Elite Junior Research Articles

Differences in Psychological Characteristics of Elite Junior Handball Players

Differences in Psychological Characteristics of Elite Junior Handball Players

Vertical Jump Performance in Hungarian Male Elite Junior Soccer Players

ABSTRACTPurpose: Vertical jump is a common test to measure impulsive ability in soccer; however, limited normative data have been published on young soccer players from vertical jump measurements on a force platform. The purpose of this study was to provide normative values for three chronological age groups of male junior soccer players (U16, U17 and, U18 years). Method: Vertical jump performance of 365 soccer players (16.4 ± 0.8 years) was assessed using a force platform measurement system. Net impulse, force, power, jump height (impulse-momentum), jump height (flight time) were reported for each age group for squat jump (SJ) and countermovement jump (CMJ). Results: Mean values ± SD of jump height were 32.9 ± 4.1, 33.5 ± 4.0, and 33.9 ± 4.2 cm for the three age groups respectively in SJ and 36.3 ± 3.8, 37.5 ± 3.9, and 38.6 ± 4.4 cm in the CMJ. Mean values of all age groups for maximum force and maximum power were 1559 ± 211 N and 3261 ± 492 watt respectively for SJ and 1598 ± 241 N and 3287 ± 502 watt for CMJ. Based on descriptive data, percentiles were reported for all examined variables. Conclusions: Jump height and relative values were less sensitive discriminator variables between age groups in the studied age range, while maximum impulse, maximum force, and maximum power were more sensitive to changes in maturational status. Normative values can be used by the coaches in the interpretation and evaluation of their athletes’ performance and for training and talent identification purposes.

Getting Ahead in Singapore: How Neighborhoods, Gender, and Ethnicity Affect Enrollment into Elite Schools

Is education the social leveler it promises to be? Nowhere is this question better addressed than in Singapore, the emblematic modern-day meritocracy where education has long been hailed as the most important ticket to elite status. In particular, what accounts for gender and ethnic gaps in enrollment into Singapore’s elite junior colleges—the key sorters in the country’s education system? We consider how the wealth of neighborhoods has combined with the elite status of schools to affect the social mobility of gender and ethnic groups. Analyzing data from 40 years of junior college yearbooks (1971–2010), we find persistent differences in educational opportunity. Women and Malays have historically experienced inequality in Singapore, and their student routes to becoming elites differ markedly. For female students, attending an elite junior college in a wealthy neighborhood is associated with wealthy neighborhoods that have a disproportionate number of elite girls’ secondary schools that feed into the junior colleges. By contrast, for Malays, not attending an elite junior college in a wealthy neighborhood has more to do with wealthy neighborhoods underrepresenting Malays in demographic composition. Elite families thus now include better educated women as well as men, yet Malays still rarely become better educated elites. These results underscore the need to carefully map the complex associations and mechanisms between gender and ethnic categorizations, the status of schools, and the characteristics of neighborhoods.

Exponential versus linear tapering in junior elite soccer players: effects on physical match performance according to playing positions

Exponential versus linear tapering in junior elite soccer players: effects on physical match performance according to playing positions

Alpine junior world ski championship: nutritional habits and performance in elite skiers.

Young athletes need to consume an appropriate diet in order to maintain health and optimize growth and athletic performance. We evaluated nutritional habits of junior elite skiers. Alpine junior elite skiers (N.=68; 42 males and 26 females; age range 16-20 years) coming from 20 countries were recruited during the Alpine Junior World Ski Championship, Roccaraso, Italy. Nutritional habits were assessed using a 3-day food record and the NHANES Food Frequency Questionnaire. Data were compared with nutritional recommendations and Recommended Dietary Allowances (RDAs) for athletes. During the training period, the energy intake in both males and females was significantly lower with respect to estimated energy needs. Carbohydrate intake expressed in terms of grams per kilogram of body weight did not meet the RDAs in both groups (4.19 and 5.15 g/kg in males and females, respectively). Protein and fat consumption exceeded the RDAs with a protein intake of 2.34 g/kg in males and 2.10 g/kg in females, and a fat intake >35% of total daily calories. During competition days, both males and females increased carbohydrate intake to 6.23 and 8.11 g/kg respectively, reaching the RDAs. Protein intake increased to 2.56 and 3.14 g/kg in males and females, respectively, and fat intake slightly decreased, still exceeding the RDAs. Junior elite skiers reported a low intake of carbohydrates and a high intake of protein and fat. Nutritional counselling should be given to athletes to maintain their health and improve their physical performance.

