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Open access

Marek Rejman, Andrzej Klarowicz and Krystyna Zatoń

An Evaluation of Kinesthetic Differentiation Ability in Monofin Swimmers

Purpose. The aim of this study was to compare the ability of monofin swimmers in reproducing the bending forces that act on a monofin's surface through the specific leg movement present in swimming as well as the forces that the swimmers generated on a kinesthesiometer as part of a dry-land simulation trial. Methods. Six men, members of the National Monofin Swimming Team, took part in the study. The level of the swimmers' kinesthetic response was defined by examining their repeatability in producing the bend forces that act on a monofin's surface as a reaction to water resistance and by investigation on the pressure force generated by a swimmer's lower limbs during dry-land tests on a kinesthesiometer. Results and conclusions. It was established that a high level of kinesthetic response, estimated in the group of monofin swimmers, was the result of an adaptation evoked from the specificity of their sensory stimulus perception, received in the form of feedback from the monofin's large surface area.

Open access

Jonas Martens and Daniel Daly

Qualitative Evaluation of Water Displacement in Simulated Analytical Breaststroke Movements

One purpose of evaluating a swimmer is to establish the individualized optimal technique. A swimmer's particular body structure and the resulting movement pattern will cause the surrounding water to react in differing ways. Consequently, an assessment method based on flow visualization was developed complimentary to movement analysis and body structure quantification. A fluorescent dye was used to make the water displaced by the body visible on video. To examine the hypothesis on the propulsive mechanisms applied in breaststroke swimming, we analyzed the movements of the surrounding water during 4 analytical breaststroke movements using the flow visualization technique.

Open access

Karini Borges Dos Santos, Jerusa P.R. Lara and Andre L.F. Rodacki

Abstract

Purpose. Intracyclic velocity variation is an important kinematic parameter to evaluate swimming performance. It can be estimated by a fixed point at the swimmer’s hip. The aim of the study was to determine the reproducibility and repeatability of active light markers to measure intracyclic velocity variation in swimming. Methods. Reproducibility and repeatability were tested by image measurement, by five manual digitizing processes and five sessions of automatic tracking of a LED marker set in a swimmer’s hip. The procedures were evaluated by the intraclass correlation coefficient, and the agreement between the methods was evaluated with Bland-Altman plots. The reproducibility was excellent in both procedures. Results. The repeatability of manual digitalization ranged between satisfactory to excellent, while the repeatability of automatic tracking was excellent. In addition, the Bland-Altman plots displayed a good agreement between manual and automatic measurements. The automatic tracking was 27% faster than manual digitization. Conclusions. Active markers are promising to evaluate the intracyclic velocity variation of swimmers, with a faster response than the common manual processing.

Open access

Piotr Makar and Grzegorz Bielec

Abstract

Purpose. The aim of the study was to assess lactate and glucose concentrations as indicators of anaerobic capacity in a highlyranked female junior swimmer. Methods. Ten trials of a 5 × 200 m backstroke step test were performed between December 2008 and July 2011. Each trial was video-recorded and blood samples were drawn from the ear lobe 1 min after completion of each step to measure lactate and glucose concentrations. Results. During maximal effort, lactate concentrations of 5.1 to 13.1 mmol · l-1 were recorded, while glucose concentration varied from 6.6 to 8.1 mmol · l-1. Correlations between lactate and glucose concentrations were significant in most tests. The shape of lactate and glucose curves revealed an improvement in the swimmer’s endurance ability during subsequent tests. Conclusions. Analysis of fluctuations in lactate and glucose concentrations appears to be a relevant indicator of the anaerobic capacity of experienced swimmers.

Open access

Katarzyna Michalak, Agnieszka Pawlicka-Lisowska and Elżbieta Poziomska-Piątkowska

Abstract

Purpose. The purpose of this study was to evaluate the effect of regular swimming activity on the respiratory system of smokers and non-smokers. Methods. The study included 196 students, aged 19 to 24 years, attending weekly swimming classes. All students underwent pulmonary function testing before and after participating in a swimming program for 10 months. Measurements included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow (PEF). Maximal inspiratory and expiratory pressure at the mouth (PImax, PEmax) and the percentage carboxyhemoglobin level in blood (%CoHb) were also measured. Results. After 10 months of regular swimming activity the values of FVC, PEF, MIP and MEP increased in the non-smoking as well as in the smoking group, while the FEV1 increased only among smokers. The percentage of CoHB level in the blood decreased in both groups. Conclusions. The study confirmed the positive effect of swimming on respiratory system function and the importance of promoting physical activity such as swimming among cigarette smokers as well as non-smokers.

Open access

Marek Strzała, Andrzej Ostrowski and Zbigniew Szyguła

Altitude Training and its Influence on Physical Endurance in Swimmers

It is possible to plan an altitude training (AT) period in such a way that the enhanced physical endurance obtained as a result of adaptation to hypoxia will appear and can be used to improve performance in competition. Yet finding rationales for usage of AT in highly trained swimmers is problematic. In practice AT, in its various forms, is still controversial, and an objective review of research concentrating on the advantages and disadvantages of AT has been presented in several scientific publications, including in no small part the observations of swimmers. The aim of this article is to review the various methods and present both the advantageous and unfavourable physiological changes that occur in athletes as a result of AT. Moreover, AT results in the sport of swimming have been collected. They include an approach towards primary models of altitude/hypoxic training: live high + train high, live high + train low, live low + train high, as well as subsequent methods: Intermittent Hypoxic Exposure (IHE) and Intermittent Hypoxic Training (IHT). Apnoea training, which is descended from freediving, is also mentioned, and which can be used with, or as a substitute for, the well-known IHE or IHT methods. In conclusion, swimmers who train using hypoxia may be among the best-trained athletes, and that even a slight improvement in physical endurance might result in the shortening of a swimming time in a given competition, and the achievement of a personal best, which is hard to obtain by normal training methods, when the personal results of the swimmer have reached a plateau.

