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

Development of an analysis of swimming techniques using instrumentation and the development of a new measurement method at Brno University of Technology

This article provides an overview of the development of measuring methods and instrumentation for the analysis of swimming techniques around the world, and describes in more detail the Tachograph method used in BUT (Brno University of Technology), including information about the currently developed method for measuring the swimmers using accelerometers. Our aim is to present a comprehensive view of the issue and describe the direction of the current development of measurement techniques used in swimming. The article further describes in detail the physical nature of the measurement methods and discusses their pros and cons. In addition to conventional methods (speedometer, accelerometer), we also mention unconventional methods (CFD method, 3D motion analysis etc.). The main contribution of the paper is in highlighting new directions and methods of measurement in swimming, including a specific approach for the evaluation of swimming techniques at the Brno University of Technology (BUT), where the scientific team at the Center of Sports Activities (CESA) has for several years developed and refined a tachograph measuring method with synchronous underwater video recording of swimmers. This method was used with swimmers from the Czech national swimming team and from Czech sports secondary schools as part of ongoing research and efforts towards more accurate measurements. Finally, the article describes current developments in measuring methods done at BUT using accelerometers

Changes in speed and efficiency in the front crawl swimming technique at 100m track

The aim of our research is to show how the speed of competitive swimmers at a 100m track (4 x 25m) develops and to find out if there are any considerable changes in swimming efficiency. As for the speed, we expect its gradual decrease caused by fatigue. Efficiency of swimming is directly determined by mastering of swimming techniques. However the question is whether it is also influenced by fatigue. It expands our earlier publications and includes measurements conducted not only at the 50m swimming track (two sections /25m legs) but also those taken at the 100m track (four sections/25m legs). Thanks to our measuring device called Tachograph, we have been able to record and subsequently analyse the results of 10 male and seven female swimmers, all being between the ages of 18 and 23 / 26. Research shows that the average mean speed in male categories declines from 1.65 m*s -1 reached in the first section down to1.50m*s -1in the fourth section. The decrease seems to be linear during the first three sections while it is not so significant in the fourth swimming legs. Efficiency of swimming slightly decreases from 0.949 to 0.936. As for the female swimmers, their average mean speed decreases from 1.46m*s -1(measured in the first section) to1.34m*s -1in the fourth section. The decline is more or less linear, with a slight reduction in value. Efficiency has a subtle declining tendency (from 0.967to0.961). In both male and female categories, the speed of swimming slightly declines, whereas changes in the efficiency of swimming are not substantial

Result interpretation of experimental calibration for milk citric acid determination via infra-red spectroscopy (MIR-FT)

Citric acid (KC) in milk is indicator of cow energy metabolism. Milk laboratories set up KC determination. A method can be infra-red analyse (MIR-FT). The goal was to develop a relevant method for reference sample preparation for MIR-FT (indirect method, Lactoscope FTIR and MilkoScan FT 6000) calibration. As reference was used a photometric method (c; 428 nm). KC was added (n = 3) into some re­fe­ren­ce milk samples (n = 10, bulk milk). Mean value was 9.220 ± 3.094 mmol . l−1 with variation range from 6.206 to 15.975 mmol . l−1. Recovery c was from 100.8 to 120.2 %. Correlation between c and ­MIR-FT were from 0.979 to 0.992 (P < 0.001). These were lower in the set of native milk samples (n = 7), from 0.751 (Lactoscope FTIR; P < 0.05) to 0.947 (MilkoScan FT 6000; P < 0.001) in comparison to original va­lues from 0.981 to 0.992 (n = 10; P < 0.001). Correlations between calibrated MIR-FT instruments were from 0.958 to 1.0 (P < 0.001). Average recovery for instruments (n = 12) was 101.6 ± 18.1 %. The mean differences between c method and MIR-FT after calibration (n = 4) moved from −0.001 across zero to 0.037 %. Standard deviation of differences was from 0.0074 to 0.0187 % at MilkoScan FT 6000 and from 0.0105 to 0.0117 % for Lactoscope FTIR. Relative variability of differences (MIR-F (filter technology) and FT) for major components fat (T), proteins (B) and lactose (L) in total and minor components KC and free fatty acids (VMK) was estimated to 1.0 and 7.2 and 34.4 %. The KC result is inferior than T, B and L superior than VMK. Autocorrelation (0.042; P > 0.05) of results demonstrated the in­de­pen­den­ce of consecutive measurements. Milk preservation effect amounted 0.2323 (P < 0.001) with bronopol and 0.0339 (P > 0.05) mmol . l−1 with dichromate. It was (3.0 and 0.44 %) practically negligible, redeemable via relevant calibration. The results of proficiency testing in post-calibration period and evaluation of double transport stress effect samples (difference was −0.006 ± 0.071 mmol . l−1 (P > 0.05)) demonstrated the useability for central calibration system. Milk KC results of MIR-FT calibration were good and can be suitable for practical screening