Fast Players Research Articles

Internal and external load profiles of male basketball players during training

Traditionally in basketball, five specific positions have been distinguished, often due to the anthropometric characteristics of the players. In recent years, different research has emerged that tries to break with this paradigm, giving rise to different classifications of players based on other characteristics that are more closely related to the actual game of basketball. The aim of this research was to determine the load profiles of players according to internal and external load values. An observational design was used, in which 12 professional players from the Spanish Men’s First Division Basketball (ACB league) team participated, obtaining data from all the training sessions carried out over two microcycles. All players were equipped with WIMUPRO™ inertial devices, using a UWB system for the players’ positioning in indoor spaces. A principal component analysis with varimax rotation was performed to group the variables and determine the profiles. The results showed four different player profiles: versatile, explosive, dynamic, and fast players. Within these load profiles are included players from the five specific positions according to the traditional basketball classification, possessing distinct anthropometric characteristics among themselves. These results allow strength and conditioning coaches to train players physically in a more efficient way, using small-sided games in mid court, or games in full court more adequately, and achieving greater specificity and applicability in their exercises and tasks.

Change-of-Direction and Deceleration Deficits in National-Team Female Rugby Sevens Players: Interrelationships and Associations With Speed-Related Performance.

To investigate the relationships between a series of direct and indirect measures of linear and multidirectional speed performance in elite female rugby sevens players. Nineteen players from the Brazilian national team performed 40-m linear sprint and 505 change-of-direction (COD) tests on the same day. Based on the linear sprint and COD test performances, the COD deficit (CODD) and deceleration deficit (DD) were also obtained. A Pearson product-moment correlation analysis was used to determine the relationships between linear sprint and COD-derived variables. Linear sprint and 505 COD velocities were not significantly associated (P > .05). Large to very large significant associations (r values ranging from .54 to .78; P < .05) were detected between linear sprint velocity for the different distances tested (10, 15, 30, and 40m) and CODD. The COD velocity presented a very large inverse significant correlation with CODD and DD (r = -.77 and -.79 respectively; P < .05). A large and significant correlation was identified between CODD and DD (r = .79; P < .05). Significant associations were observed between linear sprint and CODD, suggesting that faster players are less efficient at changing direction. No relationship was found between sprint velocity and DD, highlighting the independent nature of linear sprints and deceleration capabilities. A comprehensive and detailed analysis of multidirectional speed performance should consider not only linear sprint and COD performances but also complementary COD-derived variables such as the CODD and DD.

The profiles of single leg countermovement jump kinetics and sprinting in female soccer athletes

The purposes were to evaluate kinetics in lower limbs using single leg countermovement jump (SLCMJ) and to identify the differences in SLCMJ kinetics between sprinting fast players and sprinting slow players in elite university female soccer players. Seventeen participants at the national tournament level completed the survey. SLCMJ and 30 m sprinting tests were performed. A force-plate was used to collect the data of the SLCMJ test. Significant differences of concentric maximum rate of force development (RFD), concentric RFD, concentric RFD/body weight (BW), peak net takeoff force/BW, peak power, and peak power/BW existed between both legs during the SLCMJ among all the participants. For further analysis, the participants were divided into fast group and slow group based on sprinting performance. Significant differences existed between the two groups in concentric peak velocity (nondominant, p = 0.028) and vertical velocity at takeoff (nondominant, p = 0.021). Concentric maximum RFD (p = 0.036) was significantly different between both legs in the slow group. Among elite university female soccer players, the players who presented more increased asymmetry of kinetic characteristics of jumping, also showed weak sprinting performance. Moreover, the players presented the best performance in velocity of the jumping variables and also had the best sprinting performance. Coaches and players should focus on keeping inter-limb balance and developing jumping velocity to improve sports performance. In future, the cause-and-effect relationship between jumping and sprinting should be identified.

Determining the effect of one decade on fitness of elite Austrian youth soccer players using propensity score matching.

