Sport activities differentiating match-play improvement in elite youth footballers – a 2-year longitudinal study

This study examined contributions of different types of sport activities to the development of elite youth soccer performance. Match-play performance of 44 German male players was assessed by expert coaches twice, 24 months apart (age 11.1–13.1 years), based on videotaped 5v5 matches. Player pairs were matched by identical age and initial performance at t₁. Each player was assigned to a group of either “Strong” or “Weak Responders” based on a higher or lower subsequent performance improvement at t₂ within each pair (mean Δperformance 29% vs. 7%). A questionnaire recorded current and earlier amounts of organised practice/training and non-organised sporting play, in soccer and other sports, respectively. Group comparison revealed that “Strong Responders” accumulated more non-organised soccer play and organised practice/training in other sports, but not more organised soccer practice/training. Subsequent multivariate analyses (multiple linear regression analyses (MLR)) highlighted that higher resultant match-play performance at t₂ was accounted for R²_adj = 0.65 by performance at t₁, together with more non-organised soccer play and organised engagement in other sports, respectively, and greater current, but less earlier volume of organised soccer. The findings suggest that variable early sporting experience facilitates subsequent soccer performance development in German elite youth footballers.     

Practice and play as determinants of self-determined motivation in youth soccer players

Abstract

Based upon predictions derived from the Developmental Model of Sports Participation, we tested whether hours in domain-specific play (self-led activities) and practice (coach-led activities) during childhood (~5–12 year) in an elite group of youth soccer players from the UK (N = 144) were related to motivation. Independent analysis of three different age groups (Under 13, 15 and 17 year) did not show relations between play and practice activities during childhood and global measures of motivation. However, secondary analysis showed that when controlling for years in soccer, years in the UK Academy system were negatively related to global indices of self-determined motivation (SDI) and positively related to controlled motivation for the oldest players. Despite predictions, there was no evidence that play during childhood was positively related to more SDI. Prospective research is recommended to enable more robust conclusions about the role of early developmental practice activities, especially early specialisation in a high-performance system, on both skill and psychosocial development.     

Psychosocial outcomes associated with soccer academy involvement: Longitudinal comparisons against aged matched school pupils

ABSTRACT

Despite literature highlighting numerous risks to the healthy psychosocial development of youth elite academy soccer players, little of this research is based on high-quality research designs. This study employed a prospective longitudinal cohort design to track psychosocial outcomes of academy involvement within male youth elite soccer players (n = 33, U12-U16 age groups) compared to age-matched soccer-active school pupils (n = 44) over 12 months. Participants completed questionnaires assessing the most commonly raised psychosocial concerns at four equally spaced data collection periods (T1–T4). Repeated measures multivariate analysis of variance (MANOVAs) indicated that, over the year, both groups reported a healthy and improving stress and recovery balance, as well as positive and stable needs satisfaction and physical, psychological and social well-being. Academy players reported stable positive school-related quality of life, whereas school pupils reported increases from T3 to T4. Academy players reported consistent significantly higher total athletic identity and exclusivity of identity. Findings suggest that many concerns around negative psychosocial impacts of soccer academy involvement did not materialise in this context. However, heightened athletic identities remained a concern.     

Coach ratings of skills and their relations to practice,play and successful transitions from youth-elite to adult-professional status in soccer

Elite soccer players (~15 yr) from professional academies in the UK were rated on technical, tactical, physical and creative skills by coaches at time 1 (T1). Players estimated accumulated hours in soccer practice (coach-led activities) and play (self-led activities) during childhood. Coach-ratings were again collected 2.5 yr later (T2) for players that received a professional contract (~17 yr). Adult-professional status was determined at T3 (~ 20 yr). Skill ratings distinguished across the three “future” groups (academy-only, youth-professional only and adult-professional), for all but creative skill. For players that transitioned to youth-professional, medium sized correlations were noted between childhood practice amounts and technical and creative skill ratings at T1, although practice amounts correlated more strongly with skill ratings at T2. Play amounts were not related to any skills. Within groups of youth elite athletes, domain-specific play in childhood, and to a lesser degree practice, were generally not good discriminators of specific-skills. The effects of sport-specific practice on the development (and discriminability) of skills takes time to emerge. We consider the implications for talent development models and purported links between play and creativity.     

