De Konig, J. J., Hettinga, F. J., Mulleman, M., & Foster, C. (2008). Relative importance of changes in pacing strategy and mean power output to performance. ACSM 55th Annual Meeting Indianapolis, Presentation Number 1302.

Besides mean power output, the distribution of available energy over a race, that is the pacing strategy, is a critical factor in performance. Modeling energy flow provides a tool to study the effect of various determining factors in race performance. In this study, the model was used to determine the relative importance of variation in pacing strategy and anaerobic power output for performance in self-paced exercise.

Cyclists (N = 7) performed four 1,500 m ergometer time trials (~2 minutes). The pattern of anaerobic power output was calculated by subtracting aerobic power output from the total power output and described monoexponentially. By systematically varying anaerobic energy distribution over all trials, keeping total energy constant, performance outcomes of different pacing strategies were determined. For each S, the fastest and slowest time trials were compared and the relative importance of the measured differences in anaerobic power output and pacing strategy was determined.

The fastest trials were performed with a higher anaerobic peak power, combined with a relatively high, but statistically unchanged anaerobic rate constant. This meant that the most successful pacing strategy was characterized by a short and fast start. The variation in mean anaerobic power output accounted for 70% of the difference in final time between the fastest and slowest trials. The remaining 30% was attributable to differences in pacing strategy.

Implication. About 30% of the difference between the fastest and slowest time trials can be explained by variations in pacing strategy towards a more optimal pacing profile, consisting of an increased peak power combined with a relatively high rate constant. Approximately 70% of the difference was explained by variation in anaerobic power output generated during the trial, caused by day-to-day variation or changes in motivation. Essentially, this study showed that a short fast start (not an extended fast start) followed by a constant level of anaerobic power output (pacing performance) produces the best time over events lasting about two minutes. It is the anaerobic work that determines the effort level that produces the constant pace. The race plan of saving some energy for an impressive finish is not supported by these findings.

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