Current trends in attacking strategies and increases in external workload have led to a need for fast and well-conditioned athletes in modern soccer. More recently, progressions in speed, coordination, power and endurance were found over a decade in elite Austrian youth players. However, possible confounders such as relative age, maturation, learning effects, and academy philosophy may have influenced these changes. The present study aimed to determine the decade effect on fitness under statistical control of players' exact age, height, body mass, test location as well as total number of pretests and time interval between test and pretest. Players annually completed a battery of anthropometric, general and soccer-specific fitness tests. MANCOVA was calculated to identify the overall impacts of the covariates on fitness. To balance the covariates of initially 2,530 "former" (2002 to 2005) and 2,611 "recent" (2012 to 2015) players, 1:1 nearest neighbor propensity score (PS) matching was used, resulting in 587 U13, 573 U14, 475 U15, 325 U16, 262 U17, and 129 U18 matched pairs. The decade effect on fitness was assessed by independent t-tests and Cohen's d separately at each age group. Superior performances of recent players were found for linear sprint across all age categories (d = 0.154-0.476) as well as for agility (d = 0.125-0.340) and change-of-direction speed (d = 0.172-0.466) in U15 to U18. Reaction speed increased in U13 (d = 0.288) and U15 (d = 0.310). Flexibility reduced over the decade in all age categories (d = -0.151 to -0.589) and upper-limb power decreased (d = -0.278 to -0.347) in U13 and U14. Balancing the covariate distribution via PS matching generally confirmed previous findings, with fitness decade effects reflecting the athletic needs for modern soccer. Since fitness performance changed over time, reference values should be periodically updated. Coaches favor both physical and cognitive fast players nowadays. Thus, training should target all aspects of speed, without disregarding flexibility, upper-limb power and other preventive strategies that keep the players on the pitch.

Physical perfection of students is in group псм from volley-ball. Relevance of the study

The main objective of "Physical Education" in higher education institution is the development of students' physical qualities and motor abilities. The solution of this problem is facilitated by the students involvement in various sectional activities, in particular, volleyball. The aim of this work is to highlight the main means of ensuring the optimal level of development of the physical qualities of students involved in the volleyball section. Methods of analysis: analysis of scientific sources, comparison, synthesis. Results: Motor activity in volleyball is characterized by a variety of actions, in particular: running of different intensity, walking, jumping, hitting the ball, stopping, falling, serving, passing, blocking, etc. Therefore, special attention in the process of training should be paid to the development of physical abilities: speed, strength, agility, endurance, flexibility and jumping ability. A fast player can win the time and space compare to the opponent who has the ability to successfully solve tactical problems. The combination of speed and strength allows the player to perform successfully various game combinations. A strong player is able to overcome external resistance or counteract it with the help of muscular efforts. Agile - masters new techniques easily, adapts to different game conditions better, able to perform new motor learning accurately, economically, quickly. During the game, athletes perform multiple accelerations, so the presence of endurance is equally important for them. In volleyball, the elasticity of the muscles and ligaments of the lower extremities and the spinal column is important, therefore, in the classroom, special attention should be paid to the development of flexibility. No less important motor ability of a volleyball player is jumping ability. It depends on the level of development of speed-strength qualities and is based on the strength of the muscles, the speed of their contractions and coordination of movements. Therefore, jumping exercises should be used on every lesson. Conclusions: teaching and training in volleyball is an integral part of a single pedagogical process, in which one should keep the basic provisions, and excellent results can only be achieved with a high level of physical and technical preparedness of the players. Properly chosen teaching methodology and successful organization of classes are quite important in the preparation of the team.

Shoulder Internal Rotator Strengthening vs. Muscle Energy Technique for Shoulder External Rotators on Bowling Speed in Fast Bowlers Playing Cricket- A Quasi-Experimental Study

