the merge, delete the original activity from Garmin, and upload the new one.
Hevy API Beta: I’ve added an integration for the Hevy API. Since I don’t have a Hevy Pro subscription myself, I haven't been able to stress-test this fully. If you have a subscription and want to try it out, I’d love to hear if it works for you.
I'm just a hobbyist dev, so this is 100% free and open source. If it saves you the headache of manual data entry, that's enough for me. Happy to answer any questions or look into bugs you find.