50,096 research outputs found
Combined strength and endurance training in competitive swimmers
No full textReprinted from Journal of Sports Science and Medicine, 8, Stian Aspenes,
Per-Ludvik Kjendlie, Jan Hoff and Jan Helgerud, Combined strength and
endurance training in competitive swimmers, Pages No. 357-365,
© Journal of Sports Science and Medicine (2009) with permission from the
JOURNAL OF SPORTS SCIENCE AND MEDICINE.A combined intervention of strength and endurance training is common practice in elite swimming training, but the scientific evidence is scarce. The influences between strength and endurance training have been investigated in other sports but the findings are scattered. Some state the interventions are negative to each other, some state there is no negative relationship and some find bisected and supplementary benefits from the combination when training is applied appropriately. The aim of this study was to investigate the impact of a combined intervention among competitive swimmers. 20 subjects assigned to a training intervention group (n = 11) or a control group (n = 9) from two different teams completed the study. Anthropometrical data, tethered swimming force, land strength, performance in 50m, 100m and 400m, work economy, peak oxygen uptake, stroke length and stroke rate were investigated in all subjects at pre and post-test. A combined intervention of maximal strength and high aerobic intensity interval endurance training 2 sessions per week over 11 weeks in addition to regular training were used, while the control group continued regular practice with their respective teams. The intervention group improved land strength, tethered swimming force and 400m freestyle performance more than the control group. The improvement of the 400m was correlated with the improvement of tethered swimming force in the female part of the intervention group. No change occurred in stroke length, stroke rate, performance in 50m or 100m, swimming economy or peak oxygen uptake during swimming. Two weekly dry-land strength training sessions for 11 weeks increase tethered swimming force in competitive swimmers. This increment further improves middle distance swimming performance. 2 weekly sessions of high-intensity interval training does not improve peak oxygen uptake compared with other competitive swimmers
Effects of shoulder compensatory strength training program in rotator cuff strength of young swimmers.
No full textINTRODUCTION
The purpose of this study was to evaluate de effects of 16 week compensatory strength training program in shoulder strength and respective conventional ratios (concentric ER/IR).
METHODS
A total of 40 national level male swimmers were assessed and randomly divided in two groups – experimental group (N=20)-(age:14.65±0.67 years old, height:173.48±6.87 cm, body mass:63.15±5.68 kg) and control group (N=20)-(age:14.60±0.60 years old, height: 170.79±6.48 cm, body mass:61.73±4.68 kg). Experimental subjects participated in a 16 week shoulder strength program with Thera-Band® elastic bands (3 times a week). The peak-torque of shoulder internal (IR) and external rotators (ER) was measured in both groups at baseline and after 16 weeks. Concentric action at 60º/s (3 rep) and 180º/s (20 rep) were measured, in a seated position, with the shoulder at 90º of abduction and the elbow flexed to 90º, using an isokinetic dynamometer (Biodex System 3 – Biodex Corp., Shirley, USA). Anova with repeated measures was used to determine significant main effects in shoulder rotators strength and unilateral ER/IR ratios. The level of significance was set at 0.05.
RESULTS
Significant differences were found in all variables that measure the ER shoulder strength at 60º/s in dominant(DT) (P=0.031) and non-dominant(NDT) shoulder (P=0.001). Meanwhile concentric action at 180º/s, only showed significant differences on DT shoulder (P=0.032). In respect of ER/IR ratio, a compensatory strength training programme induces significant differences in both shoulders at 60º/s (DT: P=0.001; NDT: P=0.001). At 180º/s we just found significant effects on the DT ER/IR ratio (P=0.002).