INTRODUCTION: The shoulder joint is the most complex joint in the human body, the most mobile and least stable in relation to other joints. In bowling, using the upper extremity in the throwing motion is one of the most challenging tasks. In order to generate a precise throw, the numerous anatomical components involved in the overhead throwing motion must be coordinated. Shoulder muscular strength is a key component of excellent bowling, and the strength of various shoulder muscle groups influences bowling speed. Therefore, it is essential that bowling players exert strength in their performance. This lacks bone stability and sacrifices stability to increase mobility. OBJECTIVES: To analyse the effects of strengthening the shoulder internal rotators and the muscular energy technique of the shoulder external rotators on bowling speed in fast cricket players. METHODS AND MATERIALS: Participating rapid cricket players from sports field aged 18-30 years, were recruited and then randomly allocated into two groups: strengthening group and MET group. The strengthening group received muscle strengthening for the internal rotators of the shoulder and the MET group received the muscle energy technique for the external rotators. All the exercise interventions was involved physiotherapist supervision session with 12 repetitions and 3 sets 5 days per week up to eight weeks. Range of motion was measured by goniometer instrument and bowling speed was assessed by speed gun. All outcomes were assessed at baseline, 2nd week, 4th week and 8th week after the intervention with ANOVA of repeated measures. RESULTS: Of the 30 participants evaluated, the mean age, height, weight and BMI were, respectively, 21.40±2.36 years old, 1.74±0.09m, 71.80±16.77kg and 23.57±4.20Kg/m2 for the strengthening group and 22.53±1.55 years old, 1.70±0.04m, 62.47±8.02kg, 21.49±2.63Kg/m2 for the MET group.There was a statistically significant difference for all outcomes regarding the measured times between the two intervention groups. However, in the strengthening group, there was a greater effect size for internal rotation ROM (1.99 in the strengthening group versus 1.42 in the MET group) and for bowling speed (1.52 versus 1.39). External rotation ROM had a greater effect size in the MET group (1.66 for the MET group and 1.16 for the strengthening group). CONCLUSIONS: The result of study concludes that a significant improvement in shoulder internal rotators and external rotators strength leads to improve bowling speed, so the shoulder strength training protocol and muscle energy training can be incorporated for increasing the speed of the bowler.

Algorithm for Detecting Occluded Basketball Players Based on Adaptive Keypoint Heatmap

<p indent=0mm>Player detection is the basis of intelligent analysis of basketball events. Due to the complexity of basketball sports, such as fast player movement and serious occlusion of players, existing object detection techniques cannot afford to achieve accurate detection. To address this issue, an object detection algorithm of basketball player is proposed based on an adaptive keypoint heatmap. First, fully-convolutional encoder-decoder networks are built to extract feature of players. Then, the keypoint heatmap is rendered in feature map through an adaptive variable Gaussian kernel radius. The rendering of the keypoint heatmap adopts an adaptive strategy, in which the Gaussian kernel radius is changed with the width and height of the object, so that the network convergence can be accelerated. With the center point of the player extracted from heatmap, the player’s size, position and other information are retrieved through regression. Since the player is detected based on the center point, eliminating the complicated and time-consuming post-processing procedure in anchor-based detections, it is more conducive to distinguish two different players under occlusion conditions. The effectiveness of the proposed approach is validated on the BasketballPlayer dataset, and the experimental results show that lots of missed detection, misdetection, and low detection accuracy among densely occluded players are significantly improved at the processing rate of 26 frames per second, compared with existing algorithms.

Can discreet performance banding, as compared to bio-banding, discriminate technical skills in male adolescent soccer players? A preliminary investigation

Maturation-related changes in body dimensions and performance can lead to physical mismatches and drop out from youth sport. Here, we propose a new method termed ‘discreet performance banding’ (DPB). We aimed to determine if dividing youths by actual physical performance of a discreet skill or ability (‘change or direction’ [COD] ability) could discriminate between the most and least skilled players better than a marker of implied performance, such as an assessment of biological maturation. 182 male academy Spanish soccer players (age: 13-18 years height: 143 to 188 cm; mass: 32.3 to 81.4 kg) were divided into maturation groups (Tanner stages 2 through 5) and COD groups (‘fast’, ‘intermediate’ and ‘slow’). Players’ skills (passing, shooting, ball control) were evaluated on a six-point scale with a value of ‘1’ considered ‘very bad’ and a value of ‘6’ as ‘very good’. When divided by maturity status, analyses revealed no significant differences between groups in soccer skill. However, when divided into COD groups, the analyses revealed significant differences between the fast and intermediate players ([p &lt; 0.001] favouring the fast group) and between the intermediate and slow players ([p &lt; 0.026] favouring the slow group). There was no significant difference in skill between the fast and slow groups, though the fast group demonstrated a higher skill level as indicated by a small effect size. Fast players were more skilful than both the intermediate and slower players, indicating that COD status can be a differentiating factor between players of different skill levels. DPB could be used to equalise competition in youth sport and to enhance the overall level of enjoyment that youths derive from engagement in sport.

