How did three consecutive matches with extra time affect physical performance? A case study of the 2018 football Men's World Cup.

The purpose of this study was to ascertain the effect of playing three consecutive matches with extra time (ET) on the physical performance of selected Croatian players in their subsequent match, the final of the 2018 Men's World Cup in Russia. The case study consisted of 4 players on the Croatian national team (16 observations) who had played in all three matches up to 120 min. The consecutive full time matches (90 minutes) and extra time (30 minutes) were compared. The analysis was conducted using data collected by an advanced motion analysis system known as STATS and from interviews with the strength and conditioning coach of the Croatian national team. The recorded variables used were: total distance covered [m], distances covered [m] at intensity ranges of 20-25 km/h and above 25 km/h, and number of sprints performed. All the studied parameters systematically increased in each match up to 90 minutes of play, reached their maximum values in the semi-final and then decreased in the final match. Compared to the first extra time period, in the third extra time period the players covered twice as much distance with an intensity of 20-25 km/h and above 25 km/h, and recorded twice as many sprints. This investigation shows that players in central positions on the pitch are able to maintain or even increase high and very high intensity activity in three consecutive matches with extra time. These data complement the developing body of literature relating to the influence of accumulation of match play with extra time periods on high level players.

Are Linear Speed and Jumping Ability Determinants of Change of Direction Movements in Young Male Soccer Players?

The study was undertaken to investigate the relationships between linear speed, change of direction, and explosive power in the lower limbs of young soccer players. We aimed to determine the variables associated with effective change-of-direction speeds (time) based on the 30-m ZigZag (cutting maneuver) under 60° (CODS1), and 30 m sprint divided into forward-backward-forward movement (CODS2). Sixty young soccer players (age: 17.4 ± 0.7 years, height: 1.76 ± 0.06 m, weight: 68.1 ± 8.9 kg) from soccer sport clubs were included. The participants performed 30-m change-of-direction sprints and 30-m backward and forward sprints. For the maximum speed evaluation, a straight-line 30-m sprint test was performed. Counter-movement jumps and standing broad jumps were used to assess jumping ability. Pearson's linear correlation and a multiple stepwise linear regression model were used to adjust for variations related to the influence of functional speed and explosive power variables, which were analyzed based on the CODS1 and CODS2 data. Our results showed that 30-m CODS2 and standing broad jumps were associated with CODS1. The variation for the 30-m change-of-direction maneuvers under 60° could be explained by the results of 30-m forward-backward-forward change-of-direction. The standing broad jump explained 10% variation for the performances in change-of-direction sprint decrements and 9% variation for the 5-m change-of-direction with the best times, whereas straight-line sprinting was related to forward-backward-forward change-of-direction. The 10-m sprint explained 50% variation of the performances in the first 10-m forward running in the CODS2 and 12% variation for 10-m backward-forward change-of-direction. The 30-m sprint explained 36% variation for 30-m forward-backward-forward change-of-direction. The 30-m sprint and overall body mass also explained 58% variation for 10-m forward-backward change-of-direction. For coaching purposes, we report that forward-backward-forward and cutting maneuver change-of-direction movements are independent and highly useful skills. This information can help to provide better training prescriptions.

Match outcome and running performance in different intensity ranges among elite soccer players.

The monitoring of players' work-rate profiles during competition is now feasible through computer-aided motion analysis. The aim of the present study was to examine how various playing positions and match outcomes (i.e. won, drawn, lost) affect the total distance, and the distances covered at different intensities, by soccer players in Germany's Bundesliga. Match performance data were collected for 556 soccer players competing in the Bundesliga during the 2014/15, 2015/16 and 2016/17 domestic seasons. A total of 13 039 individual match observations were made of outfield players (goalkeepers excluded). The analysis was carried out using an IMPIRE AG motion analysis system, with records of all players' movements in all the 918 matches. The recorded variables included total distance covered [km] and distance covered at intensities in the ranges below 11 km/h, 11-14 km/h, 14-17 km/h, 17-21 km/h, 21-24 km/h, and above 24 km/h. In won matches, as opposed to drawn and lost matches, the wide midfielders and forwards ran a significantly longer distance, primarily covered at intensities of 21-23.99 and above 24 km/h (p ≤ 0.05). The analysis of full-backs, central defenders and central midfielders in won matches - as opposed to drawn and lost matches - in turn reveals that players ran a significantly shorter distance, most likely to be covered at intensities of 17-20.99 and 21-23.99 km/h (p ≤ 0.05). The results of the present study emphasise the importance of match outcome and playing positions during the assessment of physical aspects of soccer performance.

