In professional football the decline in high-intensity running activities from first to second half is more pronounced in players with a fast muscle typology.

Muscle typology is heterogeneous among national level football (soccer) players, but positional differences remain unclear. Furthermore, fast typology (FT) individuals fatigue more than slow typology (ST) individuals in lab conditions. Therefore, we investigated if muscle typology is different between playing positions and if the decay in high-intensity activities from the first to the second half is larger in FT football players than in ST players.

Multilevel modelling of longitudinal changes in isokinetic knee extensor and flexor strength in adolescent soccer players.

The purpose of the study was to model the longitudinal development of knee extension (KE) and flexion (KF) strength in adolescent soccer players. A mixed-longitudinal sample composed of 67 soccer players aged 11.0-13.

Developmental Changes in Isometric Strength: Longitudinal Study in Adolescent Soccer Players.

This study aimed to examine longitudinal changes in isometric strength of the knee extensors (ImKE) and knee flexors (ImKF) at 30° and 60°. The sample was composed of 67 players aged 11.0-13.

Correction to: Tanner-Whitehouse Skeletal Ages in Male Youth Soccer Players: TW2 or TW3?

An Online First version of this article was made available online at https://link.springer.com/article/10.

Improving the Prediction of Maturity From Anthropometric Variables Using a Maturity Ratio.

Purpose: This study aimed to improve the prediction accuracy of age at peak height velocity (APHV) from anthropometric assessment using nonlinear models and a maturity ratio rather than a maturity offset.

Methods: The dataset used to develop the original prediction equations was used to test a new prediction model, utilizing the maturity ratio and a polynomial prediction equation. This model was then applied to a sample of male youth academy soccer players (n = 1330) to validate the new model in youth athletes.

The Influence of Restricted Visual Feedback on Dribbling Performance in Youth Soccer Players.

The aim of the current study was to examine the influence of restricted visual feedback using stroboscopic eyewear on the dribbling performance of youth soccer players. Three dribble test conditions were used in a within-subjects design to measure the effect of restricted visual feedback on soccer dribbling performance in 189 youth soccer players (age: 10-18 y) classified as fast, average or slow dribblers. The results showed that limiting visual feedback increased dribble test times across all abilities.

Mental Fatigue Impairs Soccer-Specific Physical and Technical Performance.

Purpose: To investigate the effects of mental fatigue on soccer-specific physical and technical performance.

Methods: This investigation consisted of two separate studies. Study 1 assessed the soccer-specific physical performance of 12 moderately trained soccer players using the Yo-Yo Intermittent Recovery Test, Level 1 (Yo-Yo IR1).

A retrospective study on anthropometrical, physical fitness, and motor coordination characteristics that influence dropout, contract status, and first-team playing time in high-level soccer players aged eight to eighteen years.

The goal of this article was twofold, and a 2-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance, and motor coordination characteristics that influence dropout from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a "club group" or a "dropout group.

A longitudinal study investigating the stability of anthropometry and soccer-specific endurance in pubertal high-level youth soccer players.

We investigated the evolution and stability of anthropometric and soccer-specific endurance characteristics of 42 high-level, pubertal soccer players with high, average and low yo-yo intermittent recovery test level 1 (YYIR1) baseline performances over two and four years. The rates of improvement were calculated for each performance group, and intra-class correlations were used to verify short- and long-term stability. The main finding was that after two and four years, the magnitudes of the differences at baseline were reduced, although players with high YYIR1 baseline performance still covered the largest distance (e.

Stature and jumping height are required in female volleyball, but motor coordination is a key factor for future elite success.

It was hypothesized that differences in anthropometry, physical performance, and motor coordination would be found between Belgian elite and sub-elite level female volleyball players using a retrospective analysis of test results gathered over a 5-year period. The test sample in this study consisted of 21 young female volleyball players (15.3 ± 1.

Multilevel Development Models of Explosive Leg Power in High-Level Soccer Players.

Purpose: The aim of the present study was to model developmental changes in explosive power based on the contribution of chronological age, anthropometrical characteristics, motor coordination parameters, and flexibility.

Methods: Two different longitudinal, multilevel models were obtained to predict countermovement jump (CMJ) and standing broad jump (SBJ) performance in 356 high-level, youth soccer players, age 11-14 yr at baseline. Biological maturity status was estimated (age at peak height velocity [APHV]), and variation in the development of explosive power was examined based on three maturity groups (APHV; earliest < P33, P33 < average < P66, latest > P66).

Generic anthropometric and performance characteristics among elite adolescent boys in nine different sports.

The aim of the present study was to evaluate the Flemish Sports Compass (FSC), a non-sport-specific generic testing battery. It was hypothesised that a set of 22 tests would have sufficient discriminant power to allocate athletes to their own sport based on a unique combination of test scores. First, discriminant analyses were applied to the 22 tests of anthropometry, physical fitness and motor coordination in 141 boys under age 18 (16.

Modeling developmental changes in yo-yo intermittent recovery test level 1 in elite pubertal soccer players.

Purpose: To model the development of soccer-specific aerobic performance, assessed by the Yo-Yo Intermittent Recovery Test Level 1 in 162 elite pubertal soccer players, age 11-14 y at baseline.

Methods: Longitudinal multilevel modeling analyses comprised predictors related to growth (chronological age, body size [height and weight] and composition [fat mass, fat-free mass]), and motor coordination [3 KÖrperkoordination Test für Kinder subtests: jumping sideways, moving sideways, backward balancing] and estimated biological-maturation groups (earliest [percentile 66]).

Results: The best-fitting model on soccer-specific aerobic performance could be expressed as -3639.

Reliability and validity of the Yo-Yo intermittent recovery test level 1 in young soccer players.

The present study investigated the test-retest reliability from the Yo-Yo IR1 (distance and heart rate responses), and the ability of the Yo-Yo IR1 to differentiate between elite and non-elite youth soccer players. A total of 228 youth soccer players (11-17 years) participated: 78 non-elite players to examine the test-retest reliability within 1 week, added with 150 elite players to investigate the construct validity. The main finding was that the distance covered was adequately reproducible in the youngest age groups (U13 and U15) and highly reproducible in the oldest age group (U17).

Changes in physical fitness and sports participation among children with different levels of motor competence: a 2-year longitudinal study.

The goal of this study was to investigate differences in physical fitness and sports participation over 2 years in children with relatively high, average, and low motor competence. Physical fitness and gross motor coordination of 501 children between 6-10 years were measured at baseline and baseline+2 years. The sample compromised 2 age cohorts: 6.

A longitudinal study of multidimensional performance characteristics related to physical capacities in youth handball.

Longitudinal research provides valuable information about change and progress towards elite performance. Unfortunately, there is a lack of longitudinal research in handball. In this study, 94 youth handball players (oldest group: n = 41; age 15-17 and youngest group: n = 53; age 13-15) were followed over a three-year period.