Competitive swimmers tend to specialise in either sprint or distance events to suit their innate and conditioned physiological characteristics. As a result, coaches design specific training programs to direct the swimmers` optimal performance in their chosen event. Despite the specialisation of the swimmer, these training programs often include a wide range of intensities in order to develop physiological aspects regarded as deficient (Lydersen, 1999; Johnson and Gadboy, 1999). However, the possible impact of this accepted practice on the swimmers` stroke mechanics has not been considered adequately. For example, it is unknown whether sprinters training at a distance pace, or vice versa, will adapt their technique to the extent that may negatively effect their performance. Bearing in mind the principle of specificity with regard to training, this is an important consideration. Researchers have suggested that sprint and distance freestyle swimmers utilise distinct stroke characteristics (Costill et al., 1992; Ito and Okuno, 2002; Cappaert, 1998). Compared to their distance counterparts, sprint swimmers have been reported to have a deeper pulling action of the hand (Cappaert 1998), a greater extension of the elbow during the underwater phases of the stroke cycle (Wilke, 1992; Cappaert, 1998), a reduced magnitude of shoulder roll angle (Cappaert, 1998) and a greater knee range of motion during the flutter kick (Cappaert, 1998). Researchers have suggested that sprinters stroke in this manner to maximise propulsion (Schleihauf et al., 1983) whereas distance swimmers place an emphasis on maximising the efficiency of the stroke (Voronstov and Rumyantsev, 2000). A limitation with the majority of investigations into differences between swim groups is that the swimming pace has not been considered. Therefore, it is unclear whether sprint and distance freestyle swimmers may differ due to their specialisation or due to the actual race distance/swim velocity. It is important to determine, with three-dimensional methods, whether there are distinct technique differences between these groups in order to help coaches direct a sprint or distance swimmer to an ideal pattern which is most effective for their particular event. To find out whether sprint and distance swimmers use different techniques we conducted a study investigating seven sprinters and eight distance swimmers who compete at a national/international (McCabe, 2008). After a warm-up, each swimmer swam four repeat 25m sprints and one repeat 400m at a maximal effort and evenly paced. The order in which the swimmers performed the sprint block of trials and distance swim was randomly assigned to prevent any order effects. All trials were recorded by six synchronised cameras (four cameras below and two above the water surface) and one stroke cycle (the period between the instant of entry of one hand to the instant of entry of the same hand for the next stroke) was selected for analysis. Within each stroke cycle, four separate phases were identified; entry, pull, push and recovery. Each phase was determined from the swimmer`s horizontal movement of the hand at instances throughout the stroke cycle. All stroke phases were expressed as a percentage of the stroke cycle.
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