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Export guides/Supported

FIT vs TCX vs GPX vs CSV

Different apps hand you different file formats. Here's what each one contains and which one Baseline reads best.

Can you export this data?

This isn't an export guide as such — it's a reference. If you have a choice of formats when exporting from Garmin or a similar app, use this page to pick the best one for Baseline.

Step-by-step

  1. 1FIT: the native binary format used by Garmin, Wahoo and most modern devices. Contains everything the device recorded — heart rate, cadence, power, laps, GPS. Baseline prefers FIT.
  2. 2TCX: an XML format Garmin used before FIT became the default. Similar coverage to FIT for training metrics, but slightly lossier and much larger on disk.
  3. 3GPX: an XML format focused on GPS routes. Contains locations and timestamps and usually little else — no cadence, no power, minimal HR. Fine for a route map, poor for fitness analysis.
  4. 4CSV: plain text with one row per data point. Concept2 exports CSV; Withings exports CSV; you can also produce CSV yourself from a spreadsheet. Baseline reads several CSV shapes.

What’s in the file

In practice: FIT and TCX are the two you'll see most often for endurance activities. CSV is the format for Concept2 rowing and for body-metric sources like Withings. GPX shows up when nothing better is available.

What Baseline does with it

Baseline reads FIT, TCX and CSV natively in the beta. GPX support is planned. When the same activity is available in multiple formats, upload FIT.

Common issues

  • Renaming a file from .fit to .tcx doesn't convert it — the format is the file's contents, not its name.
  • Some apps hand you a ZIP containing several activity files. Baseline can accept the ZIP directly.
  • A GPX from a running watch usually strips the heart-rate trace — if your app offers a FIT version, use that.

Privacy note

Whichever format you upload, Baseline treats it as private data belonging to you. We don't share your files, we don't sell them, and we don't train public AI models on them.

Frequently asked

My app only gives me GPX. Can I still use Baseline?
You can. Baseline reads GPX for basic activity summaries, but you'll get more out of the report if you can grab a FIT file instead — for example, from Garmin Connect for the same activity.
Which format contains heart rate?
FIT and TCX both do. GPX usually doesn't. CSV depends on the source — Concept2 CSV includes HR when a chest strap was paired.
Do I need to convert files before uploading?
No. Baseline auto-detects the format from the contents of the file, not the extension. Upload what you have.

Ready when your file is

Once you have your export, upload it to Baseline and get one joined-up profile across rowing, endurance and body metrics.

Instructions last reviewed against the vendor documentation on 11 August 2026. View the official documentation.