Profile Of Players Research Articles

The Play of Champions: Toward a Theory of Skill in eSport

ABSTRACT This article advances a tentative theory of skill in relation to eSports. This conjectural theory of skill rests on hypothesizes informed by assumptions from watching 100+ hours of eSport events on Twitch, YouTube, and AfreecaTV and is supported by discussions, reflections and evaluations with eSport players. The case material of this article includes the games Clash Royale (CR), StarCraft 2 (SC2), Counter-Strike: Global Offensive (CS:GO), and online battle arenas (mobas) such as League of Legends (LOL) and Defense of the Ancient 2 (DOTA2). This inferred theory of skill is conjoined and composed of seven strands, which provide a framework for explaining how to understand skill in eSport. These seven strands are presented under the headings: (1) knowledge about game objects, (2) insights into game systems, (3) understanding metagaming, (4), yomi: ‘reading’ the opponent, (5) ability to execute, (6) emotional discipline, and finally (7) team coherency (depending upon whether the skill is associated with a one-versus-one or team-versus-team game). In conclusion, the proposed theory of skill will expose its explanatory power and reach by providing an example of how it can both be implemented to create profiles of players’ skill, and how these profiles in turn can serve as guides to help players improve their skill levels in eSport.

Effects of passive, active, and mixed playing strategies on external and internal loads in female tennis players.

This study aimed to investigate the effects of different playing strategies on external and internal loads in female tennis players during match play. Also, the underlying effects on the technical-tactical actions and activity profiles were examined. Twelve well-trained female players (age: 25±5 years; maximum oxygen uptake: 40.9±4.3 ml/kg/min) played points against an opponent of similar ability outdoors on red-clay courts. The players played points over five playing conditions. Before each condition, the players were instructed to apply either a passive, an active, or their own playing strategy (free play) to succeed. The five conditions were played in a randomized order, whereas the condition with the own strategy was always played first and served as control. During play, the external and internal loads were investigated by 10 Hz global positioning system, 100 Hz inertial measurement unit, short-range telemetry, capillary blood, and visual analog scale procedures. A 25 Hz video camera was used to examine the technical-tactical actions and activity profiles. Compared to the control condition, the passive, active, and mixed playing strategy conditions induce up to large effects on the external loads (running distances with high acceleration and deceleration), up to moderate effects on the internal loads (energy expenditures spent with high metabolic power, lactate concentration, and rating of effort), and up to very large effects on the technical-tactical actions (number of ground strokes and errors) and activity profiles (strokes per rally, rally duration, work to rest ratio, and effective playing time). Our study shows that passive, active, and mixed playing strategies have an impact on the external and internal loads, technical-tactical actions, and activity profiles of female tennis players during match play. This finding should be considered for practical purposes like match analyses and training procedures in the tennis environment.

Comparison of Physical Profiles of State-Level Netball Players by Position.

Graham, S, Duthie, G, Aughey, R, and Zois, J. Comparison of physical profiles of state-level netball players by position. J Strength Cond Res 34(9): 2654-2662, 2020-Understanding the physical profiles of state-level netball athletes provides conditioning professionals with testing norms and an understanding of important capacities within particular positions. The purpose was to examine positional differences in physical capacities of state-level netball athletes. Forty-six state-level netball athletes completed physical capacity assessments in the second week of their preseason, over 2 seasons. Tests included stature, 20-m sprint (with 5 and 10 m splits), 505 change-of-direction, countermovement jump, single-leg bounding, and the Yo-Yo intermittent recovery test level one. A linear mixed-model with fixed and random effects was used in conjunction with magnitude-based inferences to determine meaningful differences with 90% confidence limits (CLs). Midcourt athletes were shorter in stature than shooters (effect size [ES]: 1.26, CL 0.88-1.63) and defenders (-2.58, -3.35 to -1.80). Midcourt athletes were faster than shooters and defenders in linear acceleration over 5 and 10 m distances and 505 change-of-direction (ES range: -0.34 to -0.59). Shooters presented poorer intermittent endurance than midcourt (-0.82, -1.34 to -0.31) and defenders (-0.56, -1.19 to 0.07). Defenders jumped higher than midcourt athletes (-0.56, -1.30 to 0.19) and shooters (-0.61, -1.18 to -0.04), and possessed greater bounding ability compared with shooters (ES range: -0.23 to -0.57). Midcourt athletes require a more holistic set of physical capacities including acceleration, change-of-direction, jumping, and intermittent endurance. For defender and shooter positions, results indicate physical requirements that may be more specific to their positions. Conditioning professionals can use these findings to target specific physical qualities to maximize position-specific performance.

