Bio-banding in junior soccer players: a pilot study.

Objective: Bio-banding (BB) has been introduced to account for varying maturity and to improve the talent development of junior soccer players. To date, research that investigated the physiological and technical effects of BB is sparse. Therefore, the aim of the study was to compare effects of BB with CA on selected technical and tactical parameters in U13 and U14 soccer players. Results: BB significantly increased the number of duels (p = 0.024) and set pieces (p = 0.025) compared to chronological age. The mean time of ball possession per action was reduced (p = 0.021) and the rate of successful passes was lower with BB (p = 0.001). Meanwhile, the total number of passes was unaffected (p = 0.796), and there was a trend towards a lower difference in ball possession between BB teams (p = 0.058). In addition, BB reduced the distances covered while jogging (p = 0.001), running (p = 0.038) and high-speed running (p = 0.035). With BB, an increased number of duels, unsuccessful passes and set pieces resulted in a quicker change of match play situations between teams. While physical demand was reduced, BB seems to result in a more technically and tactically challenging game. Benefits in long-term player development, however, require further investigation

Biological Maturity Status in Elite Youth Soccer Players: A Comparison of Pragmatic Diagnostics With Magnetic Resonance Imaging

The influence of biological maturity status (BMS) on talent identification and development within elite youth soccer is critically debated. During adolescence, maturity-related performance differences within the same age group may cause greater chances of being selected for early maturing players. Therefore, coaches need to consider players' BMS. While standard methods for assessing BMS in adolescents are expensive and time-consuming imaging techniques (i.e., X-ray and MRI), there also exist more pragmatic procedures. This study aimed to evaluate commonly used methods to assess BMS within a highly selected sample of youth soccer players. A total of N = 63 elite male soccer players (U12 and U14) within the German Soccer Association's talent promotion program completed a test battery assessing BMS outcomes. Utilizing MRI diagnostics, players' skeletal age (SAMRI) was determined by radiologists and served as the reference method. Further commonly used methods included skeletal age measured by an ultrasound device (SAUS), the maturity offset (MOMIR), and the percentage of adult height (PAHKR). The relation of these alternative BMS outcomes to SAMRI was examined using different perspectives: performing bivariate correlation analyses (1), modeling BMS as a latent variable (BMSlat) based on the multiple alternative diagnostics (2), and investigating individual differences in agreement (3). (1) Correlations of SAMRI and the further BMS variables ranked from r = 0.80 to r = 0.84 for the total sample and were lower for U12 (0.56 ≤ r ≤ 0.66), and U14 (0.61 ≤ r ≤ 0.74) (2). The latent structural equation modeling (SEM) (R 2 = 51%) revealed a significant influence on BMSlat for MOMIR (β = 0.51, p <0.05). The additional contribution of PAHKR (β = 0.27, p = 0.06) and SAUS (β = -0.03, p = 0.90) was rather small (3). The investigation of individual differences between the reference method and alternative diagnostics indicated a significant bias for MOMIR (p <0.01). The results support the use of economical and time-efficient methods for assessing BMS within elite youth soccer. Bivariate correlation analyses as well as the multivariate latent variable approach highlight the measures' usefulness. However, the observed individual level differences for some of the utilized procedures led to the recommendation for practitioners to use at least two alternative assessment methods in order to receive more reliable information about players' BMS within the talent promotion process

Biological Maturity Status in Elite Youth Soccer Players: A Comparison of Pragmatic Diagnostics With Magnetic Resonance Imaging