Physiological adaptations in the dominant and non-dominant shoulder in male competitive junior volleyball players

Summary Background In the overhead sport volleyball, the glenohumeral joint is subject to repeatedly high biomechanical loading. For injury prevention, especially in adolescent players, periodic orthopaedic and biomechanical monitoring of the stabilising structures is advisable, thereby contributing to a well-balanced state of shoulder mobility and stability. The aim of the study was to examine 20 healthy male competitive junior volleyball players (16 ± 1 years) to quantify sport-specific orthopaedic and biomechanical adaptations at that age. Material and methods Standard sport-orthopaedic testing was combined with overhead-specific isokinetic shoulder strength and mobility tests. The isokinetic tests were carried out in the volleyball-specific anatomic planes of external/internal rotation (ER/IR) and horizontal abduction/adduction (hAbd/hAdd) in a typical overhead posture. Results Sport-orthopaedic testing did not yield any pathological adaptations, yet revealed significant functional differences between sides (p Conclusions Mean lateral asymmetries in shoulder strength and mobility as derived in this study for healthy male adolescent volleyball players may serve as a reference of functional shoulder adaptations for future sport-orthopaedic and biomechanical shoulder diagnostics and thereby contribute to a well-balanced training control in competitive junior and junior elite sports.

INVESTIGATION OF OPTIMAL LUMBAR SPINE POSTURE DURING A SIMULATED LANDING TASK IN ELITE GYMNASTS

Lumbar spine range of motion (ROM) is a key component of injury prevention and normative data has not currently been determined for an elite gymnastics population. In current clinical practice, it is commonplace to measure sagittal spinal alignment, during 'high-load, low-dynamic' control tasks, subjectively, while also only considering the lumbar spine as a single segment. To develop normative data for total lumbar spine ROM and ROM during a simulated landing task (SLT) in an elite gymnastics population, evaluating findings in the context of the existing biomechanical literature. Repeated measures, cross sectional design. Lumbar spine and low lumbar spine (LLS) ROM during a SLT were measured, using the Dorsa Vi: Vi Perform™ system in asymptomatic male and female elite gymnasts. Values for maximal ROM and LLS angle during the SLT were collated and descriptively analyzed. Lumbar ROM and posture was evaluated in relation to the current biomechanical literature and a proposed Conceptual Compressive Lumbar Load Distribution Model (CCLLDM). Thirty elite gymnasts (15 male, 15 female), participated. Participants were members of the British Artistic Gymnastics elite senior and junior training program and were between the ages of 16 to 30 years. Mean (SD) maximal lumbar spinal movements were 64.23˚ (6.34 °) for flexion and 25.89˚ (11.14 °) for extension. During the SLT, participants performed lumbar spine flexion of 15.96˚ (8.80 °), when considered as a single segment. When considering the lumbar spine as a two segment model the LLS position during the SLT was towards end range anterior pelvic tilt, suggesting LLS extension. These data provide a baseline for asymptomatic lumbar spine movements in an elite gymnastics population and provides insight into upper and lower lumbar spine movement during a SLT. The data and newly developed CCLLDM provide clinicians with a potential framework to identify sporting skills that may be associated with increased spinal tissue load. 3b.

Effects of a 6-Week Period of Polarized or Threshold Training on Performance and Fatigue in Elite Swimmers.

To quantify the impact of a polarized distribution of training intensity on performance and fatigue in elite swimmers. Twenty-two elite junior swimmers (12 males, age = 17 [3]y, and 10 females, age = 17 [3]y) participated in a crossover intervention study over 28 wk involving 2- × 6-wk training periods separated by 6 wk. Swimmers were randomly assigned to a training group for the first period: polarized (81% in zone 1, blood lactate concentration, [La]b ≤ 2mmol·L-1; 4% in zone 2, 2mmol·L-1 < [La]b ≤ 4mmol·L-1; and 15% in zone 3, [La]b > 4mmol·L-1) or threshold (65%/25%/10%). Before and after each period, they performed a 100-m maximal swimming test to determine performance, maximal [La]b, and oxygen consumption and an incremental swimming test to determine speed corresponding to [La]b = 4mmol·L-1 (V4mmol·L-1). Self-reported indices of well-being were collected with a daily questionnaire. Polarized training elicited small to moderately greater improvement than threshold training on 100-m performance (within-group change ± 90% confidence interval: 0.97% ± 1.02% vs 0.09% ± 0.94%, respectively) with less fatigue and better quality of recovery. There was no substantial gender effect. No clear differences were observed in physiological adaptations between groups. In elite junior swimmers, a 6-wk period of polarized training induced small improvements in 100-m time-trial performance and, in combination with less perceived fatigue, forms a viable option for coaches preparing such cohorts of swimmers for competition.