Ser futbolista juvenil en Argentina. Orígenes, escolarización, vivienda, sentimientos y expectativas de los deportistas en formación de un club de fútbol profesional.

Este artículo se propone trazar un perfil socio-demográficode los futbolistas en formación en Argentina a partir del análisis de múltiples dimensiones de la vida de esos jóvenes, que masivamente depositan en el fútbol sus sueños y deseos, desarrollando intensas e inciertas carreras socio-profesionales en los clubes de fútbol.Habitualmente, los clubes se ocupan exclusivamente de las variables de rendimiento (físicas, técnicas, tácticas), obviando cuestiones como origen, familia, escolaridad, vivienda, sentimientos, opiniones, consumos y otras dimensiones que hacen a la formación integral de los jóvenes. El artículo propone un abordaje cuantitativo y descriptivo de esas dimensiones, basado en 6 encuestas realizadas en 2018 a todos los futbolistas juveniles (entre 13 y 20 años) de un club de Primera División argentino.

Optimal Body Composition and Anthropometric Profile of World-Class Beach Handball Players by Playing Positions

Profiling of beach handball players is required to optimize sports performance, talent identification, and injury prevention. The study aimed to describe the anthropometric characteristics, somatotype, and body composition of elite male and female beach handball players classified by playing positions. Thirty elite beach handball players (15 male, 15 female) of the Spanish National Beach Handball Team, which ranked fifth and first in the VII World Championships, respectively, were categorized as front (wings/specialists), back (pivots/defenders) players and goalkeepers. Independent from position, male players showed larger values of anthropometric characteristics, girths, breadths, and absolute components of body composition than female players. Contrastingly, skinfolds, and body fat mass percentage were higher in female players. All these results were statistically significant (p < 0.05) with large to extremely large effect sizes (d = 1.4–5.4). The position-related differences indicated that male back players were taller (p = 0.008; ηp2 = 0.56), heavier (p = 0.016; ηp2 = 0.50) and showed larger arm span (p = 0.036; ηp2 = 0.42) than front players. In contrast, female goalkeepers showed larger body mass (p = 0.007; ηp2 = 0.57) and BMI (p = 0.035; ηp2 = 0.43), whereas back players showed higher muscular mass than goalkeepers (p = 0.022; ηp2 = 0.47). The present study provides anthropometric reference values of elite beach handball players, and indicates differences between playing positions, providing normative data for talent identification of male and female players.

Acceleration and sprint profiles of professional male football players in relation to playing position.

The study aims were to describe positional differences in the acceleration and sprint profiles of professional football players in match-play, and analyse start speeds required based on the intensity of accelerations and decelerations. This longitudinal study was conducted over thirteen competitive microcycles in a professional football team from LaLiga 123. Data were collected through electronic performance tracking systems. Every player was categorised based on the playing position: central defender (CD), full-back (FB), forward (FW), midfielder (MF), and wide midfielder (WMF). In respect of acceleration profile, positional differences were found for all variables (p < 0.05), except average magnitude of accelerations (ACCAVG, p = 0.56) and decelerations (DECAVG, p = 0.76). The sprint profile also showed positional differences for all variables (p < 0.05), apart from sprint duration (p = 0.07). In addition, although low-intensity accelerations required significantly greater start speeds (Vo) than high-intensity accelerations in WMF (0.4 ± 0.2 km/h; p < 0.05) and FW (0.4 ± 0.2 km/h; p < 0.05), no significant differences (p > 0.05) were found in CD, FB, and MF. However, high-intensity decelerations were performed at significantly higher Vo than low-intensity decelerations in MF (2.65 ± 0.1 km/h; p < 0.05), FW (3.3 ± 0.1 km/h; p < 0.05), FB (3.9 ± 0.4 km/h; p < 0.05), WMF (4.3 ± 0.3 km/h; p < 0.05), and CD (4.1 ± 0.7 km/h; p < 0.05). Therefore, positional differences exist for most variables of the acceleration and sprint profiles. In addition, different Vo were observed between high-intensity and low-intensity accelerations as well as high-intensity and low-intensity decelerations.

