UNLABELLED Variations in rates of growth and development in young football players can influence relationships among various fitness qualities. PURPOSE To investigate the relationships between repeated-sprint ability and other fundamental fitness qualities of acceleration, agility, explosive leg power, and aerobic conditioning through the age groups of U11 to U18 in highly trained junior foot...

Controlling harmful algae blooms (HABs) using microbial algicides is cheap, efficient and environmental-friendly. However, obtaining high yield of algicidal microbes to meet the need of field test is still a big challenge since qualitative and quantitative analysis of algicidal compounds is difficult. In this study, we developed a protocol to increase the yield of both biomass and algicidal com...

Aim: To validate thePsychological Skills Inventory for Sport – Youth(PSIS-Y) questionnaire on a sample of youth Croatian female volleyball players, and to determine psy- chological characteristics players aged 12 15 years, as well possible differences according team (competitive) performance level in variables: motivation, self-confidence, anxiety control, mental preparation, emphasis, concentr...

The aim of this study was to quantify the prominence levels of elite and highly competitive young soccer players. This study also analyzed the variation in general network properties at different competitive levels and periods of the season. A total of 132 matches, played by 28 teams during the 2015/2016 season, were analyzed. The results revealed significant differences in the composition of g...

The evaluation of change-of-direction (COD) performance is strongly focused on the time spent to perform the test trials, while much less is known about the technical execution adopted during the COD movements. Thus, the purposes of this study were to evaluate (1) the relationship between straight- and COD-sprint tests and (2) the technical execution of COD movements in relation to different ag...

Purpose: The main aim of this study was to examine and analyse the body composition young soccer players across different age groups. Methods: A cross-sectional carried out among 126 divided into categories: U15 – 53 (age=14.68±0.47); U17 51 (age=16.47±0.50); U19 22 (age=18.05±0.38). subjects’ height measured using an anthropometer, while their TANITA BC-420MA digital scale. Results: On average...

This study analyses the relative age effect (RAE) in basketball athletes, considering categories (U13, U15, U17, and U19), sex, number of games average points. The participants were 1,455 Brazilian athletes aged between 9 19 who participated Santa Catarina State Basketball Championship 2018 season. To test RAE, Chi-square (χ2) was performed to compare observed distribution expected birth quarti...

Background: Moderate to very large correlation between internal training load, external and recovery status have been reported in elite youth football. However, little is known about subelite football environments. Objective: The purpose of this study was assess the association load young players. Methods: Twenty under-15, twenty under-17, under-19 players were monitored over a 6-week period du...

This study investigated the associations between biological maturation status (classified using Khamis–Roche method for percentage of predicted adult height at time observation) and relative age (expressed as a decimal value to difference birth date competition cut-off date) extent which their selection biases existed across competitive groups in an analysis players within Football Association ...