RELAY EXCHANGE PRACTICE PRODUCES IMPROVEMENTS IN PERFORMANCE
Kibele, A., & Fischer, S. (2010). Relay start strategies in elite swimmers. A paper presented at the XIth International Symposium for Biomechanics and Medicine in Swimming, Oslo, June 16–19, 2010.
Two studies were conducted to evaluate the effects of different feedback sources on relay exchange performance. In both studies, the time between wall-contact of the incoming swimmer and the time at the first 7.5 m of the outgoing swimmer was used as the criterion for the relay exchange performance.
Study 1: Junior elite swimmers (N = 26) were examined during a four-day learning experiment with three relay-exchanges on each day. Two experimental groups were randomly assigned to two different feedback categories. While one group received feedback on the maximum in the horizontal take-off force the other group received feedback on the exchange-time.
Ss receiving feedback on their horizontal force clearly showed higher improvements in their relay start performance when compared to Ss receiving changeover-time feedback. Individual improvements in the force feedback groups could be as much as 0.5 seconds. While both groups showed similar improvements in the changeover-time, only the force feedback group yielded increases in horizontal force.
Study 2: Elite swimmers (N = 16) participated in a one-day learning experiment concerning feedback for two different take-off movement techniques. While one group practiced the traditional arm-swing start, the second group practiced a single-step start. Both groups received feedback on the maximum horizontal force as well a video presentation on their exchange performance.
Both groups reduced their exchange-time within one day by up to 50%. Despite considerable improvement in the exchange-time, no improvement was found in the relay start performance.
Implication. When practicing relay starts, an instructional emphasis on increasing force production (e.g., explosiveness) off the block is likely to produce performance improvements. Practice also improves exchange-time (touch to 7.5 m). The movement form in the exchange has little effect on exchange-time.