Stroking techniques of elite swimmers

Abstract

The average stroking speed (S) in swimming competition is governed by the average stroke length (SL) and average stroke frequency (SF). The purposes of this study were: (a) to determine the SL, SF and S of five complete stroking cycles in each length of the race for elite swimmers of four competitive strokes; (b) to compare the results obtained by male and female swimmers, by swimmers using the same stroke in races over different distances and by swimmers at different stages of the same race; (c) to determine the relationships between SL, SF and S. The stroking techniques employed by finalists in 15 of 16 100 m and 200 m individual swimming events in the 1982 British Commonwealth Games in Brisbane, Australia were recorded with the aid of a motion-picture camera. The SL, SF and S were then calculated from the film analysis. Subsequent analyses of these data led to the following conclusions: (1) The S for the four competitive strokes followed a descending order from freestyle, to butterfly, to backstroke, to breaststroke in 100 m and 200 m events for male and female swimmers. The mean SFs for freestyle, butterfly and breaststroke were very similar. The SL determined their rank order in S. Backstroke had the longest SL and the lowest SF. (2) The coefficient of variation for SL, SF and S indicated that these well-trained swimmers achieved very similar S with very different combinations of SL and SF. (3) In all events, SF was significantly higher in 100 m events than in 200 m events; SL was longer in all 200 m events except the women's butterfly and men's backstroke. (4) Male swimmers had significantly longer SLs than their female counterparts in the freestyle and butterfly events. (5) In general, the S decreased as the event progressed. A decrease in SL or SF from the first to the second length was found in several 100 m events. A significant increase (instead of decrease) in SF was found in the men's 200 m breaststroke, which reduced the drop in S. (6) A significant negative correlation was found between SL and SF in all events except the 100 m women's butterfly.