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Open access

Athanasios A. Dalamitros, Vasiliki Manou, Kosmas Christoulas and Spiros Kellis

Abstract

Previous studies demonstrated significant increases in the shoulder internal rotators’ peak torque values and unilateral muscular imbalances of the shoulder rotators after a competitive swim period. However, there are no similar data concerning the knee muscles. The purpose of the current study was to examine the effects of a six-month training period on knee flexor and extensor peak torque values, examine a possible bilateral strength deficit and evaluate the unilateral strength balance in competitive swimmers. Eleven male adolescent swimmers (age: 14.82 ± 0.45 years) were tested for concentric knee extension and flexion peak torque (60°/s) with an isokinetic dynamometer, before and after a regular combined swim and dry-land strength training period. A trend towards greater improvements in the knee extensor compared to flexor muscles peak torque was observed. Furthermore, the bilateral strength deficit remained almost unchanged, whereas unilateral strength imbalance was increased for both limbs. However, all results were nonsignificant (p > 0.05). According to the data presented, a six-month regular combined swim and dry-land strength training period caused non-significant alterations for all the parameters evaluated during isokinetic testing. This study highlights the fact that competitive adolescent swimmers demonstrated unilateral knee strength imbalances throughout a long period of their yearly training macrocycle.

Open access

Irena Pusica, Ivan Srejovic, Jovana Bradic, Jelena Smigic, Stefani Bolevich, Sergey Bolevich, Vladimir Jakovljević and Dusica Djordjevic

Abstract

Energy drinks (EDs) contain caffeine and other active ingredients which affect cardiovascular system. The aims of this study were to examine direct effects of Red Bull (RB) on cardiodynamics and oxidative stress in isolated hearts of rats. The rats were divided into four groups: untrained rats who never consumed ED (dED-UT); untrained rats who consumed ED 5 days a week during 4 weeks (ch+dED-UT); rats trained 5 times a week for 4 weeks, but did not consume ED (dED-T); rats trained and consumed ED 5 times a week for 4 weeks (ch+dED-T). After sacrificing, hearts were isolated and perfused according to Langendorff technique. Through the isolated heart of all rats in each group, RB was administered. The parameters of cardiac function were recorded, and the levels of prooxidants were measured in the coronary effluent during coronary autoregulation. Rats in ch+dED-UT group had significantly lower rates of myocardial contraction and relaxation compared to rats in dED-UT group. The same effect was recorded in the dED-T group compared to dED-UT group. The levels of hydrogen peroxide were significantly higher in trained rats. Rats in ch+dED-T group also had significantly higher levels of superoxide anion radical and index of lipid peroxidation, as well as lower levels of nitrites when compared to ch+dED-UT group, while opposite effect was recorded in rats in dED-T group compared to dED-UT group. The RB could have a potentially negative inotropic effect in chronic consumers. Prooxidative effect of RB was most pronounced in trained chronic consumers.

Open access

Argyris G. Toubekis, Evgenia Drosou, Vassilios Gourgoulis, Savvas Thomaidis, Helen Douda and Savvas P. Tokmakidis

Abstract

The study examined the changes of training load and physiological parameters in relation to competitive performance during a period leading to a national championship. The training content of twelve swimmers (age: 14.2±1.3 yrs) was recorded four weeks before the national championship (two weeks of normal training and two weeks of the taper). The training load was calculated: i) by the swimmer’s session-RPE score (RPE-Load), ii) by the training intensity levels adjusted after a 7x200-m progressively increasing intensity test (LA-Load). Swimmers completed a 400- m submaximal intensity test, a 15 s tethered swimming and hand-grip strength measurements 34-35 (baseline: Test 1), 20-21 (before taper: Test 2) and 6-7 (Test 3) days before the national championship. Performance during the national championship was not significantly changed compared to season best (0.1±1.6%; 95% confidence limits: -0.9, 1.1%; Effect Size: 0.02, p=0.72) and compared to performance before the start of the two-week taper period (0.9±1.7%; 95% confidence limits: 0.3, 2.1%; Effect size: 0.12, p=0.09). No significant changes were observed in all measured physiological and performance related variables between Test 1, Test 2, and Test 3. Changes in RPE-Load (week-4 vs. week-1) were correlated with changes in performance (r=0.63, p=0.03) and the RPE-Load was correlated with the LALoad (r=0.80, p=0.01). The estimation of the session-RPE training load may be helpful for taper planning of young swimmers. Increasing the difference between the normal and last week of taper training load may facilitate performance improvements.