Effects of a Rugby League Match Simulation on Decision-Making in Elite Junior Rugby League.

Redman, K, Steel, K, Kelly, V, and Siegler, J. Effects of a rugby league match simulation on decision-making in elite junior rugby league. J Strength Cond Res 35(7): 1972-1980, 2021-The paucity of research on decision-making in Rugby league within the context of a match, and the potential for age and playing experience to influence decision-making ability, warrants further investigation. Therefore, the aim of this study was to determine the effects of a simulated rugby league match on decision-making in elite junior rugby league players. Twenty male junior rugby league players (age 15.9 ± 0.9 years, body mass 87.3 ± 14.3 kg, height 1.82 ± 0.07 m, playing experience 10.2 ± 2.4 years) completed a match simulation protocol that replicated the physiological demands of an elite junior rugby league match. Decision-making performance was measured prematch, midmatch, and postmatch simulation through a reactive agility test and video-based temporal occlusion task. Upper- and lower-body neuromuscular measures as well as ratings of perceived exertion were obtained before decision-making assessments to quantify fatigue. A 2-way mixed analysis of variance with Bonferroni corrections was used to assess changes during the simulation, and significance was accepted at p < 0.05. The main finding of this study was despite observing a decline in neuromuscular function during the match simulation protocol (countermovement jump declined 1.9 ± 0.6 cm [95% confidence intervals 0.4-3.5]; p < 0.05), this decline did not significantly affect decision-making performance (reactive agility test [p = 0.58]; temporal occlusion [p = 0.88]). These results suggest elite junior rugby league players are capable of sustaining performance during a progressively fatiguing match simulation.

Study on stress level in elite junior gymnasts

Study on stress level in elite junior gymnasts

Pressure to Provide a Solution: One-to-One Support With an Elite Junior Gymnast

This article presents a reflective case study, from the perspective of a trainee sport and exercise psychologist, of an applied consultancy experience with a 14-year-old gymnast. The case study highlights a number of applied challenges such as working with a client in an unfamiliar sport, questioning who the client is throughout the consultancy process, adopting a philosophy of practice different from the expectations of the parents, and further difficulties when including parents in the consultancy process. The case study also highlights how challenges to a practitioner’s philosophy of practice can be deeply uncomfortable and lead the practitioner to question his or her approach to service delivery. Although the intervention only lasted 3 sessions, there are a number of observations and lessons to be learned from an applied perspective, such as being aware of countertransference when building relationships with a client and understanding how the dynamics of the consultancy process might change when involving parents.

Dynamic rifle stability is not influenced by exercise intensity in young biathletes

The aim of the study was to analyse and find out potential dependence between the dynamic rifle stability during targeting and percentage pressure value on the trigger 1 second and 0.5 second before the shot in different intensities of the physical load. Fifteen national youth and junior elite biathletes (ten women, five men) from a team of the Czech Republic participated in the study. All participants completed measuring of the dynamic behavior of the rifle in rest and after roller skiing in three different exercise intensities: Intensity 1 = 70 % of HRmax (maximum heart rate), average speed 4.1 – 4.6 m·s-1; Intensity 2 = 80 % of HRmax, average speed 4.5 – 5.0 m·s-1; Intensity 3 = 90 % of HRmax, average speed 4.9 – 5.4 m·s-1. Each bout consisted from a distance of one km. They shot in standing position with using their own biathlons rifle with a fixed accelerometer and trigger sensor. The data used in our research showed that the dynamic rifle stability is not influenced by exercise intensity neither in the men nor women group. However, our study demonstrated that the rifle stability is better in time 0.5 second before the shot than in time 1 second before the shot. The measurement of triggering in our study showed that participants are able to work with their fingers on the triggers in similar quality in the racing load as well as without the previous physical load

Psychological reactions during competitive season and association with sleep among Norwegian junior elite athletes

The current study investigated whether athletes with negatively charged psychological reactivity that includes worry and negative affect experience more sleep disturbance in comparison with athletes whose psychological reactivity involves positive affect. Objective sleep monitoring for a period of 3-4 months was utilized in 32 junior elite athletes. Athletes completed the Positive and Negative Affect Scale, and the Penn State Worry Questionnaire before and after the sleep-monitoring period. Results showed changes and disturbances in sleep as a result of a specific psychological reactivity involving high worry and negative affect. On the other hand, positive affect was associated with normal sleep/wake patterns.

