The reliability of a simulated uphill time trial using the Velotron electronic bicycle ergometer.

This study was conducted to measure the reliability of an indoor uphill time trial (TT) using the Velotron electronic bicycle ergometer with a computer-generated pacer that represented a subject's prior TT performance. A total of 12 trained cyclists (42 ± 7.79 years, 63.0 ± 6.12 ml/kg/min) completed three 8-mile uphill TT with 2-7 days between subsequent tests. A repeated measure ANOVA found no difference between finishing times for TT1 (2,154 ± 246 s) and TT2 (2,078 ± 185 s, p = 0.055) or TT2 and TT3 (2,047 ± 167 s, p = 0.075). All measures of reliability showed an increased reliability for finishing times in TT2-TT3 [95% CI for: coefficient of variation (CV) = 1.0-2.3%, intraclass correlation coefficient (ICC) = 0.953-0.996, standard error of measurement (SEM) = 2.1-4.9 s] versus TT1-TT2 (95% CI for: CV = 2.0-4.9%, ICC = 0.827-0.986, SEM = 9.8-23 s). An uphill TT using the Velotron bicycle ergometer with a prior performance as a pacer is a reliable assessment for indoor TT performance testing, but a familiarization trial improves reliability. Although there were no significant differences found for completion times between TT1-TT2 or TT2-TT3, the absolute mean differences, small sample size and low p values may be suggestive of a Type II error.