Andrzej Mastalerz

Effectiveness of the Power Dry-Land Training Programmes in Youth Swimmers

Effectiveness of the Power Dry-Land Training Programmes in Youth Swimmers The aim of the study was to evaluate the effects of the dry-land power training on swimming force, swimming performance and strength in youth swimmers. Twenty six male swimmers, free from injuries and training regularly at least 6 times a week, were enrolled in the study and randomly assigned to one of two groups: experimental (n=14, mean age 14.0 ± 0.5 yrs, mean height 1.67±0.08 m and mean body mass 55.71 ±9.55 kg) and control (n=12, mean age 14.1 ± 0.5 yrs, mean height 1.61±0.11 m and mean body mass 49.07 ±8.25 kg). The experimental group took part in a combined swimming and dry-land power training. The control group took part in swimming training only. The training programmes in water included a dominant aerobic work in front crawl. In this research the experimental group tended to present slightly greater improvements in sprint performance. However, the stroke frequency insignificantly decreased (-4.30%, p>0.05) in the experimental group and increased (6.28%, p>0.05) in the control group. The distance per stroke insignificantly increased in the experimental group (5.98%, p>0.05) and insignificantly decreased in the control group (-5.36%, p>0.05). A significant improvement of tethered swimming force for the experimental group (9.64%, p<0.02) was found, whereas the increase was not statistically significant in the control group (2.86%, p>0.05). The main data cannot clearly state that power training allowed an enhancement in swimming performance, although a tendency to improve swimming performance in tethered swimming was noticed.

Benefits of Bandwidth Feedback in Learning a Complex Gymnastic Skill

The aim of this study was to examine the effects of two different frequencies of feedback during the process of learning a complex gymnastic skill, the round-off salto backward tucked. Thirty male acrobats participated in the study. They were randomly assigned to two groups: B - bandwidth feedback (n=15) or C - 100% feedback (n=15). Group B was provided with error information regarding the key elements of movement techniques only (bandwidth feedback). Our research demonstrates the advantage of augmented feedback information related to errors in the key elements. Information about errors in the key elements during learning a complex gymnastic skill prevents the gymnast from becoming overwhelmed, which promotes better motor control. These results provide support for the generalisation of bandwidth feedback principles to a complex task. Our research shows that the guidance hypothesis can also be tested in practical settings for a complex movement task.

THE EFFECTS OF SWIMMING AND DRY-LAND RESISTANCE TRAINING PROGRAMME ON NON-SWIMMERS

Abstract 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.

P 034 - the effect of treadmill geometry on muscle fatigue

The purpose of this study was to determine the influence of curve radius of the indoor (200 m) and outdoor (400 m) treadmill on bioelectrical muscle activity. Four professional male athletes that have an international master class in mens 400 m took part in that research. EMG measurements were recorded during the run on tartan athletic track in the indoor (200 m) and outdoor (400 m) treadmill. The athlete had to run 400 m distances with maximal speed. The mean power frequency (MPF) was calculated. Muscle fatigue was evaluated by the slope of regression line. The rate of fatigue was different and was related to the side of the body (3-24%) and the type (5-43%) of the muscle. Results indicate that muscle fatigue was greater for the right leg and during running on indoor truck.

Effect of two Backpack Designs on Cop Displacement and Plantar Force Distribution in Children during Upright Stance

Abstract Introduction. Many studies have compared different backpack designs and their influence on the carrier; however, no data referring to school students aged 7-8 years are currently available. Therefore, the aim of the research was to assess the influence of backpack design on centre of pressure (COP) displacement and plantar force distribution in children during an upright stance. Material and methods. Nineteen school students (9 males and 10 females) volunteered for the study. Two Polish backpacks intended for school use were evaluated: backpack A, which had two main compartments, and backpack B, which had one main compartment. The backpack load was composed of books, binders, and regular school equipment. During the measurements, the subjects were asked to look ahead with the head straight and arms at the sides in a comfortable position and to stand barefoot on the F-Scan® sensors (Tekscan, F-Scan®) attached to the force platform (Kistler), carrying a load corresponding to 10% of their body mass. Results. The study found insignificant differences between the two backpack designs. Moreover, COP parameters increased significantly during an upright stance while carrying backpack B in comparison to the empty backpack condition. Additionally, we observed significantly higher values of plantar force distribution in the heel region for the condition without load and insignificantly higher ones for carrying backpack A. Conclusions. The results of the current study suggest that the differences between the two backpack designs are too marginal to be detected through COP displacement. Disturbances in plantar force distribution suggest a lack of posture control and a lower stability of the standing position with a backpack, but these disturbances were significant only when the backpack with one main compartment was used.

Cross education after power training

The purpose of the study was to determine whether cross-education, defined as the increase in strength and power of an untrained limb after training of the contralateral homogenous limb, is specific for load types applied during the power training. Twenty four men attended the research After control measurement they were randomized into two groups (n=12 each). Subjects trained five times per week during 4 weeks and performed unilateral concentric training of the right knee on the special designed stand. Different load types were applied for each group: A - elastic bands (linear resistance load - elastic load) and B - weight discs (inertial load). Quantities of disc weights and elastic bands were established individually based on force-speed characteristics. Every Monday, before the training session, bilateral knee force during extension and flexion was measured on the Biodex System 3 Pro under isometric conditions and average power under isokinetic condition (240 deg/sec, 180 deg/sec, 60deg/sec and 30deg/sec). The above factors were measured four times in the post-training period again. Power training causes similar increase of force generating capacity for trained leg and no influence on homogenous force improvement for untrained leg. Until the end of experiment that trend was significantly evaluated in the group A to13 % and B to 9,3 % for the knee extensors. Moreover, 11 % increase of isometric force of agonists for untrained leg was noticed. Higher value occurred in the end of experiment was probably the effect of pelvis stabilization. Cross training effect for homogenous muscles was occurred for power of motion, but only for velocity similar to velocity of knee extension obtained for load quantity applied during power training. The increase of power in the absence of direct training confirmed hypothesis of alterations in neural control specific to training procedures. The influence of mechanical characteristics of external load on cross education was proved.