Reproducibility Of A 20 Km Cycling Time-trial In Competitive Cyclists Using The Velotron Pro Cycle Ergometer

Abstract

Evaluation of performance enhancement in elite athletes is best achieved when using a test that closely simulates actual sport performance. It is also important that the test is as reliable and reproducible as elite athlete performance between competitions (∼ 1% coefficient of variation [CV]). Cycling time trial tests using air-braked cycle ergometers have been shown to be both valid and reproducible in trained cyclists. Reproducibility of time-trial performance using the Velotron Pro electronically-braked cycle ergometer has not yet been reported in such a group. Purpose The purpose of this study was to evaluate performance reproducibility in a laboratory-based 20 km cycling time-trial using the Velotron Pro cycle ergometer in competitive cyclists. Methods Fifteen (13 males, 2 females) highly trained competitive cyclists(maximal aerobic power [VO2max] = 68.4 ± 5.7 ml kg−1min−1) participated in this study. Each subject performed one VO2max test and 3 separate 20 km time trials (TT1, TT2, TT3). Each time trial was separated by a minimum 48 hours with no intense exercise 24 hours prior. Subjects received no feedback as to their performances during the time trial. Data from all time trials were compared using a one-way analysis of variance with alpha set at 0.05. CV and 95% confidence limits (CI) were calculated between individual trials. Results Performance time (Ttot) (30.4 ± 1.9, 30.6 ± 1.9, and 30.7 ± 2.1 min) and average power output (Wavg) (319 ± 47, 314 ± 47, 310 ± 49 watts) were not different across TT1–TT3. Ttot was highly related between TT1 and TT2 (r = 0.99; p<0.01) as well as between TT2 and TT3 (r = 0.99; p<0.01). A low CV was demonstrated between individual trials for Ttot (TT1–TT2 = 0.5% and 95% CI was 0.4% to 0.9%; TT2–TT3 = 0.9% and 95% CI was 0.7% to 1.5%). Conclusions These data show that performance in a 20 km time-trial using the Velotron Pro ergometer is highly reproducible in competitive cyclists. Furthermore, the CV variance demonstrated between trials is comparable to that expected during actual performance in elite athletes. Supported by the World Anti-Doping Agency and Racermate Inc.