Reliability of Accuracy and Precision Tests for Elite Para Table Tennis Players.

The primary purpose of this study was to adapt selected accuracy and precision tests in table tennis to the specific skills of elite table tennis players with impairment. The study included a sample of 23 Para table tennis players with an average age of 31.8 ± 12.22 years (including 30.4% females) who belonged to the senior Polish Para table tennis team. A battery of six tests evaluating stroke accuracy and serve precision was assessed. The analysis of the reliability of these tests confirmed the legitimacy of using this battery of accuracy and precision tests to assess the skills of Para table tennis players in all three integrated sport classes: players in wheelchairs, in a standing position, and with intellectual impairment. Analysis of the data obtained from the tests could provide coaches with relevant information regarding elite Para table tennis players' level of performance and examine selected accuracy and precision elements of their individual technique.

How training loads in the preparation and competitive period affect the biochemical indicators of training stress in youth soccer players?

Background: Physical fitness optimization and injury risk-reducing require extensive monitoring of training loads and athletes' fatigue status. This study aimed to investigate the effect of a 6-month training program on the training-related stress indicators (creatine kinase - CK; cortisol - COR; serotonin - SER; brain-derived neurotrophic factor - BDNF) in youth soccer players. Methods: Eighteen players (17.8 ± 0.9 years old, body height 181.6 ± 6.9 cm, training experience 9.7 ± 1.7 years) were blood-tested four times: at the start of the preparation period (T0), immediately following the preparation period (T1), mid-competitive period (T2), and at the end of the competitive period (T3). CK activity as well as concentrations of serum COR, SER and BDNF were determined. Training loads were recorded using a session rating of perceived exertion (sRPE). Results: Statistical analyzes revealed significant effects for all biochemical parameters in relation to their time measurements (T0, T1, T2, T3). The statistical analyzes of sRPE and differences of biochemical parameters in their subsequent measurements (T0-T1, T1-T2, T2-T3) also demonstrated significant effects observed for all variables: sRPE (HKW = 13.189 (df = 2); p = 0.00), COR (HKW = 9.261 (df = 2); p = 0.01), CK (HKW = 12.492 (df = 2); p = 0.00), SER (HKW = 7.781 (df = 2); p = 0.02) and BDNF (HKW = 15.160 (df = 2); p < 0.001). Discussion: In conclusion, it should be stated that the most demanding training loads applied in the preparation period (highest sRPE values) resulted in a significant increase in all analyzed biochemical training stress indicators. The reduction in the training loads during a competitive period and the addition of recovery training sessions resulted in a systematic decrease in the values of the measured biochemical indicators. The results of the study showed that both subjective and objective markers, including training loads, are useful in monitoring training stress in youth soccer players.

A Practical Approach to Monitoring Biomarkers of Inflammation and Muscle Damage in Youth Soccer Players During a 6-Month Training Cycle.

The aim of the study was to determine the effects of a 6-month training cycle on muscle damage and inflammatory markers in youth male soccer players. Twenty-one soccer players were tested four times: at the beginning (T1) and immediately after the pre-season period (T2), in the middle (T3) and at the end of the competitive period (T4). Muscle damage and inflammatory markers were determined in blood taken 36 hours after the match. Throughout the training cycle significant increases (p < 0.05) of creatine kinase (T1: 254.4 U·L-1; T4: 304.2 U·L-1) and lactate dehydrogenase (T1: 382.8 U·L-1; T4: 453.2 U·L-1) activities were observed. Significant changes (p < 0.05) in platelet count (T1: 210.5·109·L-1; T4: 234.2·109·L-1), percentage of lymphocyte (T1: 39.80%; T4: 42.97%), monocyte (T1: 6.88%; T4: 9.99%) and granulocyte (T1: 53.32%; T4: 47.05%) as well as in granulocyte-to-lymphocyte (T1: 1.41; T4: 1.17) and lymphocyte-to-monocyte (T1: 6.21; T4: 4.46) ratios were noted. The correlation analysis revealed statistically significant relationships (p < 0.05) between: myoglobin and the percentage of leukocyte subpopulations and the granulocyte to lymphocyte ratio; lactate dehydrogenase and the percentage of monocyte; lactate and leukocyte count. In conclusion, the reported muscle damage and inflammatory markers in T3 and T4 indicate the need for fatigue status monitoring in youth soccer players, especially in the competitive period. Moreover granulocyte to lymphocyte and lymphocyte to monocyte ratios proved to be sensitive to fatigue changes and therefore can provide coaches and sport scientists with a broader perspective on the biochemical monitoring of training status in soccer players.