Physical activity profile of 2014 FIFA World Cup players, with regard to different ranges of air temperature and relative humidity.

The present study attempts to assess changes in soccer players' physical activity profiles under the simultaneous influence of the different combinations of ambient temperature and relative humidity characterising matches of the 2014 FIFA World Cup hosted by Brazil. The study material consisted of observations of 340 players representing 32 national teams taking part in the tournament. The measured indices included total distances covered; distances covered with low, moderate, or high intensity; numbers of sprints performed, and peak running speeds achieved. The analysis was carried out using FIFA official match data from the Castrol Performance Index system. Ultimately, consideration was given to a combination of three air temperature ranges, i.e. below 22 °C, 22-28 °C, and above 28 °C; and two relative humidity ranges below 60 % and above 60 %. The greatest average distance recorded (10.54 ± 0.91 km) covered by players at an air temperature below 22 °C and a relative humidity below 60 %, while the shortest (9.83 ± 1.08 km) characterised the same air temperature range, but conditions of relative humidity above 60 % (p ≤ 0.001). Two-way ANOVA revealed significant differences (p ≤ 0.001) in numbers of sprints performed by players, depending on whether the air temperature range was below 22 °C (40.48 ± 11.17) or above 28 °C (30.72 ± 9.40), but only where the relative humidity was at the same time below 60 %. Results presented indicate that the conditions most comfortable for physical activity on the part of players occur at 22 °C, and with relative humidity under 60 %.

Manifestations of Proprioception During Vertical Jumps to Specific Heights.

Jumping and proprioception are important abilities in many sports. The efficiency of the proprioceptive system is indirectly related to jumps performed at specified heights. Therefore, this study recorded the ability of young athletes who play team sports to jump to a specific height compared with their maximum ability. A total of 154 male (age: 14.8 ± 0.9 years, body height: 181.8 ± 8.9 cm, body weight: 69.8 ± 11.8 kg, training experience: 3.8 ± 1.7 years) and 151 female (age: 14.1 ± 0.8 years, body height: 170.5 ± 6.5 cm, body weight: 60.3 ± 9.4 kg, training experience: 3.7 ± 1.4 years) team games players were recruited for this study. Each participant performed 2 countermovement jumps with arm swing to 25, 50, 75, and 100% of the maximum height. Measurements were performed using a force plate. Jump height and its accuracy with respect to a specified height were calculated. The results revealed no significant differences in jump height and its accuracy to the specified heights between the groups (stratified by age, sex, and sport). Individuals with a higher jumping accuracy also exhibited greater maximum jump heights. Jumps to 25% of the maximum height were approximately 2 times higher than the target height. The decreased jump accuracy to a specific height when attempting to jump to lower heights should be reduced with training, particularly among athletes who play team sports. These findings provide useful information regarding the proprioceptive system for team sport coaches and may shape guidelines for training routines by working with submaximal loads.

Doubly Disadvantaged? The Relative Age Effect in Poland's Basketball Players.

The aim of this study was to identify the relative age effect (RAE) in young Polish male (n = 3849) and female (n = 3419) basketball players aged 14 to 22 years competing in the elite games of the Polish Youth Championships. The distribution of birth dates, body height, players' match statistics, and the results of teams participating in championships were identified. The RAE was observed in male and female group, regardless of players age. Nevertheless, the greatest disproportion in the distribution of dates of birth was found in U16 group of boys (V = 0.25, p < 0.0001). Significant differences in body height were identified in U14 and U16 groups of boys (p < 0.0001) and U14 group of girls (p < 0.01). The RAE was the most detrimental in the group of boys from teams ranked 9th or lower (p < 0.0001). The groups of male and female basketball players from the top 3 teams had the highest average body height (p < 0.001). In U14 boys, significantly higher match results and performance index ratings (PIR) were observed for players born in the first half of a calendar year. The research results show the impact of the RAE on the success of youth basketball teams in Poland. The month of birth, body height and sex may determine sporting achievements in youth basketball. Coaches should consider the chronological age and pubertal growth acceleration (APHV-age at peak height velocity) of players to optimize the process of identifying gifted basketball players, especially among boys of 14 years of age.