Characteristics of Relative Age Effects and Anthropometric Data in Japanese Recreational and Elite Male Junior Baseball Players

BackgroundThe mechanisms underlying the relative age effect (RAE), a biased distribution of birth dates, in sport events have been investigated for more than two decades. The present study investigated the characteristics of the RAE in baseball and anthropometric data (height and weight) among recreational junior baseball players as well as elite players, using data extracted from national surveys.MethodsBirth and anthropometric data were obtained from 4464 Japanese students as elementary school, junior high school, and high school players.ResultsSignificant RAEs were noted in recreational junior high school and high school players, but not in elementary school players, and the effect size became larger with increasing grade (0.063 in elementary school players, 0.151 in junior high school players, and 0.227 in high school players). We also observed a significant RAE for elite elementary, junior high, and high school players. However, the effect size of elite players became smaller with increasing grade (0.563 in elementary school players, 0.358 in junior high school players, and 0.343 in high school players). Height and weight values were significantly larger in elite elementary and junior high school players than in recreational elementary and junior high school players, but height was almost the same between recreational and elite high school players.ConclusionThe characteristics of RAEs differed between recreational and elite junior baseball players. Anthropometric data were also different, depending on birth data, and between recreational and elite baseball players in elementary and junior high school students.

The effects of playing two consecutive matches in the shoulder rotational profiles of elite youth badminton players

ObjectiveThe aim of the present study was to analyse the effects of playing two badminton matches on the same day on the shoulder profile (i.e., range of motion (ROM) and strength) of young badminton players. DesignCross-sectional study. SettingIndoor sports facility. ParticipantsThirty-one elite junior badminton players (age 16.6 ± 1.0 years, body mass 63.9 ± 6.1 kg, height 174.8 ± 6.1 cm), including 19 boys and 12 girls. Main outcome measuresShoulder passive internal rotation (IR) and external rotation (ER) ROM as well as shoulder IR/ER maximal isometric strength were measured before and after a competition including two competitive matches. ResultsSignificant decreases (p < 0.05) were found in the shoulder ROM (i.e., dominant and non-dominant ER ROMs as well as in the dominant and non-dominant total arc of motion [TAM]) in boys, while in girls, significant increases (p < 0.05) were found in the non-dominant ER absolute strength, with significant decreases were found in the non-dominant ER ROM and the non-dominant TAM. ConclusionPlaying two badminton matches on the same day led to gender-specific changes on the shoulder profile (i.e., ROM and strength) of young elite badminton players, with more impact on the shoulder profile of boys compared to girls.

Application of representative learning design for assessment of common practice tasks in tennis

ObjectivesThis study assessed the representativeness of four common tennis practice tasks. DesignCross-sectional. MethodIn pairs, ten elite junior male and female tennis players (12.8 ± 1.05 yrs old) performed four, 4-min practice tasks and a 2-set tennis match. The previously validated representative practice assessment tool (RPAT – see Krause et al., 2018) was used to gain subjective assessments of each practice tasks representative design. Additionally, three-dimensional ball and player movement data was collected using an 8-camera HawkEye system. Mixed models were conducted to compare each practice task to matchplay revealing significant differences across a range of shot and movement characteristics. ResultsWhile players hit the ball faster and with more spin they consistently made contact with the ball further behind the baseline and generated fewer winners in most practice tasks compared to matchplay. ConclusionCommon practice tasks are not representative of the shot and movement characteristics typical of matchplay. More careful design of practice appears to be needed.

MRI bone marrow oedema precedes lumbar bone stress injury diagnosis in junior elite cricket fast bowlers

ObjectivesLumbar bone stress injury (‘bone stress injury’) is common in junior fast bowlers. The repetitive loading of cricket fast bowling may cause bone marrow oedema (BMO), detectable on MRI, before...