Prediction models for musculoskeletal injuries in professional sporting activities: A systematic review

The purpose of this systematic review was twofold: (a) identify prediction models for musculoskeletal injuries during the participation of professional sporting activities and (b) evaluate these models by their predictive performances. A systematic review of the PubMed and Embase databases was performed using specific search terms selected according to the PRISMA guidelines. Ten studies met the eligibility criteria and were included. The most commonly employed data component for data pre-processing was body composition data (most commonly, body mass and height), followed by player profile (most commonly, age followed by position). The most common machine learning technique for data processing was the decision tree, followed by logistic regression. The median AUC of the best performing models indicated per study was 0.75 (0.16), median sensitivity/recall was 0.78 (0.15), median specificity was 0.81 (0.27), and median precision was 0.53 (0.13). The performance of prediction models in the literature has been poor, caused by a fundamental difficulty in discovering real effects in small sample sizes with low injury rates. A better understanding of how training and game exposure is associated with the data components for data pre-processing and ultimately associated with injury is vital for the future development of robust injury prediction models.

Occurrences of near-to-maximal speed-running bouts in elite soccer: insights for training prescription and injury mitigation

ABSTRACT Aim: To quantify the occurrence of near-to-maximal speed-running bouts in elite soccer players. Methods: Tracking match data from 35 professional players (23 ± 3 yrs) were analysed over four seasons (2015–2019). The number of runs reaching >80, >85 and >90% of players’ individual maximal sprinting speed (MSS) was computed. Differences in peak speed occurrences between halves and positions were analysed. Results: Occurrences were not different between halves, but slightly-to-moderately position-dependent, with wingers (3.5 ± 2.0 runs >80% per half) and central midfielders (1.6 ± 1.5 runs >80% per half) performing the most and the least number of near-to-maximal speed-running bouts. Players did not reach >90% of MSS at all in 35% (Attackers) to 65% (Midfielders) of their matches; they reached ≥3 times >90% MSS per match in 2% (Midfielders) to 11% (Attackers) of their matches only. The maximal number of cumulated match occurrences during congested periods was observed in acentral defender (2 runs >90% of MSS every 4 days for 31 days) and a winger (1 run every 4 days for 52 days). Conclusions: The occurrence of near-to-maximal speed-running bouts is low in elite soccer. Match context, playing position and individual player profile are the main determinants of those occurrences.

Longitudinal differences in the injury profile of professional male handball players according to competitive-level

ABSTRACT The aim was to analyse the differences in professional handball players` injury profile according to the team`s competitive-level (i.e., First division vs. Second division). Fifty-three professional male handball players participated in this study during four consecutive seasons in the same team (2015–16 and 2016–17 for the First division league and 2017–18 and 2018–19 for the Second division league). No significant differences in overall incidence were observed between groups (3.69 vs 4.19 injuries/1000 h, RR = 0.88, 95% CI 0.64–1.22, P = 0.44), although significantly greater injury incidence during training sessions was observed in the Second division group (3.06 vs 1.61 injuries/1000 h, RR = 0.52, 95% CI 0.34–0.81, P = 0.01), while greater injury incidence during matches was reported in the First division group (84.03 vs 49.88 injuries/1000 h, RR = 1.68, 95% CI 1.00–2.83, P = 0.05). The second division group presented the greatest injury burden attending to overall, training and match exposure, as well as in most locations and injury types. Given the between groups differences found in the injury profile of handball player, it is suggested to implement specific preventive strategies attending to the characteristics of each level-group.

Assessing the Anthropometric Profile of Spanish Elite Reserve Soccer Players by Playing Position over a Decade.