Somatic Characteristics and Special Motor Fitness of Young Top-Level Polish Table Tennis Players.

In the present study, we aimed to identify the impact of chosen anthropometric measurements on the special physical fitness of elite junior table tennis players at different stages of sport training. A total of 87 table tennis players aged 13.4 ± 1.74 years (43.7% girls and 56.3% boys) from two Polish teams were analyzed. The anthropometry measurements included height, sitting height, body weight, arm span, humerus and femur breadths, five skinfold thicknesses, and five girths were assessed. Participants' somatotypes were also calculated using the Heath-Carter method as well as body mass index (BMI), which was constructed using the lambda, mu, sigma (LMS) method. Body composition via a bioelectric impedance analysis was also analyzed. The level of special fitness of athletes was determined using tests from the Table Tennis Specific Battery Test, assessing reaction and displacement speeds. Mesomorphic (4.1) and ectomorphic (3.8) profiles were registered for boys and girls, respectively. Boys achieved higher scores than girls for almost all variables, with the exception of ectomorphic somatotype (p = 0.274), skinfold triceps (p = 0.444), and calf skinfold medial (p = 0.609). The relationship between the body height, thickness of the skinfolds of the triceps and suprailiac, biceps, and waist circumference and arm span in all three motor tests was observed, simultaneously significantly higher results were obtained by competitors at the specialist stage of training. Knowledge of the somatic and motor characteristics of young athletes can help coaches in creating a specific training program for improved health and performance, taking into consideration the athletes' biological development, potential, and pre-disposition.

Comparison of Physical Activity Levels in Youths before and during a Pandemic Lockdown.

This study aimed to compare physical activity (PA) levels before and during a pandemic lockdown among adolescent Polish youths in relation to meeting the World Health Organization's (WHO) recommendations of moderate-to-vigorous physical activity (MVPA) and identify potential environmental factors that may affect these levels. An online survey tool that included validated measures of adolescents' MVPA and socio-environmental, potential confounders was administered to youths (e.g., lack of classmates, motivation, possibility of choosing any physical exercise time, possibility of choosing your own exercises, home environment). The analytic sample comprised 127 adolescents aged 15.4 ± 0.5 years on average (52% girls and 48% boys). The results highlight that among adolescents who did not meet the WHO MVPA recommendations before the lockdown, 13.4% had an increased frequency of PA (from 2.9 to 5.4 day/week) (p = 0.01) during the lockdown. In the group who did meet these recommendations before the lockdown, 50% significantly decreased their level of MVPA below the WHO's recommendations (p = 0.01). Self-rated health for PA showed a significantly strong correlation with MVPA in the group of students who met the WHO recommendations before the pandemic (r = 0.76; p < 0.05) but failed to maintain that recommendation during the COVID-19 restriction. The results suggest a negative impact of the pandemic on PA undertaken by youths. Based on these results we see the need for increased action by both Physical Education (PE) teachers and parents to motivate and support youngsters in taking up systematic PA consciously.

Anabolic-catabolic hormonal responses in youth soccer players during a half-season.

This study sought to evaluate the hormonal response (i.e. total testosterone, free testosterone, cortisol, and their ratios TT/C and FT/C) in the under-19 youth soccer team (n = 18) throughout a six-month period. All sport medical examinations were conducted four times: before the beginning of the preparation period (T1), just after preparation period (T2), in the middle of the competitive period (T3), and at the end of the season (T4). The cortisol concentration was decreased at the T3 (-16.9%; p = 0.014), then increased at the T2 (16.8%; p = 0.001) and at the T4 (12.7%; p = 0.062), respectively, compared to the initial value. The analyses for total and free testosterone demonstrated no differences between the measurements. Finally, values of the TT/C and FT/C ratios were increased during the T3 (25%; p = 0.017, 24.4%; p = 0.021) in comparison with the initial measurement and decreased at the T4 (-28.9%; p = 0.001, - 30.8%; p = 0.001) in comparison with the T3. The study results showed that the lowest level of peripheral fatigue was recorded in the T3, which may suggest that a correct selection of training loads does not affect the severity of catabolic processes in youth players.

Associations between adolescents' physical activity behavior and their perceptions of parental, peer and teacher support.

