Performance In Youth Soccer Players Research Articles

Assessment of Performance in Youth Soccer Players: Should We Consider the Maturation Status?

The influence of biological maturity status on talent identification and development in youth soccer has been debated extensively. Alternative methods have thus recently emerged to estimate maturity status, such as the Pubertal Development Scale (PDS), but their relationship with physical capabilities of young soccer players still needs to be determined. The present study investigated the relationships of different PDS-derived pubertal status measures, chronological age, and relative age with selected performance variables in youth soccer. Sixty-one male soccer players were assessed for physical capabilities using field tests for sprinting, vertical jumps (countermovement jump, CMJ), intermittent high-intensity endurance, and repeated sprint ability. Chronological age was defined as the number of days since birth, and relative age was defined in terms of age quarters. PDS-derived measures of puberal status, otherwise, were determined as an average PDS score, a PDS category score, and a pubertal category. Chronological age, relative age, and measures of pubertal status were scarcely related (p > 0.05) to selected measures of soccer performance. Significant correlations were only found between different measures of pubertal status and the variable "work" in the CMJ test (range r = 0.33–0.36; p < 0.01) and between chronological age and CMJ height (r = −0.297; p = 0.02). The present results suggest that physical performance of young soccer players is poorly related to chronological age, relative age, and pubertal status. Potential effects of biological maturity status on physical capabilities may not be easily identifiable in a group of young soccer players narrowed in terms of chronological age and training status.

Combined effects of speed-endurance and speed training on speed performance in youth soccer players

Combined effects of speed-endurance and speed training on speed performance in youth soccer players

Evaluation of multi-directional speed qualities throughout adolescence in youth soccer: The non-linear nature of transfer

ABSTRACT Training and assessment of agility is often prioritised by soccer coaches and practitioners aiming to develop multi-directional speed. Although the importance of agility is advocated throughout childhood and adolescence, limited data evidence agility performance at different stages of adolescence. The purpose of this study was to examine differences in multi-directional speed performance in youth soccer players spanning an entire soccer academy. A total of 86 male junior-elite soccer players volunteered to participate. Anthropometric data were collected, alongside performance data from a battery of physical tests including sprinting, jumping, change of direction, reaction time, and agility. Bayesian models using log-likelihoods from posterior simulations of parameter values displayed linear or curvilinear relationships between both chronological and biological age and performance in all tests other than agility and reaction time. For agility and reaction time tests, performance improved until ~14 years of age or the estimated age of peak height velocity whereby arrested development in performance was observed. Our results demonstrate that while most performance skills improve as chronological or biological age increases, measures of agility and reaction time may not. These findings support the notion that agility performance is complex and multifaceted, eliciting unique, challenging physical demands and non-linear development.

More than just a side effect: Dynamic knee valgus and deadbug bridging performance in youth soccer players and alpine skiers have similar absolute values and asymmetry magnitudes but differ in terms of the direction of laterality.

From a preventative perspective, leg axis and core stabilization capacities are important for soccer players and alpine skiers; however, due to different sport-specific demands, the role of laterality clearly differs and may result in functional long-term adaptations. The aims of this study are 1) to determine whether there are differences in leg axis and core stability between youth soccer players and alpine skiers and 2) between dominant and non-dominant sides, and 3) to explore the outcomes of applying common sport-specific asymmetry thresholds to these two distinct cohorts. Twenty-one highly trained/national-level soccer players (16.1years, 95% CI: 15.6, 16.5) and 61 alpine skiers (15.7years, 95% CI: 15.6, 15.8) participated in this study. Using a marker-based 3D motion capture system, dynamic knee valgus was quantified as the medial knee displacement (MKD) during drop jump landings, and core stability was quantified as the vertical displacement during deadbug bridging exercise (DBB displacement ). For the analysis of sports and side differences, a repeated-measures multivariate analysis of variance was used. For the interpretation of laterality, coefficients of variation (CV) and common asymmetry thresholds were applied. There were no differences in MKD or DBB displacement between soccer players and skiers or between the dominant and non-dominant sides, but there was an interaction effect side*sports for both variables (MKD: p = 0.040, η2 p = 0.052; DBB displacement : p = 0.025, η2 p = 0.061). On average, MKD was larger on the non-dominant side and DBB displacement laterality on the dominant side in soccer players, whereas this pattern was reversed in alpine skiers. Despite similar absolute values and asymmetry magnitudes of dynamic knee valgus and deadbug bridging performance in youth soccer players and alpine skiers, the effect on the direction of laterality was opposite even though much less pronounced. This may imply that sport-specific demands and potential laterality advantages should be considered when dealing with asymmetries in athletes.