The influence of biological maturity status (BMS) on talent identification and development within elite youth soccer is critically debated. During adolescence, maturity-related performance differences within the same age group may cause greater chances of being selected for early maturing players. Therefore, coaches need to consider players' BMS. While standard methods for assessing BMS in adolescents are expensive and time-consuming imaging techniques (i.e., X-ray and MRI), there also exist more pragmatic procedures. This study aimed to evaluate commonly used methods to assess BMS within a highly selected sample of youth soccer players. A total of N = 63 elite male soccer players (U12 and U14) within the German Soccer Association's talent promotion program completed a test battery assessing BMS outcomes. Utilizing MRI diagnostics, players' skeletal age (SAMRI) was determined by radiologists and served as the reference method. Further commonly used methods included skeletal age measured by an ultrasound device (SAUS), the maturity offset (MOMIR), and the percentage of adult height (PAHKR). The relation of these alternative BMS outcomes to SAMRI was examined using different perspectives: performing bivariate correlation analyses (1), modeling BMS as a latent variable (BMSlat) based on the multiple alternative diagnostics (2), and investigating individual differences in agreement (3). (1) Correlations of SAMRI and the further BMS variables ranked from r = 0.80 to r = 0.84 for the total sample and were lower for U12 (0.56 ≤ r ≤ 0.66), and U14 (0.61 ≤ r ≤ 0.74) (2). The latent structural equation modeling (SEM) (R 2 = 51%) revealed a significant influence on BMSlat for MOMIR (β = 0.51, p <0.05). The additional contribution of PAHKR (β = 0.27, p = 0.06) and SAUS (β = -0.03, p = 0.90) was rather small (3). The investigation of individual differences between the reference method and alternative diagnostics indicated a significant bias for MOMIR (p <0.01). The results support the use of economical and time-efficient methods for assessing BMS within elite youth soccer. Bivariate correlation analyses as well as the multivariate latent variable approach highlight the measures' usefulness. However, the observed individual level differences for some of the utilized procedures led to the recommendation for practitioners to use at least two alternative assessment methods in order to receive more reliable information about players' BMS within the talent promotion process

Bio-banding in youth elite soccer players: a pilot study

Introduction: By the age of 12 to 16 years the biological age (BA) can differ in the same chronological age (CA) group up to five years and affects the athlete’s physical and psychological abilities. Early developed players show superior strength, speed, willingness to take responsibility and leadership, which may play a decisive role in the talent identification and development (1). Bio-banding describes the grouping of young athletes based on their BA rather than the CA in order to reduce the differences in maturity. So far, research investigated the qualitative effects of bio-banding on psycho-social parameters (1). The aim of the underlying pilot study was to quantify the effects of bio-banding on technical, tactical and physical parameters in youth elite soccer games. Methods: 61 male and two female youth elite soccer players from two Swiss top club’s youth academies U13 and U14 participated in the study. All participant’s peak height velocity was estimated with the Mirwald-Method and the BA calculated. On a single match-day, 4x20 min matches were played. For two matches, the teams were grouped based on the BA. As a control condition, two matches were played with the conventional CA grouping. All matches were monitored ball-oriented with video cameras for the subsequent analysis of technical and tactical parameters. Physical parameters were determined using GPS (ASI, Field Wiz). Data between the bio-banded and control condition were compared using a paired t-test and Wilcoxon signed-rank for non-normally distributed samples. In addition, Cohen’s d effect sizes were calculated. Results: Within bio-banding, the number of duels increased (p=.02, d=.89) and resulted in a reduced time per action on the ball (p=.01, d=.58). Also, the number of standard situations increased (p=.03, d=1.0) and the percentage of successful passes decreased (p<.01, d=1.23). Medium effect sizes indicated a decreased difference of ball possession [%] (p=.08, d=0.68) within bio-banding. Physical data showed a reduced total running distance (p<.01, d=0.28). Conclusion: The increased number of duels may indicate a reduced dominance of the early maturing players and consequently may create more opportunities for late maturing players. The reduced time per action on the ball might result from the accelerated match play. Bio-banding created a more balanced and competitive match play and possibly results in a better environment for the development of talented players. From a coach’s perspective, bio-banding could improve the talent identification and selection process and help to detect potential future champions

Player-labelling as a solution to overcome maturation selection biases in youth football

The fact that potentially skilled, but biologically later-maturing athletes are less likely to be selected into talent development programmes (TDP) can represent a failure of Talent Identification (TID) in sports. To overcome maturation selection biases, maturation independent TID should be established to include less mature, but talented athletes in TDP more frequently. Using a randomised parallel-group design, this study aimed to evaluate the effect of labelling under-11 (U11) Swiss male youth football players (n = 24, age = 11.0 ± 0.3 years) via maturation-ordered shirt numbers during rank assessment by talent scouts (n = 83, scout experience = 4.8 ± 2.4 years). Following observation of video recorded selection tournaments, player-labelling “informed” scouts were significantly more likely to rank less mature players higher on their player potential, t(81) = 2.57, p = .012, d = −0.6, 95% CI [−1.00, −0.13], than “uninformed” scouts. As altered rankings assisted less mature players, player-labelling may offer a practical and feasible strategy to improve TID by removing possible maturation selection biases. To address maturation selection biases and the potential positive impact of player-labelling more broadly, further research on both male and female athletes in various age categories and sports contexts is recommended