Two devices, one truth, and a lesson in trusting the run

Thursday is a double day in this phase: gym in the dark, run in the light. We’re at the gym by 5am and out by quarter to seven — back and shoulders — then a run at nine, with a banana, a slice of cheese and some pineapple bridging the gap so I’m not running on empty.

The run itself was fine. Easy effort, ran more than I walked, no drama in the legs. The drama was in the data.

My Da Fit watch said 5.35 km. Samsung Health on my phone said 3.68 km. Strava got dizzy, lost signal, and recorded essentially nothing except the fact that I ran. Nearly two kilometres of disagreement on the same run.

Which one is telling the truth?

Here’s the thing I learned: when your devices disagree on distance but agree on duration and step count, the GPS is the liar. Both said roughly forty minutes. Both counted somewhere around 5,400–5,800 steps. Those two numbers don’t depend on satellites — the steps come from the motion sensor on your wrist and in your pocket.

So I used steps as the tie-breaker. The watch’s numbers were internally consistent — its distance matched a believable running stride. The phone’s did not; its distance implied a stride far too short for running, which means it under-measured when the signal dropped.

Reconciled answer: about 5 km in 40 minutes. Logged, and moving on.

Lesson banked: pick one device, wear it every run, and trust the trend over any single day’s number.

Nothing heroic today. But a clean data habit on day one of tracking is its own kind of win — and there are 332 of these to go.