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1

Biomechanical Studies on Running the 400 M Hurdles

100%

Iskra J., Coh M.

Human Movement

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2011

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vol. 12

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issue 4

315-323

EN

Purpose. Biomechanical research conducted on hurdling are the basis for analysis of technique used in running disciplines. However, the 400 m hurdle run is an athletic discipline rarely subjected to individual biomechanical study. The aim of this study was to introduce the various forms of biomechanical studies on this difficult-to-quantify athletic event. Methods. In this study, 64 biomechanical articles were assessed, each covering various topics such as kinematics, dynamics, accelometrics and rhythm knowledge in the both the men's and women's 400 m hurdles. This was conducted with regard to the specificity of studies on the 400 m hurdles, including their types, methods and difficulties. The characteristics of the study were divided, among others, into: physiological effort, centrifugal force, dynamics of movement, stride rhythm, the level of abilities, laterality and type of body build. Results. Numerous sources allowed the creation of a general outline of present biomechanical studies. Conclusions. Within the context of the conducted analysis on the present state of biomechanical analysis on the 400 m hurdles, a number of basic principles were outlined that could determine the effectiveness of future research possibilities for scientists on the 400 m hurdles.

2

Changes in women’s 400 m hurdle run from 1978 to 2014

100%

Pietrzak M., Iskra J.

Physical Activity Review

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2016

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vol. 4

132-138

EN

Introduction : 400m hurdle run (400m H) is hel d on a track consisting of nine 35 - meter sections separated by ten 91 cm high hurdles. Numerous analyses of the run structure carried out at major events (Olympic Games, World and European Championships) indicate that the tactics of the run consists of tw o parts: "stride pattern" and "split times". Material and methods : The exploration of spacio - temporal structure of the 400m H run included in this study is a meta - analysis, involving all major competitions that were held within the period of 36 years (from 1978 to 2014). The analysis included 260 runs from two periods of time: 1978 - 1999 (Group A; n = 128) and 2000 - 2014 (Group B; n = 132). Detailed data included in the analysis involved temporal parameters (times of particular sections and fragments of the run) and spatial parameters (number of strides). To evaluate the differences between the groups, the analysis of variance (ANOVA) was used. Results : The sports performance level was similar in both groups (53.65 ± 0.72s vs. 0.83s ± 53.60.60). The body buil d was differentiated only by body mass – the female hurdlers competing after 2000 were heavier (p≤0.05). The analysis of time structure proves that modern female hurdlers cover the distance of 400 m faster in the first part (p≤0.01), and significantly decr ease the running speed in the final part of the run. The number of strides in Group B is significantly lower at the beginning of the run (p≤0.01), but increases significantly in its following part. Conclusion : The tactics of women’s 400m H run has changed after 2000. It affects indirectly changes in the training process.

3

Principal Component Analysis in the Study of Structure of the Best Polish Decathlon Competitors from the Period between 1985–2015

81%

Dziadek B., Iskra J., Przednowek K.

Central European Journal of Sport Sciences and Medicine

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2018

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vol. 23

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issue 3

77-87

EN

The modern decathlon is a sport consisting of ten different events held over two days, played by men. Depending on the complexity of combined events, variety of events (runs, throws, jumps), the multi-stage, time-consuming and difficult training process the sport is considered as one of the most difficult. The analysis of careers of the best decathlon participants and applying advanced data-mining methods can help define the patterns occurring between each decathlon event and the final result. The research material encompasses career data of the 25 top competitors from Poland in years 1985–2015. Principal component analysis (PCA) was used in the research in order to designate new uncorrelated variables (components), representing input data across a new plane. Data analysis involved appointment of correlations between the events, determining the number of main components taken into account in further studies, analysis of the weight of each variable in formation of main components as well as visualisation and interpretation of results in the new plane described by the determined main components. Through the implementation of PCA method in the process of analysis it was possible to designate over 69% of compound data volatility with the use of the first three components. The first component, comprised of seven variables, displays the largest share in the total variability. The study of the relationship between variables in the new plane displayed strong correlations between sprint events (100 m, 110 m hurdles) and long jump and pole vault. No correlations between the 1500 m run and other events were found.

4

THE USE OF ARTIFICIAL NEURAL NETWORKS IN SUPPORTING THE ANNUAL TRAINING IN 400 METER HURDLES

81%

Iskra J., Przednowek K., Wiktorowicz K., Krzeszowski T.

