Javier Raya-González

Universidad de Extremadura | UNEX · Department of Didactics of Music, Plastic and Body Expression

This study aimed to analyse the influence of the match status on the conditional characteristics of tactical sprint actions among Spanish professional soccer players, considering playing positions. Thirty-two Spanish male professional soccer players from a LaLiga Spanish Second Division (LaLiga SmarthBank) team participated in this study. Actions a...

Background In the sports context, coaches must be able to improve their players physically, psychologically, and socially. Hence, a fundamental part of this process is the athlete’s individual resilience (IR). Methods Three hundred and fifteen youth team-sport players (boys: n = 283; Mage = 16.02, SD = 0.56; and girls: n = 32; Mage = 15.92, SD = 0...

(1) Background: Cyberbullying is a growing problem among adolescents, and deeper knowledge of this phenomenon could facilitate the implementation of adequate prevention and intervention strategies. Therefore, the aim of this study was to analyze the relationships between victimization and aggression patterns in cyberbullying and physical fitness le...

This study aimed to analyse the influence of different physical fitness levels of youth basketball players on match-related physical performance, using Random Forest clustering to distinguish between high-fitness level players and low-fitness level players. Twenty male youth basketball players completed the following physical performance tests in t...

Este estudio tuvo como objetivo analizar la influencia de la edad en variables como el número de participaciones, confederación de clubes, confederación de selecciones nacionales, posición de juego, rendimiento del equipo, celebración del año y minutos totales jugados durante la Copa Mundial de la FIFA (FWC) de 1998 a 2018. La muestra estuvo compue...

The aim of this study was to analyse the effects of sprint and power performance on physical fitness and small-sided game-related physical performance in youth male soccer players, using a median split analysis to separate faster and slower players, and powerful and weaker ones. Thirty youth male soccer players (age = 16.9 ± 1.4 years; height =...

Abstract. Objective: The objective of this study was to analyze the effect of playing several friendly matches on consecutive days affects neuromuscular fatigue evaluated with countermovement jump (CMJ), session rate of perceived effort (sRPE) and wellness in young male soccer players. Participants: Forty-four young male soccer players from Under 1...

Background. Optimizing the soccer players' match preparation is one of the most relevant concerns of coaches for strength and conditioning training. Thus, the aim of this study was to analyze the effects of three pre-match warm-up structures on the physical condition of male professional soccer players. Materials & Methods. Seventeen male professi...

Futsal is one of the most harmful sports due to its great physical demands. The asymmetries have been proposed as one of the most important risk factors of suffering an injury. However, no study has analysed the relationship between neuromuscular assessment and its implication on the likelihood of suffering injuries comparing male and female player...

Background: In soccer, the day of the week with the highest external load is match day (MD), with starters (>60 minutes per match) showing higher levels of physical fitness and seasonal high-intensity loading. It is necessary, therefore, to determine training strategies to reduce the differences between starters and nonstarters. The aim of this st...

Purpose: Physical fitness has shown to be positively related with young people's general mental health, mainly due to the changes in body composition derived from a regular sportive practice. Thus, the aim of this study was three-fold: 1) to analyze the relationship between physical fitness with the mental health status assessed as physical self-co...

Flywheel (isoinertial) resistance training is a valid strength training method that has been incorporated in sport for decades, yet little is known about how therapists working in sport apply flywheel resistance training. We aimed to describe and understand current application and perception of flywheel resistance training amongst therapists workin...

One of the most often-used task constraints in designing small-sided games (SSGs) is the manipulation of pitch size to promote increases or decreases in the relative area per player. Such adjustments cause changes in the acute responses during SSGs. This systematic review with meta-analysis aimed to compare the effects of smaller vs. larger pitch s...

The aim of this study was two-fold: (i) analyze the variation of kinematic measures between using preferred and non-preferred legs while braking during the 5–0–5 change of direction test; and (ii) test the relationships between kinematic measures, and change-of-direction deficit (CODD). A cross-sectional study using twenty adult male soccer players...

Background Knowing the impact of injuries is essential for their adequate management during reconditioning programs. Objective This study aimed to analyze the changes in match performance parameters in professional soccer players after sustaining an injury, which was defined according to injury severity. Methods Two-hundred and seven injuries rel...

This study aimed to analyze the isolated and combined effects of non-modifiable factors on adolescents' physical fitness. This cross-sectional, descriptive study involved 1475 adolescents, aged 12 to 19 years, of whom 721 were girls, from four public schools in southern Spain. Physical activity, birth weight and breastfeeding time, and physical fit...

