U16 Age Group Research Articles

Quadriceps Muscle Geometry and Strength Throughout Maturation in National-Level Male Soccer Players: A Cross-Sectional Study.

Adolescent soccer players experience distinct physiological changes due to chronological and biological maturation, impacting their soccer performance. Here, we explored age-related variations and associations between quadriceps geometry and strength in male national-level adolescent soccer players. We used ultrasonography to examine the regional architecture and morphology of the rectus femoris (RF) and vastus lateralis (VL) muscles, and we assessed knee extension strength by isometric and isokinetic dynamometry. Players were categorized into four age groups: under (U) 15 (n=18, age=13.7±0.5 years), U16 (n=15, age=14.7±0.5), U17 (n=19, age=15.7±0.5), U18 (n=18, age=16.7±0.5) and U21 (n=25, age=18.5±0.5). The absolute and relative strengths were higher in the U16 compared to U15 by 12-15% and 6-8%, 11-12% and 6-7% in the U17 compared to U16, 5-7% and -1-2% in the U18 compared to U17 and 0-15% and -1-11% in the U21 compared to U18 age groups, respectively. VL architecture did not change relevantly between the age groups. The muscle anatomical cross-sectional area (ACSA) of the VL and RF differed non-uniformly and muscle region-specific by 10-36%, with highest values in the U21 age group. Moderate correlations between the VL architecture and knee extension strength in both legs were observed only in the U16 age group. The quadriceps ACSA showed age-specific correlations with knee extension strength. Our findings highlight non-uniform differences in quadriceps muscle morphology and absolute and relative strength among male national-level adolescent soccer players in different age groups. The correlations observed between muscle morphology or architecture and strength were muscle, muscle region, leg and age dependent.

A 1-year longitudinal study of physical fitness in Tunisian junior tennis players

Background: Tennis, a sport demanding high levels of physical fitness, combines various aspects of athleticism such as agility, endurance, strength, and speed. The development of these attributes in junior players is crucial for their progress in the sport. Understanding the impact of structured tennis training on the physical fitness of junior players can provide valuable insights into the effectiveness of training programs and guide future coaching strategies. Objective: This study aimed to assess the effects of 1-year of tennis practice on the physical fitness of Tunisian junior players. Methods: Sixty-two healthy participants were enrolled, divided into two groups, tennis players (TP) (n = 36) and controls, where the participants sedentary, (n = 26), each group was divided into two subgroups U14 and U16 age-groups. Physical fitness tests were conducted at baseline (T0) and after one-year (T1), including standing long jump, countermovement jump, medicine ball throw (MBT), 5m, 10m, and 20m sprints, sideways shuffle, Zigzag, spider drill, 20m shuttle run, and sit and reach (SAR) tests. Results: Jump performances increased significantly for TP in U14 and U16 compared to controls at T0 and T1. In both age-groups, MBT performance increased significantly for TP, with U16 for both groups were higher at T0 and T1 (p<0.05). The 5m and 10m sprints increased significantly for TP in both age-groups, though controls decreased in the 5m sprint in U14 (p<0.05). The 20m sprint increased significantly for TP in U14 and U16 (p<0.05), with U16 outperforming U14 at T0 and T1 (p<0.05). Sideway shuffle and spider drill performances significantly improved for TP (p<0.05), while decreased in controls (p<0.05). The Zigzag test and the maximum oxygen intake increased significantly for TP across both age-groups at T0 and T1, whereas controls' performance decreased in U14 (p<0.05). Conclusion: TP's SAR was significantly better than controls (p<0.05). In conclusion, tennis training enhances young athletes' physical fitness, improving agility, sprinting, jumping, and endurance compared to controls, reporting better results in U16 compared to U14 for most of tests.

The selection advantages associated with advanced biological maturation vary according to playing position in national-level youth soccer.

This study investigated the extent to which biological maturation selection biases existed according to playing position in national-level youth soccer. A total of 159 players from the U13 to U16 age groups in the Football Association of Ireland's national talent pathway and international representative squads had their relative biological maturity status assessed using the Khamis-Roche method for the percentage of predicted adult height at the time of observation. Players were categorised as goalkeeper (GK), central defender (CD), full-back (FB), centre defensive midfielder (CDM), centre midfielder (CM), centre attacking midfielder (CAM), wide midfielder (WM) or centre forward (CF). A series of one-sampled means t-tests were used to examine the degree to which biological maturation selection biases existed across playing positions. A non-parametric Kruskal-Wallis test was used to evaluate inter-positional differences. A small to very large selection bias in favour of early maturing players existed for GK (D = 0.7), CD (D = 1.65), FB (D = 0.49), CM (D = 0.62), WM (D = 0.78), and CF (D = 0.76) (p < 0.05). Maturational selection biases did not exist for CDM or CAM. Moreover, CD were significantly more advanced in maturation compared to FB, CDM and CAM (p < 0.05). This study supports the contention that maturation selection biases exist in youth soccer, but the magnitude of this bias is highly dependent upon playing position. The very strong maturity selection biases at the national level evidenced in this investigation highlight the need for Football Associations to explore strategies, such as futures programmes, to help to retain talented, yet late maturing athletes.

