Predictive Modeling in Race Walking

This paper presents the use of linear and nonlinear multivariable models as tools to support training process of race walkers. These models are calculated using data collected from race walkers’ training events and they are used to predict the result over a 3 km race based on training loads. The material consists of 122 training plans for 21 athletes. In order to choose the best model leave-one-out cross-validation method is used. The main contribution of the paper is to propose the nonlinear modifications for linear models in order to achieve smaller prediction error. It is shown that the best model is a modified LASSO regression with quadratic terms in the nonlinear part. This model has the smallest prediction error and simplified structure by eliminating some of the predictors

Physical fitness profiles of junior athletes practicing selected combat sports

[EN] Every sport has its specific requirements for physical fitness that depend on the stage of the training process

The Use of Artificial Neural Networks in Supporting the Annual Training in 400 meter Hurdles

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

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

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

Weekday and Weekend Physical Activity of Preschool Children in Relation to Selected Socioeconomic Indicators

Physical activity (PA) is as vital for improving the health of young children as it is positively associated with a broad range of psychological, cognitive, and cardio-metabolic outcomes. The aims of this study were to: (1) to assess the level of PA and meeting the WHO recommendations: moderate-to-vigorous physical activity (MVPA) and the number of steps in Polish preschool boys and girls on weekdays and on weekends; (2) to investigate the relationship between selected socioeconomic indicators (self-reported by parents) and PA, including meeting the WHO recommendation for daily MVPA and the number of steps on weekdays and on weekends among Polish preschoolers. Data were collected in the 2017/2018 school year. The study included a total of 522 boys and girls both aged between 5 and 6 years. The ActiGraph GT3X-BT tri-axial accelerometer was used to measure PA. Selected socioeconomic indicators as well as parental body weight and body height were self-reported by parents/caregivers using a questionnaire. In most of the PA indicators analyzed for girls (moderate, vigorous, total MVPA, and steps/day), the averages were higher during the week than during the weekend. Moreover, significantly more boys met the criteria of MVPA, both on weekdays and over the weekend (32.3% boys and 19.2% girls on weekdays and 31.1% boys and 18.1% girls on weekends). Additionally, more boys met the step recommendations, but only on weekends (15.5% boys and 6.6% girls). It was found that if there were two people in a household, there was an almost a three-fold greater chance (adj. OR = 2.94, p = 0.032) of meeting the MVPA criterion with an even stronger association (over fivefold greater chance) in meeting the step recommendation (adj. OR = 5.56, p = 0.033). The differences in the day schedule may potentially contribute with the level of PA in girls. Among the analyzed selected socioeconomic indicators, only the number of people in a household had a significant association on PA

Characterization of Static Strength, Vertical Jumping, and Isokinetic Strength in Soccer Players According to Age, Competitive Level, and Field Position

: Muscular strength is strongly related to speed and agility tasks, which have been described as the most decisive actions preceding goals in the soccer game. This study aimed to characterize the players’ strength indicators and to analyze the variation associated with age, competition level, and positional role. Eighty-three male soccer players from A team (n = 22), B team (n = 17), U-23 (n = 19), and U-19 (n = 25) participated in this study. Handgrip strength was assessed using a hand dynamometer (Jamar Plus+), countermovement jump (CMJ) and the squat jump (SJ) were evaluated using Optojump Next, and a Biodex System 4 Pro Dynamometer was used to assess the isokinetic strength of knee extension/flexion. Team A players showed increased lower-body strength compared to their peers, mainly through their increased vertical jumping capacity (i.e., CMJ and SJ; ps < 0.019), and superior performance in isokinetic assessments (i.e., peak torque, total work, and average power). Overall, older players outperformed their younger peers regarding vertical jumping, static strength, and average power in isokinetic strength (ps < 0.005). This study emphasizes the superior strength levels of professional soccer players compared with their lower-division peers, even after controlling by age. This information is of great value to sports agents and coaches, underlining the need to design and include strength-specific content during soccer training.info:eu-repo/semantics/publishedVersio

A System for Analysing the Basketball Free Throw Trajectory Based on Particle Swarm Optimization

This paper describes a system for the automatic detection and tracking of a ball trajectory during a free throw. The tracking method is based on a particle swarm optimization (PSO) algorithm. The proposed method allows for the measurement of selected parameters of a basketball free throw trajectory. Ten parameters (four distances, three velocities, and three angle parameters) were taken into account. The research material included 200 sequences captured by a 100 Hz monocular camera. The study was based on a group of 30 basketball players who played in the Polish Second Division during the 2015/2016 season and the Youth Polish National Team in 2017. The experimental results showed the differences between the parameters in both missed and hit throws. The proposed system may be used in the training process as a tool to improve the technique of the free throw in basketball

INFLUENCE OF FATIGUE IN THE SELECTED KINEMATIC PARAMETERS OF HURDLE CLEARANCE IN 400 METRE RACE - IN SEARCH OF AN ACCURATE TRAINING TEST

The paper describes a initial study on the effects of fatigue on the selected kinematic parameters of hurdle clearance. Original test involving a hurdles race over 5 hurdles on a curve was used. The analysis concerned clearing the third hurdle in the initial and final (after the 200 m hurdles race) phase of the race. The study analyzed 15 parameters in five phases of hurdle clearance estimated using the particle swarm optimization algorithm. The material was recorded with a 100 Hz industrial camera. The results indicate that the basic parameters in the changes of a hurdling technique influenced by fatigue include: length of the hurdle clearance and landing distance past the hurdle

Рівень і темп морфофункціонального розвитку дітей 7–10 років, які походять із мало- й багатодітних сімей

From the research that the number of children in families in some extent is an important factor with respect to the value of the investigated somatic symptoms, as well as the level of development of physical qualities of children of 7–10 years old, who live in the province of Prykarpatia . It was found that girls and boys which have one or two brothers / sisters are characterized by higher somatic symptoms, in comparison with their peers from large families. It was found that the girls and guys who have one or two brothers / sisters are characterized by higher somatic symptoms, in comparison with their peers from large families. Testing confirmed that the population of boys and girls from small families have the highest level of endurance, reactions (except for the 7- and 10-year-olds) as well as the spatial orientation (only in the group of children with the exception of 10-year-olds). But from large families have found the highest level of power abilities (except for the 7- and 9-year-old girls, and spatial orientation. The dynamics of the rate of development of somatic symptoms and motor abilities (except reaction and spatial orientation) among the population of children regardless of the amount children in the families. Із проведених досліджень очевидно, що кількість дітей у сім’ї деякою мірою є вагомим чинником щодо величини досліджених нами соматичних ознак, а також рівня розвитку фізичних якостей дітей 7–10 років, котрі проживають на території Підкарпатського воєводства. Установлено, що дівчата й хлопці, які мають одного або двох братів/сестер, характеризуються вищими соматичними ознаками, порівняно зі своїми ровесниками з багатодітних сімей. Проведені тестування засвідчили, що популяції хлопців і дівчат із небагатодітних сімей відзначаються вищим рівнем розвитку витривалості, швидкості реакції (за винятком 7- й 10-річних хлопців), а також просторової орієнтації (лише в групі хлопців, за винятком 10-річних). Натомість респонденти з багатодітних сімей виявили вищий рівень силових здібностей (за винятком 7- й 9-річних дівчат), а також просторової орієнтації. Динаміка темпу розвитку соматичних ознак та рухових здібностей (за винятком швидкості реакції й просторової орієнтації) серед популяції хлопців не залежить від кількості дітей у сім’ї