Key Performance Indicators in Freestyle Swimming: Comparing Start, Turn, and Swimming Velocity in Top-Elite Female Junior and Adult Swimmers

Abstract

Introduction Due to the increasing importance of start and turn performance in swim races throughout the recent years, the aim of the study was to compare the effect of start performance, turn performance, and swimming velocity on the race result between top-elite female junior and adult swimmers across all distances of freestyle pool races (50 m to 1500 m) and to provide a software tool to predict race outcomes based on the various key performance indicators.

Methods In the present study, a total of 289 individual freestyle races from female participants at the European long-course championship, as well as 391 freestyle races at the Junior European long-course championship were analysed. All heats, semi-finals, and finals across all freestyle distances (50 m to 1500 m) were included. Linear regression analyses were used to assess the relationship between overall race time and three independent variables: start performance, turn performance, and swimming velocity. Regression equations were used to develop the predictor software tool.

Results Start times showed the greatest effect on sprint distances, i.e. 50 m and 100 m. However, the effect diminished towards longer race distances. While swimming velocity had the largest effect on the race results across all distances for both junior and adult swimmers, the effect of turn times increased from 100 m to 400 m for both, junior and adult swimmers. Interestingly, the effect of turn times decreased again for 800 m and 1500 m races. Generally, there was a trend towards a greater effect of turn times in adult swimmers. The regression model explained 98-99% of the variance in race performance (R-squared = 0.98-0.99). Based on the regression equations a software tool (potential predictor) was created to allow coaches and federation officials to identify individual swimmers’ potentials and create benchmarks for future development.

Discussion/Conclusion For both junior and adult swimmers, swimming velocity had the greatest effect on race results. While the effect of start performance decreased from short to long race distances, turn performances showed a U-shaped, hence largest effect on middle-distance races, i.e. 200 m and 400 m. The prediction tool that was developed from the regression model allows the prediction of individual performance progressions and rankings at international swimming competitions by combining isolated performance analysis with race analysis data.

References

Born, D.-P., Romann, M., & Stöggl, T. (2022). Start fast, swim faster, turn fastest: Section analyses and normative data for individual medley. Journal of Sports Science & Medicine, 21(2), 233–244. https://doi.org/10.52082/jssm.2022.233

Born, D.-P., Schönfelder, M., Logan, O., Olstad, B. H., & Romann, M. (2022). Performance development of European swimmers across the Olympic cycle. Frontiers in Sports and Active Living, 4, Article 894066. https://doi.org/10.3389/fspor.2022.894066

Polach, M., Thiel, D., Kreník, J., & Born, D.-P. (2021). Swimming turn performance: The distinguishing factor in 1500 m world championship freestyle races? BMC Research Notes, 14(1), Article 248. https://doi.org/10.1186/s13104-021-05665-x