The Effect of Contextual Variables on Match Performance across Different Playing Positions in Professional Portuguese Soccer Players.

This study investigated the position-specific physical demands of professional Portuguese players. The effects of situational variables on the physical performance demands were also analysed (match location, match half and match result). Match performance observations were collected using Global Navigation Satellite System devices across 11 matches during a competitive season (2019–2020). Data were analysed according to five playing positions: goalkeepers (n = 11), central defenders (n = 42), wide defenders (n = 31), central midfielders (n = 34), open attackers (n = 28), and centre forwards (n = 14). Central midfield players completed the greatest total distance (10,787 ± 1536 m), while central defenders covered the least distance (9272 ± 455; p < 0.001). Open attackers covered the greatest high and very-high-speed distance (1504 ± 363 m), number of high-speed decelerations per match (11 ± 4) and were the fastest players (30.6 ± 1.5 km/h), along with center forwards (30.6 ± 2.0 km/h), versus all other positions (p < 0.05). Greater distances were performed in teams that were winning (9978 ± 1963 m) or drawing (10,395 ± 875 m) versus losing (9415 ± 2050) p = 0.036 and p = 0.006, respectively. Increases in distance covered at walking speeds were observed during the 2nd half (1574 ± 179 m) compared with the 1st half (1483 ± 176; (p < 0.003). A higher number of decelerations across all speeds were performed in the 1st half (144 ± 39) versus the 2nd half (135 ± 37). The distance covered in home matches (10,206 ± 1926 m) far exceeded away matches (9471 ± 1932 m; p < 0.001). The number of faster accelerations were higher in away (7 ± 5) versus home matches (6 ± 4; p < 0.049). The data demonstrate the different physical demands of each playing position and suggest that situational variables influence physical performance. These findings suggest position-specific physical training is required to condition players for the bespoke demands of each playing position.

Personalized task difficulty adaptation based on reinforcement learning

Traditionally, the task difficulty level is often determined by domain experts based on some hand-crafted rules. However, with the adoption of Massive Open Online Courses (MOOCs), it has become harder to manually personalize task difficulty as the system designers are faced with a very large question bank and a user base of individuals with diverse backgrounds and ability levels. This research focuses on developing a data-driven method to adaptively adjust difficulty levels in order to maintain a target user performance level over a series of tasks whose difficulty level is highly variable among different individuals. Specifically, the issue of difficulty adaptation was formulated as a reinforcement learning problem. To ensure responsiveness of the interactive systems, a novel bootstrapped policy gradient (BPG) framework was developed, which can incorporate prior knowledge of difficulty ranking into policy gradient to enhance sample efficiency. To obtain high-quality prior information on difficulty ranking, a clustering-based approach was proposed which can learn a personalized difficulty ranking to capture users’ individual differences. To evaluate the effectiveness of the difficulty adaptation method, we focused on a visual memory training problem with a large question bank and a diverse user base. Specifically, the proposed algorithms were combined and applied to a real-world application consisting of an online visual-spatial memory recall game and were shown to outperform the traditional rule-based adaptation approach in adapting to the slow players while achieving comparable performance in adapting to the fast players.

Міні-футбол як особливий вид фізичного вдосконалення студенток у процесі навчання

