Reproducibility of a Laboratory Based 1-km Wattbike Cycling Time Trial in Competitive Cyclists

The purpose of this study was to evaluate the reliability of a 1-km cycling time trial using a Wattbike cycling ergometer in competitive cyclists. Ten competitive male cyclists (mean ± SD; 63.9 ± 5.1 mL•kg -1 •min -1 ) performed a VO2max test and a familiarization of the 1-km time trial (TT) on the same day, and 3 separate 1-km TT (TT1, TT2 and TT3) separated by >24 hours. Mean performance time was not significantly different between TT (70.27 ± 5.95 vs. 70.06 ± 5.75 vs. 69.79 ± 6.0; P = 0.47) and displayed a low coefficient of variation (CV%; 90% CI: 0.6%; 0.4 – 1.1%). The mean reliability, expressed as the coefficient of variation and typical error of measurement over the three TT was performance time 0.6%, 0.42 s (95% CL 0.28-0.77); mean power 1.2%, 6.3 W (95% CL 4.7-12.0); peak power 7%, 64.8 W (95% CL 45.3-124.9); blood lactate concentration 3.2%, 0.5 mmol•L -1 (95% CL 0.9-0.3); heart rate 0.8%, 1.4 bpm (95% CL 1.1-2.5). Such high reliability makes the combination of the Wattbike, athlete and test protocol very suitable for detecting "real" changes in performance where improvements may be small but still considered worthwhile in a competitive sport setting.