What a FIT file is

FIT is the binary format most watches and bike computers write — Garmin, Wahoo, Coros, Suunto, Polar — and the format Strava keeps as Export Original. It holds everything the device recorded: position, time, altitude, heart rate, power, cadence, temperature, laps. It is also unreadable without a parser, which is why a FIT file opened in a text editor is noise. This page has the parser.

What you see

The route drawn as a line, plus the distance measured from the points, the moving time, the elevation gain and the point count. A `.fit.gz` from a Strava bulk export opens as it is — no need to unzip.

Save it as GPX

Under each card, Save as GPX writes a GPX 1.1 file with position, elevation and time. Heart rate, power and cadence have no standard field in GPX and are left in the FIT; if you need them, keep the FIT — the editor reads FIT directly, so nothing is lost on the way to a print. The dedicated FIT to GPX converter is the same tool with the download in front.

When there is nothing to draw

Indoor activities have time, heart rate and power but no position. The viewer tells you so rather than drawing a dot. Nothing is wrong with the file; there was no route.

Then what

Print this route opens the editor with the file already loaded. What each format carries, field by field, is in what your file carries; how to get the file out of Strava is in the Strava guides.