Open access

Damian Jerszyński, Katarzyna Antosiak-Cyrak, Małgorzata Habiera, Krystian Wochna and Elżbieta Rostkowska

The study aimed to examine changes in selected angular characteristics and duration of the stroke cycle in the back crawl and the front crawl in children learning to swim. Nine boys and two girls, aged 8-13 years, performed seven consecutive swimming tests. The children’s movement technique was recorded with the use of three video cameras. The studied parameters included the angle of incidence between the trunk long axis and the waterline, elbow angle, shoulders roll, stroke cycle duration and stroke length. The results illustrate the development of swimming technique in youth swimmers. The results of the present study indicate the variability and phasing of learning of swimming technique by children.

Open access

Maria Teresa da Silva Pinto Marques-Dahi, Flavio Henrique Bastos, Ulysses Okada de Araujo, Cinthya Walter and Andrea Michele Freudenheim

Abstract

Purpose. In Front-Crawl swimming stroke, the interaction between two of its components, i.e. arm stroke and breathing, affects the performance of the motor skill as a whole and therefore can be considered a critical aspect of the skill. The purpose of our study was to investigate if a verbal instruction emphasizing this interaction could lead to learning gains when provided along with video demonstrations.

Methods. Participants (children) were randomly assigned to three experimental groups according to the type of verbal instruction provided. Component and Interaction groups received their specific instructions along with video demonstrations of a model execution of the Front-Crawl. The Control group watched the same video, but received no further instruction concerning the movement pattern. In the Acquisition phase (AQ) all groups performed 160 trials (organized in 4 sessions) of the task that consisted in swimming 8 meters the Front-Crawl at a comfortable velocity. To assess learning gains, a retention test (RT) and a transfer test (TR) were carried out one week after the end of the AQ.

Results. Regarding RT and TR, the one-way ANOVA on the movement pattern score showed a significant difference between groups, with post-hoc tests revealing that the Interaction group achieved higher score than the Control group.

Conclusions. The results reveal that enhancing aspects of a video demonstration with verbal instruction improves learning gains of the Front-Crawl in children. Additionally, the results suggest that providing verbal instructions about the interaction between stroke and breathing might promote learning gains, compared to providing instructions about the stroke component individually.

Open access

Alexander Khapalov

Abstract

In this addendum we address some unintentional omission in the description of the swimming model in our recent paper (Khapalov, 2013)

Open access

Ryszard Zarzeczny, Mariusz Kuberski, Agnieszka Deska, Dorota Zarzeczna, Katarzyna Rydz, Anna Lewandowska, Tomasz Bałchanowski and Janusz Bosiacki

Effects of 8-week training on aerobic capacity and swimming performance of boys aged 12 years

Study aim: To assess the effects of 8-week endurance training in swimming on work capacity of boys aged 12 years.

Material and methods: The following groups of schoolboys aged 12 years were studied: untrained control (UC; n = 14) and those training swimming for two years. The latter ones were subjected to 8-week training in classical style (CS; n = 10) or free style (FS; n = 13). In all boys maximal oxygen uptake (O2max) was determined, and the CS and FS groups were subjected to 6 tests: swimming at 50 and 400 m distances (time recorded) and to 12-min swimming (distance recorded), all by free and classical styles pre- and post-training. From swimming times at 50 and 400 m distances the so-called critical swimming speed (CSS) was computed: CSS = (400 - 50) / (t400 - t50).

Results: No training-induced improvement in O2max was noted in any group. Yet, boys subjected to classical style training significantly (p<0.05) improved their free-style swimming velocity at CSS and at the 400-m distance by about 6%, and their heart rate following the 12-min test in classical style decreased by nearly 16% (p<0.001) compared with the pre-training values.

Conclusions: The 8-week training in given swimming style does not negatively affect the performance in other style than the trained one. This may be of importance in competitive training.

