Jerzy Sadowski, Andrzej Mastalerz, Wilhelm Gromisz, Ewa Jówko and Mariusz Buszta
Introduction. The aim of the study was to estimate the influence of combined swimming and dry-land resistance training on swimming force, swimming performance and strength in non-swimmers.
Material and methods. Thirty male non-swimmers took part in the research. They were randomly assigned to one of the two groups: experimental (n=17) and control (n=13). The experimental group took part in combined swimming and dry-land resistance training. The control group took part in swimming training only. The swimming and dry-land resistance training programme lasted twelve weeks (48 training sessions of swimming and 36 sessions of dry-land resistance training). Average training volume and intensity were the same for all swimmers throughout the study protocol. The training programme included dominant aerobic work in front crawl.
Results. Dry-land resistance training applied in the experimental group significantly improved the upper body strength. In spite of the theory that dry-land strength training is probably not specific enough to improve the sprint swim performance, the experimental group tended to demonstrate greater improvement in sprint performance. The imitation of the underwater phase of shoulder work during front crawl provided by the ergometer can be a useful training method in non-swimmers.
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.
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.
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.
This paper reports on findings of a pilot research to determine the level of swimming ability of children with weak respiratory system aged between 10 - 11 years, who attended special classes for asthmatics. Swimming ability was assessed by 25 m free style swimming test. The results of asthmatics were compared with healthy peers (Benčuriková 2006; Kováčová 2010; Labudová 2011). The results confirmed that the level of swimming capability of asthmatic children, despite their handicap, is significantly higher than their healthy peers.
The text deals with neurophysiological and kinesiological developmental principles associated with the early development of young children as the fundamental prerequisites for physical education in the aquatic environment. Swimming in infancy and early childhood using the developmental principles and understanding of individual variability represent enormous potential to create a positive attitude of the child to exercise in aquatic environments. We believe that the experience with these basic tasks can play a key role in future exercise habits and swimming literacy of the individual. Parents attending infant swimming courses led by an instructor acquire practical skills and deeper insight into principles of their child's motor learning. All activities in the aquatic environment at an early age should allow transfer of child’s experiences to preswimming education and result in full swimming literacy.
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.
Agata Grenda, Marek Sawczuk, Mariusz Kaczmarczyk, Agnieszka Maciejewska, Danuta Umiastowska, Wioletta Łubkowska, Piotr Żmijewski and Paweł Cięszczyk
Single nucleotide polymorphism C825T located within the GNB3 gene has been proposed in the literature as the performance enhancing polymorphism in highly trained athletes. Therefore, the aim of the present study was to verify the hypothesis assuming an association between the C825T polymorphic site and performance of competitive swimmers. The frequencies of C/T alleles and distribution of CC, CT and TT genotypes of the C825T GNB3 polymorphism were compared between athletes and nonathletic controls as well as between sprint and endurance swimmers. Genomic DNA was extracted from 197 competitive swimmers (50 long distance swimmers (LDS) and 147 short distance swimmers (SDS)) and 379 sedentary volunteers. The allele frequencies and genotype distribution of the C825T polymorphic site were not significantly different when LDS and SDS were compared to sedentary controls. Gender-specific analysis did not reveal any significant differences in allele and genotype distribution, neither between female controls and female swimmers nor between male controls and male swimmers. No significant differences in allele frequencies and genotype distribution were observed when LDS and SDS as well as groups of swimmers stratified by gender were compared. The results of this study do not support the hypothesis that the C825T polymorphism of the GNB3 gene is associated with swimming performance in competitive swimmers.
The aim of this study was to investigate the effect of the head position on passive drag with a towing-line experiment in a swimming pool. The tests were performed on ten male swimmers with regional level swimming skills and at least 10 years of competitive swimming experience. They were towed underwater (at a depth of 60 cm) at three speeds (1.5, 1.7 and 1.9 m/s) and in two body positions (arms above the swimmer’s head and arms alongside the body). These two body positions were repeated while the swimmer’s head was positioned in three different ways: head-up, head-middle and head-down in relation to the body’s horizontal alignment. The results showed a reduction of 4-5.2% in the average passive drag at all speeds when the head was down or aligned to the swimmer’s arms alongside the body, in comparison to the head-up position. A major significant decrease of 10.4-10.9% (p < 0.05) was shown when the head was down or aligned at the swimmer’s arms above the swimmer’s head. The passive drag tended to decrease significantly by a mean of 17.6% (p < 0.001) for all speeds examined with the arms alongside the body position rather than with the arms above the head position. The swimmer’s head location may play an important role in reducing hydrodynamic resistance during passive underwater gliding.
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.