Open access

Maria Novais, António Silva, Vishveshwar Mantha, Rui Ramos, Abel Rouboa, J. Vilas-Boas, Sérgio Luís and Daniel Marinho

The Effect of Depth on Drag During the Streamlined Glide: A Three-Dimensional CFD Analysis

The aim of this study was to analyze the effects of depth on drag during the streamlined glide in swimming using Computational Fluid Dynamics. The Computation Fluid Dynamic analysis consisted of using a three-dimensional mesh of cells that simulates the flow around the considered domain. We used the K-epsilon turbulent model implemented in the commercial code Fluent® and applied it to the flow around a three-dimensional model of an Olympic swimmer. The swimmer was modeled as if he were gliding underwater in a streamlined prone position, with hands overlapping, head between the extended arms, feet together and plantar flexed. Steady-state computational fluid dynamics analyses were performed using the Fluent® code and the drag coefficient and the drag force was calculated for velocities ranging from 1.5 to 2.5 m/s, in increments of 0.50m/s, which represents the velocity range used by club to elite level swimmers during the push-off and glide following a turn. The swimmer model middle line was placed at different water depths between 0 and 1.0 m underwater, in 0.25m increments. Hydrodynamic drag decreased with depth, although after 0.75m values remained almost constant. Water depth seems to have a positive effect on reducing hydrodynamic drag during the gliding. Although increasing depth position could contribute to decrease hydrodynamic drag, this reduction seems to be lower with depth, especially after 0.75 m depth, thus suggesting that possibly performing the underwater gliding more than 0.75 m depth could not be to the benefit of the swimmer.

Open access

Radosław Gola, Czesław Urbanik, Dagmara Iwańska and Anna Madej

Abstract

Purpose. competitive performance in swimming depends on a number of factors including, among others, the development of relevant muscle groups. The aim of the study was to clarify the relationship between muscle strength and swimming velocity and the role of individual muscle groups in front crawl swimming. Methods. sixteen physical education university students participated in the study. The strength values, defined as torque produced during isometric contractions, of eight upper and lower extremity muscle groups were measured. Data were compared with participants' front crawl swim times in the 25m and 50m distances. Results. correlation analysis demonstrated a relationship between muscle strength and swimming velocity. statistically significant relationships were observed between swimming velocity and the torque values of the elbow flexor and shoulder extensor muscles as well as the sum of upper extremity muscle torque values (p ⋋ 0.05). Conclusions. The results indicate the need for a focus on training those muscle groups identified as having a statistically significant relationship with swimming velocity for a given distance, as the sample showed deficiencies in the strength of those muscle groups responsible for generating propulsive force in the front crawl. Additionally, the collected data can serve as a diagnostic tool in evaluating the development of muscle groups critical for swimming performance.

Open access

Pedro Figueiredo, Leandro Machado, João Vilas-Boas and Ricardo Fernandes

Reconstruction Error of Calibration Volume's Coordinates for 3D Swimming Kinematics

The aim of this study was to investigate the accuracy and reliability of above and underwater 3D reconstruction of three calibration volumes with different control points disposal (#1 - on vertical and horizontal rods; #2 - on vertical and horizontal rods and facets; #3 - on crossed horizontal rods). Each calibration volume (3 × 2 × 3 m) was positioned in a 25 m swimming pool (half above and half below the water surface) and recorded with four underwater and two above water synchronised cameras (50 Hz). Reconstruction accuracy was determined calculating the RMS error of twelve validation points. The standard deviation across all digitisation of the same marker was used for assessing the reliability estimation. Comparison among different number of control points showed that the set of 24 points produced the most accurate results. The volume #2 presented higher accuracy (RMS errors: 5.86 and 3.59 mm for × axis, 3.45 and 3.11 mm for y axis and 4.38 and 4.00 mm for z axis, considering under and above water, respectively) and reliability (SD: underwater cameras ± [0.2; 0.6] mm; above water cameras ± [0.2; 0.3] mm) that may be considered suitable for 3D swimming kinematic analysis. Results revealed that RMS error was greater during underwater analysis, possibly due to refraction.

Open access

Ricardo Fernandes, João Ribeiro, Pedro Figueiredo, Ludovic Seifert and João Vilas-Boas

Kinematics of the Hip and Body Center of Mass in Front Crawl

The kinematic profiles of the hip and center of mass in front crawl swimming were compared to quantify the error of using a fixed body point to assess intracyclic velocity variations at moderate intensity exercise. The practical goal was to provide a useful tool, easy and fast to assess, and to use as feedback, for assessing swimming efficiency. Sixteen swimmers performed an intermittent incremental protocol that allowed assessing the individual anaerobic threshold velocity. One complete stroke cycle was analysed at the step intensity corresponding to each swimmer's anaerobic threshold. The subjects were videotaped in the sagittal plane using a double camera set-up for two-dimensional kinematical analyses. The hip and the center of mass presented similar mean velocity and displacement values, being highly related to both parameters. However, the hip reflects the center of mass forward velocity and horizontal displacement with 7.54% and 3.24% associated error, respectively. Differences between hip and center of mass were observed for intracyclic velocity variations (0.19±0.05 and 0.25±0.08, respectively, for a p<0.001), and the negative mean error value found (-0.06) evidenced a tendency of the hip to overestimate the center of mass velocity variation. It is possible to conclude that the hips forward movements might provide a good estimate of the swimmer's horizontal velocity and displacement that is relevant for diagnostic purposes, especially to assess swimming efficiency through the intracyclic velocity variations. Nevertheless, the hip point error magnitude should be taken into consideration in data interpretation.