Effects of six-week stroboscopic training program on visuomotor reaction speed in goal-directed movements in young volleyball players: a study focusing on agility performance.

BACKGROUND: In team sports, deficits in visuomotor reaction speed are considered a significant and modifiable risk factor that can lead to decreased performance and an increased risk of injuries. Thus, identifying effective methods to enhance visuomotor abilities is crucial. The main objective of this research was to investigate the impact of a six-week stroboscopic intervention on visuomotor reaction speed in goal-directed specific movements based on agility among young volleyball players. Additionally, the study aimed to explore the impact of saccade dynamics on visuomotor reaction speed performance throughout the experiment. METHODS: There were 50 athletes (26 males and 24 females) with an average age of 16.5 years (± 0.6) who participated in this study. Over a six-week training period, athletes performed volleyball-specific training either wearing stroboscopic glasses (intervention) or under normal visual conditions (control). Prior to and after the training period, the agility tests based on change-of-direction speed (CODS) and reactive agility (RA) were used to identify visuomotor reaction speed performance. To measure agility performance a five-repetition shuttle run to gates was conducted. The REAC-INDEX, which represents visuomotor reaction speed, was analyzed as the resulting difference between the CODS test and the RA test. To elicit saccadic dynamics, a laboratory visual search task was performed. RESULTS: A significant GROUP×TIME interaction was observed for the REAC-INDEX (p = 0.012, ηp2 = 0.13). ANCOVA analyses revealed significant GROUP differences, indicating improved post-training REAC-INDEX results (p = 0.004, d = 0.87), regardless of gender. Training-induced modulations in saccade acceleration did not reach significance, but a significant relationship was observed between changes in saccade acceleration and changes in the REAC-INDEX (r = -0.281, p = 0.048), indicating that higher performance gains following training were associated with a stronger increase in saccade acceleration. CONCLUSIONS: This study demonstrates that stroboscopic training effectively enhances visuomotor reaction speed in goal-directed movements based on agility. Furthermore, visuomotor reaction speed gains could potentially be mediated by saccade dynamics. These findings provide valuable insights into the effectiveness of stroboscopic eyewear for training sport-specific visuomotor skills among young volleyball players.

In which rounds were the most rotations of key players made, and how did this affect physical activity? Analysis of the eight best teams of the 2018 FIFA world cup Russia.

BACKGROUND: Team management, especially player selection, rotation, and availability, are critical issues when dealing with the high demands of modern training and gameplay. As such, research continuously seeks ways to improve these actions or implement new ideas to gain a competitive advantage through the rotation of players in the starting line-up. The current study aimed to examine the rounds of the 2018 FIFA World Cup Russia in which the most rotations of key players were made and how this affected physical activity. METHODS: The sample consisted of 110 players from the top eight teams in the 2018 World Cup Russia who played entire matches for up to 90 min in seven consecutive games. All players were divided into key players (KPs, n = 58) and non-key players (NKPs, n = 52). The analysis used data collected by an advanced motion analysis system known as STATS®, with physical activity variables analyzed, including total distance covered (TDC), distance covered with high intensity over 20 km/h (HIR), and the number of sprints undertaken. In statistical analysis, differences between categories and consecutive matches were calculated using the Kruskal-Wallis H test, and if a significant effect size was found, a multiple comparisons p values test was performed. RESULTS: The best teams at the 2018 FIFA World Cup Russia used the most KP rotations with NKPs in the third match of the group stage. In addition, this was even more visible among more successful teams than less successful teams. The rotation strategy among the best eight teams allowed them to maintain the physical activity of KPs and NKPs in all rounds of the tournament. CONCLUSIONS: Coaches and coaching staff should incorporate squad rotation that includes a large group of players in their team management to improve their success. Team management expertise in player rotation during matches played over congested schedules at top tournaments maintains high levels of physical activity indicators (TDC, HIR, and sprints).

Effects of in-situ stroboscopic training on visual, visuomotor and reactive agility in youth volleyball players.