Warm-up stretching exercises and physical performance of youth soccer players.

This study aims to compare the effects of standard warm-up versus warm-up using stretching exercises on the physical performance of male youth soccer players. Eighty-five male soccer players (age: 10.3 ± 4.3years; body mass index: 19.8 ± 4.3kg/m2) were assessed for countermovement jump height (CMJ, cm), 10m, 20m and 30m running sprint speed (s) and ball kicking speed (km/h) for the dominant and non-dominant leg under five (randomized) warm-up conditions. Using 72h of recovery between conditions, the participants completed a control condition (CC) and four experimental conditions, including static stretching (SSC), dynamic stretching (DSC), ballistic stretching (BSC), and proprioceptive neuromuscular facilitation (PNFC) exercises. All warm-up conditions had a duration of 10minutes. The main results indicate that no significant differences (p > 0.05) were found between warm-up conditions compared to CC in CMJ (CC = 28.1 ± 4.9; SSC = 28.4 ± 4.9; DSC = 30.9 ± 4.8; BSC = 30.9 ± 5.2; PNFC = 28.4 ± 5.0), 10m sprint (CC = 2.42 ± 0.4; SSC = 2.50 ± 0.4; DSC = 2.30 ± 0.3; BSC = 2.27 ± 0.3; PNFC = 2.53 ± 0.4), 20m sprint (CC = 5.42 ± 0.9; SSC = 5.59 ± 0.9; DSC = 5.37 ± 0.9; BSC = 5.40 ± 0.9; PNFC = 5.44 ± 0.9), 30m sprint (CC = 8.05 ± 1.3; SSC = 8.27 ± 1.3; DSC = 8.01 ± 1.3; BSC = 8.00 ± 1.3; PNFC = 8.12 ± 1.3), ball kicking speed for dominant (CC = 56.2 ± 4.9; SSC = 55.3 ± 5.2; DSC = 56.9 ± 5.8; BSC = 57.3 ± 5.8; PNFC = 55.7 ± 5.2) and non-dominant leg (CC = 52.8 ± 3.4; SSC = 51.8 ± 4.6; DSC = 53.5 ± 5.4; BSC = 53.6 ± 4.9; PNFC = 52.5 ± 4.0). In conclusion, compared to standard warm-up, stretching-based warm-up exerts no effect on male youth soccer players jump height, sprint speed and ball kicking speed.

The manipulation of task constraints and the effect on creative performance of youth soccer players

Creativity is a popular topic that has been increasingly researched over the years. Recently, creativity is suggested as a relational concept (Zahno & Hossner, 2020). This conceptualization implies that creativity is not solely an individual ability. By contrast, creative actions emerge in the athlete’s search to adapt to task and environmental constraints (Orth et al., 2017; Withagen & van der Kamp, 2018). Manipulating task constraints that serve to increase variability might, therefore, evoke creative actions. Such manipulations in soccer are often conducted in training situations with small sided games. This was recently shown with a numerical assessment of creative actions comparing small sided soccer games (SSGs) with 11v11 matches in elite adult soccer players (Caso & van der Kamp, 2020). They found that players performed more actions, a broader action repertoire and more creative actions in smaller formats (5v5, 6v6 and 7v7) than in an 11v11 format. The purely quantitative method of Caso & van der Kamp (2020), however, uses an arbitrarily 5% benchmark for originality. More importantly, although subjective, the coaches opinions are not meaningless and should not be neglected.
 Our research examined whether the latter task manipulation also increased the action repertoire and creative performance of elite youth soccer players (O11-O13). A numerical method was introduced, assessing creative performances as a frequency of the action types emerging in an environment. A notational video-analysis identified all (not-) functional actions. Next, a threshold defined whether the action was original. This threshold has been determined with expert coaches ranking action types following the procedure of the consensual assessment technique (CAT; Amabile, 1996). If the action was both original and functional, then it was defined a creative action. The data consisted of 293 minutes small sided game (4v4) and 263 minutes regular sided game (11v11). Results indicated that small sided games hold relative more actions, more functional action and more creative actions compared with regular sided games. This is in line with previous studies, that small sided games induce more variation of actions which increase the possible emergence of creative actions (Orth et al., 2017).
 References
 Amabile, T. M., Amabile, T. M., Collins, M. A., Conti, R., Phillips, E., Picariello, M., Ruscio, J., & Whitney, D. (1996). Creativity in Context: Update to The Social Psychology of Creativity (1st ed.). Routledge.
 Caso, S., & van der Kamp, J. (2020). Variability and creativity in small-sided conditioned games among elite soccer players. Psychology of Sport and Exercise, 48, Article 101645. https://doi.org/10.1016/j.psychsport.2019.101645
 Orth, D., van der Kamp, J., Memmert, D., & Savelsbergh, G. J. P. (2017). Creative motor actions as emerging from movement variability. Frontiers in Psychology, 8, Article 1903. https://doi.org/10.3389/fpsyg.2017.01903
 Withagen, R., & van der Kamp, J. (2018). An ecological approach to creativity in making. New Ideas in Psychology,49, 1–6. https://doi.org/10.1016/j.newideapsych.2017.11.002
 Zahno, S., & Hossner, E.-J. (2020). On the issue of ceveloping creative players in team sports: A systematic review and critique from a functional perspective. Frontiers in Psychology, 11, Article 575475. https://doi.org/10.3389/fpsyg.2020.575475

