Open an indoor-cycling .fit file — trainer power and virtual speed
On a smart trainer the .fit file inverts the outdoor situation: the power is measured and real, and the speed is a number the software made up.
Open your file
Drop your file here
a .fit file from a watch or bike computer
No account. No upload. The file is read on this device and never leaves it.
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The speed is virtual
Indoors there is no wheel moving through space and no GPS, so an indoor-cycling file’s speed and distance are computed — a trainer or app turns your power and a rider/road model into a plausible pace. That makes indoor “distance” a function of the software’s physics, not a measurement, and comparing an hour on the trainer to an hour outdoors on speed alone is comparing a real quantity to a simulated one. Trainer platforms differ in their models, so the same watts produce different virtual distances on different apps.
The power is the real number
What is measured is power, straight from the trainer’s or a separate meter’s strain gauges, in watts. That is the field to read and to compare across your own sessions. Heart rate is real too. Everything spatial — speed, distance, elevation on a virtual course — is model output, and reading the file makes the split obvious: the trustworthy fields and the narrated ones.
What you get from this page
This page opens the file on your device, shows there is no GPS track, and lists the power and cadence the trainer wrote alongside the virtual speed — so the measured and the simulated are never mistaken for each other.
In the corpus this tool is tested against, 170 activities resolved to this sport. See the full activity-type list for every sport a .fit file can declare, and open any .fit file whatever its sport.