Purpose: Pacing has a substantial effect on endurance performance. The authors characterize pacing and identify its parameters for optimal performance in 1500-m freestyle swimming.
Methods: Web sites provided 50-m lap and 1500-m race times for 330 swims of 24 elite male swimmers. Pacing for each swim was characterized with 7 parameters derived from a general linear model: linear and quadratic coefficients for the effect of lap number; reductions from predicted time for first, second, penultimate, and last laps; and lap-time variability. Scatter plots of race time vs each parameter for each swimmer were used to identify optimum values of parameters.
Results: Most scatterplots showed only weak relationships between the parameter and performance, but one-third to one-half of swimmers had an optimum value of the parameter that was substantially different from their mean value. A large improvement in performance time (1.4% ± 0.9%, mean ± SD) could be achieved generally by reversing the sign of the linear parameter to make the slowest lap occur earlier in the race. Small to moderate improvements might also accrue by changing the quadratic parameter, by making the first and second laps slower and the penultimate and last laps faster, and reducing lap-time variability.
Conclusions: This approach to analysis of pacing may help improve performance in swimmers and other endurance athletes in sports with multiple laps, but data from many competitions are required.