BACKGROUND: The aim of this study was to examine adolescents' perceptions of parental, teacher, and peer support for physical activity, and to examine the associations between these perceptions and physical activity behavior. METHODS: The study included 902 secondary school students, who completed the Short Scale of Youth's Social Support Assessment (SSYSS). The level of physical activity - more specifically, moderate to vigorous physical activity - was measured using a Physical Activity Screening Measure. The associations were examined by a five-step hierarchical regression. Body mass index (BMI) was defined using the LMS method, which summarizes the distribution of BMI by age and gender in terms of three curves, L (lambda), M (mu), and S (sigma), and was based on a nationally representative sample of Polish children and adolescents. RESULTS: The study indicated a positive correlation between MVPA (moderate to vigorous physical activity) and three sources of social support; however, in the regression model, this explained only part of the variance. In the hierarchical multiple regression analysis, MVPA level was predicted by five variables involvement in sports training, teachers support, parents support, gender and BMI. The direct effects for teachers and parents support were similar. This demonstrates that both teachers' and parents' social support exert influence on adolescent MVPA. CONCLUSIONS: The findings from this research suggest that school-based interventions for adolescents should specifically take into consideration family, teachers, and peers as important sources of social support for general physical activity promotion that aims to increase its levels.

Morphological asymmetry, sex and dominant somatotype among Polish youth.

The aim of the present study was to determine the level of morphological asymmetry among the general population of Polish youth as it correlates to sex and body type. The anthropometric characteristics of a group of 618 Polish youths (354 males aged 19.5 ± 1.2 years and 264 females aged 19.2 ± 1.2 years) were evaluated to assess their somatotypes using the Heath-Carter method. Body composition was calculated using the bioelectrical impedance method, and the absolute asymmetry index was used for comparisons between the right and left sides of the body. Significant differentiation was observed between all morphological characteristics (≤ 0.0001) and two body types (≤ 0.0001) among sexes. Females and males largely exhibited endomorphic and mesomorphic somatotypes, respectively. The findings demonstrated that dominant somatotype and sex both affect the level of fat mass asymmetry in the arms and legs. Furthermore, significant variations in the levels of asymmetry between sexes were observed in fat mass in both the arms and legs, with greater variation observed in the arms. In the case of muscle mass, no great differences were observed between men, women, or body types. This study provides new data on the morphological asymmetry of given body composition according to somatotype and sex. This study has potential medical implications, given that a large degree of inter-limb imbalance could be shown to have a negative effect on health; the findings of the present study would therefore be important for arriving at an understanding of how to prevent such imbalances, or to mitigate their negative effects.

The Motor and Leisure Time Conditioning of Young Table Tennis Players' Physical Fitness.

The purpose of the study was to assess the association between physical fitness and the lifestyle determinants of elite junior table tennis players. The basic anthropometric characteristics (body height and body weight) were collected of 87 Polish table tennis players (girls, n = 38 and boys, n = 49, at different stages of sport training, targeted and specialized) aged 11-17 years. The level of special fitness tests from the Table Tennis Specific Battery Test were used, assessing reaction speed and displacement speed. All eight International Physical Fitness Test trials were also used to determine the level of general fitness of the participants. Selected questions from the Health Behaviour in School-Aged Children questionnaire were asked to measure factors associated with leisure time. The findings confirm a relationship between sedentary forms of leisure time activity and the training of young players at the targeted stage (Z = -2.93, p = 0.003 school days and Z = -2.12, p = 0.034 days off). Moreover, competitors with longer training experience more often chose active forms of spending free time. Knowledge of the global physical activity undertaken by young athletes during their leisure time provides a better understanding of their individual needs and may help young table tennis players to succeed at a world-class level in the future.

Health-related Fitness Components - Links Between Parents and Their Child.

Objectives: Health-related fitness is a good predictor of health status of children and adults. Less is known about relationships of health-related fitness components between parents and children. Methods: Our study involved 58 children (30 girls and 28 boys, mean age = 7.97) and 58 parents (33 mothers, mean age = 39.32, and 25 fathers, mean age = 38.73) who were voluntarily enrolled in the program in 3 selected primary schools in the city of Poznan, Poland. Physical fitness was measured using the Eurofit test battery. Assessment of body composition was performed by measuring the bioimpedance. Results: Positive relationships were found among the levels of strength of abdominal muscle, flexibility of parents, and the slenderness of children. Slimmer parents also had more physically active children. Body composition parameters also were related to physical activity. More relationships were found between children and parents of the same sex. Conclusion: Data support the hypothesis that health-related risk factors are linked between parents and children and that sex plays an important role in these relationships. Our findings reinforce the need to develop health promotion programs that include children and their parents.

Physical Activity of Polish and Norwegian Local Communities in the Context of Self-Government Authorities' Projects.

