Relative age effect in elite soccer: More early-born players, but no better valued, and no paragon clubs or countries.
Ontology highlight
ABSTRACT:
SUBMITTER: Doyle JR
PROVIDER: S-EPMC5805271 | biostudies-literature | 2018
REPOSITORIES: biostudies-literature
Publications
Relative age effect in elite soccer: More early-born players, but no better valued, and no paragon clubs or countries.
Doyle John R JR Bottomley Paul A PA
PloS one 20180208 2
The paper analyses two datasets of elite soccer players (top 1000 professionals and UEFA Under-19 Youth League). In both, we find a Relative Age Effect (RAE) for frequency, but not for value. That is, while there are more players born at the start of the competition year, their transfer values are no higher, nor are they given more game time. We use Poisson regression to derive a transparent index of the discrimination present in RAE. Also, because Poisson is valid for small frequency counts, it ...[more]
Similar Datasets
Project description:The relative age effect (RAE) refers to the asymmetrical distribution of birthdates in a cohort found in many achievement domains, particularly in sports with many participants like soccer. Given the uniqueness of the one-child policy in China, this study examined the existence of the RAE in elite Chinese male and female soccer players generally and relative to their playing position on the field. Results showed a clear and obvious RAE for all age groups (U20 male, U18 male, adult female and U18 female) with the observed birthdate distributions for each age group significantly different from expected distributions (p<0.05). Additionally, we noticed a differential RAE according to the players' position on the field as reflected in different effect sizes. In male players, the RAE was significantly greater in Defenders (DF) and Goalkeepers (GK) compared to Midfielders (MF) and Forwards (FW) (VDF = 0.266>VGK = 0.215>VMF = 0.178>VFW = 0.175). In female players, GKs had a larger RAE (VGK = 0.184>0.17, VDF = 0.143, VMF = 0.127, VFW = 0.116). To reduce the negative consequences associated with RAEs throughout player development systems, potential solutions are discussed.
| S-EPMC7021294 | biostudies-literature
Project description:Sport confidence is a psychological characteristic considered vital for youth soccer players to possess. However, only limited research has explored the types and sources of sport confidence important to elite youth performers in professional soccer academies. Semi-structured interviews were conducted with 11 academy footballers (aged 10 or 11). Abductive hierarchical content analysis identified types of confidence to include achievement, skill execution, psychological factors, superiority to opposition and tactical awareness. Key sources of confidence identified by players were performance accomplishments, coaching, social support, and preparation. Even though the dimensions reported were similar to previous research, a number of unique sub-themes of confidence sources emerged, including pre-training/competition emotions, coach and team-mate feedback. The results demonstrate the importance of considering maturation levels and context when seeking to understand and develop confidence in youth performers.
| S-EPMC8617682 | biostudies-literature
Project description:Objective: There are growing concerns about the short- and long-term consequences of sports-related concussion, which account for about 5–9% of all sports injuries. We hypothesized there may be sex differences in concussion history and concussion-related symptoms, evaluated among elite soccer players in Sweden. Design: Retrospective survey study. Participants and Setting: Soccer players (n = 1,030) from 55 Swedish elite soccer teams. Questionnaires were completed prior to the start of the 2017 season. Assessment of Risk Factors: Player history of soccer-related concussion (SoRC), symptoms and management following a SoRC were evaluated. Main Outcome Measures: Before the start of the season the players completed a baseline questionnaire assessing previous concussions. The Sports Concussion Assessment Tool 3 was included with regard to symptom evaluation. Results: Out of 993 responding players 334 (34.6%) reported a previous SoRC and 103 players (10.4%) reported a SoRC during the past year. After sustaining a SoRC, 114 players (34.2%) reported that they continued their ongoing activity without a period of rest, more commonly female (44.9%) than male players (27.7%; P = 0.002). Symptom resolution time was 1 week or less for 61.3% of the players that reported having persisting symptoms. A positive correlation was observed between number of previous concussions and prevalence of three persisting symptoms: fatigue (P < 0.001), concentration/memory issues (P = 0.002) and headache (P = 0.047). Conclusion: About 35% of male and female elite soccer players in Sweden have experienced a previous SoRC, and about 10% experienced a SoRC during the last year. Female players continued to play after a SoRC, without a period of rest, more often than males. A higher risk of persisting symptoms was observed in players with a history of multiple concussions.