Soccer coaches vs. sport science and medicine staff: who can more accurately predict the skeletal age of high-level youth soccer players?

ABSTRACT Biological maturity is an important aspect in the context of talent identification and development processes within elite youth soccer players. The aim of this study was to investigate the accuracy of soccer coaches (SC) as well as sports science and medicine staff (SSMS) to predict the skeletal age of high-level youth soccer players. We also aimed to evaluate the inter-rater reliability of the skeletal age predictions among the SC and SSMS. Skeletal ages were collected for 89 male academy soccer players registered for the U12 to U16 age groups at a professional German Bundesliga club. In addition, 12 SC and five SSMS provided their skeletal age predictions for each player of their respective age group. Standardised mean differences and equivalence testing were performed between actual and predicted skeletal ages. Intra-class correlations (ICC) were calculated to assess the inter-rater reliability. For the SC, differences between predicted and actual skeletal ages were trivial and equivalent to zero for the U12, U14, and entire sample, while for the SSMS, standardised mean differences ranged from trivial to small for all age groups and the entire sample. ICC for skeletal age predictions for the entire sample was good among the SC and excellent among the SSMS, but was somewhat lower when age groups were analysed separately. While, on average, predictions were close to the actual skeletal age, SC were slightly more accurate than the SSMS. However, variability among the SSMS was large on an individual level.

The incidence and burden of injuries in elite English youth female soccer players

ABSTRACT This study aimed to investigate the incidence, severity and burden of injury in English elite youth female soccer players. Qualified therapists at six English girls’ academies prospectively recorded all injuries that required medical attention or caused time loss for matches and training in 375 elite youth female soccer players (under-10 [U10], U12, U14 and U16) during the 2019/2020 season. One hundred- and eleven time-loss injuries (52 from training, 59 from matches) were sustained, resulting in 1,946 days absent (779 days from training injuries, 1,167 days from match injuries) from soccer activities. The injury incidence for matches (9.3/1000 hours, 95% CIs: 7.2–11.9) was significantly greater than training (1.1/1000 hours, 95% CIs: 0.9–1.5, p < 0.001). Additionally, the injury burden for matches (183 days lost/1000 hours, 95% CIs: 142–237) was significantly greater than training (17 days lost/1000 hours, 95% CIs: 13–22, p < 0.001). Injury incidence and burden were greatest in the U16 age group and were found to increase with age. Whilst injury incidence and burden are greater in matches than training, a large proportion of preventable injuries, soft-tissue and non-contact in nature, were sustained in training. Findings provide comparative data for elite youth female soccer players.

Seasonal change of aerobic performance of young soccer players

Longitudinal studies evaluating the seasonal change of aerobic capacity in young soccer players of different age categories are limited. The aim of this study was to investigate the seasonal changes in the aerobic level of the youth academy players of a professional soccer team. This research study was carried out with a total of 51 soccer players in the U14, U15, U16, U17, and U18 categories of an elite soccer team. Aerobic capacities of the athletes were measured by Yo-YoIRT 1 Test. In the analyses, the normal distribution evaluations of the data were made with the Shapiro-Wilk test and the variance homogeneities were tested with the Levene’s Test. One Way ANOVA test was used to analyze all the parametric data. All statistical evaluations were performed with the help of the SPSS 21 package program. According to the Yo-YoIRT 1 test, increases or decreases were determined in the pre-season, mid-season and end-of-season evaluations. As a result, in the present study conducted to examine the seasonal changes of the young elite soccer players in the U14, U15, U16, U17, and U18 categories, Yo-YoIRT 1 values ​​in all categories increased significantly at the end of the season when compared to the pre-season and the mid-season. U14 and U16 age groups gained increasing acceleration starting from the pre-season. However, in the U15, U17, U18 age groups, the case is that acceleration decreases in the middle of the season and increases at the end of the season. It is thought that differences can be observed in the responses to the training loads during maturation. It can be suggested that the increase at the end of the season compared to the pre-season in all groups may be due to the fact that the adaptation of the athletes to the training programs are affected by the developmental characteristics regarding the age categories over time.

