Changes in mean swimming speed and efficiency in the front crawl at 2x25m track

Between the years 2009 and 2014 our team have collected data from more than 2000 measurements of four different swimming techniques. The swimmers that have participated in the research study include members of the Czech national swimming team and, competitive swimmers at national level. This article focuses on the measurements conducted during 50m front crawl swimming at a 25m pool, using data of 96 swimmers (52 men, 44 women). The aim of the study was to compare swimming efficiency and mean speed during two consecutive 25m segments. The average swimming efficiency and standard deviation during two successive 25m segments of the 50m distance were: 1) All measurements 0,979; s =0,013396; 0,972 s = 0,017616 2) Males 0,974; s = 0,018071; 0,962 s = 0,024814 3) Females 0,983; s = 0,008431; 0,979 s = 0,004562 The mean speed and standard deviation during two successive 25m segments of the 50m distance were: 1) All measurements 1,639; s = 0,129161; 1,556; s = 0,121743 2) Males 1,504; s = 0,042109; 1,443; s = 0,056049 3) Females 1,734; s = 0,060302; 1,637; s = 0,082359 Results show that swimming efficiency and mean speed decrease during the second 25m segment of the 50 m distance in both groups - men and women. The decrease in medium speed and efficiency between the first and the second section was higher in the male category