Day to Day Variation in Time Trial Cycling Performance

Abstract

In an attempt to assess the reproducibility of laboratory cycling performance, eight well-trained (V̇O₂max = 4.6+0.21· min^-1) male cyclists completed 12 trials involving 4 successive performance rides at each of three total work outputs (approximately 1600, 200, and 14 kilojoules, respectively). These trials, deisgnated as long, medium, and short trials (LT, MT, ST), represented exercise bouts of 105.12±0.41, 12.03±0.17 and 0.55±0.11 minutes, respectively. The trials, conducted on a computerized cycle ergometer in an isokinetic mode, were separated by a minimum of 72hrs. All trials for each subject were completed at the same time of day. In all trials, subjects were allowed to select the pace in order to complete the ride in the shortest possible time. The mean coefficient of variation (CV) for performance time in each trial was: LT = ±1.01%, MT = ±0.95%, and ST = ±2.43%, respectively. The CV for performance time in ST was significantly greater than the CV in either LT or MT. In LT, performance time was significantly faster, and the mean % V̇O₂max was significantly higher in trial 4 versus trials 1-3. There was no order effect in the MT or ST rides. The CV for mean V̇O₂ (l·min^-1), mean % V̇O₂max, and RER during the LT rides were ±3.02%, ±3.64%, and ±3.53%, respectively. These data suggest that trained cyclists have the ability to reproduce endurance performance with a CV of approximately 1.0% in a time-trial protocol. The observation that performance was significantly improved in LT-4 while no differences were observed between LT 1-3 suggests that psychological factors (i.e., the last ride”) may contribute to significant improvements in endurance performance independent of experimental manipulations.

Key words

Exercise performance - cycling - time trial - reproducibility