INFLUÊNCIA DO TREINAMENTO COM PESOS SOBRE A FORÇA DE MEMBROS INFERIORES EM JOGADORES DE FUTEBOL

ABSTRACT Introduction Soccer games are of long duration and more confrontational; in the second half of the game, many players have a decline in their physical level, leading to loss of matches. Objective To explore the effect of weight training on lower limb fitness in soccer players. Methods 60 athletes were included as subjects and randomly divided into control group, weight training group, and traditional physical fitness training group. All athletes trained for 45 minutes 3 times a week for 6 weeks. Before and after training, lower limb strength and proprioception were evaluated, and the strength of the knee flexor and extensor group was assessed by isokinetic muscle tester. Results Both weight training and traditional physical training were able to improve the vertical jump performance of young soccer players, the training effects of both groups were equivalent. Conclusion Weight training has the same enhancing effect as traditional physical training in terms of strength and explosive power, promoting athletic performance in youth soccer players. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Testing the effects of 4-week training programs based on extreme and medium-sided soccer games: a study focusing on change-of-direction, vertical jump height and locomotor profile

AimThis study tested the effects of two training programs (one program based on extreme sided-games of 1v1 vs. one program based on the medium-sided game of 5v5) on the physical fitness adaptations of youth soccer players. In specific, it was analyzed the effects of the training programs on the 5–0–5 change-of-direction time (5–0–5 time), countermovement jump (CMJ), and final velocity in the 30–15 Intermittent Fitness test (VIFT).MethodsThis study followed a randomized parallel study design. Twenty male regional-level soccer players (age: 17.0 ± 0.3 years old) were randomly assigned to two groups: (1) the 1v1 format; and (2) the 5v5 format. The training intervention lasted four weeks. The week before (baseline) and the week after the intervention, the participants were assessed in the 5–0–5 change-of-direction test (measured using timing gates), CMJ (measured by photoelectric cells), and 30–15 Intermittent Fitness test. The training intervention consisted of 8 sessions (2 sessions per week). The 1v1 group performed four repetitions of 30 s in each session, while the 5v5 group performed four repetitions of 4 min.ResultsThe 5–0–5 time changed − 4.82% (p = 0.004; d = 1.115) for the 1v1 group and − 4.26% (p = 0.004; d = 0.859) for the 5v5 group. CMJ changes occurred both in the 1v1 and 5v5 group and amounted to 1.7% (p = 0.003; d = 0.509) and 1.2% (p = 0.263; d = 0.155) respectively. VIFT changed 2.6% (p = 0.718; d = 0.178) for the 1v1 group and 3.0% (p = 0.593; d = 0.274) for the 5v5 group. The 1v1 group reported significantly lower post-intervention 5–0–5 time than the 5v5 group (− 4.3%; p = 0.048; d = 0.954), although no significant differences in CMJ (3.2%; p = 0.147; d = 0.678) and VIFT (2.5%; p = 0.697; d = 0.177) were revealed.ConclusionsThe extreme-sided games meaningfully beneficiated the vertical jump height and change-of-direction performance of youth soccer players. The extreme-sided games seem more beneficial than medium-sided games for improving these physical abilities while showing that four weeks were enough to impact the players significantly.