| S-EPMC7538773 | biostudies-literature
Project description:The purpose of this study is to identify lower-extremity (LE) musculoskeletal characteristics of elite female soccer players and to determine whether differences between dominant and nondominant extremities exist with respect to strength, flexibility, and range of motion. Physical data were collected from 26 female professional soccer players. Core control, hip and knee passive range of motion (PROM), LE flexibility, hip abductor strength, and dynamic functional alignment were assessed for each LE. Of 26 subjects, 21 scored 2/5 or less on core control. Mean hip internal rotation and external rotation were 33 degrees (+/-8 degrees) and 25 degrees (+/-6.7 degrees), respectively. All subjects had shortened two-joint hip flexors with an average knee flexion angle of 50 degrees (+/-11 degrees) and increased femoral anteversion. Forty one of 48 dominant limbs and 42 of 48 nondominant limbs demonstrated deviations from neutral alignment during step down or single-leg squat. Of 25 subjects, 15 demonstrated a stiff-knee landing and/or takeoff. All subjects demonstrated limitations in hip external rotation PROM and hip flexor length. There was no difference between dominant and nondominant LEs in all variables including hip abductor strength. Additional research is needed to determine if there is a correlation between the musculoskeletal characteristics, LE biomechanics, and potential risk for injury.IV.
| S-EPMC2744746 | biostudies-other
Project description:Introduction: Laterality (i.e., handedness, footedness, and eyedness) could have an impact on highly repeated soccer movements and thus, could influence performance. The purpose of this study was to examine the laterality of high-level football players and its effects on 180° left and right U-turn movements. Materials and Methods: Handedness, footedness, and eyedness were determined in 72 elite football players (EFP, 18.2 ± 2.2 years) from the Stade Rennais Football Club (French League 1) and 9 amateur football players (AFP, 19.6 ± 2.1 years). Players performed a visual-motor task on a synthetic pitch consisting of 180° left and right rotations as fast as possible in response to a visual light on a computer screen. Movement times and reactive times for each left and right rotation were recorded with an accelerometer and video display. Results: Laterality profiles showed a majority (?2 = 9.42, df = 2, p = 0.031) of crossed formulas (i.e., dominant leg or hand is controlateral to the dominant eye) for EFP (53 ± 7%) and a majority of non-crossed formulas for AFP (63 ± 9%). Reaction times were significantly faster (p = 0.028, effect size = 0.148, trivial) in EFP right-eyed (568.2 ± 55.5 ms) than in AFP (610.0 ± 43.9 ms). For the left rotation and for right-footed players, movement times were significantly different (p = 0.043, effect size = 0.413, small) between EFP (1.15 ± 0.07 s) and AFP (1.17 ± 0.07 s). A significant difference (p < 0.033) was observed between footedness and rotation movement times in the EFP. Conclusion: Our results showed that laterality profiles differed between EFP and AFP. Hence, in EFP, reaction times depended on the side of the visual stimulus. Moreover, leg laterality of EFP influenced 180° left or right rotation speed. Our results indicate the importance of determining laterality in soccer players and identifying deficits in performance when turning.