Impact of European Youth Basketball League (EYBL) on the Development of the U16 Men’s Basketball Teams

The main focus of our research was the U16 age group since it is one of the most significant in terms of the young athlete’s future - probably professional - career. It was very helpful in research that this age group was a priority in the Basketball Academy of Debrecen’s program and they were competing in an international basketball league, in the European Youth Basketball League (EYBL). Thanks to the EYBL tournaments we have got a chance to analyze this youth category completely. For primer research we have chosen three teams, two Hungarian, and one Italian, to get an impression why is so important to play basketball at the international level in this age. We have made interviews with the coaches, organizers and the manager of the league to have an international comparison of this age group.

Injury patterns differ with age in male youth football: a four-season prospective study of 1111 time-loss injuries in an elite national academy

ObjectivesTo describe age group patterns for injury incidence, severity and burden in elite male youth football.MethodsProspective cohort study capturing data on individual exposure and time-loss injuries from training and matches...

A Longitudinal Investigation of Muscle Injuries in an Elite Spanish Male Academy Soccer Club: A Hamstring Injuries Approach

The aims of this study were to analyze the muscle injury incidence in an elite Spanish soccer academy during three consecutive seasons attending to different chronological age groups (i.e., U14, U16, U19 and senior) and to examine the hamstring injury incidence in this elite soccer academy. Elite male youth soccer players (227) participated in this study. A total of 207 time-loss injuries (i.e., injuries that involve at least one absence day) were observed during this study period. The overall incidence rate of muscle injury was 1.74 muscle injuries/1000 h. In addition, higher muscle injury incidence was observed during match play in comparison to training sessions (6.78 vs. 3.20 muscle injuries/1000 h, p &lt; 0.05). The oldest age group presented the highest injury rate (2.73 muscle injuries/1000 h, p &lt; 0.05), with the burden (i.e., number of absence days per 1000 h of exposure) peak values recorded in the U16 age group (26.45 absence days/1000 h). In addition, muscle tears accounted for the greatest percentage of muscle injuries (43.5%), and the most frequent anatomical site of injury was the hamstring (30.4%). Muscle tear was the most common type of hamstring injury (49.2%), with the biceps femoris the most commonly injured muscle of the hamstring complex (39.7%). Fullbacks (FB), wide midfielders (WM) and forwards (F) suffered a greater number of hamstring injuries. Hamstring injury incidence showed a seasonal variation, as indicated by peaks in August and October. Specifically, the highest injury incidence was observed in the final part of each period during match play. These results reinforce the necessity to implement individual preventive strategies according to each specific injury profile across the youth soccer development phase.

Relative age and maturation selection biases in academy football

ABSTRACT This study examined the simultaneous effects of relative age and biological maturity status upon player selection in an English professional soccer academy. A total of 202 players from the U9 to U16 age groups, over an eight-year period (total of 566 observations), had their relative age (birth quarter) and biological maturity (categorised as late, on-time or early maturing based upon the Khamis-Roche method of percentage of predicted adult height at time of observation) recorded. Players born in the first birth quarter of the year (54.8%) were over-represented across all age groups. A selection bias towards players advanced in maturity status for chronological age emerged in U12 players and increased with age; 0% of players in the U15 and U16 age group were categorised as late maturing. A clear maturity selection bias for early maturing players was, however, only apparent when the least conservative criterion for estimating maturity status was applied (53.8% early and 1.9% late maturing in the U16 age group). Professional football academies need to recognise relative age and maturation as independent constructs that exist and operate independently. Thus, separate strategies should perhaps be designed to address the respective selection biases, to better identify, retain and develop players.

The Impact of European Youth Basketball League (EYBL) on the Development of the U16 Men’s Basketball Teams

The main focus of our research was the U16 age group since it is one of the most significant in terms of the young athlete’s future - probably professional - career. It was very helpful in research that this age group was a priority in the Basketball Academy of Debrecen’s program and they were competing in an international basketball league, in the European Youth Basketball League (EYBL). Thanks to the EYBL tournaments we have got a chance to analyze this youth category completely. For primer research we have chosen three teams, two Hungarian, and one Italian, to get an impression why is so important to play basketball at the international level in this age. We have made interviews with the coaches, organizers and the manager of the league to have an international comparison of this age group.

