A systematic review of intervention programs that produced changes in speed and explosive strength in youth footballers

Effects of Mental Visualization on Plyometric Performance and Self-Confidence of Football Players

Plyometric training in football is essential for enhancing athletic performance, as it allows for increasing strength and speed in gameplay. Meanwhile, mental visualization improves players' technical play and motor performance during both training and competitions, thereby contributing to an overall sports performance enhancement. Collectively, physical and technical training is thought to boost athletes' confidence in facing competitive demands. Our aim in the present study was to analyze the effectiveness of mental visualization during a plyometric training program for improving strength speed, and competitive self-confidence in young adult football (soccer) players. Our sample consisted of 40 male players aged between 19 and 25 years (M = 20.82; SD = 1.26). We used a quasi-experimental design with a control group and pretest/posttest measurements. The experimental group participated in an 8-week plyometric training program that incorporated visualization tasks, while the control group underwent the same program but without visualization exercises. We found significant improvements for the experimental group on vertical jump (p = .047) and speed (50-m sprints) (p < .034) tests, as well as in their perceived competitive self-confidence (p < .017). These findings suggest that combining plyometric exercises with visualization tasks may contribute to better motor learning, increased lower limb muscle speed and strength, and self-confidence to face competition.

Maturation Selection Biases and Relative Age Effect in Italian Soccer Players of Different Levels

Simple Summary

Soccer academies and societies research young players who are supposed to possess great motor skills. In association with these, adolescents who appear to be talented exhibit more developed anthropometric and body composition features than untalented players. Although many selected soccer players appear to present an earlier maturation than their contemporaries, it is not clear whether soccer teams of different competition levels are aware of this aspect and considered these discrepancies in the scouting selection process. In addition, it remains unclear if the biological maturity and relative effect are two interchangeable methods of evaluation and if one of them deserves to be preferred by the soccer scouters. This research aims to investigate the effect of the team level, maturity status and relative-age effect, and their interactions, on body characteristics, cellularity, and physical performance in adolescent soccer players. Despite the relative age effect remaining the easier analysis to consider, the evaluation of maturity status seems to be the most reliable method to detect better capabilities due to early growth.

Abstract

Soccer is a sport practiced all over the world, in which players are expected to show specific physical and technical skills. Soccer academies look for young talented individuals to develop promising players. Although several parameters could affect the players’ performance, the relative age effect (RAE) and the maturity status appeared debated. Therefore, this study compared the differences in RAE and biological maturity among the players of two Italian soccer teams of different levels and to understand their interaction effects with the competition level on youth players’ physical characteristics and abilities. One hundred and sixty-two young soccer players from the U12 to U15 age categories of the elite (n = 98) and non-elite (n = 64) teams were recruited. The prevalence of maturity status and RAE was observed. Many anthropometric parameters, BIA vectors, and motor tests (CMJ, Sprint, RSA) were carried out. The maturity status had a greater effect on several anthropometric characteristics and on 15 m sprint, while it affected the CMJ only in U12 (F = 6.187, p ≤ 0.01). Differently, the RAE seemed to priorly affect the U13 and U15 categories in body composition, whereas its effect appeared on the 15-m sprint (F_{(3, 45)} = 4.147, p ≤ 0.01) and the RSA (F_{(3, 45)} = 3.179, p ≤ 0.05) in the U14 category. In addition, early matured players or those who were born in the first six months presented cellular characteristics similar to adult elite players. Soccer professionals should be encouraged to monitor the maturity status to better interpret changes in the physical performance of young soccer players to guide adequate training plans.