Swimmer's evaluation: technical differences between sprint and middle distance analyzed by inertial sensors

BACKGROUND: When studying aquatic sports, the direct evaluation during the full and unconstrained swim is dif-ficult as compared to that which is performed on a terrestrial environment. For the cinematic analysis and for the indirect evaluation of the fitness state of the swimmer, inertial sensors have been used, with encouraging results. The aim of this study was to evaluate if through a maximal crawl swimming test with an inertial sensor it is possible to distinguish between the cinematic and technical characteristics of sprint and middle distance swimmers.METHODS: A 75 mt all-out Test (3 laps) in breaststroke technique was performed by athletes wearing an inertial sen-sor. Starting in the water, each swimmer was instructed to reach the maximum velocity as fast as possible and keep it till the end of the test. In addition, the athletes were instructed not to perform any underwater phase and to perform open turns. Blood lactate concentrations were analysed 3, 5, 7, and 9 minutes after the end of the test.RESULTS: Through this test we were able to verify that the sprinters obtained a high average and top speed as com-pared to the middle-distance swimmers but presented ample differences between their average and top speeds. In regard to the fatigue indicators, the sprinters obtain parameters that are noticeably higher, possibly due to their physi-ological characteristics that cause fatigue to affect them earlier than the middle distance swimmers.CONCLUSIONS: The proposed protocol could be a valid procedure for analysing the technical capability in swim-mers and analysing which is the race distance more suitable for each of them. It could also be easily and effortlessly utilised to monitor the swimmer's qualities along all the training season.

Automated summary

This study successfully differentiated the biomechanical and technical characteristics of sprint and middle-distance swimmers through a maximal crawl swimming test using inertial sensors.