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The altitude is not saved in the FIT file #6
Description
I have generated a route in Suunto Route Planner (https://routeplanner.suunto.com/) and downloaded it in GPX format. It contains the elevation data of the points. However, when generating the FIT file with coursepointer (https://coursepointer.app/), it no longer contains altitude data.
I am attaching both the GPX and FIT files.
Activity
mshroyer commentedon Jul 15, 2026
Sorry that I didn't make it clear, but I never got around to piping elevation through to the FIT output (even though it does get parsed from the GPX input)—I just didn't have a use case for it, since all my Garmin devices have internal elevation profiles anyway.
It wouldn't be hard to add if this would be useful, though. The main thing would be for me to test that if I add the FIT
altitudefield to my definition of therecordmessage, I can safely use the 0xFFFF uint16 value to mean "there's actually no elevation data here" without breaking stuff on devices.Out of curiosity, how are you using the elevation data in the output? To generate an on-device elevation profile?
juanfcocontreras commentedon Jul 15, 2026
It is to send the FIT file directly to the device without going through Garmin Connect. There are devices where Garmin Connect does not send the course_point to the device, but if they have them (by cable), the device can interpret them and display Turn by Turn directions. That is what I am trying to do, but I lose the elevation profile for the route, which is crucial for the training.
Merge pull request #8 from mshroyer-bot/fit-record-altitude
mshroyer commentedon Aug 18, 2026
Added, but not yet in the current release. After manually testing on my devices I found they got confused if the inputs contained only partial elevation data (FIT encodes this as 0xFFFF to mean "invalid", but my Edge and Fenix misinterpreted it as a literal, super-high elevation). So elevation data will only get passed through if it's present for all the points in the input.
I used this as an excuse to see how well Claude could handle opening and responding to comments on a PR
juanfcocontreras commentedon Aug 18, 2026
Thank you very much, as soon as I can try it, I'll let you know!