Effects of Age and Playing Tactics on the Individual Tactical Behavior in U10 and U12 Elite Spanish Soccer Players.

The aim of this paper was to explore the effects of age and playing tactics on the individual tactical behavior and performance in young soccer players. A total of 1247 individual possessions during 16 knockout matches from LaLiga Promises U12 tournament (n = 621) and LaLiga U10 Iscar Cup (n = 626) were analyzed by observational methodology. Multilevel and multivariate logistic regression models were created to explain the interdependent effects of age category and playing tactics on the individual tactical behavior and performance. Youth players performed most of their actions against defensive pressure (72.5%), during offensive support (91.3%) and receiving the ball facing forward (62.6%). The most frequent action was to receive and pass the ball (69.6%) and the level of offensive success was 56.9%. The multilevel mixed models revealed that U10 players presented higher odds of running with the ball vs. passing the ball (OR = 1.823; 95% CI: 1.333-2.493; p < 0.001) and lower odds of achieving offensive success (OR = 0.698; 95% CI: 0.525-0.928; p < 0.05) than U12 players. Regarding playing tactics, technical-tactical dimensions such as the players' body shape when receiving the ball, offensive support, defensive pressure, collective type of attack and type of technical action presented a significant and combined effect on the offensive success regardless of age category, playing position and match status. This study found tactical differences between U10 and U12 age categories and revealed important interactive effects of multiple tactical dimensions on the individual offensive behavior and performance in youth soccer players.

Exploring the effects of physical fatigue on cognitive performance of youth soccer players

ABSTRACTThis study aimed to verify whether the peripheral perception and decision making of young soccer players are influenced by physical fatigue. The sample was composed of 48 soccer players from two youth academies of Brazilian clubs (17.03 ± 2.33 years old). In laboratory conditions, the Vienna Test System and the TacticUP® video test was used to assess peripheral perception and decision making (response time and decision-making quality), respectively. Physical fatigue was induced through T-SAFT90 that simulated the metabolic and physical demands of a soccer game (e.g., acceleration, deacceleration, change direction, jump, and technical action). Peripheral perception and decision-making abilities were compared between the control and physical fatigue “conditions”. Results displayed that physical fatigue did not influence peripheral perception and decision-making quality, although it improved decision-making response time for the tactical principles of penetration, width and length with the ball, delay, defensive coverage, and recovery balance. In summary, physical fatigue did not affect players’ ability to detect information from the peripheral visual field and did not influence the quality of decision-making of soccer players. In addition, physical fatigue induced players to make quicker decisions regarding tactical actions near the ball and inside the centre of play. Thus, we conclude that only the response time of decision-making of youth soccer players is influenced by physical fatigue.

An exploratory study on the effect of a four-week stroboscopic vision training program on soccer dribbling performance

BACKGROUND: Perceptual-cognitive skill is a crucial component of expert performance in sport as expert athletes rely on the integration and processing of sensory information to execute complex actions. One of the topics of interest to skill acquisition researchers is therefore how the perceptual-cognitive system can be trained, and how that affects sport skill performance. One of the methods suggested to be able to aid in the training of perceptual-cognitive skill is restricted visual feedback training. Recently, stroboscopic vision glasses have been proposed as a tool that can restrict visual feedback during sport training and may therefore provide a useful tool for training sport-specific skills.However, despite its use in practice, evidence for the beneficial effect of stroboscopic vision on sport-specific performance across youth athletes with a range of performance levels is currently lacking. AIM: Therefore, this study aimed to investigate the effect of a four-week soccer training program with (experimental group) or without (control group) stroboscopic vision on the dribbling performance of relatively fast and slow dribblers. METHOD: To measure dribbling performance, this study used the Ugent Soccer dribbling task. RESULTS: A Repeated Measures MANOVA revealed that four weeks of stroboscopic vision training did not improve soccer dribbling skill measured through the time taken to complete the dribbling task as well as the number of touches of the ball while dribbling. CONCLUSION: While stroboscopic vision can likely lead to short term changes in perceptual-cognitive skill, it is likely not related to persistent changes in soccer dribbling performance in youth soccer players.

