How non-expert swimmers structure 100 m freestyle.

Objective. - The purpose of this study was to determine the ways in which pre-graduate sport science students of different performance levels swam 100 m freestyle. Methods. - The sample was composed of 402 male subjects, 19.3 +/- 1.7 years of age, and was divided into five groups according to their rough chronometric performances. The study examines the criteria which affect swimming speed (frequency and distance per stroke) as well as the disparity (measured in percentage) between the first and second 50 m times as a basis for analysis. Results. - The results showed that the best performance level was associated with the greatest distance per stroke (from 1.42 +/- 0.19 for slow group [group 1] to 1.95 +/- 0.20 m.cycle(-1) for high group [group 5]). Furthermore, the differences in speed (from 32.54% for group 1 to 9.8% for group 5), in frequency (from 12.77% for group 1 to 4.78% for group 5) and in distance per swimming stroke (from 19.41% for group 1 to 5% for group 5) during both 50 m of the 100 m are indicators of differences in performance for this non-expert sample of swimmers. Conclusion. - It seems that differences in velocity and in distance per stroke can be used to characterise the different practice levels of swimmers. (C) 1998 Elsevier, Paris.