The aims of this study were to describe the evolution of the anthropometric profile of soccer players over a decade and to compare the anthropometric profiles of players promoted from an elite reserve team to high-level soccer with those players who were not promoted. We examined the body mass, height, body-mass index, and body fat of 98 players enrolled in the reserve team from 2008 to 2018. The players were classified in terms of (a) the highest competitive level they achieved up to the 2019/2020 season (i.e., Spanish 1st–2nd divisions or semi-professional); (b) the period in which they played their last season on the team; and (c) their playing position. Over time, the height of goalkeepers, lateral midfielders, and attackers has increased (effect size = 0.66 ± 1.13) but has decreased in central midfielders (effect size = 0.83). The body fat of defenders has also fallen (effect size = 0.55 ± 0.95). Spanish high-level goalkeepers, lateral midfielders, and attackers were taller than their semi-professional player counterparts (effect size = 1.20 ± 1.98). Body fat did not determine promotion from a reserve team to high-level soccer, but height may be an advantage for several playing positions. The assessment of the anthropometric profile and the application of interventions should be designed according to the playing position.

Body Composition Changes after One Year in Professional Male Ice Hockey Players.

Body composition measurements remain one of the best objective ways to analyze tissue distribution in athletes. The purpose of this study was to establish an average body composition profile for professional male ice hockey players, assess the yearly fluctuations of body composition after a single season, and assess body composition changes among different positions. Body composition was measured using dual-energy X-ray absorptiometry in 36 professional male ice hockey players. Descriptive statistics were used to determine average values. A paired samples t-test was applied to determine differences over a one-year period. A one-way analysis of variance was used to determine differences between positions, at both time points. Alpha levels were set a priori at p<0.05. Significant increases were observed in percent body fat across time points for all positions (p=0.019). There were significant differences in percent body fat between positions played (p=0.012) after one year. We demonstrated that there was low variability among the different positions in professional male ice hockey players. Additionally, we observed how a single year minimally influences changes in body composition. More research is required to evaluate body composition in male ice hockey players.

Anthropometric and conditional profile in semiprofessional futsal players: differences between sexes. A case study. [Perfil antropométrico y condicional en jugadores semiprofesionales de futbol sala: diferencias entre sexos. Un estudio de caso

Anthropometrical profile is one of the indicators associated to optimal performance of futsal players. However, no studies have analyzed these factors in both sexes neither created an anthropometrical profile of each sex. For these reasons, the goals of this study were: to describe and compare the anthropometric and conditional profiles of sub-elite futsal players, and to analyze possible correlations between anthropometric and conditional parameters. 11 female and 8 male sub-elite futsal players participated in the study. Several tests were performed: an anthropometric and body composition analysis, leg power with squat jump (SJ) and countermovement jump (CMJ) tests, and psoas and major gluteus flexibility test. Male futsal players reported a better performance in SJ and CMJ (p<0.001, big ES), as well as a lower fat percentage (10.2%) and a greater muscular percentage (50.8%) than female futsal players (20.1% and 44.9%, respectively). No significant differences were found regarding flexibility between sexes (p>0.05). Fat percentage presents a reversal correlation (r=-0.84; ES very large), as well as muscular performance, a direct correlation (r=0.73; ES very large) with explosive performance. There are significant differences between sexes regarding anthropometric and leg power parameters, not in flexibility values. Finally, the training methods and conditional goals along the season should be adapted to anthropometric and conditional profile of each competitive level, with special focus in neuromuscular performance.

Fitness profile of young female volleyball players

Fitness profile of young female volleyball players

Hematological profiles of football players according to playing positions in Tigray region, Ethiopia

The Objectives study was to compare hematological profiles of different playing position football players in the Tigray region, Ethiopia. The study was conducted in northern parts of Ethiopia, had played in the Ethiopian premier league, super league, and National league competition programs. Descriptive Cross-sectional design and quantitative research methods were employed to compare hematological variables of different position soccer players. To get appropriate data voluntary health soccer players were selected through purposive sampling techniques. Goalkeepers (GK, 15), Defenders (DF, 27), Midfielders (MF, 36) and Strikers (ST, 23) based on player’s position 101 players were selected from a total of 200 Tigray regions. Data were analyzed by one-way analysis of variance (ANOVA) to conclude the differences between GK, DF, MF, and ST soccer players and Post Hoc test (LSD) applied at p &amp;lt; .05. No significant difference was found between playing positions in WBC, RBC, HGB, HCT, MCV, MCH, MCHC, PLT, LYM%, NEUT%, LYM#, NEUT#, RDW, PDW, MPV, and PCT (p &amp;gt; .05). Coaches and Medicals might take into consideration positional differences, age, BMI, and training status of players during testing hematological profiles.