Актуальність. Основним завданням дисципліни «Фізичне виховання» в закладі вищої освіти є розвиток у студентів фізичних якостей та рухових здібностей. Виконанню цього завдання сприяє залучення студентської молоді до різноманітних секційних занять, зокрема міні-футболу, який користується популярністю не лише серед осіб чоловічої, а й жіночої статі. Мета роботи – висвітлення основних засобів забезпечення оптимального рівня розвитку фізичних якостей студенток, які займаються в секції міні-футболу. Методи – аналіз і синтез наукових літературних джерел, педагогічне спостереження, узагальнення експериментальних досліджень науковців та систематизація отриманих результатів дослідження. Результати. Рухова діяльність у міні-футболі характеризується різноманітними діями, зокрема бігом різної інтенсивності, ходьбою, стрибками, ударами по м’ячу, зупинками, падінням, фінтами тощо. Тому надзвичайно важливою якістю футболісток є швидкість. Швидкий гравець може виграти час у суперника, має можливість успішно виконувати тактичні завдання. Спритний – легко оволодіває новими технічними прийомами, краще пристосовується до різних ігрових умов, здатний точно, економно, швидко виконувати нове рухове завчання. Футболістки мають справу з постійною власною вагою й вагою м’яча, тому їм потрібна раціональна сила, яка б відповідала вимогам ігрової діяльності. Протягом гри спортсменки виконують багаторазові спринтерські прискорення, що вимагають витривалості. У міні-футболі важливе значення має еластичність м’язів і зв’язок нижніх кінцівок та хребта, тому на заняттях потрібно приділяти значну увагу розвитку гнучкості. Висновки. Навчання й тренування в міні-футболі – невід’ємні частини єдиного педагогічного процесу, у якому потрібно дотримуватися основних положень, а відмінних результатів можна досягти лише за умови високого рівня фізичної та технічної підготовленості гравців. Правильно обрана методика навчання та вдала організація занять досить важливі у підготовці жіночої команди.

Contextual factors influencing the characteristics of female football players.

Women's football participation rates are projected to increase to 60 million worldwide by 2026, doubling the current participation. Growing investment and the increase in research in women's football has had a positive effect on the level of performance over the last 10 years. The present review aimed to examine the literature on the physical and physiological characteristics of female football players from 2010 to 2019 to reflect the recent changes in professionalism. Characteristics investigated include anthropometry, strength, speed, endurance, power, change of direction and repeated sprint ability. These characteristics are presented in relation to playing position, age and competition-level. Results revealed that goalkeepers (171 cm, 66 kg) and defenders (168 cm, 61 kg) were the tallest and had the greatest body mass, while attackers were the fastest players over 20 m (3.05 s) and 30 m (4.38 s) and midfielders had the highest endurance (55.4 mL∙kg-1∙min-1) (P<0.05). Characteristics tended to improve with age until full biological maturity around 17 to 18 years of age. Competition comparisons demonstrated international players have significantly greater speed, repeated sprint ability, power and endurance characteristics (P<0.05). By identifying influential factors, coaches may be able to optimize their training and physical assessment practices, to better expose players to the required stimulus to develop these characteristics considered crucial to improved performance.

Bilateral Deficit and Bilateral Performance: Relationship with Sprinting and Change of Direction in Elite Youth Soccer Players.

The purpose of the study was to examine the differences in bilateral deficit (BLD) at different loadings during the half-squat jump (SJ) and horizontal countermovement jump (HCMJ) to determine if there is a relationship with linear sprint or change of direction (COD). The second goal was to check if fast players were more powerful in SJ and HCMJ than slow players in bilateral performance (BP). Twenty-seven male youth soccer players participated in the study. Players were divided in two groups, faster and slower, according to their sprint performance (10 and 40 m). BLD average power with body weight (BW) and 25%BW were significantly higher than 50%BW (p < 0.01). BLD during HCMJ was significantly higher than BLD during SJ with BW, 25%BW and 50%BW (p < 0.01). There were no statistical relationships between BLD and sprint or COD performance (p > 0.05). Fast players showed significantly higher SJ power with all the different loads and HCMJ than slow players (p < 0.01), and fast players lost more time executing COD-90° than slow players (p < 0.01). There were no statistical differences between fast and slow players in BLD. BLD seems to be dependent on motor task, contraction type and load and could not be a proper measure to estimate sprint and COD performance. Faster players are confirmed to be more powerful players than slow players, and decrements in COD could be a key benchmark to identify deficit between linear and COD performance.

PENERAPAN LOGIKA FUZZY SUGENO UNTUK PENENTUAN REWARD PADA GAME EDUKASI AKU BISA

This study discusses an application of fuzzy logic in educational game. This game requires a fast player response. We made this game in order to raise children awareness to encounter strangers. In this game, strangers are enemies in the form of hand drawings. The main characters in this game are boy and girl. The player can choose a character as desired. Each selected character has a different level. At each level, there is a level of difficulty based on the ease of passing enemies to reach the goal. The player would win the game once he/she manages to escape from strangers and arrives at home. Each level of the game has an enemy who tries to approach the player. If the enemy caught by the player, it will get consequences according to the fuzzy rules that applied to the game. The application of fuzzy logic in this game is to regulate the form of reward that will receive by the player. The basis for determining reward is the living conditions, time, and scores obtained by the player. In this research, we use fuzzy Sugeno logic for giving rewards. We conclude that fuzzy logic applies to our educational game.