Sport-specific and non-specific practice of strong and weak responders in junior and senior elite athletics – A matched-pairs analysis

Elite track and field athletes with greater and lesser multi-year performance improvement were compared regarding their developmental sport-specific and non-specific, organised (coach-led) and non-organised (peer-led) sporting activities. Athlete pairs were matched on gender, discipline and baseline performance in competitions (at 13/19 years). Their unequal subsequent performance development during junior (13–17 years; n = 138) and senior (19–23+ years; n = 80) age ranges defined “strong responders” and “weak responders”. Analyses revealed that junior-age strong responders accumulated more organised practice in athletics than weak responders, while the amounts of all other types of activities were indifferent. Senior-age strong responders did not accumulate a greater total sum of all kinds of sport activities or greater amounts of organised practice in athletics or non-organised involvement in athletics or other sports than weak responders. But they engaged in more organised practice and competitions in other sports over more years (9 vs. 2 years) and specialised in athletics at a later age than weak responders (16 vs. 11 years). The results were also robust among senior international medallists vs. national medallists. The findings are reflected relative to the hypotheses of “multiple sampling and functional matching”, “learning transfer as preparation for future learning” and “authenticity of variable learning experiences”.     

The developmental and professional activities of female international soccer players from five high-performing nations

ABSTRACT

We study the developmental and professional activities engaged in by 86 female adult soccer players from the senior national teams of Australia, Canada, England, Sweden, and the United States of America. Players completed the Participation History Questionnaire (PHQ) to elicit the amount and type of activities engaged in across their developmental and professional years, including milestones, soccer-specific activity and engagement in other sport activity. Greater specialisation than diversification characterised their childhood developmental activities, including all players starting in soccer in childhood and accumulating more hours in soccer activity than other sports during this period. However, interindividual variation further characterised these childhood activities, with a proportion of players diversifying into other sports and/or soccer play to a greater or lesser degree during childhood when compared to the other players. The amount of coach-led soccer practice increased for all players across their development culminating in an average of 15–16 h/wk across a 40-week season in early adulthood. In contrast, the amount of engagement in other sports and soccer peer-led play varied between players but generally decreased across adolescence to negligible amounts in late adolescence. Findings are commensurate with the deliberate practice framework and early engagement.     

Academic performance and self-regulatory skills in elite youth soccer players

Abstract

Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self-efficacy) of elite youth soccer players aged 12–16 years (n = 128) with those of 164 age-matched controls (typical students). The results demonstrate that the elite youth soccer players are more often enrolled in the pre-university academic system, which means that they are high academic achievers, compared with the typical student. The elite players also report an increased use of self-regulatory skills, in particular self-monitoring, evaluation, reflection, and effort. In addition, control students in the pre-university system had more highly developed self-regulatory skills than those in the pre-vocational system, whereas no difference was observed within the soccer population. This suggests that the relatively stronger self-regulatory skills reported by the elite youth soccer players may be essential for performance at the highest levels of sport competition and in academia.     

Anthropometric and physical performance characteristics of top-elite,elite and non-elite youth female team handball players

In order to maximise the potential for success, developing nations need to produce superior systems to identify and develop talent, which requires comprehensive and up-to-date values on elite players. This study examined the anthropometric and physical characteristics of youth female team handball players (16.07 ± 1.30 years) in non-elite (n = 47), elite (n = 37) and top-elite players (n = 29). Anthropometric profiling included sum of eight skinfolds, body mass, stature, girths, breadths and somatotype. Performance tests included 20 m sprint, counter-movement jump, throwing velocity, repeated shuttle sprint and jump ability test, and Yo-Yo Intermittent Recovery Test Level 1. Youth top-elite players had greater body mass, lean mass, stature, limb girths and breadths than elite and non-elite players, while only stature and flexed arm were higher in elite compared to non-elite players (all P < 0.05). Sum of skinfolds and waist-to-hip ratio were similar between groups (P > 0.05). Top-elite performed better in most performance tests compared to both elite and non-elite players (P < 0.05), although maximal and repeated 10 m sprints were similar between playing standards (P > 0.05). Elite outperformed non-elite players only in throwing velocity. The findings reveal that non-elite players compare unfavourably to top-elite international European players in many anthropometric and performance characteristics, and differ in a few characteristics compared to elite European club team players. This study is useful for emerging team handball nations in improving talent identification processes.     