Central European Journal of Sport Sciences and Medicine

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2017

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vol. 17

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issue 1

15-24

EN

This paper presents an evaluation of the annual cycle for 400 m hurdles using artificial neural networks. The analysis included 21 Polish national team hurdlers. In planning the annual cycle, 27 variables were used, where 5 variables describe the competitor and 22 variables represent the training loads. In the presented solution, the task of generating training loads for the assumed result were considered. The neural models were evaluated by cross-validation method. The smallest error was obtained for the radial basis function network with nine neurons in the hidden layer. The performed analysis shows that at each phase of training the structure of training loads is different.

5

Running preparation and the final decathlon score in terms of sports career development

81%

Dziadek B., Iskra J., Przednowek K.

Physical Activity Review

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2016

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vol. 4

115-123

EN

Introduction: Success in decathlon contests is achieved by athletes of all ages - from 18 to almost 40 yea rs. The development and importance of individual competitions in the final point score have changed during many years of sports ontogenesis. The aim of the study was to evaluate the changes taking place in sports performance level within the decathlon runn ing competitions and their impact on the final result during the long - term sports championship (sports career) development. Materials and methods: In the analysis, data concerning the "sports ontogenesis” of the world’s best decathletes (N = 25, mean score 8198 points) were used. The final point score and results in three running competitions, i.e. 100, 400 and 1500m runs were taken into account. In the evaluation of sports championship development, four stages were singled out: junior (up to 19 years), yout h (to 23 years), the age in which the best results are achieved (up to 30 years), and the final stage of sports championship (decrease of the performance level - 31 years and more). The changes in performance level were evaluated based on analysis of varia nce (ANOVA), the relationship between the partial results (runs) and the final score (decathlon) was evaluated based on the Pearson correlation analysis. Results: The calculated values of correlation coefficient showed that there is a relationship between the results achieved in the running events and the total score at the individual stages of athletes’ sports development. The highest Pearson correlation values in all researched periods were determined for the 400m run (|r xy | > 0.59 ; p < 0.05) . Additionall y, at the third stage of sports career development (stage, at which athletes achieve the best results), the final score is also impacted by the level of results achieved at the distance of 100m. The correlation values for distances of 100 and 400m, are at this stage comparable and are approx. |r xy | = 0.6. Conclusions: The greatest impact on the final score achieved by decathletes at all stages of their sports career is running preparation over the distance of 400m.

6

Effects of Long-term Regular Exercise on Cognitive Function, Lipid Profile and Atherogenic Biomarkers in Middle-aged Men

52%

Kłapcińska B., Kroemeke A., Tataruch M., Tataruch R., Szołtysek-Bołdys I., Derejczyk J., Kimsa E., Iskra J.

Journal of Human Kinetics

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2008

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vol. 20

89-98

EN

Several studies on exercise and its effect on cognitive function in human and animal populations have documented the beneficial impact of regular physical activity on maintenance of good cognitive abilities and satisfactory health-related quality of life well into older age. The aim of the study was to evaluate the effects of long-term regular running on metabolic profile and cognitive function in middle-aged men.A total of 24 regularly exercising, middle-age men (Group A), all being members of the Runners Club, and 22 age-matched sedentary subjects (Group B), as the control group, were enrolled in this study. The control group included 8 non-overweight (BMI=23.5±5.2) individuals (Group C) and 14 overweight/obese (BMI=30.7±1.6) subjects (Group D). Serum lipid profile, glucose and homocysteine concentrations were assessed by routine laboratory methods. Subjects' cognitive function was evaluated based on Trail Making Test (TMT) and Digit Symbol Test (DST) scores.In a majority of runners (Group A), the BMI and the parameters of lipid profile (TC, HDL, LDL, TG, glycerol) were close to those recorded in non-overweight controls (Group C) and, in both groups, results were ideally within the reference ranges for healthy male subjects. However, as compared to the whole control group (Group B), which may be considered as an average population sample of sedentary middle-age men, significant differences were observed in BMI and concentrations of TC and LDL, as well as in the pro-atherogenic biomarkers (TC/HDL, LDL/HDL), which were lower in runners. A similar tendency was found in concentrations of TG (independent cardiovascular risk factor), glycerol and TG/HDL ratio (surrogate measure of insulin resistance), however the differences did not reach the level of significance. The level of homocysteine (pro-atherogenic biomarker) was comparable in all groups, and in most cases, within the reference range for male adults. Results of cognitive function tests did not reveal any significant between-group differences. The TMT score was found to be correlated positively (r=0.492, p<0.05), whereas DST score was correlated negatively (r=-0.549, p<0.005), with age. The DST performance, as evaluated in the group of runners (Group A), appeared to be strongly dependent (r=0.809, p<0.005) on the educational level of the subject.These data provided evidence of beneficial effects of a long-term regular endurance running exercise on lipid profile and cardiovascular health in middle-aged men. However, we failed to confirm the findings of a favorable impact of regular physical activity on improvement in cognitive abilities.

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