The Acute Effects of Weighted Vest Protocols on 20-Metre Sprint Performance in Youth Soccer Players

This investigation examined the effects of a warm-up containing weighted vest (WV) sprints on subsequent 20-metre sprint time relative to a control (C) condition in youth soccer players (n=12, mean ± SD age 16 ± 0.60 years, height 175.17 ± 5.92 cm and body mass 61.85 ± 5.88 kg). The main experimental trials consisted of three WV conditions at 10, 20 and 30% of body mass (WV10, WV20 and WV30) and C. Participants were required to complete one 20-metre sprint with each of WV conditions or without additional mass as part of C prior to a 20-metre sprint at 4-, 8- and 12-minutes. A two-way repeated measures ANOVA revealed no significant difference between any of the conditions and rest periods (p = >0.05). The between condition effect sizes for 20-metre sprint times were moderate at 4- and 12-minutes post WV10 (d = -0.86 and -1.15, respectively) and 12-minutes post WV20 (d = -0.84) and WV30 (d = -0.80). Moderate effect sizes were also observed at 4-minutes post WV10 (d = -1.04) and WV20 (d = -0.67) for 10-metre sprint times. These findings demonstrate that WV loading has no significant effect on 20-metre sprint time in youth soccer players. However, there is an opportunity for S&C coaches to implement WV warm-ups of no more than 30% body mass to improve 20-metre sprint times.

Perceptual-cognitive performance of youth soccer players in a 360°-environment – An investigation of the relationship with soccer-specific performance and the effects of systematic training

IntroductionSoccer is a complex game in which athletes perform in a dynamic 360°-environment. The results of numerous studies highlight the importance of perceptual-cognitive functions for soccer performance. Moreover, in recent years, the idea of improving sports performance through systematic perceptual-cognitive training has been increasingly investigated. Contradictory results and limitations in previous research call for further investigation. The current study aims to investigate both the relationship between perceptual-cognitive performance in a dynamic 360°-environment and soccer performance as well as the effects of perceptual-cognitive training in such an environment on soccer performance. Methods42 youth soccer players aged 11–13 years were tested at a first time of measurement (T1) on their perceptual-cognitive functions using a 360°-multiple object tracking task (360-MOT) and a visuospatial attention task. Soccer performance was assessed using an isolated, validated 360°-passing task and a small-sided game. Subsequently, participants were randomly divided into a perceptual-cognitive training group, an active control group, or a passive control group. Participants in the training group received 360-MOT training twice per week during a 5-week intervention phase, while participants in the active control group received a pseudo video training. Perceptual-cognitive and soccer-specific performance was assessed after the intervention phase at a second time of measurement (T2). ResultsAt T1, there was a significant positive relationship between 360-MOT performance and both the accuracy score in the 360°-passing task and the defensive performance score in the small-sided game. Regarding the perceptual-cognitive training intervention, the analysis at T2 revealed significant task-specific training effects but no transfer effects on perceptual-cognitive or soccer-specific performance. ConclusionsThe results highlight the relevance of perceptual-cognitive performance in a 360°-environment for soccer-specific performance but question the effects of short isolated perceptual-cognitive training interventions on soccer-specific performance.

Relationship between Variations in the Accumulated Workload and the Change of Direction Ability in Elite Young Soccer Players

Background: The main aim of this study was to evaluate the relationships between training workload (WL) parameters with variations in the change of direction (COD) in under-16 soccer players. Methods: Twenty-seven under-16 elite soccer players were daily monitored for their WL across 15 weeks during the competitive soccer season. Additionally, players were assessed two times for anthropometric measures (weight, height, sitting height and leg length), COD performance (modified 505 test) and maturity offset measured using the peak height velocity (PHV). Results: A correlational analysis was performed to determine the relationship between the variation in COD performance and accumulated WL parameters. Moreover, a regression analysis was executed to explain the variations in the percentage of COD performance considering the accumulated WL parameters and PHV of the season (r = 0.93; p ≤ 0.01) and training monotony during the early-season (r = 0.53; p ≤ 0.05). There were associations between the acute workload during the start of the season and the COD during the end of the season (r = 0.47; p ≤ 0.05). The multiple linear regression analysis showed that 55% of the variation in COD performance between the early and end of season could be explained by the acute or chronic WL, training monotony or strain and the PHV. Conclusions: This information might be useful for practitioners and coaches aiming to improve the COD performance in youth soccer players during an entire competitive season.