The aim of this paper is to evaluate the relationship between the physical activity (PA) undertaken by two groups of residents living in Poland and Norway, and projects run by their respective local authorities. A secondary goal is to determine PA levels in the studied social groups. Two representative groups (one from each country) were examined using a diagnostic survey, supported by questionnaires and interviews. The Polish cohort consisted of 382 respondents who were residents of 11 municipalities in the Kalisz district of the Greater Poland voivodship. The Norwegian cohort was made up of 378 residents of 8 Indre Sogn municipalities from the Sogn og Fjordane region. Norwegians are twice as physically active as Poles and assess their municipal sport and recreation facilities to be much better. There is no statistically significant relationship between Polish and Norwegian PA levels in the two studied groups and their positive views on the impact of their local governments' projects to promote PA. Statistically significant correlations occurred between the frequency of PA undertaken, the time pattern of class unit, MET level (metabolic equivalent) and the declared use of the sport and recreation facilities of the two communities. Both groups are more willing to be active outdoors than indoors and thus municipal authorities should take particular care about the state of outdoor sports and recreation infrastructure. An innovative and original action model is presented to assist local authorities in their attempts to raise PA levels in their communities.

Positive Impact on Physical Activity and Health Behaviour Changes of a 15-Week Family Focused Intervention Program: "Juniors for Seniors".

The promotion of physical activity (PA) in children and their parents requires effective planning and sometimes even interventions. This study shows the effect of PA during a 15-week intervention program "Junior for Seniors" by applying a socioecological model to the interpretation of the data. This comprehensive approach emphasizes the fact that health promotion should focus not only on intrapersonal factors but also on the multilevel factors that might be determinants and modulators of increased PA. In 2015, 24 children ("juniors," 14 girls and 10 boys, aged M = 7.96 ± 0.69) and 22 parents ("seniors," 14 mothers aged M = 38.86 ± 2.96 and 8 fathers aged M = 37.38 ± 2.97) were voluntarily enrolled in a study spread across three primary schools in the city of Poznan, Poland. The effectiveness of the intervention was determined according to postintervention behavioural changes in PA in comparison to preintervention levels, as reported by the parents and children. Overall, the study found increases in PA levels and reductions in sedentary time. Although the changes are modest, there are some unrecognized benefits of the intervention which may have occurred, such as improved sport and motor skills, more frequent family social behaviours (walks, meals, and visiting relatives), or simply improved quality of "do-together" leisure time PA.

Analysis of sprinting activities of professional soccer players.

The aim of the study was a detailed analysis of the sprinting activity of professional soccer players. The study involved 147 players who played in 10 matches of the 2008-09 and 2010-11 UEFA Europa League seasons. The number of performed sprints and total sprint distances covered by the players were examined using collected statistical material. Two types of sprints were distinguished based on their duration: S, short-duration sprint (below 5 seconds) and L, long-duration sprint (above 5 seconds). Additionally, sprints were classified according to their distance: 0-10, 10.1-20.0, and >20 m, respectively. The analysis of the sprinting activity of soccer players also involved their respective positions of play. The study was carried out using Amisco Pro (version. 1.0.2), one of the most comprehensive up-to-date computer systems for match analysis. The statistical analysis revealed that the mean total sprint distance covered by players (≥24 km·h) amounted to 237 ± 123 m. With regard to the position of play, the forwards covered the longest sprint distance (345 ± 129 m), that is, 9% longer than midfielders (313 ± 119 m) and over 100% longer than central midfielders (167 ± 87 m). The average number of sprints performed by the soccer players was 11.2 ± 5.3. It should also be emphasized that about 90% of sprints performed by professional soccer players were shorter than 5 seconds, whereas only 10% were longer than 5 seconds. Analysis of physical loads of soccer players during matches can be useful for individualization of training of soccer players' speed capabilities. It is an essential instrument of modern planning and application of training loads.

Analysis of motor activities of professional soccer players.

The objective of this study was to determine the distance covered by professional soccer players during matches with the use of the computerized match analysis system Amisco Pro® (version 1.0.2, Nice, France). Kinematic examination included the specification of the distance covered by 31 players participating in 4 matches in the Union of European Football Association Cup competitions during the 2008-2009 season. Data were analyzed based on players' positions on the pitch, changes in the players' motor activity intensity level, and match period (first or second half). The results of statistical analysis revealed that the average total distance covered by all players (n = 31) was 11,288 ± 734 m. With respect to the player's position on the pitch, the midfielders traveled the longest average distance (11,770 ± 554 m) during the game. This was 3% longer than the distance achieved by the attackers at 11,377 ± 584 m, and 7% longer than that achieved by the defenders 10,932 ± 728 m. The analysis of physical loads on soccer players during a match is highly useful for training individualization. It provides a tool for effective planning and for recording the loads on players, which is an indispensable element of modern coaching.