packages = [] [[fetch]] files = ["core.py", "app.py"]

Triathlon Activity Merger

Many watches and fitness trackers don’t let you record a full Triathlon (Swim → Bike → Run) as a single activity. Instead, they save each leg separately. This tool merges those files back into one clean multi-sport activity that Strava and Garmin will recognize.

✅ Runs entirely in your browser — data never leaves your computer.
✅ Free to use

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1. Download activity files

Export your individual Swim, Bike, and Run sessions from Strava, Garmin, etc. as .GPX, .FIT, or .TCX files.

2. Convert FIT → TCX (if needed)

If your files are in .FIT format, convert them first: Sport Calculator: FIT to TCX Converter

3. Choose your activity files

4. Scan & review activities

5. Choose options

Infer missing transitions If you don’t upload separate T1/T2 files, the app will calculate transition times from gaps between swim → bike and bike → run.

Compact timeline (back-to-back) Shifts all activities to run consecutively (no real-world gaps), but keeps transition durations. Useful if you want a clean continuous session in Strava.

Swim distance (m) Only needed if your swim file has no GPS points (e.g. pool swim recorded without a watch track). Leave blank if the swim file already contains GPS or distance data.