Background: Stroboscopic training is based on an exercise with intermittent visual stimuli that force a greater demand on the visuomotor processing for improving performance under normal vision. While the stroboscopic effect is used as an effective tool to improve information processing in general perceptual-cognitive tasks, there is still a lack of research focused on identifying training protocols for sport-specific settings. Therefore, we aimed at assessing the effects of in-situ stroboscopic training on visual, visuomotor and reactive agility in young volleyball players. Methods: Fifty young volleyball athletes (26 males and 24 females; mean age, 16.5 ± 0.6 years) participated in this study and were each divided randomly into an experimental group and a control group, who then both performed identical volleyball-specific tasks, with the experimental group under stroboscopic influence. The participants were evaluated three times using laboratory based tests for simple and complex reaction speed, sensory sensitivity and saccade dynamics; before the after the 6-week-long training (short-term effect) and 4 weeks later (long-term effect). In addition, a field test investigated the effects of the training on reactive agility. Results: A significant TIME vs GROUP effect was observed for (1) simple motor time (p = 0.020, ηp2 = 0.08), with improvement in the stroboscopic group in the post-test and retention test (p = 0.003, d = 0.42 and p = 0.027, d = 0.35, respectively); (2) complex reaction speed (p < 0.001, ηp2 = 0.22), with a large post-test effect in the stroboscopic group (p < 0.001, d = 0.87) and a small effect in the non-stroboscopic group (p = 0.010, d = 0.31); (3) saccade dynamics (p = 0.011, ηp2 = 0.09), with post-hoc tests in the stroboscopic group not reaching significance (p = 0.083, d = 0.54); and (4) reactive agility (p = 0.039, ηp2 = 0.07), with a post-test improvement in the stroboscopic group (p = 0.017, d = 0.49). Neither sensory sensitivity nor simple reaction time was statistically significantly affected as a result of the training (p > 0.05). A significant TIME vs GENDER effect was observed for saccadic dynamics (p = 0.003, ηp2 = 0.226) and reactive agility (p = 0.004, ηp2 = 0.213), with stronger performance gains in the females. Conclusions: There was a larger effectiveness from the 6-week volleyball-specific training in the stroboscopic group compared to the non-stroboscopic group. The stroboscopic training resulted in significant improvements on most measures (three of five) of visual and visuomotor function with more marked enhancement in visuomotor than in sensory processing. Also, the stroboscopic intervention improved reactive agility, with more pronounced performance gains for short-term compared to the long-term changes. Gender differences in response to the stroboscopic training are inconclusive, therefore our findings do not offer a clear consensus.

The effects of high-intensity interval training at the anaerobic and psychomotor fatigue thresholds on physiological parameters in young soccer players: a prospective study.

This study aimed to investigate the effects of a 4-week specific high-intensity interval training (HIIT) program performed between the anaerobic threshold (ANT) and the psychomotor fatigue threshold (PFT) on physiological parameters in 14 professional soccer players at the under-17 level. The first and second stages of the research protocol included a treadmill running exercise with increasing load and six 3-min four-versus-four games of soccer with a 3-min break between games. Players then participated in a training microcycle involving three specific HIIT exercises twice per week for 4 weeks, after which they repeated stages one and two, followed by an assessment of changes. The measurement of lactate (LA) determined ANT, whereas the choice reaction time (CRT) indicated PFT among other selected physiological parameters. The repeated-measure analysis of variance (ANOVA) compared mean values for the examined variables using Bonferroni post hoc test. It demonstrated significantly increased maximal oxygen consumption (VO2 max) from 45.9 ± 3.0 to 48.7 ± 2.6 at the ANT and from 49.1 ± 3.4 to 52.0 ± 3.6 on the PFT after 4 weeks of training. A significant increase in the running speed (RS) at both thresholds and heart rate (HR) at the ANT (p ≤ 0.05) was also recorded. Moreover, the players exceeded their intensity of effort during ANT while playing four-versus-four soccer matches, but they did not reach intensity during PFT. In conclusion, the findings of the study demonstrated that both thresholds shifted toward higher loads and the proposed specific HIIT effectively increased the exercise capacity of soccer players.

Effectiveness of Brainball program on physical fitness of primary school pupils in Vietnam. A longitudinal study.

