RACLET: the Ramp Above Critical Level Endurance Test to evaluate critical velocity in running
Résumé
Critical velocity (Vc) is an important fatigability threshold in running, but only strenuous methods exist to assess it (e.g. time-trials). Based on a novel mathematical model of fatigability, the Ramp Above Critical Level Endurance Test (RACLET), a simple 5-min test to evaluate Vc was developed. This study aimed to test the measurement properties of this novel non-exhaustive test. Thirty-eight participants performed two RACLET (session 1) and three time-trials (sessions 2–4). For the RACLET, velocity target tracking was guaranteed by either a pacing bike or cones and whistle signals. Using GPS to measure participants’ running velocities, Vc, fatigability index τ , and distance reserve above Vc DACmax were determined by adjusting the fatigability model on the measured Vmax. The RACLET test vs. retest and RACLET test vs. time-trials parameters were compared for reliability and validity testing, respectively. Vc differed by −1.9±2.9% between test and retest, and by 5.4±7.1%, between RACLET test and time-trials. Although τ and DACmax presented important variability (s.d. difference ≈30%), the combination of the RACLET parameters enabled a good prediction of time-trials performance (mean error=8.5±5.0%, 0.1±7.6%, −2.0±5.5% for 400, 1500, and 3000 m, respectively). RACLET is a promising non-exhausting test to assess the velocity–time relationship parameters.