A single test for the determination of parameters of the speed-time relationship for running.

A validated expeditious method is needed to determine critical speed (CS) and the finite distance that can be covered above CS (D'). We tested the hypothesis that a single all-out 3-min running test would accurately determine CS and D'. Seven healthy subjects completed three constant-speed runs on a treadmill for the determination of CS and D', as well as an all-out 3-min test on a track for the determination of end-test speed (ES) and the distance above end-test speed (DES). ES (13.4 ± 2.8 km h(-1)) was not significantly different from the speed-1/time model CS (13.3 ± 2.8 km h(-1)). While DES (141 ± 34 m) was not significantly different from D' (204 ± 103 m), it underestimated D' in 5 of 7 subjects. Thus, the speed-1/time model CS can be accurately determined using a single 3-min test, while caution should be used in relating DES to D'.