| S-EPMC6033993 | biostudies-literature
Project description:Real Madrid was named as the best club of the 20th century by the International Federation of Football History and Statistics. The aim of this study was to compare if players from Real Madrid covered shorter distances than players from the opposing team. One hundred and forty-nine matches including league, cup and UEFA Champions League matches played by the Real Madrid were monitored during the 2001-2002 to the 2006-2007 seasons. Data from both teams (Real Madrid and the opponent) were recorded. Altogether, 2082 physical performance profiles were examined, 1052 from the Real Madrid and 1031 from the opposing team (Central Defenders (CD) = 536, External Defenders (ED) = 491, Central Midfielders (CM) = 544, External Midfielders (EM) = 233, and Forwards (F) = 278). Match performance data were collected using a computerized multiple-camera tracking system (Amisco Pro®, Nice, France). A repeated measures analysis of variance (ANOVA) was performed for distances covered at different intensities (sprinting (>24.0 km/h) and high-speed running (21.1-24.0 km/h) and the number of sprints (21.1-24.0 km/h and >24.0 km/h) during games for each player sectioned under their positional roles. Players from Real Madrid covered shorter distances in high-speed running and sprint than players from the opposing team (p < 0.01). While ED did not show differences in their physical performance, CD (p < 0.05), CM (p < 0.01), EM (p < 0.01) and F (p > 0.01) from Real Madrid covered shorter distances in high-intensity running and sprint and performed less sprints than their counterparts. Finally, no differences were found in the high-intensity running and sprint distances performed by players from Real Madrid depending on the quality of the opposition.
| S-EPMC5548164 | biostudies-other
Project description:The purpose of the present study was to investigate the explosive strength and endurance adaptations in young elite soccer players who underwent a supervised training program for a period of two years. Nineteen players, with seven years of training experience (age: 13.3 ± 0.1 years; body weight: 57.9 ± 4.9 kg; height: 168.9 ± 4.7 cm; BMI: 20.1 ± 1.1 kg/m2), voluntarily participated in the present study. The testing sessions were performed at the beginning of the preparation period in the first (T1), second (T2), and third year (T3). The following performance variables were measured: explosive strength [squat-jump (SJ) and counter-movement-jump (CMJ)], pre-stretch augmentation (CMJ-SJ), leg stiffness [hopping test (HT)], short sprint performance [15 m (SSP15) and 30 m (SSP30)], aerobic endurance [test of Leger (VO2max)], maximal heart rate [at the last step of Leger (HR)], and speed-strength endurance [continuous counter-movement-jumps (CCMJ)]. A significant main effect on the VO2Max (+5.72%; F(2.49) = 3.822; p = 0.029; ES = 1.00), HR (-1.70%; F(2.54) = 3.472; p = 0.038; ES = 0.97), CCMJ (+7.64%; F(2.54) = 5.438; p = 0.007; ES = 1.15), SJ (+10.26%; F(2.54) = 15.254; p = 0.0001; ES = 1.53), CMJ (+7.36; F(2.54) = 8.270; p = 0.001; ES = 1.33), HT (+8.34%; F(2.48) = 3.297; p = 0.046; ES = 1.01), SSP15 (-3.50%; F(2.44) = 12.760; p = 0.0001; ES = 1.53), and SSP30 (-4.44%; F(2.44) = 5.797; p = 0.006; ES = 1.16) was observed in the two soccer seasons. These results highlight that, in long-term training, the monitoring of the adaptive responses in relation to the training load may provide a guideline to optimize the trainability of some performance variables in young elite soccer players (13-15 years). In the present study, we cannot exclude the influence of growth and maturation on some performance variables; therefore, the monitored adaptive responses should be considered as the possible results of an interaction between the applied training load and maturation.
| S-EPMC5305282 | biostudies-literature
Project description:PurposeAthletes who meet return to play (RTP) criteria after anterior cruciate ligament reconstruction (ACLR) rehabilitation still have a substantially increased risk of second ACL injury. One of the contributing factors to this increased risk could be that the RTP criteria are often not tested in an ecologically valid environment and in a fatigued state. The purpose of this cross-sectional case-control study was to investigate the influence of neuromuscular fatigue on both movement quantity and quality in fully-rehabilitated soccer players after ACLR and to compare them with healthy soccer players.MethodsACL-reconstructed soccer players (n?=?14) and healthy soccer players (n?=?19) participated in the study and were matched by playing level and training hours. RTP measurements were performed on the soccer field, in both a non-fatigued and fatigued state. The RTP measurements focussed on both movement quantity (hop tests) and quality [countermovement jump with a Landing Error Scoring System (LESS) score].ResultsMovement quantity did not differ between ACL-reconstructed and healthy soccer players, both expressed in absolute values and the LSI-D/ND (calculated as dominant/non-dominant*100%). However, movement quality decreased more in the ACL-reconstructed soccer players in the fatigued state compared to the non-fatigued state.ConclusionsIdeally, RTP measurements should focus on movement quality and should be conducted on the soccer field in a fatigued state, creating an ecologically valid environment. The LSI-D/ND can be used as an outcome parameter for RTP measurements of movement quantity and should be at least 95%.Level of evidenceTherapeutic, Level III.