Biomechanical analysis of the “waiter’s serve” on upper limb loads in young elite tennis players

Waiter’s serve (WS) is a specific tennis serve posture frequently observed in young players, and commonly considered as a technical error by tennis coaches. However, biomechanical impact of WS is unknown. The aims of this study were to identify the potential consequences of WS in young elite players relating to performance and injury risk, and to explain the kinematic causes of WS. Serve of 18 male junior elite players (Top 10 national French ranking, aged 12–15 years) was captured with a 20 camera, 200 Hz VICON MX motion analysis system. Depending on their serve technique, the players were divided into two groups (WS versus Normal Serve [NS]) by experienced coaches. Injury data were collected for each player during a 12-month-period following the motion capture. Normalized peak kinetic values of the dominant arm were calculated using inverse dynamics. In order to explain WS posture, upper limb kinematics were calculated during the cocking and the acceleration phases of the serve. Shoulder internal rotation torque, wrist proximal and anterior forces (P < .05) and elbow varus torque (P < .01) were significantly higher in WS group, with no difference from NS group concerning serve velocity. Moreover, significant lower shoulder abduction and higher wrist extension (P < .05) were observed for WS players during the cocking phase. Even if no significant difference was found between groups concerning injuries, higher upper limb joint loads suggested WS could be considered as pathomechanical in young elite players and could lead to upper limb joint injuries.

Are oral health and fixed orthodontic appliances associated with sports injuries and postural stability in elite junior male soccer players?

BackgroundDental caries and periodontitis are associated with elevated levels of pro-inflammatory cytokines which may trigger muscle fatigue during exercise, a strong risk factor for sports injuries. Fixed orthodontic appliances (FOA) may cause poor oral health and may disturb proprioceptive inputs of the stomatognathic system. This study aims to explore associations of poor oral health and of use of a FOA with injury frequency and postural stability.MethodsOne hundred eighty seven Belgian elite junior male soccer players, aged 12–17 years, completed a self-report questionnaire asking about injuries in the past year, oral health problems, use of a FOA, demographics and sports data, and stood in unipedal stance with eyes closed on a force plate to assess postural stability.ResultsOrdinal logistic regression with number of injuries in the past year as ordinal dependent variable and dental caries and/or gum problems, age and player position as covariates, showed that participants who reported dental caries and/or gum problems and never had had a FOA reported significant more injuries in the past year compared to the reference group of participants who reported no oral health problems and never had had a FOA (adjusted OR = 2.45; 95% CI, 1.19–5.05; p = 0.015). A 2 (temporomandibular joint problems) × 2 (FOA) × 2 (age) ANOVA with postural stabilities as dependent variables, showed a significant FOA x age interaction for the non-dominant (standing) leg. Post-hoc t-tests showed a significant better postural stability for the non-dominant leg (and a trend for the dominant leg) for the older compared with the younger participants in the non-FOA group (p = .002, ES = 0.61), while no age differences were found in the FOA-group.ConclusionsThese results indicate that poor oral health may be an injury risk factor and that a FOA may hinder the development of body postural stability.

Running Intensities in Elite Youth Soccer by Age and Position.

Duthie, GM, Thornton, HR, Delaney, JA, Connolly, DR, and Serpiello, FR. Running intensities in elite youth soccer by age and position. J Strength Cond Res 32(10): 2918-2924, 2018-The purpose of this investigation was to examine differences between the peak running speed, acceleration, and metabolic power of elite youth soccer across a range of age levels by position. Ninety-six elite junior soccer players were assessed between 2015 and 2017. Ninety-six elite junior soccer players (at time of match: age, 15.8 ± 0.9 years; body mass, 69.1 ± 8.0 kg) were assessed during 61 games within the 2015, 2016, and 2017 season, for a total of 441 individual match observations (4.8 ± 3.3 matches per player, range 1-13). Participants were classified by age group: under 15 (U15, n = 121, 14.7 ± 0.3 years), under 16 (U16, n = 176, 15.8 ± 0.3 years), or under 17 (U17, n = 144, 16.7 ± 0.4 years), and according to their playing position: Attacker (ATT), Defender (DEF), Mid-Fielder (MID), or Wide (WIDE). Participants wore global positioning system units during each match, where speed (m·min), acceleration/deceleration (m·s), and metabolic power (Pmet) were established. A 1- to 10-minute moving average was applied to establish the intercept (c) and slope (n) of running intensity variables as a power law y = cx relationship. Linear mixed models were used to examine differences in the intercept and slope between age group and player position. There were no substantial differences in peak (intercept) or decline (slope) in running intensity between playing levels. Several differences were observed in the peak running speeds (m·min), particularly peak running speeds of ATT and DEF being substantially lower than the MID. Despite variability between positions, we suggest that the magnitude of these differences would not warrant the prescription of different running intensities across positions at the elite junior level. These findings describe the peak running intensities of elite junior soccer, useful in the monitoring and prescription of training to ensure that players are prepared for the most demanding periods of competition.