Reliability and validity of two tests of soccer skill

Abstract

Twenty-four players from the 1st/2nd (elite) and 24 players from the 3rd/4th (non-elite) university football teams were recruited to evaluate the Loughborough Soccer Passing Test (LSPT) and Loughborough Soccer Shooting Test (LSST) as tools to assess soccer skill. The LSPT requires players to complete 16 passes as quickly as possible. The LSST requires players to pass, control, and shoot the ball to targets on a full-sized goal. Participants completed two main trials each separated by at least one day. During both trials, the participants were given practice efforts before recording the mean of the next two (LSPT) or 10 (LSST) attempts as the performance score. For the LSPT, the mean time taken, added penalty time, and overall performance time were less in the elite players (elite: 43.6 s, s = 3.8; non-elite: 52.5 s, s = 7.4; P = 0.0001). For the LSST, there was no difference in the mean points scored per shot between groups (elite: 1.34, s = 0.46; non-elite: 1.28, s = 0.53). However, the elite players had higher mean shot speed (elite: 80 km · h^?1, s = 4.5; non-elite: 74 km · h^?1, s = 4.2; P < 0.0001) and performed each shot sequence faster (elite: 7.87 s, s = 0.29; non-elite: 8.07 s, s = 0.35; P = 0.037) than the non-elite players. Performance on both tests was more repeatable in elite players. In conclusion, the LSPT and LSST are valid and reliable protocols to assess differences in soccer skill performance.     

Differences in game reading between selected and non-selected youth soccer players

Applying an established theory of cognitive development―Skill Theory―the current study compares the game-reading skills of youth players selected for a soccer school of a professional soccer club (n = 49) and their non-selected peers (n = 38). Participants described the actions taking place in videos of soccer game plays, and their verbalisations were coded using Skill Theory. Compared to the non-selected players, the selected players generally demonstrated higher levels of complexity in their game-reading, and structured the information of game elements―primarily the player, teammate and field―at higher complexity levels. These results demonstrate how Skill Theory can be used to assess, and distinguish game-reading of youth players with different expertise, a skill important for soccer, but also for other sports.     

Biomechanical mechanisms of jumping performance in youth elite female soccer players

ABSTRACT

We aimed to determine key biomechanical parameters explaining age-related jumping performance differences in youth elite female soccer players. Multiple biomechanical parameters from countermovement (CMJ) squat (SJ) and drop (DJ) jump testing of elite female soccer players (n = 60) within the same national training centre were analysed across ages 9-11y, 12-14y and 15-19y. Effects of age group and jump type on jump height were found, with the older jumping higher than the younger groups in all jumps (P < 0.05). For DJ, higher reactive strength index was found for older, compared to each younger group (P < 0.001). For CMJ and SJ, peak power was the most decisive characteristic, with significant differences between each group for absolute peak power (P < 0.0001) and body-weight-normalised peak power in CMJ (57 ± 7W/kg, 50 ± 7W/kg, 44.7 ± 5.5W/kg; P < 0.05) and between the older and each younger group in SJ (56.7 ± 7.1W/kg, 48.9 ± 7.1W/kg, 44.6 ± 6W/kg; P < 0.01). Age-related differences in jumping performance in youth elite female soccer players appear to be due to power production during standing jumps and by the ability to jump with shorter ground contact times during reactive jumps.     

“Macro-structure” of developmental participation histories and “micro-structure” of practice of German female world-class and national-class football players

The study examined the “micro-structure” of football practice and the “macro-structure” of participation history of female professional football players. Participants were 29 German 1st league (Bundesliga) players, 14 of whom played on the senior national team (Olympic Champion in 2016). A questionnaire recorded the players’ positions, proportions of physical conditioning, drill-type skill exercises and playing forms within coach-led football practice, and the volume of coach-led practice and peer-led play, in both football and other sports, from childhood to adulthood. Analyses revealed that most athletes played various attacker and defender positions during development. National team players differed from their Bundesliga peers by less physical conditioning and greater proportions of playing forms within football practice. National team players also accumulated less total football practice until age 18 years, but more peer-led football and coach-led practice in other sports compared to their Bundesliga counterparts. Based on these variables, a binary logistic regression classified 93% of the national team and Bundesliga players correctly. Conclusion: A combination of long-term coach-led football practice involving a relatively large proportion of playing forms with considerable childhood/adolescent peer-led football play and coach-led practice in other sports may have facilitated adult performance among German female world-class football players.     

Laterality related to the successive selection of Dutch national youth soccer players

In the general population, estimates of left-foot preference are around 20%. In soccer, specific tasks create positional demands, requiring 40% of the players to be left-footed. Whether and how this is related to the selection of players is unknown. To examine the successive selection of soccer players for Dutch national youth teams in relation to foot preference, 280 youth players (age = 16.2 ± 1.08 years) were monitored from the U16 through the U19 teams over the last 5 years. No difference in successive selection between left- and right-footed players was found (p < 0.05). Regardless of foot preference, more than 50% of the selected players were deselected out of a national youth team after 2 years. On average, 31% of the national youth players were left-footed, which is higher than expected, based on population estimates (χ² (1) = 37.49, p < 0.001, w = 0.27). However, there was an under-representation of left-footed players, based on expected positional demands (i.e., attack, midfield, defence) (χ² (1) = 16.83, p < 0.001, w = 0.18). The conclusion is that left-foot preference increases the probability of selection in Dutch national youth soccer teams.     