Different Pathways Leading up to the Same Futsal Competition: Individual and Inter-Team Variability in Loading Patterns and Preseason Training Adaptations.

During the preseason, futsal players deal with large internal load, which may result in a reduction in physical performance. The aims of this study were to compare the session rating of perceived exertion training load (s-RPE TL) during the preseason between two teams; and to analyze the changes on the delayed-onset muscle soreness (DOMS), aerobic- and speed-power characteristics in players accumulating different s-RPE TL (Low (LTL) vs. High (HTL)). Twenty-eight players (Team A, n = 15; Team B, n = 13) were recruited. The s-RPE TL was monitored throughout the preseason phase (five weeks) in both teams. The coaches of each team planned the activities that comprised their training programs, without any interference from the researchers. Team A evaluated countermovement jumps (CMJ) and DOMS weekly. Team B performed squat jumps (SJ), CMJ, 5 m and 15 m sprints, and a futsal intermittent endurance test (PVFIET) before and after the preseason. Team B accumulated an almost-certainly greater s-RPE TL than Team A. In Team A, the CMJ height was likely to almost certainly improved for the HTL group from week 3. In Team B, the 5 m and 15 m sprint likely decreased after the preseason. Changes in 5 m (r = −0.61) and 15 m (r = −0.56) were correlated with total s-RPE TL. Changes in PVFIET were positively associated with changes in sprint, but inversely related to the baseline. s-RPE TL differed between both teams, and substantial gains in neuromuscular performance were observed for the HTL group in Team A. Slower and faster players in Team B showed distinct intermittent-endurance and speed adaptive responses during the high-volume preseason.

Effects of short-term in-season break detraining on repeated-sprint ability and intermittent endurance according to initial performance of soccer player.

To better understand the detraining effects in soccer, the purpose of the study was to analyse if performance level of soccer players modulate repeated-sprint ability (RSA) and intermittent endurance changes during 2-weeks of detraining (i.e., in-season break). Seventeen professional and sixteen young elite soccer players of two different teams performed, before and after 2-weeks of detraining, the RSA test and the Yo-Yo Intermittent Recovery Test, level 1 (YYIR1). Before detraining, professional players perform better (p < 0.05) RSA best time (RSAbest) than young players. A decrease (p < 0.05) in RSAbest, RSA total time (RSAtotal) and mean time (RSAmean) performance was observed in both teams, without changes in RSA fatigue index (Sdec). No significant changes in distance covered during YYIR1 was observed in any team. Before detraining, faster players from both teams (FG) (following the median split technique, soccer players with RSAbest ≤ 3.95 s) performed better (p < 0.01) in RSAtotal, RSAmean and RSAbest, but worse (p < 0.01) in Sdec. Although FG and the slower players (SG, RSAbest > 3.95 s) showed a worse (p < 0.05) RSAtotal, RSAbest and RSAmean performance after detraining (ES = 1.5, 1.4 and 2.9; ES = 0.6, 1.2 and 0.6; for FG and SG, respectively), the deterioration was greater in the FG for RSAbest (p < 0.05) and RSAtotal (ES = 1.46). After detraining, FG improved (p < 0.05) Sdec performance. In conclusion, a 2-week in-season break (detraining) period induced a worse RSA, with no effect on intermittent endurance in professional and elite young soccer players, with greater detrimental effects on RSAtotal and RSAbest in FG. In addition, Sdec does not seem to be sensitive to changes in RSA after a 2-week in-season break.

Dribbling determinants in sub-elite youth soccer players

Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s−1, P < 0.01); reduced CoM mediolateral (0.91 ± 0.05 vs. 1.14 ± 0.16 m, P < 0.05) and vertical (0.19 ± 0.01 vs. 0.25 ± 0.03 m, P < 0.05) RoMs; higher right stride cadence (+20%, P < 0.05) with lower variability (P < 0.05); reduced hip and knee flexion RoMs (P < 0.05). In conclusion, faster players are able to run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.