DISCUSSION
The results of this study support earlier research [1] that showed that the unilateral shoulder strength ratios increases substantially after a period of a strength training program. Since the ratios describe the quality of muscular balance/imbalance [1], we can conclude that a 16 week compensatory shoulder strength training program using Thera-Band® elastic bands, reduces muscular imbalances in rotator cuff of competitive young swimmers. These results highlight the useful of this kind of compensatory program to prevent shoulder injuries
Movement patterns in free water play after swimming lessons with flotation aids
No full textThe aim of this study was to investigate the movement patterns of children during free play in a swimming school setting. It was hypothesized that children being taught using flotation vests would be less likely to surface dive, jump, and dive during free play. In this study, 24 participants were observed using a video camera during a 10-minute free play period at the end of a learn-to-swim session. Each subject had undergone 10 lessons either using a flotation vest (n = 11) or without (n = 13). The results showed that the flotation aid group (FLOAT) had significantly fewer surface dives (p = 0.006, using a two sample t-test) compared to the control group (CON) and that FLOAT asked for flotation toys significantly more often than CON (p = 0.03) during free play. No statistically significant differences between groups were observed for breathing, diving, and water entry skills, and the distance moved on land and in water due to low statistical power, but FLOAT participants seemed to be less likely to do vertically-oriented movements. We concluded that children learning to swim using flotation aids had a tendency to move more horizontally during free play and to not choose vertical axis movements (jumping and surface diving) compared to children being taught without the flotation vest
Co-ordination Changes during a Maximal Effort 100 m Short Course Breaststroke Swim
No full textThe aim of the study was to establish the changes in co-ordination that occur during a 100 m breaststroke swim from a water start by: 1) measuring the kinematic changes that occur as the swimmer progressed through the four laps and, 2) analysing the co-ordination of the arms and legs (transition phase) corresponding to the time between the end of the leg propulsion and the start of the arm propulsion phases. Breaststroke participants (n=8, females and n=18, males) performed a 100 m maximal swim in a 25 m pool. They were recorded underwater using three 50 Hz cameras (one at each end of the pool and one mounted on a trolley). The last three strokes prior to turns were analysed. Significant changes in clean swim speed (
Movement patterns in free water play after swimming lessons with flotation aids
No full text© 2012 Human Kinetics, Inc.The aim of this study was to investigate the movement patterns of children during free play in a swimming school setting. It was hypothesized that children being taught using flotation vests would be less likely to surface dive, jump, and dive during free play. In this study, 24 participants were observed using a video camera during a 10-minute free play period at the end of a learn-to-swim session. Each subject had undergone 10 lessons either using a flotation vest (n = 11) or without (n = 13). The results showed that the flotation aid group (FLOAT) had significantly fewer surface dives (p = 0.006, using a two sample t-test) compared to the control group (CON) and that FLOAT asked for flotation toys significantly more often than CON (p = 0.03) during free play. No statistically significant differences between groups were observed for breathing, diving, and water entry skills, and the distance moved on land and in water due to low statistical power, but FLOAT participants seemed to be less likely to do vertically-oriented movements. We concluded that children learning to swim using flotation aids had a tendency to move more horizontally during free play and to not choose vertical axis movements (jumping and surface diving) compared to children being taught without the flotation vest
Breaststroke swimmers moderate internal work increases toward the highest stroke frequencies
No full textA model to predict the mechanical internal work of breaststroke swimming was designed. It allowed us to explore the frequency–internal work relationship in aquatic locomotion. Its accuracy was checked against internal work values calculated from kinematic sequences of eight participants swimming at three different self-chosen paces. Model predictions closely matched experimental data (0.58±0.07 vs 0.59±0.05 J kg−1 m−1; t(23)=−0.30, P=0.77), which was reflected in a slope of the major axis regression between measured and predicted total internal work whose 95% confidence intervals included the value of 1 (β=0.84, [0.61, 1.07], N=24). The model shed light on swimmers ability to moderate the increase in internal work at high stroke frequencies. This strategy of energy minimization has never been observed before in humans, but is present in quadrupedal and octopedal animal locomotion. This was achieved through a reduced angular excursion of the heaviest segments (7.2±2.9° and 3.6±1.5° for the thighs and trunk, respectively, P<0.05) in favor of the lightest ones (8.8±2.3° and 7.4±1.0° for the shanks and forearms, respectively, P<0.05). A deeper understanding of the energy flow between the body segments and the environment is required to ascertain the possible dependency between internal and external work. This will prove essential to better understand swimming mechanical cost determinants and power generation in aquatic movements
We\u27re in the Same Boat - Brother! Aquatic Movement Research and Drowning Prevention Research
No full textLudvik Kuba in njegov pomen za razvoj kulturnih odnosov med Čehi in Jugoslovani
No full textThe author describes the life and work of Ludvik Kuba (1863-1956), the Czech musician, painter, writer, folklorist and melograph. He also gives a picture of his relations to the South Slavs.Avtor daje sliko življenja in dela Ludvika Kube (1863-1956) češkega glasbenika, slikarja, pisatelja, folklorista in melografa ter njegovih stikov z južnimi Slovani
A proposed framework for developing a plan for research in lifesaving and water safety
No full textIn the centers for aquatic
research, the infrastructure, methodology, and expertise already exist. What remains
is to integrate the needs and interests of lifesaving research into these programs.
Especially in physiology and biomechanics, the tools are already in place. The ILS,
with two world congresses under its belt, is the ideal agency to foster systematic
lifesaving research. This article addresses that issue and recommends a framework
for developing a plan for research in lifesaving and water safety
Drag characteristics of competitive swimming children and adults
No full textThe aims of this study were to compare drag in swimming children and adults, quantify technique using the technique drag index (TDI), and use the Froude number (Fr) to study whether children or adults reach hull speed at maximal velocity (vmax). Active and passive drag was measured by the perturbation method and a velocity decay method, respectively, including 9 children aged 11.7 ± 0.8 and 13 adults aged 21.4 ± 3.7. The children had significantly lower active (kAD) and passive drag factor (kPD) compared with the adults. TDI (kAD/kPD) could not detect any differences in swimming technique between the two groups, owing to the adults swimming maximally at a higher Fr, increasing the wave drag component, and masking the effect of better technique. The children were found not to reach hull speed at vmax, and their Fr were 0.37 ± 0.01 vs. the adults 0.42 ± 0.01, indicating adults’ larger wave-making component of resistance at vmax compared with children. Fr is proposed as an evaluation tool for competitive swimmers
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