REF-931 · Dekerle et al., 2002 · International Journal of Sports Medicine, Vol. · Paper · PubMed

Validity and Reliability of Critical Speed, Critical Stroke Rate, and Anaerobic Capacity in Relation to Front Crawl Swimming Performances

Blimited evidenceMeasured on highly trained athletesWritten before October 2026, being re-checked

The authors asked whether critical swimming speed, critical stroke rate and anaerobic swimming capacity can serve coaches as reliable indices for monitoring endurance performance in competitive swimmers.

In well-trained swimmers, the speed of a 30-min test (V30) was not different from the critical swimming speed determined from 200- and 400-m tests, although critical speed overestimated it by 3.2 %.

The number of stroke cycles plotted against time was linear for each swimmer, and the slope of that line — the critical stroke rate — matched the 30-min stroke rate after a correction of minus 3.9 %. Anaerobic swimming capacity, the y-intercept of the distance-time line, did not track a sprint-based measure and is judged not to be a reliable estimate of anaerobic capacity.

Participants

Well-trained competitive swimmers (abstract: "well-trained swimmers"); the abstract gives no sample size. MEDLINE indexing lists adolescent, male and female participants.

Protocol

Critical swimming speed and critical stroke rate determined from 200- and 400-m tests (distance on time, and number of stroke cycles on time, for each swimmer).
A 30-min test giving velocity (V30) and stroke rate (SR30) for comparison.
Anaerobic swimming capacity (ASC) = y-intercept of the distance-time regression, compared with the distance over which maximal speed dropped significantly on a 25-m test.

Key Results

V30 was not different from critical swimming speed from the 200- and 400-m tests, but was overestimated by 3.2 %.
Stroke cycles on time: linear for each swimmer (r(2) greater than 0.99 and p less than 0.01).
SR30 was not different from critical stroke rate after a correction of minus 3.9 %.
ASC was not correlated (p > 0.05) with the sprint-test distance: "ASC does not provide a reliable estimation of the anaerobic capacity".

Practical Application

In well-trained competitive swimmers, the critical swimming speed taken from a 200-m and a 400-m test was not statistically different from the speed held in a 30-min swim, but sat 3.2 % above it; the critical stroke rate from the same two tests matched the 30-min stroke rate after a correction of minus 3.9 %. To "can a 200 + 400 test really give my threshold pace?": yes as an anchor, with the caveat that it reads slightly fast against what is held for 30 min.
The authors' own conclusion: coaches can use critical swimming speed together with critical stroke rate to set aerobic training loads and to control technique during training.
Do not use the y-intercept of the CSS line as an "anaerobic capacity" number: it did not agree with a sprint-based measure here.
Inference, not tested here: for a long continuous swim (a triathlon leg, a long open-water set) pace a little under CSS rather than at it, because CSS came out above the 30-min speed.
Not from this paper; the base's own practice: the swim framework SYNTH-74 anchors swim paces to a tested CSS.

Limitations

The abstract gives no sample size and no absolute speeds or stroke rates.
"Not different" is a statistical statement beside a stated 3.2 % overestimate; the abstract gives no limits of agreement.
Well-trained competitive swimmers; not triathletes, masters or adult learners.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

test validation study; sample size not given in the abstract