The effect of self- even- and variable-pacing strategies on the physiological and perceptual response to cycling.

It has been proposed that an even-pacing strategy is optimal for events lasting <120 s, but this assertion is not well-established. This study tested the hypothesis that even-paced cycling is less challenging than self- or variable-paced cycling. Ten well-trained male cyclists (VO2max, 4.89 ± 0.32 L min(-1)) completed a self-paced (SP) 20-km time trial followed by time- and work-matched even-paced (EP 100% SP mean power) and variable-paced (VP 142 and 72% SP mean power, 1:1.5 high:low power ratio) trials in a random, counterbalanced order. During all trials expired air and heart rate were analysed throughout, blood lactate was sampled every 4 km, and perceptual responses (rating of perceived exertion (RPE) and affect) were assessed every 2 km and post-trial. There were no whole trial statistically significant differences between trials for any of the respiratory variables measured, although there was a trend for higher RER's in VP compared to EP (P = 0.053). Blood lactate was lower in EP compared to VP (P = 0.001) and SP (P = 0.001), and higher in SP compared to VP (P = 0.008). RPE was lower, and affect more positive, in EP compared to both SP and VP (P > 0.05). The results of this study show that, for a time- and work-matched 20-km time trial, an even-paced strategy results in attenuated perturbations in the physiological response and lower perception of effort in comparison to self- and variable-paced strategies.