Analysis of breathing in the crawl as a function of skill and stroke characteristics

The purpose of this study was to measure and compare the durations of exhal ation (DE), inhalation (DI), and inhalatory apnea (DAI) expressed as percen tage of stroke-cycle duration using two groups (more expert and less expert ) of 6 front crawl swimmers each at near 100-m speed thigh speed) and 800-m speed (low speed). Two breathing conditions were considered, breathing to the preferred side with and without a nose-dip. The relationships between s troking characteristics (swimming speed, stroke rate, and stroke length) an d the three durations of breathing were examined as a function of skill and swimming speed. The data show that use of a nose-clip does not significant ly change those measures. At high speed, the more expert group had a lower inhalation and a higher exhalation than the less expert group. The stroke r ate correlated with speed .92 (p<.01 and was mainly associated with inhalat ion (r=-.78, p<.01). Inclusion of exhalation as a second variable improved significantly (p<.01) the accuracy of the regression up to .97. At low spee d, the less expert had lower inhalatory apnea than the more expert. Stroke length correlated with speed .86 (p<.01) and was mainly associated with inh alatory apnea (r=.70, p<.05). At high speed, the more expert had a lower in halation than at low speed, while durations of exhalation and inhalatory ap nea did not vary significantly. On the contrary, the less expert had a lowe r exhalation and a higher inhalatory apnea, while duration of inhalation re mained relatively unchanged. The present study shows that these durations a nd their relations to stroking characteristics could be considered signific ant indicators of skill in swimming.