Objective: The present study aimed to evaluate the effectiveness of the Brainballs on the physical fitness of 2nd-grade students at a primary school in Vietnam during and eight months after the experiment. Methods: The study included 55 pupils (23 boys and 32 girls) aged seven years. The study design was a pedagogical experiment with a parallel-group technique, including experimental and control groups. The examination was carried out in 2019/2020 in three terms pre- (September 2019), post- (January 2020), and follow-up (September 2020). Physical fitness was tested with the use of the International Physical Fitness Test. The Brainball program, conducted twice a week for 35 minutes, combined physical education (PE) with subject-related content, utilizing 100 balls with painted letters, numbers, and signs. Results: Results show that the fitness level was not increased significantly after 20 weeks of the intervention program, neither in experimental nor control groups. However, it significantly improved eight months later at the follow-up examination. The analysis of covariance indicated that pupils from the experimental group improved significantly on most physical fitness as compared to the control group, specifically on the following tests: 50-meter running (p = 0.0044), toe touch (p = 0.0137), standing long jump (p = 0.0076), 4 × 10 m sprint (p = 0.0333), hand strength (p = 0.0233). Conclusions: These results have shown long-term positive effects of the use of "Brainball" educational balls in physical education classes on the physical fitness development of students, especially in the qualities of speed, strength, and flexibility.

Do players competing in the UEFA Champions League maintain running performance until the end of the match? Positional analysis between halves and 5-minute intervals.

BACKGROUND: This investigation aimed to analyze differences in running performances amongst playing positions between the first and second halves of soccer matches and at 5-minute intervals during matches. METHODS: Data were collected from 179 soccer players during 20 UEFA Champions League (UCL) 2020/2021 group stage matches. Data were examined using the InStat Fitness semi-automatic video system. Eight variables were selected to quantify players' running performance (RP). Players were categorized based on positional groups: central defenders (CD), fullbacks (FB), central midfielders (CM), wide midfielders (WM), and forwards (FW). Univariate differences in RP were analyzed using ANOVA and the t-test for dependent samples and multivariate differences were identified using canonical discriminant analysis. RESULTS: The main findings were that all positions achieved significantly higher average speeds and walking distances in the first half of the match than in the second half. Furthermore, analysis of positions showed that CM covered more distance than CD in all 5-minute intervals. In addition, WM performed more high-intensity running than CD in all 5-minute intervals and FW performed more high-intensity running than all other playing positions. CONCLUSIONS: The findings from the present study should help coaches design training exercises that are specific to parts of a match. Moreover, the findings can help provide better understanding of match demands and individualization of training. Analysis of 5-minute intervals may also help coaches understand the stages of a match where player substitutions will be most effective.

Physical activity and sedentary behaviors in Polish children and adolescents.

OBJECTIVE: Participating in physical activity (PA) is essential for children's proper development. Promoting physical activity from early school years is considered a highly important prevention task for good health. The aim of this study was to evaluate the level of PA and sedentary behavior of children and adolescents aged 6-17 years attending primary and junior high schools in Wroclaw, Lower Silesia, Poland. The study assessed the frequency of various forms of PA and sedentary behavior in children and adolescents. The age differences in PA and sedentary behavior in the cohort studied was also analyzed. DESIGN: Survey study to assess children's and adolescents' physical activity and sedentary behavior were based on a parent-reported questionnaire. PARTICIPANTS: A total of 2913 children and adolescents aged 6-17 years (average age, 11.38 years) from Wroclaw, Poland, who participated in a pro-health campaign "Let's Get the Kids Moving." This project promotes a healthy lifestyle among primary and middle school students. RESULTS: The frequency of physical activity significantly decreased as children grew older (p < 0.0001). As many as 18.6% of adolescents 13-17 years old undertook the recommended level of physical activity less than once a week. Time spent in front of the television or computer by pupils in group 3 was longer than in younger children (p < 0.0001). Nearly 19% of adolescents (13-17 years old) spent 5 h or more daily in a sitting position in front of the television or computer on weekends. CONCLUSIONS: Polish children and adolescents do not spend the recommended level of time on physical activity and spend excessive time in front of the television and other electronic devices. The level of physical activity decreases as the number of hours spent in a sitting position increases with increasing age. Actions should be taken to avoid the long-term consequences of these behaviors.

Reactive Agility in Competitive Young Volleyball Players: A Gender Comparison of Perceptual-Cognitive and Motor Determinants.