The Impact of European Youth Basketball League (EYBL) on the Development of the U16 Men’s Basketball Teams

The main focus of our research was the U16 age group since it is one of the most significant in terms of the young athlete’s future - probably professional - career. It was very helpful in research that this age group was a priority in the Basketball Academy of Debrecen’s program and they were competing in an international basketball league, in the European Youth Basketball League (EYBL). Thanks to the EYBL tournaments we have got a chance to analyze this youth category completely. For primer research we have chosen three teams, two Hungarian, and one Italian, to get an impression why is so important to play basketball at the international level in this age. We have made interviews with the coaches, organizers and the manager of the league to have an international comparison of this age group.

The Impact of European Youth Basketball League (EYBL) on the Development of the U16 Men’s Basketball Teams

The main focus of our research was the U16 age group since it is one of the most significant in terms of the young athlete’s future - probably professional - career. It was very helpful in research that this age group was a priority in the Basketball Academy of Debrecen’s program and they were competing in an international basketball league, in the European Youth Basketball League (EYBL). Thanks to the EYBL tournaments we have got a chance to analyze this youth category completely. For primer research we have chosen three teams, two Hungarian, and one Italian, to get an impression why is so important to play basketball at the international level in this age. We have made interviews with the coaches, organizers and the manager of the league to have an international comparison of this age group.

Motion analysis of match-play in elite U12 to U16 age-group soccer players

The aim of this study was to quantify the motion demands of match-play in elite U12 to U16 age-group soccer players. Altogether, 112 players from two professional soccer clubs at five age-group levels (U12–U16) were monitored during competitive matches (n = 14) using a 5 Hz non-differential global positioning system (NdGPS). Velocity thresholds were normalized for each age-group using the mean squad times for a flying 10 m sprint test as a reference point. Match performance was reported as total distance, high-intensity distance, very high-intensity distance, and sprint distance. Data were reported both in absolute (m) and relative (m · min−1) terms due to a rolling substitute policy. The U15 (1.35 ± 0.09 s) and U16 (1.31 ± 0.06 s) players were significantly quicker than the U12 (1.58 ± 0.10 s), U13 (1.52 ± 0.07 s), and U14 (1.51 ± 0.08 s) players in the flying 10 m sprint test (P < 0.001). The U16 age-group covered significantly more absolute total distance (U16 > U12, U13, U14), high-intensity distance (U16 > U12, U13, U14, U15), very high-intensity distance (U16 > U12, U13), and sprint distance (U16 > U12, U13) than their younger counterparts (P < 0.05). When the data are considered relative to match exposure, few differences are apparent. Training prescription for youth soccer players should consider the specific demands of competitive match-play in each age-group.

Risk Factors For Injury An Adolescent Soccer

PURPOSE To implement and validate an injury surveillance program and examine risk factors for injury in adolescent soccer. METHODS This is a prospective cohort study. The study population was a random sample of 21 soccer teams from a Calgary Minor Soccer Club (n = 317 players). One team was randomly selected to participate from each skill division, from each of U18, U16, and U14 age groups for both boys and girls. A Certified Athletic Therapist completed pre-season baseline evaluations and assessed any identified injury occurring in soccer on a weekly basis. The injury definition included any injury occurring during the regular soccer season that required medical attention and/or removal from a session and/or missing a subsequent session. RESULTS Based on completeness of data for both injury and exposure information in addition to validity of diagnosis and time-loss, this method of surveillance has proven to be effective. The overall injury rate (IR) during regular season was 4.37 injuries/1000 player hours (95% CI; 3.34–5.61). The mechanism of injury was identified as direct contact with another player or equipment in 44.9% of all injuries reported. Soccer injury resulted in time loss of at least one soccer session in 86.9% of the players. Ankle and knee injuries were the most common injuries by body region in both boys and girls. It appears that girls may be at greater risk of knee ligament injuries than boys (RR = 2.53 [95% CI; 0.73–11.05]). The risk of injury in U14 and U16 age groups was greatest in the most elite division. There was an increased risk of injury in players who reported an injury in the previous one year (RR = 1.74 [95% CI; 1.0–3.1]). Players who are left leg dominant may be at greater risk of injury compared to those who are right leg dominant (RR=2.06 [0.84–4.37]). There was no apparent increased risk of injury associated with baseline measures of lower extremity flexibility, dynamic balance ability, endurance or lower extremity functional strength at baseline. CONCLUSION There were significant differences in injury rates found by division, previous injury history, and session type (practice vs. game). Future research includes the use of such a surveillance system to examine prevention strategies for injury in minor soccer.