The present study presents a novel specific multi-joint isometric test to assess upper limb strength impairment for evidence-based classification in wheelchair sports. Sixteen wheelchair athletes participated in this study and were classified according to their type of physical impairment and health condition as follows: athletes with neurological...

Accelerometers can estimate the intensity, frequency, and duration of physical activity in healthy adults. Although thresholds to distinguish varying levels of activity intensity using the Actigraph wGT3X-B have been established for the general population, their accuracy for Huntington’s disease (HD) is unknown. We aimed to define and cross-validat...

Background High metabolic load distance provides global information about the soccer players’ total high-intensity activities. Thus, this study aimed to examine the Spanish professional soccer players’ high metabolic load distance profile, comparing competitive level and playing positions. Methods A total of 18,131 individual match observations we...

The aim of this paper was to examine how contextual factors affect match demands in amateur referees. Twenty-three field referees participated in this study. Match physical and physiological demands were monitored. Results showed that referees recorded greater total distance (p<0.01), Powermean (p<0.01), Speedmean (p<0.05) and Cadencemean (p<0.05)...

Background Consumer and research activity monitors have become popular because of their ability to quantify energy expenditure (EE) in free-living conditions in a cost-efficient way. However, there is not research on the validity of this devices in people with Huntington’s disease (HD). Aims To determine the accuracy of the Actigraph and Fitbit co...

Rationale Risk for or established malnutrition is frequent in Huntington´s disease (HD), accompanied by functional limitations, increased morbidity, and mortality. Phase angle is associate with changes in the structure of the cell membrane of soft tissue mass, alterations in fluid balance and it has been shown as an indicator of prognostic clinic i...

Rationale Sarcopenia is associated with frailty, and dependence in older patients. Mediterranean Diet (MeDi) is one of the best models for healthy eating, associated with a better life quality in Huntington´s disease (HD). Targeted physical activity intervention has been identified as beneficial in several health disorders, including sarcopenia. Ou...

Background Thermoregulation is the maintenance of a relatively constant core body temperature which influences tolerance to physical activity. Brown adipose tissue, skeletal muscle, and hypothalamus are components involved in this process. Transgenic animal models of Huntington’s disease (HD) have provided informative models of thermoregulatory dis...

BACKGROUND Among the different clinical manifestations, weight loss and energy balance (EB) deficit have been described frequently in Huntington's disease (HD), contributing to HD progression. To develop a therapeutic approach to prevent weight loss and EB deficit in HD, we will conduct a study designed to validate the usefulness of accelerometers...

The aim of this study was to analyze the effects of a nutritional education program combined with the FIFA 11+ program on physical fitness attributes, physical activity levels, food and nutritional habits and nutritional knowledge in young basketball players. Twenty-three under 14 elite basketball players (13 males and 10 females) belonging to a pr...

This umbrella review aimed to analyze the different variables of resistance training and their effect on hypertrophy, and to provide practical recommendations for the prescription of resistance training programs to maximize hypertrophy responses. A systematic research was conducted through of PubMed/MEDLINE, SPORTDiscus and Web of Science following...

This book systematically summarizes the accuracy, precision, and repeatability levels of field-based tests applied in soccer. It considers such details as the effectiveness of tests for different age categories and sexes. In this book, the readers will be able to check all the field-based tests conceived for fitness assessment in soccer through a l...

Flywheel (FW) resistance training is a valid and time-efficient method to improve force production and muscular hypertrophy. However, no definitive consensus exists regarding FW parameters for optimizing chronic training responses. Therefore, this review aims to examine the FW training literature and provide evidence-based conclusions and practical...

This study aimed to analyze the effects of a 16-week jump training program on the physical performance and lower extremities injury profile in semi-professional male soccer players. Participants were randomly assigned to the control group (CG; n=13; age = 21.7 ± 3.6 years) or the experimental group (EG; n=10; age = 22.3 ± 3.5 years). Countermovemen...

The theory and methodology of training combine different factors that support the coach’s intervention for maximizing the athlete’s performance. Among these factors can be included the testing and monitoring, the definition of targets and structure of intervention, the planning, and the intervention itself or in a larger concept a hybrid model fact...

The theory and methodology of training combine different factors that support the coach’s intervention for maximizing the athlete’s performance. Among these factors can be included the testing and monitoring, the definition of targets and structure of intervention, the planning, and the intervention itself or in a larger concept a hybrid model fact...