Limited evidence is available providing specific details about the perceptual-cognitive and motor factors that contribute to reactive agility (RA) and variations between genders in young athletes. The aim of the study was to investigate perceptual-cognitive and motor determinants of RA in competitive youth volleyball players. A total of 135 volleyball players (61 males, 74 females) aged 16-18 years were included in this study. The independent variables were as follows: explosive strength, maximal frequency of movements, simple and complex reaction time, selective attention, sensory sensitivity, and saccadic dynamics. Multiple linear regression analyses showed that explosive strength (ß = - 0.494; p < 0.001) and complex reaction time (ß = 0.225; p = 0.054) accounted for 23% of the variance in RA performance in male players. The best exploratory model for RA contributed 34.5% of the variance in RA for female players with significant determinants of explosive strength (ß = -0.387; p < 0.001), sensory sensitivity (ß = -0.326; p = 0.001) and selective attention (ß = 0.229; p = 0.020). Male athletes obtained better results in RA, in all motor tests (effect size of 0.88 to 2.58) and in five variables of perceptual-cognitive skills (effect size of 0.35 to 0.98). Motor and perceptual-cognitive components significantly contributed to performance in RA in competitive youth volleyball players. Gender differentiates between players' RA performance, motor properties and saccadic dynamics to a large extent, while the remaining analyzed perceptual-cognitive components vary between female and male players to a small and moderate extent.

The high-intensity interval training introduced in physical education lessons decrease systole in high blood pressure adolescents.

Increased resting blood pressure (BP) is a risk factor for many health complications. The prevalence of elevated BP is growing among adolescents. There is a need to investigate effective ways of decreasing excessive blood pressure in this age group. The study aim was to determine the effect of 10-weeks High-Intensive Interval Training (HIIT)-Tabata protocol-introduced in physical education (PE) lessons on resting blood pressure in adolescents. The sample included 52 boys aged 16.23 ± 0.33 years body height176.74 ± 6.07 (m), body weight 65.42 ± 12.51 (kg), BMI 20.89 ± 3.53 (kg/m2) and 89 girls aged 16.12 ± 0.42 years, body height 164.38 ± 6.54 (m), body weight 56.71 ± 10.23 (kg), BMI 20.93 ± 3.08 (kg/m2) from secondary school. Based on resting BP, the fractions of boys and girls with normal BP and high BP were identified and divided into experimental (EG) and control (CG) groups. EG completed a 10-weeks HIIT program (three cycles of Tabata protocol) implemented in one PE lesson during a week. The duration of the effort was 14 min. The intensity was at 75-80% of maximal heart rate. Changes in systolic and diastolic BP after the experiment were examined. The results indicated the improvement in SBP in EG with high BP compared to the rest of the groups (average reduction of 12.77 mmHg; p < 0.0001). The EG normotensive had a statistically significant higher reduction of SBP comparing CG normotensive (average decrease of 1.81 mmHG; p = 0.0089). HIIT effectively decreases BP in adolescents. Implementing HIIT in PE lessons in secondary school is recommended to improve BP parameters.

Strength Abilities and Serve Reception Efficiency of Youth Female Volleyball Players.

Success in volleyball largely depends on motor abilities, particularly on maximum strength, power, jumping, and speed performance. However, a small number of studies assess the relationship between motor abilities and the effectiveness of volleyball technical skills. Therefore, the aim of the study was to assess the impact of the strength of the upper and lower limbs on the efficiency of serve reception during a 2 vs. 2 game, as well as to evaluate the results of motor measurements in the context of determining the usefulness of current testing procedures. The study involved a carefully chosen group of 12 girls aged 12-13 years (body height: 176.5 ± 4.2 cm, body mass: 58.6 ± 5.1 kg, and training experience: 43 ± 15 months) selected for the Lower Silesian Regional Volleyball Team. The following tests were conducted: handgrip strength with a hand dynamometer, bent-arm hang, 2 kg medicine ball throw, shoulder joint internal rotators (IR) peak torque, standing long jump, spike jump, and countermovement jump. The measurements of the shoulder joint IR peak torque were performed under isometric (at 10°, 35°, and 65° rotation angles) and isokinetic (at 60°/s, 180°/s, and 300°/s) conditions. The efficiency of serve reception was evaluated during a 2 vs. 2 games by using Data Volley statistical software. The strongest positive relationships were observed between the serve reception efficiency and the peak torque and power of the shoulder joint IR, the medicine ball throw distance, and handgrip strength. Jumping variables showed no associations with efficient of serve reception. Consequently, we suggest adding protocols to volleyball training that include strength exercises aimed at developing the IR muscle group. The isokinetic upper limb test should be introduced as a valid tool in selection process. Coaches who do not have access to modern research equipment should use the medicine ball throw test to evaluate strength abilities as an alternative assessment of the serve reception efficiency.

Hand Grip Strength Vs. Locomotor Efficiency in Sitting Volleyball Players.

