TEMPORAL ANALYSIS OF THE STARTING TECHNIQUE IN FREESTYLE SWIMMING

Abstract

INTRODUCTION The starting technique in swimming is an important performance factor, especially in short-distance events. Hay (1986) defines starting time as the block time plus the glide time and plus the glide time When the data for the three part times were correlated with the total starting time, it was found that the glide time was the most important of the three in determining the total starting time (Hay et al. 1983), with similar results for 10m fixed distance (Arellano et al. 1994). Analysing the results obtained in the Barcelona Olympic Games revealed values of r=089 male and r=0,90 females’ between the start time (10 m) and the event time in 50 m freestyle events (Arellano et al. 1994). Our research aim was to find the relationship between some freestyle start and swimming variables and start distances using 72 male swimmers, being the elite in each age-group in Andalucia (age 15.83±1,38 years, height 175.4±7.5 cm, weight 67.4 ±8 7 kg). The data was obtained using three video-cameras connected to a S-VHS video-recorder (50 Hz) through a video selector. The image from the first two video-cameras was mixed to see the over and under-water phases on the start in the same frame (until 10 m), A third camera was used to measure the 15 m time. Each swimmer performed 50 m plus turn with all-out effort simulating competitive conditions An electronic timing system was used to measure the 50 m time synchronized with the video-recording equipment. The start time was measured tor 5m, 7.5 m, 10mand 15 m. The phases of the block time, f1ight time and entry time were measured as ware the 25 m and 50 m time plus the mean speed between 15 m and 42.5 m. RESULTS The means were: BT = 0,91s±0.09, FT = 0.37s±0.06, ET= 0.31 s±0,09, T5m= 1.875 ±0.13,T7.5m=3.28±0.25,T10m=4.79s± 03 T15m= 7.75s±0.45, T25m= 13.62s±0.70 T50m= 29.45±1,50,MS= 1.66m/s±0.08. We excluded the effect of age, using partial correlation, resulting in the following va• lues for r (" p<0.o5; .... p<0.01 ): T5 T7.5 T10 T15 T7.5 0,738** T10 0,590** 0,849** T15 0,476** 0,758** 0,930** T25 0,385** 0,680** 0,851** 0,949*• T50 0,247* 0,555** 0,719** 0,930** MS -0.157 -0,441" 0,657** 0,730** There was no significant correlation between BT, FT and ET on the ona hand and the other variables on the other hand apart fram BT and T5, When we used the shorter distances (T5 & n.5) for measuring the ST the relationship with the longer distances measured (T25 and T50) and MS was very low. CONCLUSIONS The influence of swimming technique in the start is greater if the swimming distance included in ST is longer. This was particularly so in the young groups studied where there were no long underwater phases. The start technique should playa bigger role than it does now in the final results, and, therefore, special training techniques for the start must•• be developed. REFERENCES Arellano,Brown,Cappaert, & Nelson, (1994a) Ana• lysis of 50, 100, & 200m Free Swimmers allhe 92 Olympics Jour. of Appl. Biom .12, 189-199. Arellano, Moreno, Martinez, & ona (1994). A Oevice for Quantitative Measurement of Starting Time in Swimming. In Vlllh In\. Svmp. on Biom, and Med. in Swimming , 1 . Atlanta (Georgia) Hay, J. G, (1986). Swimming. In Hay (Eds.). Star: ling Stroking & Tumina lowa Uniy ,83-86) (pp. 1-51). lowa: Biomechanics Lab. Dep. of Ex. Sc. Hay, Guimaraes, &Grimston (1983). A Quanlilive Look at Swimming Biomechanics. In J, G. Hay (Eds.), Stafting. Slroking & Tuming. Jowa Univ,83§ID(pp.76-82).lowa:Biomech. Lab.Dep, of Ex. Sc,