Validity and reliability of a 6-a-side small-sided game as an indicator of match-related physical performance in elite youth Brazilian soccer players

ABSTRACT

The aims of this study were: (i) to compare the external and internal load during a 6-a-side small-sided game (6v6-SSG) according to age-group; (ii) to relate these parameters between the 6v6-SSG and official matches; and (iii) to test the reliability of the 6v6-SSG. A total of 51 Brazilian youth soccer players participated in this study (U11 [n = 16]; U13 [n = 10]; U15 [n = 9]; U17 [n = 8]; U20 [n = 8]). Three experiments were conducted. Experiment A: fifty-one U11 to U20 players were submitted to 6v6-SSGs (n = 10 games; two for each age-group). Experiment B: thirty-two players were randomized to also play official matches (n = 6 matches). Experiment C: thirty-five youth players played the 6v6-SSG twice for test and retest reliability analysis. External load was obtained using Global Positioning Systems and the internal load parameter was calculated through mean heart rate. Statistical approaches showed progressive increases in all parameters according to categories (U11< U13< U15< U17< U20; p < 0.05; ES = 0.42?23.68). Even controlling for chronological age, all parameters showed likely to almost certain correlations between 6v6-SSG and official matches (r = 0.25?0.92). Collectively, the proposed protocol indicates good reliability (CV% = 2.0?12.6; TE% = 2.3?2.7%; ICC = 0.78?0.90). This research suggests that the 6v6-SSG is an alternative tool to indicate match-related physical performance in youth soccer players.     

A Coding System to Quantify Powerful Actions in Soccer Match Play: A Pilot Study

Purpose: The powerful activity profile of elite soccer match play has not been documented appropriately to inform specific maximal power assessment and development criteria. The aims of the current study were to develop a reliable soccer-specific powerful action (SSPA) notational analysis coding system that could be used to compare frequency and durations of powerful actions during elite youth soccer match play. Methods: Sixteen elite male English Premier League (EPL) Academy players (19 ± 1 yrs) were recorded by an individual camera during 16 competitive EPL U18 and U21 games. Video footage was analyzed using performance analysis software and SSPAs were coded according to the following categories: initial acceleration, leading acceleration, sprint, unilateral jump and bilateral jump. Results: The SSPA coding system demonstrated very good inter- and intra-rater reliability (kappa coefficients ≥ 0.827). Elite youth EPL soccer players undertook significantly more initial (31 ± 9) and leading (37 ± 12) accelerations than sprints (8 ± 3; p = .014, d = 1.7, and p < .001, d = 1.7, respectively) and jumps (6 ± 5; p = .002, d = 1.7 and p < .001, d = 1.7, respectively). Players performed a significantly greater number of initial and leading accelerations with action durations below 1.5 s compared to above 1.5 s (p = .001, d = 1.6, and p = .002, d = 1.4), respectively. Conclusions: Our SSPA coding system provides a reliable observational instrument for quantifying the frequency and duration of powerful actions performed during elite soccer match play. In our sample of elite youth soccer players, horizontal accelerations of short duration (< 1.5 s) from different starting speeds appear the most dominant powerful action in elite youth soccer match play.     

Childhood football play and practice in relation to self-regulation and national team selection; a study of Norwegian elite youth players

Childhood sport participation is argued to be important to understand differences in self-regulation and performance level in adolescence. This study sought to investigate if football-specific activities in childhood (6–12 years of age) is related to self-regulatory skills and national under 14- and 15-team selection in Norwegian elite youth football. Data of practice histories and self-regulatory skills of 515 youth football players selected at Norwegian regional level were collected and further analysed using multilevel analyses. The results revealed that high self-regulated players were more likely to be selected for national initiatives, and increased their involvement in peer-led football practice and adult-led football practice during childhood, compared to players with lower levels of self-regulation. While national level players reported higher levels of peer-led football play in childhood, the interaction effect suggest that the regional level players increased their involvement in peer-led play during childhood compared to national level players. In conclusion, the findings indicate that childhood sport participation may contribute to later differences in self-regulation, and highlights the importance of childhood engagement in football-specific play and practice in the development of Norwegian youth football players.     

