Differences between elite and sub-elite swimmers in a 100 m breaststroke: a new race analysis approach with time-series velocity data.

The purpose of the present study was to investigate differences in a 100 m breaststroke time-trial between elite and sub-elite swimmers. Elite and sub-elite male swimmers (seven each; 772.1 ± 35.2 and 610.6 ± 24.7 FINA point, respectively) performed 100 m breaststroke, which was recorded by a multi-camera system that provided the mean and time-series velocity data in the glide, pull-out, and clean-swimming segments. The mean velocity in each segment was compared between the groups using an independent-samples t-test (for the 1 lap) and two-way mixed-design ANOVA (for the 2-4 laps), which suggested a larger mean clean-swimming (in all laps; 7-11% difference) and glide (in the 2 and 3 lap; about 13% difference) velocity for the elite swimmers. The time-series data displayed faster velocity in elite swimmers than in the sub-elite group during the first part (up to 40% time) of the glide segment ( < 0.05). Differences in the clean-swimming segment between the groups were observed ( < 0.001) apart from the first 5-15% time of the segment. No differences in the pull-out and at the beginning of the clean-swimming imply that coaches and swimmers should not assume that a good clean-swimming technique also guarantees fast velocity in these segments.