| Lap time |
Accuracy required to within ±2 seconds to monitor trends over time. A variance of 2 seconds over a lap time of 30 seconds equates to a 6.7% error. |
Accuracy required to within ±0.3 seconds in order to be comparable with a stopwatch (current standard) |
| Stroke count |
Accuracy within ±2 strokes sufficient to monitor trends over time |
Accuracy required to lesson more than ±1 stroke per lap |
| Swim distance |
Key determinant of training progression, accuracy required to within ±5% of actual (i.e. no more than 2 missed/additional laps included per 1,000 m completed in a 25 m pool) |
Not applicable to user, training distances pre-prescribed and monitored by coach |
| Swim speed |
Not applicable to user, lap times provide a sufficient metric |
Accuracy within ±0.01 m/s required to relate to required lap time accuracy and also to compare with other reported methods. More concerned with instantaneous speed or speed during different race segments |
| Stroke rate |
Not applicable to user, stroke counts provide a sufficient metric |
Accuracy within ±5% adequate (i.e. ±2 str/min).More concerned with instantaneous stroke rate or stroke rate during different race segments |
| Stroke length |
Accuracy within ±0.2 m sufficient and related to accuracy of stroke count measure |
Accuracy close to 100% required (i.e. errors of no more than 0.1 m) and related to stroke rate measure. More concerned with stroke length during different race segments |
| Stroke identification |
100% accuracy required as errors will be very apparent |
100% accuracy required as errors will be very apparent |