Comparative efficacy of active recovery and cold water immersion as post-match recovery interventions in elite youth soccer

ABSTRACT

The current study compared cold-water immersion (CWI) and active recovery (AR) to static stretching (SS) on muscle recovery post-competitive soccer matches in elite youth players (n = 15). In a controlled crossover design, participants played a total of nine competitive soccer games, comprising three 80 minute games for each intervention (SS, CWI and AR). Muscle oedema, creatine kinase (CK), countermovement jump performance (CMJA) and perceived muscle soreness (PMS) were assessed pre-, immediately post-, and 48 hours post-match and compared across time-intervals and between interventions. Following SS, all markers of muscle damage remained significantly elevated (P < 0.05) compared to baseline at 48 hours post-match. Following AR and CWI, CMJA returned to baseline at 48 hours post-match, whilst CK returned to baseline following CWI at 48 hours post-match only. Analysis between recovery interventions revealed a significant improvement in PMS (P < 0.05) at 48 hours post-match when comparing AR and CWI to SS, with no significant differences between AR and CWI observed (P > 0.05). Analysis of %change for CK and CMJA revealed significant improvements for AR and CWI compared to SS. The present study indicated both AR and CWI are beneficial recovery interventions for elite young soccer players following competitive soccer matches, of which were superior to SS.     

Yo-Yo IR2 testing of elite and sub-elite soccer players: Performance,heart rate response and correlations to other interval tests

Abstract

We examined performance, heart rate response and construct validity of the Yo-Yo IR2 test by testing 111 elite and 92 sub-elite soccer players from Norway and Denmark. VO₂max, Yo-Yo IR1 and repeated sprint tests (RSA) (n = 51) and match-analyses (n = 39) were also performed. Yo-Yo IR2 and Yo-Yo IR1 performance was 41 and 25% better (P < 0.01) for elite than sub-elite players, respectively, and heart rate after 2 and 4 min of the Yo-Yo IR2 test was 20 and 15 bpm (9 and 6% HRmax), respectively, lower (P < 0.01) for elite players. RSA performance and VO₂max was not different between competitive levels (P > 0.05). For top-teams, Yo-Yo IR2 performance (28%) and sprinting distance (25%) during match were greater (P < 0.05) than for bottom-teams. For elite and sub-elite players, Yo-Yo IR2 performance was correlated (P < 0.05) with Yo-Yo IR1 performance (r = 0.74 and 0.76) and mean RSA time (r = ?0.74 and ?0.34). We conclude that the Yo-Yo IR2 test has a high discriminant and concurrent validity, as it discriminates between players of different within- and between-league competitive levels and is correlated to other frequently used intermittent elite soccer tests.     

From childhood to senior professional football: elite youth players’ engagement in non-football activities

Abstract

Despite the large amount of research available on how engagement in football practice relates to future performance level among football players, similar information about the contribution of non-football activities is scarce. Based on data from 745 elite youth players this study aimed to identify the characteristics and contribution of diverse participation towards elite youth and senior professional status. The data were collected using a retrospective questionnaire where the players reported the amount of time spent in other sports than football, in addition to their perceived contribution of different non-football activities for developing football skills. The accumulated hours of time spent in other sports of players who had obtained a senior professional contract were compared to non-professional players, using multilevel modelling (n = 558), while a t-test compared the activity ratings to each other. No significant differences were identified between professional and non-professional players’ engagement history, but overall, the players rated sports similar to football to be significantly more relevant for developing football skills than other sports. The results suggests that spending time in non-football activities did not contribute to present differences in performance attainment in football, but also that potential advantages of such activities may be related to their characteristics.     

Tensiomyography parameters and jumping and sprinting performance in Brazilian elite soccer players

Tensiomyography has been suggested as an indirect marker of muscle stiffness, which is associated with strength/power performance. Therefore, it is reasonable to suggest that tensiomyography parameters could be associated with power-related motor tasks. The purpose of this study was to investigate the association between tensiomyography parameters (from rectus and biceps femoris) and jumping and sprinting abilities in elite soccer players. In addition, we used tensiomyography parameters to compare the lateral symmetry between dominant and non-dominant legs. Twenty elite soccer players (age: 23.3 ± 4.8 years; height: 183.5 ± 6.6 cm; weight: 77.8 ± 7.5 kg) volunteered to participate in the study. Significant moderate negative correlations between biceps femoris displacement and contact time (r = –0.5, p = 0.03), rectus femoris displacement and contact time (r = –0.51, p = 0.02), and a significant moderate correlation between biceps femoris displacement and reactive strength index (r = 0.5, p = 0.03) were found. There were no correlations between tensiomyography parameters and power-related motor tasks. In addition, no differences in tensiomyography parameters between dominant and non-dominant legs were found. Our data suggest that tensiomyography parameters are not associated with power-related motor tasks performance in elite soccer players.