The objective of this paper was to determine the relationship between hand grip strength and movement time (locomotor efficiency in a seated position using the upper and lower extremities) in sitting volleyball players. In addition, a comparison was made between the velocity curves for forward and backward locomotion. Nine male members of the sitting volleyball team participated in the study. Hydraulic and spring manual dynamometers were used to measure hand grip strength. Movement times were registered for distances of 1, 2, 3, 4, 5, 6 and 10-m with the use of the Smart Speed System photocells. Significant relationships between hand grip strength of the left (rs=-0.78) and right (rs=-0.73) hands and the forward movement time over a distance of 1-m were found. Hand grip strength had no significant relationship with either forward movement times at other distances or backward movement times. Results suggest that hand strength is linked to locomotor efficiency of sitting volleyball players. High hand grip strength makes the start easier by pushing away from the ground with the upper limbs.

No Motor Costs of Physical Education with Eduball.

Numerous neuroscience studies demonstrate that when motor and cognitive tasks are performed simultaneously, there is dual-task interference. Experiments show that the cost is a temporal deterioration in motor functioning. However, there is no comprehensive research on the developmental costs of dual-task exercises incorporated into physical education (PE). Such an approach is called the interdisciplinary model of PE and is used to stimulate cognitive development. Therefore, there is a knowledge gap regarding the motor costs of methods based on this model, e.g., Eduball. The Eduball method integrates core academic subjects with PE using a set of educational balls printed with letters, numbers, and other signs. To fill this knowledge gap, we replicated the Eduball experiment, focusing on motor development. The half-year intervention occurred in one primary school class. The control group was a peer class participating in traditional PE, not based on dual tasks. We tested students' space-time orientation and graphomotor, locomotor, and object control skills. We found no motor costs of the intervention. Eduball-based PE stimulated motor development as much as traditional PE. Our study suggests that methods based on the interdisciplinary model of PE are safe for motor development. As such, it is worth considering their use in children's education.

Everyone Can Implement Eduball in Physical Education to Develop Cognitive and Motor Skills in Primary School Students.

Studies suggest that incorporating core academic subjects into physical education (PE) stimulates the development of both motor and cognitive skills in primary school students. For example, several experiments show that children's participation in Eduball, i.e., a method that uses educational balls with printed letters, numbers, and other signs, improves their physical fitness while simultaneously developing their mathematical and language skills. However, the question of who should conduct such classes to make them most effective (regular classroom teachers, physical education teachers, or maybe both in cooperation?) remains unanswered. Here, we replicated a previous Eduball experiment, but now, instead of one experimental group, there were three. In the first, Eduball-classes were conducted by the classroom teacher, in the second, by the physical education teacher, and in the third, collaboratively. After one year intervention, all experimental groups significantly improved both their cognitive (mathematical, reading, and writing) and gross motor (locomotor and object control) skills, and these effects were larger than in the control group participating in traditional PE. Importantly, there were no differences in progression between the Eduball-groups. Thus, our study demonstrates that methods linking PE with cognitive tasks can be effectively used by both PE specialists and general classroom teachers.

Physical Education with Eduball Stimulates Non-Native Language Learning in Primary School Students.

Although the neuronal mechanisms of action and cognition are related, the division of intellectual and physical lessons is standard in schools. This is surprising, because numerous studies show that integrating physical education (PE) with teaching content stimulates critical skills. For example, several experiments indicate that Eduball-based PE (i.e., lessons in a sports hall during which students play team mini-games with educational balls with printed letters, numbers, and other signs) develops mathematical and language competencies. At the same time, the Eduball method does not slow down learners' physical development. However, we have little knowledge about the effects of such techniques on non-native language learning. Consequently, the absence of incorporating core academic subjects into PE in dual-language schools or during foreign language education is exceptionally high. Here, we replicated the Eduball experiment, but with the goal of testing this method for non-native language learning. Thus, the intervention occurred in a dual-language primary school and we evaluated second language (L2) learning. As before, we used the technique of parallel groups (experimental and control); in both groups, there were three 45-min PE classes per week. In the experimental class, two of them were held using Eduball. After a half-year experiment, children from the experimental group (one second-grade, N = 14) improved their non-native language skills significantly more than their peers from the control group (one second-grade, N = 12). These findings demonstrate that Eduball-type intervention stimulates non-native language learning in children. Hence, our report suggests that specific body training forms can support L2 learning.