Open access

Ahmet Alptekin

Abstract

The purposes of this study were to compare the kinematic variables in youth swimmers during the grab start between sexes and to investigate the relationship between body composition and kinematic variables of the participants. Six female (Mage = 13.71 ± 0.49 yrs) and seven male (Mage = 14.00 ± 1.07 yrs) swimmers participated in this study. All participants were required to perform grab start tests in random order (three trials by each participant), while the best attempt was analyzed. Nineteen kinematic parameters consisting of block time, flight time, flight distance, total time, total distance, horizontal and vertical displacement of the center of mass (CM) at take-off, horizontal and vertical displacement of the CM at entry, height of take-off and entry, relative height of take-off, horizontal and vertical velocity of the CM at take-off, horizontal and vertical velocity of the CM at entry, angle of take-off, angle of entry and angle of knee at block were analyzed. Out of the 19 evaluated kinematic parameters, a statistical difference between the female and male group was found only in the total distance. Therefore, both female and male groups are considered as only one group and merged after analyzing the results. Statistical analysis showed positive and negative correlations between horizontal / vertical velocity of CM at take-off and several kinematic variables (e.g. angle of entry (rhorizontal = -.868, p=.000 / rvertical = .591, p=.02), total distance (rhorizontal = .594, p=.02 / rvertical = .54, p=.04), and height of take-off (rvertical = .888, p=.000), respectively). On the other hand, positive and negative correlations were found between somatotype components and several kinematic variables (e.g. horizontal displacement of CM at entry (rendomorphy = -.626, p=.013), angle of entry (rmesomorphy = -.686, p=.005 / rectomorphy = .52, p=.047), total distance (rendomorphy = -.626, p=.012), and height of take-off (rendomorphy = -.633, p=.011 / rectomorphy = .515, p=.05)). In conclusion, results show that in order to be successful at grab start performance, a swimmer should target to get higher horizontal velocity of CM at take-off and optimize the angle of take-off so this movement form supplies more total distance to the swimmer. Coaches should consider improving start performance and adding start training to regular training sessions. Moreover, youth male and female swimmers can participate together in the grab start training

Open access

Ryszard Zarzeczny, Mariusz Kuberski, Agnieszka Deska, Dorota Zarzeczna and Katarzyna Rydz

Abstract

Purpose. It has been suggested that the critical swimming speed (CSS ) of young swimmers may be estimated by using two timed maximum exertion efforts at distances of 50 and 400 m. The aim of this study was to find out if the estimated CSS for a group of boy swimmers corresponds to the results obtained from a 12-min swim test and to examine if there was a difference whether these tests were completed using different swimming strokes. Methods. The study was carried out on 24 boys (age 12.2 ± 0.1 y, height 158.0 ± 1.8 cm, weight 47.7 ± 2.2 kg), all of whom were competing at the regional level. The participants were timed completing the 50 and 400 m distances at maximal effort, while the 12-min test was assessed by the total distance swum, all three trials performed in the front crawl and breaststroke. Results. The results found a close relationship between CSS determined by the 50 and 400 m distances and the distance covered during the 12-min test for both strokes (breaststroke r = 0.79, p = 0.0000; front crawl r = 0.83, p = 0.0000). There were no significant differences between CSS and the mean velocity of the 12-min swim test with swum in the front crawl (0.862 ± 0.027 m · s-1 and 0.851 ± 0.027 m · s-1, respectively); however, CSS was significantly higher (p = 0.002) than the mean velocity found in the 12-min test in the breaststroke (0.769 ± 0.018 m · s-1 and 0.727 ± 0.022 m · s-1, respectively). Conclusions. CSS estimated on the basis of the front crawl but not breaststroke is a good predictor of the average velocity of the 12-min swim test for young male swimmers.

Open access

Stefan Szczepan, Krystyna Zatoń and Andrzej Klarowicz

Abstract

Introduction. Developing the ability to control the speed of swimming is an important part of swimming training. Maintaining a defined constant speed makes it possible for the athlete to swim economically at a low physiological cost. The aim of this study was to determine the effect of concurrent visual feedback transmitted by the Leader device on the control of swimming speed in a single exercise test. Material and methods. The study involved a group of expert swimmers (n = 20). Prior to the experiment, the race time for the 100 m distance was determined for each of the participants. In the experiment, the participants swam the distance of 100 m without feedback and with visual feedback. In both variants, the task of the participants was to swim the test distance in a time as close as possible to the time designated prior to the experiment. In the first version of the experiment (without feedback), the participants swam the test distance without receiving real-time feedback on their swimming speed. In the second version (with visual feedback), the participants followed a beam of light moving across the bottom of the swimming pool, generated by the Leader device. Results. During swimming with visual feedback, the 100 m race time was significantly closer to the time designated. The difference between the pre-determined time and the time obtained was significantly statistically lower during swimming with visual feedback (p = 0.00002). Conclusions. Concurrently transmitting visual feedback to athletes improves their control of swimming speed. The Leader device has proven useful in controlling swimming speed.