REF-876 · Galbraith et al., 2014 · International Journal of Sports Physiology and Performance, Vol. · Paper · PubMed

A Single-Visit Field Test of Critical Speed

Blimited evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

Ten male distance runners did a traditional treadmill protocol (runs to exhaustion at 100%, 105% and 110% of velocity at VO2max, 24 h apart) and a field test on an outdoor track: three runs of 3600, 2400 and 1200 m in a single visit, with either 30-min or 60-min recovery between runs.

Critical speed did not differ between the treadmill and either field protocol and correlated highly with it, and repeat field tests of CS were very consistent. D′ (the distance that can be run above CS) did not agree between the treadmill and field tests and was far less repeatable.

The authors conclude that the single-visit method is a useful alternative for assessing CS in the field.

Participants

n=10 male distance runners (abstract: "Ten male distance runners").

Protocol

Treadmill: runs to exhaustion at 100%, 105% and 110% of velocity at VO2max, with 24 h recovery between runs.
Field (single visit, outdoor track): 3 runs over 3600, 2400 and 1200 m; two versions with 30-min or 60-min recovery between runs.
CS and D′ calculated from each protocol's distance-time relationship.

Key Results

CS: no difference between treadmill and the 30-min and 60-min recovery field tests; treadmill CS correlated highly with field CS (r = .89 and r = .82).
D′: differed between treadmill and field tests and did not correlate (r = .13; r = .33, P > .05).
Typical error of the estimate: 0.14 m/s (95% confidence limits 0.09-0.26 m/s) for CS; 88 m (60-169 m) for D′.
Repeat tests: coefficient of variation 0.4% (0.3-0.8%) for CS and 13% (10-27%) for D′.

Practical Application

In ten male distance runners, three track runs of 3600, 2400 and 1200 m on one visit (30 or 60 min apart) gave the same critical speed as a multi-day treadmill protocol (r = .89 and .82) with a repeat-test variation of only 0.4%, but D′ did not agree and varied by 13% between repeats. To "can I test my critical speed on a track in one session?": yes — run 3600, 2400 and 1200 m all-out with 30 min between them and use the CS it gives; do not lean on the D′ number from the same test.
30 min between runs was as good as 60 min, which keeps the session practical.
Inference, not tested here: the test assumes each run is a true best effort on a flat track in stable weather; a paced-too-easy run shifts the line.
Not from this paper; the base's own practice: SYNTH-53 and SYNTH-60 use CS to set running threshold work; the first threshold sits below it (REF-178).

Limitations

Ten men; the runners' performance level is not described in the abstract.
One track distance set (3600/2400/1200 m); other combinations were not tested.
The typical error of the CS estimate (0.14 m/s) is not trivial for an individual even though the group means agree.
D′ from this test is neither valid against the treadmill nor repeatable.
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, n=10