| S-EPMC6394549 | biostudies-literature
Project description:Soccer players are required to anticipate and react continuously in a changing, relatively unpredictable situation in the field. Cognitive functions might be important to be successful in soccer. The current study investigated the relationship between cognitive functions and performance level in elite and sub-elite youth soccer players aged 13-17 years. A total of 47 elite youth soccer players (mean age 15.5 years, SD = 0.9) and 41 sub-elite youth soccer players (mean age 15.2 years, SD = 1.2) performed tasks for "higher-level" cognitive functions measuring working memory (i.e., Visual Memory Span), inhibitory control (i.e., Stop-Signal Task), cognitive flexibility (i.e., Trail Making Test), and metacognition (i.e., Delis-Kaplan Executive Function System Design Fluency Test). "Lower-level" cognitive processes, i.e., reaction time and visuo-perceptual abilities, were also measured with the previous tasks. ANOVA's showed that elite players outscored sub-elite players at the "higher-level" cognitive tasks only, especially on metacognition (p < .05). Using stepwise discriminant analysis, 62.5% of subjects was correctly assigned to one of the groups based on their metacognition, inhibitory control and cognitive flexibility performance. Controlling for training hours and academic level, MANCOVA's showed differences in favor of the elite youth soccer players on inhibitory control (p = .001), and cognitive flexibility (p = .042), but not on metacognition (p = .27). No differences were found concerning working memory nor the "lower-level" cognitive processes (p > .05). In conclusion, elite youth soccer players have better inhibitory control, cognitive flexibility, and especially metacognition than their sub-elite counterparts. However, when training hours are taken into account, differences between elite and sub-elite youth soccer players remain apparent on inhibitory control and cognitive flexibility in contrast to metacognition. This highlights the need for longitudinal studies to further investigate the importance of "higher-level" cognitive functions for talent identification, talent development and performance in soccer.
| S-EPMC4691195 | biostudies-other
Project description:Introduction: Biological aging is associated with changes in the metabolic pathways. Leukocyte telomere length (LTL) is a predictive marker of biological aging; however, the underlying metabolic pathways remain largely unknown. The aim of this study was to investigate the metabolic alterations and identify the metabolic predictors of LTL in elite male soccer players. Methods: Levels of 837 blood metabolites and LTL were measured in 126 young elite male soccer players who tested negative for doping abuse at anti-doping laboratory in Italy. Multivariate analysis using orthogonal partial least squares (OPLS), univariate linear models and enrichment analyses were conducted to identify metabolites and metabolic pathways associated with LTL. Generalized linear model followed by receiver operating characteristic (ROC) analysis were conducted to identify top metabolites predictive of LTL. Results: Sixty-seven metabolites and seven metabolic pathways showed significant associations with LTL. Among enriched pathways, lysophospholipids, benzoate metabolites, and glycine/serine/threonine metabolites were elevated with longer LTL. Conversely, monoacylglycerols, sphingolipid metabolites, long chain fatty acids and polyunsaturated fatty acids were enriched with shorter telomeres. ROC analysis revealed eight metabolites that best predict LTL, including glutamine, N-acetylglutamine, xanthine, beta-sitosterol, N2-acetyllysine, stearoyl-arachidonoyl-glycerol (18:0/20:4), N-acetylserine and 3-7-dimethylurate with AUC of 0.75 (0.64-0.87, p < 0.0001). Conclusion: This study characterized the metabolic activity in relation to telomere length in elite soccer players. Investigating the functional relevance of these associations could provide a better understanding of exercise physiology and pathophysiology of elite athletes.
| S-EPMC8716766 | biostudies-literature