The genetic profile of elite youth soccer players and its association with power and speed depends on maturity status.

We investigated the association of multiple single nucleotide polymorphisms (SNPs) with athlete status and power/speed performance in elite male youth soccer players (ESP) and control participants (CON) at different stages of maturity. ESP (n = 535; aged 8-23 years) and CON (n = 151; aged 9-26 years) were genotyped for 10 SNPs and grouped according to years from predicted peak-height-velocity (PHV), i.e. pre- or post-PHV, to determine maturity status. Participants performed bilateral vertical countermovement jumps, bilateral horizontal-forward countermovement jumps, 20m sprints and modified 505-agility tests. Compared to CON, pre-PHV ESP demonstrated a higher ACTN3 (rs1815739) XX ('endurance') genotype frequency distribution, while post-PHV ESP revealed a higher frequency distribution of the PPARA (rs4253778) C-allele, AGT (rs699) GG genotype and NOS3 (rs2070744) T-allele ('power' genotypes/alleles). BDNF (rs6265) CC, COL5A1 (rs12722) CC and NOS3 TT homozygotes sprinted quicker than A-allele carriers, CT heterozygotes and CC homozygotes, respectively. COL2A1 (rs2070739) CC and AMPD1 (rs17602729) GG homozygotes sprinted faster than their respective minor allele carrier counterparts in CON and pre-PHV ESP, respectively. BDNF CC homozygotes jumped further than T-allele carriers, while ESP COL5A1 CC homozygotes jumped higher than TT homozygotes. To conclude, we have shown for the first time that pre- and post-PHV ESP have distinct genetic profiles, with pre-PHV ESP more suited for endurance, and post-PHV ESP for power and speed (the latter phenotypes being crucial attributes for post-PHV ESP). We have also demonstrated that power, acceleration and sprint performance were associated with five SNPs, both individually and in combination, possibly by influencing muscle size and neuromuscular activation.

Lower-Limb Flexibility Profile Analysis in Youth Competitive Inline Hockey Players.

During puberty, the growth of the bones is faster than that of the muscles, which may result in muscular tightness. Muscular tightness and asymmetry have been associated with an increase in injury incidence. The assessment of a joint range of motion (ROM) could help to identify athletes classified as high injury risk. The objectives of the present study were to describe the lower-extremity flexibility profile (LEFP) of youth competitive inline hockey players using the ROM-SPORT battery (I) and to identify muscular tightness and asymmetry (II). Seventy-four young players were examined for maximum passive ankle, knee, and hip ROMs. Muscle asymmetry or tightness was classified according to cutoff scores previously described. The LEFP of the 74 players was 10.8° for hip extension, 26° for hip adduction, 33.6° for ankle dorsiflexion, 38.6° for ankle dorsiflexion with knee flexed, 36.7° for hip abduction, 46° for hip internal rotation, 60.6° for hip external rotation, 65.1° for hip abduction with the hip flexed, 66.3° for hip flexion with the knee extended, 119.7° for knee flexion, and 133.7° for hip flexion. The individual analysis of the flexibility values identified tightness in all players for one or more movement, except for hip abduction. A low prevalence of asymmetries was observed (range: 5.4% to 17.6% of players) depending on the ROM.

ANTHROPOMETRIC VALUES OF SPANISH BEACH VOLLEYBALL PLAYERS IN RELATION TO SPORTS PERFORMANCE LEVEL

ABSTRACT Introduction Since its debut at the 1996 Atlanta Olympics, beach volleyball has grown on the international sports scene. An extensive collection of data from several countries and levels of competition will provide a database that can be used to characterize beach volleyball players and define references for training stages. Objective The purpose of this study was to describe and compare the anthropometric profiles of Spanish male and female beach volleyball players at different levels of competition in relation to sports performance. Methods The sample comprised 150 players participating in the 2011 Spanish Beach Volleyball Championships (Under 19, Under 21, and Senior categories). Using the ranking provided by the Royal Spanish Volleyball Federation, the subjects were distributed by performance level (level 1: players ranked first to fourth; level 2: players ranked fifth to ninth; and level 3: players ranked tenth to seventeenth). The study comprised a group of male players, with 18 level 1 ( M1 ), 39 level 2 ( M2 ), and 22 level 3 players ( M3 ), and a group of female players, with 18 level 1 ( F1 ), 41 level 2 ( F2 ), and 12 level 3 players ( F3 ). Results The top level male sample ( M1 ) had a significantly lower average age (19.33 years) than the men’s international elite players (30 years). The top Spanish players of both genders had much lower values for height and body weight than the international elite players. Conclusions Height and fat component are responsible for the differences between top and lower level beach volleyball players, for both men and women. Moreover, as the level of performance increases, players are taller and have a lower fat component. In view of the data observed in this study, the talent selection process in Spanish beach volleyball should aim to select taller individuals than at present. Level of evidence III; Therapeutic studies-Investigating the results of treatment.