Peak match speed and maximal sprinting speed in young soccer players: effect of age and playing position.

This study assessed the relationship between peak match speed (PMS) and maximal sprinting speed (MSS) in regard to age and playing positions. MSS and absolute PMS (PMSAbs) were collected from 180 male youth soccer players (U13-U17, 15.0 ± 1.2 y, 161.5 ± 9.2 cm, and 48.3 ± 8.7 kg). The fastest 10-m split over a 40-m sprint was used to determine MSS. PMSAbs was recorded using a global positioning system and was also expressed as a percentage of MSS (PMSRel). Sprint data were compared between age groups and between playing positions. Results showed that regardless of age and playing positions, faster players were likely to reach higher PMSAbs and possibly lower PMSRel. Despite a lower PMSAbs than in older groups (eg, 23.4 ± 1.8 vs 26.8 ± 1.9 km/h for U13 and U17, respectively, ES = 1.9 90%, confidence limits [1.6;2.1]), younger players reached a greater PMSRel (92.0% ± 6.3% vs. 87.2% ± 5.7% for U13 and U17, respectively, ES = -0.8 90% CL [-1.0;-0.5]). Playing position also affected PMSAbs and PMSRel, as strikers were likely to reach higher PMSAbs (eg, 27.0 ± 2.7 vs 23.6 ± 2.2 km/h for strikers and central midfielders, respectively, ES = 2.0 [1.7;2.2]) and PMSRel (eg, 93.6% ± 5.2% vs 85.3% ± 6.5% for strikers and central midfielders, respectively, ES = 1.0 [0.7;1.3]) than all other positions. The findings confirm that age and playing position affect the absolute and relative intensity of speed-related actions during matches.

Does On-Field Sprinting Performance in Young Soccer Players Depend on How Fast They Can Run or How Fast They Do Run?

The aim of this study was to examine the impact of maximal sprinting speed (MSS) on the peak speed attained during soccer matches. Time-motion analysis of running activity was collected from 14 highly trained young male outfield footballers (8 wide midfielders [WM] and 6 central defenders [CD], 173.2 ± 0.06 m, 60.8 ± 8.1 kg, 16.7 ± 0.7 years) during 14 different friendly international club level matches. The 2 fastest players (a WM and a CD) were compared with the slower players who played in the same position. Each player's MSS was determined using the fastest 10-m split time during an electronically timed 40-m sprint. Game speed was recorded via portable global positioning systems. Faster players reached higher absolute peak running speeds in games than did their slower counterparts regardless of the playing position, with large to very large effect sizes and qualitative indications of "almost certain" and "very likely" positive effects associated with being fast. None of the players reached their MSS during the matches; however, the fastest CD attained a lower percentage of his MSS compared to both, his slower CD counterparts and the fastest WM. Given the higher peak speeds reached in games by the fastest players, and the fact that all players (irrespective of their MSS) used a high percentage of their MSS, these preliminary results provide direct support to the hypothesis that MSS can impact on what a player can do in actual playing conditions. Our results also indicate that playing position has an important role in influencing the expression of MSS.

A novel multimedia data mining framework for information extraction of a soccer video stream

A video stream is usually massive in terms of data content with abundant information. In the past, extracting explicit semantic information from a video stream; i.e. object detection, object tracking and information extraction; has been extensively investigated. However, little work has been devoted on the problem of discovering global or implicit information from huge video streams. In this paper, a framework has been presented for extracting information for a specified player from soccer video broadcast by data mining techniques. Concepts and information which exist in a soccer video broadcast are useful for team coaches. But, due to various reasons; i.e. wide field of view of a video stream, huge data, existence of great number of important objects in the play field of a soccer match and the occurrence of number of important events, manual extraction of information from soccer video broadcast is difficult and time consuming task. In this paper, a set of techniques is presented that automatically extract some useful information of a player, i.e. velocity and traversed distance, from a soccer video broadcast. Processing of video sequence under change of lighting conditions, fast camera movement and player`s occlusion is a challenging task. Our proposed framework comprise of 3 stages, player segmentation, player tracking and information extraction. All three stages must be robust under various challenges. The performance of our proposed system has been evaluated using a variety of soccer video broadcast having different characteristics in term of lighting conditions. The experiments showed that the efficiency of our system is satisfactory.