Choose two comparable workouts
Start with the same stroke, pool length and a similar training goal. Check total distance and whether length data is complete. Total time alone is not a fair comparison when distances differ.
- Check that both workouts have uploaded.
Use the same account on Android and inspect the date, distance and workout details.
- Open workout comparison and select two records.
Check which is the baseline and which is the comparison. Different training goals can explain a difference.
- Match distance before reading the detail.
Length, 100 m and 200 m views help reveal changes at different scales. Check the selected grouping and the actual distance of each segment.
Read pace alongside distance and heart rate
Pace is the time needed per 100 metres: a smaller value means faster swimming. Compare equal-distance segments to see whether a gap comes from the beginning, the finish or the whole workout.
Compare heart rate only where both records contain valid samples. Missing data is not zero. Lower heart rate or faster pace alone does not prove better technique or support a health conclusion.
Workout elapsed time and recorded length durations may use different timing scopes. Do not compare one record’s elapsed time including rests with another record’s swimming time, or assume all rest is automatically removed.
A 400-metre worked example
These are hypothetical teaching values, not a user’s workout or the data in the screenshots. Each segment is 100 metres. The table uses the recorded segment durations only, without adding rest between segments.
| Segment | Workout A | Workout B | B time change |
|---|---|---|---|
| First 100 m | 2:20 | 2:15 | 5 s less |
| Second 100 m | 2:22 | 2:18 | 4 s less |
| Third 100 m | 2:28 | 2:25 | 3 s less |
| Fourth 100 m | 2:30 | 2:30 | Unchanged |
| 400 m total | 9:40 | 9:28 | 12 s less |
| Pace per 100 m | 2:25 | 2:22 | 3 s less |
B gains time over the first 300 metres; the last 100 metres is unchanged. A faster total does not mean every segment was faster. Overall pace is total duration ÷ total distance × 100; do not take an unweighted average of segment paces when distances differ.
Where did the 12 seconds come from?
- Compare two swims over the same distance. Use the same timing basis for both, especially when rest is included.
- Subtract B’s time from A’s for each matching segment. Here B gains 5, 4, 3 and 0 seconds, so the largest gain comes in the first 100 metres.
- Add the gains as you go. B leads by 5, 9, 12 and 12 seconds at the four checkpoints. The final 100 metres keeps the gap steady.
Each segment in this example covers 100 metres. To find the difference on a particular pool length, compare the recorded lengths at that point.
How to read the two-lane replay
The replay turns recorded length data into simulated pool progress for two workouts. Observe where a lead appears or narrows. Play, pause or drag the progress slider to inspect a moment, then check it against the recorded segments.
The swimmers and movements illustrate progress, not your recorded body position or stroke mechanics. Do not treat the on-screen gap as a precise distance measurement.
Check the source when data is incomplete
- Different workout distances: find comparable distances and segments first.
- Different strokes or pool lengths: a length may represent different distances or conditions.
- Missing length or heart-rate data: check the original workout and permissions; do not fill gaps with zeros.
- A workout has not appeared: check Watch upload completion, the Android account and refresh state.
See the setup and upload guide or help and troubleshooting.
Choose a workflow and check test scope
Compare three viewing workflows · Device test dates and limits · Interface walkthrough