scholarly journals Bioimpedance Vector Patterns Changes in Response to Swimming Training: An Ecological Approach

Author(s):  
Joana F. Reis ◽  
Catarina N. Matias ◽  
Francesco Campa ◽  
José P. Morgado ◽  
Paulo Franco ◽  
...  

Background and aim: Monitoring bioelectric phase angle (PhA) provides important information on the health and the condition of the athlete. Together with the vector length, PhA constitutes the bioimpedance vector analysis (BIVA) patterns, and their joint interpretation exceeds the limits of the evaluation of the PhA alone. The present investigation aimed to monitor changes in the BIVA patterns during a training macrocycle in swimmers, trying to ascertain if these parameters are sensitive to training load changes across a 13-week training period. Methods: Twelve national and international level swimmers (four females; eight males; 20.9 ± 1.9 years; with a competitive swimming background of 11.3 ± 1.8 years; undertaking 16–20 h of pool training and 4–5 h of dry-land training per week and 822.0 ± 59.0 International Swimming Federation (FINA) points) were evaluated for resistance (R) and reactance (Xc) using a single frequency phase sensitive bioimpedance device at the beginning of the macrocycle (M1), just before the beginning of the taper period (M2), and just before the main competition of the macrocycle (M3). At the three-time assessment points, swimmers also performed a 50 m all-out first stroke sprint with track start (T50 m) while time was recorded. Results: The results of the Hotelling T2 test showed a significant vector displacement due to simultaneous R and Xc changes (p < 0.001), where shifting from top to bottom along the major axis of the R-Xc graph from M1 to M2 was observed. From M2 to M3, a vector displacement up and left along the minor axis of the tolerance ellipses resulted in an increase in PhA (p < 0.01). The results suggest a gain in fluid with a decrease in cellular density from M1 to M2 due to decrements in R and Xc. Nevertheless, the reduced training load characterizing taper seemed to allow for an increase in PhA and, most importantly, an increase of Xc, thus demonstrating improved cellular health and physical condition, which was concomitant with a significant increase in the T50 m performance (p < 0.01). Conclusions: PhA, obtained by bioelectrical R and Xc, can be useful in monitoring the condition of swimmers preparing for competition. Monitoring BIVA patterns allows for an ecological approach to the swimmers’ health and condition assessment without resorting to equations to predict the related body composition variables.

2019 ◽  
Vol 14 (3) ◽  
pp. 393-405 ◽  
Author(s):  
Augusto Carvalho Barbosa ◽  
Pedro Frederico Valadão ◽  
Carolina Franco Wilke ◽  
Felipe de Souza Martins ◽  
Dellano Cézar Pinto Silva ◽  
...  

This study aimed to describe training characteristics as well as physical, technical and morphological changes of an elite Olympic swimming sprinter throughout his road to 21 s in the 50 m freestyle. Over a ∼2.5-year period, the following assessments were obtained: external training load, competitive performance, instantaneous swimming speed, tethered force, dry-land maximal dynamic strength in bench press, pull-up and back squat and body composition. From 2014 to 2016, the athlete dropped 3.3% of his initial best time by reducing total swimming time (i.e. the total time minus 15-m start time – from 17.07 s to 16.21 s) and improving the stroke length (from 1.83 m to 2.00 m). Dry-land strength (bench press: 27.3%, pull-up: 9.1% and back squat: 37.5%) and tethered force (impulse: 30.5%) increased. Competitive performance was associated to average (r = −0.82, p = 0.001) and peak speeds (r = −0.71; p = 0.009) and to lean body mass (r = −0.55; p = 0.03), which increased in the first year and remained stable thereafter. External training load presented a polarized pattern in all training seasons. This swimmer reached the sub-22 s mark by reducing total swimming time, which was effected by a longer stroke length. He also considerably improved his dry-land strength and tethered force levels likely due to a combination of neural and morphological adaptations.


1993 ◽  
Vol 25 (8) ◽  
pp. 952???959 ◽  
Author(s):  
HIROFUMI TANAKA ◽  
DAVID L. COSTILL ◽  
ROBERT THOMAS ◽  
WILLIAM J. FINK ◽  
JEFFREY J. WIDRICK

2013 ◽  
Vol 31 (3) ◽  
pp. 515-521 ◽  
Author(s):  
W. Gao ◽  
S.N. Liu ◽  
Y.F. Bi ◽  
X.B. Hu

AbstractWe theoretically and experimentally investigate the conditions of obtaining a narrowband flat-top Brillouin gain spectrum (BGS) based on single-frequency and multi-frequency phase modulations. Using the unequal-amplitude spectral lines, the flat-top BGS can be realized by controlling the intensity ratio and the frequency separation between them. In experiment, we obtain the flat-top gain spectra with the bandwidths of 40 MHz and 125 MHz, and with the top fluctuation of less than 0.21 dB. Based on this, we also achieve low distortion Brillouin amplification of a probe signal pulse and spectrum.


2014 ◽  
Vol 9 (2) ◽  
pp. 212-216 ◽  
Author(s):  
Renato Barroso ◽  
Ronaldo K. Cardoso ◽  
Everton Crivoi Carmo ◽  
Valmor Tricoli

Session rating of perceived exertion (SRPE) is a practical method to assess internal training load to provide appropriate stimuli. However, coaches and athletes might rate training sessions differently, which can impair performance development. In addition, SRPE might be influenced by athletes’ training experience. The authors studied 160 swimmers of different age groups and different competitive swimming experience and 9 coaches. SRPE was indicated by the swimmers 30 min after the end of a training session and before the training session by the coaches. Training-session intensities were classified into easy (SRPE <3), moderate (SRPE 3–5), and difficult (SRPE >5), based on coaches’ perception. We observed that the correlation between coaches’ and athletes’ SRPE increased with increased age and competitive swimming experience, r = .31 for the 11- to 12-y-old group (P < .001), r = .51 for the 13- to 14-y-old group (P < .001), and r = .74 for the 15- to 16-y-old group (P < .001). In addition, younger swimmers (11–12 y, P < .01; 13–14 y, P < .01) rated training intensity differently from coaches in all 3 categories (easy, moderate, and difficult), while the older group rated differently in only 1 category (difficult, P < .01). These findings suggest that the more experienced swimmers are, the more accurate their SRPE is.


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