Perceptual-cognitive performance of youth soccer players in a 360°-environment – Differences between age groups and performance levels

IntroductionAn important requirement for soccer players is the accurate and rapid processing of dynamic and complex visual scenes. Therefore, in high-level youth soccer the players’ perceptual-cognitive skills are highly relevant from a scientific and practical point of view. The aim of the present study was to investigate differences in perceptual-cognitive performance between youth soccer players of different age groups and soccer performance levels in a dynamic 360°-environment. MethodsIn a sample of 292 elite and sub-elite youth soccer players from the age groups U12–U23, perceptual-cognitive skills were assessed using a 360°-multiple object tracking task. An 8 × 2 (age group x performance level) analysis of variance (ANOVA) was conducted to examine the effects of age group and soccer performance level on performance in the task. ResultsThe analyses revealed a significant main effect of age group. Post hoc analyses showed that youth players belonging to the older age groups (U16, U17, U19, and U23) performed significantly better in the 360°-multiple object tracking task than players of the youngest age group (U12). Yet no significant age-related differences could be found from age group U16 on. Furthermore, there was a significant effect of soccer performance level on the 360°-multiple object tracking performance in favor of the elite players. Significant differences between elite and sub-elite players within the same age group were only present in the highest age groups U19 and U23. ConclusionsThe results suggest that in a dynamic 360°-environment highly talented youth soccer players show better perceptual-cognitive performance with increasing age. Furthermore, elite youth players exhibit distinctive perceptual-cognitive abilities particularly at the highest age groups. These findings provide interesting implications for science and practice regarding the perceptual-cognitive skills of talented soccer players and their role in talent development.

The Effects of Successive Soccer Matches on the Internal Match Load, Stress Tolerance, Salivary Cortisol and Jumping Performance in Youth Soccer Players.

The study aim was to analyze the effects of successive matches on the internal match load, stress tolerance, salivary cortisol concentration and countermovement vertical jump height in twelve youth soccer players (16.6 ± 0.5 yr; 175 ± 8 cm; 65 ± 8 kg) who performed four official matches within a four day-period with a 24-h recovery interval between the matches. The internal match load, monotony index and competitive strain, as well as stress tolerance were examined. Saliva samples were collected and countermovement vertical jump height was assessed 60 min pre and 30 min post each match; delta of salivary cortisol and countermovement vertical jump height for each match were analyzed. Salivary cortisol was analyzed using an enzyme-linked immunosorbent assay. The results of ANOVA with repeated measures showed no differences between matches for the internal match load (p > 0.05). The scores of the monotony index and competitive strain were 4.3 (±2.3) and 8104 (±6795) arbitrary units, respectively. There was no difference for stress tolerance between matches (p > 0.05). Delta values of salivary cortisol were not different among the assessed matches (F(3,33) = 1.397, p = 0.351, η2: 0.09); however, delta of countermovement vertical jump height decreased from match 1 to match 4 (F(3,33) = 8.64, p < 0.001, η2: 0.44). The current findings suggest that participating in four successive matches, with 24-h of recovery in between, may not lead to changes in stress tolerance and salivary cortisol of youth players, but it may induce a decrease in players’ jumping performance after the fourth match.

The Influence of Maximum Strength Performance in Squats and Standing Calf Raises on Squat Jumps, Drop Jumps, and Linear and Change of Direction Sprint Performance in Youth Soccer Players

The Influence of Maximum Strength Performance in Squats and Standing Calf Raises on Squat Jumps, Drop Jumps, and Linear and Change of Direction Sprint Performance in Youth Soccer Players

Differences in Physical and Psychological Parameters in Sub-Elite, Male, Youth Soccer Players with Jumper’s Knee Following Physical Therapy Compared to Healthy Controls: A Longitudinal Examination

