Open a pool-swimming .fit file — lengths, strokes and SWOLF
A pool swim is the one activity where the .fit file has never seen a satellite, and where a single setting decides whether the distance is right.
Open your file
Drop your file here
a .fit file from a watch or bike computer
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Distance is lengths times your pool setting
Underwater GPS is impossible, so the watch counts lengths from the pause-and-push rhythm of your turns and multiplies by the pool length you configured. Set the pool length wrong and every distance is wrong by the same ratio; miss a turn — a long glide, a one-armed length — and the count is off by one. So a pool distance that looks incorrect is almost always the setting or a detection miss, a completely different diagnosis from an open-water or cycling GPS problem.
Stroke type and SWOLF, per length
A pool file records more than distance: it classifies each length’s stroke (freestyle, breaststroke, and so on), counts strokes per length, and often stores SWOLF — a swimming-efficiency figure that adds your strokes and your seconds for a length. These are per-length fields in the file, and they are where a swim’s technique story lives, but a generic viewer collapses them to a single distance.
What you get from this page
This page reads your pool file on your device, shows the configured pool length the distance depends on, and lists the per-length stroke and SWOLF fields — so you can see why a distance is off and what technique data the file actually holds.
In the corpus this tool is tested against, 129 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.