Injury Profile of Male and Female Senior and Youth Handball Players: A Systematic Review.

Handball is a team sport in which players are exposed to high physical conditioning requirements and several contacts and collisions, so they must face various musculoskeletal injuries throughout their career. The aim of this study was to summarize the characteristics of handball injuries both in training and in competition contexts, differentiating by gender and age. A systematic review was conducted and a total of 15 studies (33 cohorts) met the inclusion criteria. Higher injury incidence was reported during matches compared to training sessions in all groups (i.e., male and female senior and youth players), with male senior players presenting the greatest values. Lower extremities were more frequently injured, being contusions and sprains the most common type of injuries. Females reported more serious injuries than males, who presented a higher percentage of acute injuries caused by direct contact, while in female players these injuries were not caused by direct contact actions. Wings and backs presented the highest injury incidence; additionally, players registered higher match incidence during international championships compared to national leagues. Due to the differences in the injury profile of handball players, specific preventive strategies should be implemented for each group to optimize the injury prevention process.

The isokinetic strength profile of semi-professional soccer players according to low back pain.

Soccer as a sport has a very high injury rate and low back pain (LBP) is considered to be the most common overuse injury typically occurring in the back and spine in elite soccer players. This study aimed to investigate differences in knee muscle strength and muscle imbalances in soccer players according to lower back pain. One hundred and thirty-six male professional soccer players (20.49 ± 3.73years, 76.57 ± 8.24kg, 182.63 ± 6.73cm) volunteered for the study. The isokinetic dynamometer PrimaDOC (EASYTECH, Italy) was used to assess the hamstring and quadriceps strength at the selected speeds of 60∘/s, whereas the Roland-Morris Disability Questionnaire (RDQ) was used as a health status measure to assess physical disability caused by low back pain. A univariate analysis of variance has shown that there is a statistically significant difference among the groups divided into Absolute peak torque right knee flexors, Absolute peak torque left knee flexors, Ratio between hamstrings and quadriceps strength right leg, and Ratio between hamstrings and quadriceps strength left leg based on the RDQ scores. On the other hand, no other significant differences among the groups were found in other parametersCONCLUSION: The current study indicates that knee muscle strength variables, resulting from an isokinetic testing, have the potential to discriminate between soccer players with and without a history of low back pain. However, low back pain is a multidimensional phenomenon and knee muscle strength or imbalance alone cannot be expected to explain low back pain.

The effects of an 8-week off-season period on the mechanical properties of sprinting in professional rugby league players: implications for training recommendations

Objectives: To determine the change in mechanical properties of sprinting performance across an 8-week off-season period in professional rugby league players. Design: Repeated measures Methods: Twenty-six professional rugby league players from a single rugby league team competing in Super League completed two assessments of linear sprint performance during final week of the season and second week of preseason. Linear split times were used to model the horizontal force-velocity profile and determine theoretical maximal force (F0), velocity (V0) and power (Pmax). Results: Our result indicated moderate-to-large increases in split times was observed at each distance across the off-season period (ES = 0.86 to 1.24; most likely), indicative of a reduced sprinting ability. Furthermore, small reductions in F0 (ES -0.34 to -0.57; likely to very likely) were observed, whilst the reduction in V0 (ES = -0.81; most likely) and Pmax (ES = -0.62 to -1.03; most likely) were considered moderate in magnitude. Conclusions: An 8-week off-season period elicited negative changes in linear sprint times and the horizontal force-velocity profile of professional rugby league players. Such findings might have implications for preseason training loads and therefore, the off-season period requires careful consideration by practitioners and clinicians with regards to content and monitoring.