Purpose/BackgroundMany adolescent athletes suffer from jumper’s knee (JK) over a long period of time and return to sports before symptoms are fully resolved. Current treatment methods may not reduce pain in the short term, especially not during a competitive season. The purpose of this study was to investigate differences in physical, psychological, and injury-/pain-related parameters in sub-elite male youth soccer players, who previously underwent physical therapy for JK compared to healthy controls (HC) over the course of a season.MethodsAll subjects were tested four times (start of the season [T1], 6 [T2], 16 [T3], and 20 [T4] weeks after the start of the season). Outcome measures included muscle power (drop jump, jump-and-reach), change of direction speed [CODS] (acyclic sprint), speed (tapping, 30-m linear sprint), endurance (Yo-Yo intermittent recovery test level 1), the Achievement Motives Scale (AMS) Sport, and injury-/pain-related data. Univariate analysis of variance was used to compare differences in variables between the two groups over the course of a soccer season.ResultsOver the season, the jumper’s knee group (JK; 15.1 ± 0.8 yr) demonstrated significantly worse physical performance in CODS (to the left side: 1.37≤ Cohen’s d ≤ 1.51 [T1-T4]; p < 0.001 / to the right side: 1.24 ≤ d ≤ 1.53 [T1-T4]; p < 0.001) and speed (0.48 ≤ d ≤ 1.26 [T1-T4]; p < 0.007) compared to healthy controls (HC; 15.0 ± 1.0 yr). Further, psychological parameters showed worse values in JK than in HC for the AMS Sport items “hope for success” and “fear of failure” that especially showed a significant difference at T1 (d = 0.65; p = 0.032 / d = 0.68; p = 0.027) and T2 (d = 0.50; p = 0.076 / d = 0.80; p = 0.012). Moreover, the JK group showed significantly higher incident rates for non-contact lower limb injuries (d = 0.69; p = 0.049) per 1,000 hours (i.e., practices/competitions), injury-related rest periods (d = 2.06; p = 0.043), and pain-related training interruptions (d = 1.35; p < 0.001).ConclusionsThe observed findings imply that there are significant differences in physical and psychological performance of youth soccer players after physical therapy for JK compared to HC. When designing rehabilitation and/or training programs, as well as determining the point of return to sport the impact of the injury needs to be taken into account.Level of Evidence:1b

The Effect of Playing Exercises According to the Training Network on the Speed of the Motor Response and the Level of Skillful Performance of Youth Soccer Players

The world is now witnessing a rapid development in all areas of life and the sports field, one of which hasreceived a share of this progress and clear development and the importance of research lies in preparing playexercises that are performed according to the training network and that contribute to developing the speedof the motor response to football players, which in turn contributes to the development of The skill level ofyoung players and the study objectives to identify the effect of these exercises on the study variables.After testing and collecting information, the results were extracted and the most important conclusionswere reached:1. The results of the post test showed that there are statistically significant differences in the researchvariables.2. The exercise exercises according to the training network have a positive effect in developing the speedof the motor response and the skill level of the research sample.

Performing Soccer-Specific Training With Blood Flow Restriction Enhances Physical Capacities in Youth Soccer Players.

Hosseini Kakhak, SA, Kianigul, M, Haghighi, AH, Nooghabi, MJ, and Scott, BR. Performing soccer-specific training with blood flow restriction enhances physical capacities in youth soccer players. J Strength Cond Res 36(7): 1972-1977, 2022-This study investigated the effect of soccer training with blood flow restriction (BFR) on physical performance in youth athletes. Nineteen semiprofessional soccer players were randomly assigned to either normal soccer training (ST; n = 9) or soccer training with BFR (STBFR; n = 10). Both groups performed identical activities during a 6-week preseason training phase, either with or without lower limb BFR. Training included soccer-specific drills, small-sided games, plyometrics, and continuous running. Before and after the intervention, players were assessed for leg extension strength and endurance, countermovement jump performance, 40-yd sprint time, change-of-direction (COD) ability, aerobic endurance, and soccer-specific endurance (while dribbling a ball). Significantly larger improvements were observed in the STBFR compared with the ST group for tests of muscular endurance (74.8 ± 34.1% vs. 4.0 ± 14.6%), COD (8.1 ± 3.7% vs. 2.8 ± 4.7%), and aerobic (54.1 ± 19.6% vs. 24.7 ± 27.2%) and soccer-specific endurance (58.4 ± 19.6% vs. 22.7 ± 10.2%). Main effects for time were observed for maximal strength, jumping, and sprinting performance (p < 0.001) but with no group and time interaction. These findings demonstrate that team sport training with BFR can enhance physical qualities that are related to performance in youth soccer players. This application of BFR may improve the adaptive responses of muscles, without having to dedicate additional training time to muscular qualities.