This study analyzes the inter- and intra-differences in external load across the microcycle in professional female soccer players. External load during four consecutive microcycles (i.e., M1, M2, M3, and M4) and training sessions (i.e., MD-4, MD-3, MD-2, and MD-1) and a match day (i.e., MD) were registered in seventeen female professional soccer pl...

The aim of this umbrella review was to provide a detailed summary of how flywheel training enhances strength and physical capacities in healthy and athletic populations. The eleven reviews included were analyzed for methodological quality according to the Assessing the Methodological Quality of Systematic Review 2 (AMSTAR 2) and the Grading of Reco...

The main objective of this study was to analyse the changes in external demand parameters (e.g., total distance, high-speed running distance, accelerations/decelerations) in Spanish professional soccer teams after the COVID-19 lockdown considering their on-field ranking (i.e., teams whose ranking worsened after the COVID-19 lockdown [WRS] vs. teams...

El objetivo fue analizar los efectos de la suplementación con zumo de remolacha (ZR) sobre el rendimiento deportivo en triatletas amateur, medido mediante un protocolo de media sentadilla bilateral y unilateral, y con una prueba de salto con contramovimiento (CMJ), en situación de fatiga. Doce triatletas amateurs participaron en este estudio aleato...

This systematic review followed the Cochrane Collaboration guidelines. The systematic review strategy was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The PICOS (Population, Intervention/exposure, Comparator, Outcome, Study design) was defined as follows: (P) soccer players from any...

The current chapter will focus in to present the main findings of validity and reliability levels of physical fitness assessment tests in soccer. The structure of the presentation will split the main findings in young & youth and adults whilst splitting into cardiorespiratory tests and tests focusing on sprinting, change-of-direction, and strength/...

High-intensity actions play a key role in soccer, since most of them are related to a better performance during matches, specially sprinting in all of its manifestations (i.e., linear, curvilinear, with change of direction, repeatedly and agility). Thus, knowing the most appropriate tests, in terms of validity and reliability, will allow practition...

This chapter presents a summary of a great variety of physical tests that can be implemented on both amateur and professional athletes from different sports. To give a practical reading of this chapter, all the physical test dimensions will be described in an order best suited to follow during a battery of tests. That is, the less metabolic demandi...

The purpose of this section is to discuss the validity and reliability of field-based soccer tests for aerobic capacity in youth and adult soccer players. In this section, results from previous studies carried out on youth and adults will be presented. Whilst there were 21 studies demonstrating the validity and/or reliability of tests related to ae...

The aims of this chapter were to analyse validity and reliability of several types of strength and power tests, as well as their usefulness in the context of soccer field. To provide a better context to the reader, by strength tests, we are referring to the maximal isoinertial tests [that include external free weights (bars or dumbbells)], isometri...

Repeated sprint training appears to be an efficient strategy for the simultaneous development of different fitness components in intermittent sport. The aim of this study was to analyze the effects of implement training with repeated sprint training on repeated sprint ability (RSA), reaction time in fatigue condition and jump height. Twenty-seven y...

The aim of this study was to quantify the acute impact of bouts duration and individual interaction space on physical and physiological demands and on physical performance. Ten young male soccer players (age: 14.8 ± 0.6 years) from the same team playing in the National U-16 Division participated. Physical (total distance [TD]; distance covered at d...

The objective of this study was to assess the effects of an additional small-sided games (SSGs) training program during Ramadan intermitting fasting (RIF) on technical performance depending on changes in body composition, sleep habits, and ratings of perceived exertion (RPE). Twenty-four professional male basketball players from the Tunisian first...

Purpose: The aim of this study was to describe the anthropometrical and cardiovascular characteristics of short course trail runners and analyze the associations, if any, between both anthropometric and cardiovascular features of amateur trail runners. Material and method: Anthropometrical evaluation and an incremental maximum test with 10% of grad...

This study analyzed the effects of a training program based on Nordic Hamstring and sprint exercises on physical performance and hamstring injuries in young male soccer players. Forty-nine U19 players were randomly assigned to a control (CG; n = 26) or experimental group (EG; n = 23). Linear sprint and with change of direction (COD) were assessed b...

This study examined the effects of body mass-based resistance training (bmRT) on selected measures of physical fitness and injury incidence and burden in soccer players. Forty-six U16 male soccer players were randomly assigned to an control (CG; n = 26) or experimental group (EG; n = 20) Countermovement jump (CMJ), change of direction (CoD) (i.e.,...

Purpose: The purpose of this study was to examine the effects of 15 weeks (2/week) of two different resistance training (RT) programs [the self-load group (SG) vs. the overload group (OG)] on selected measures of physical performance in young male soccer players. Methods: The countermovement jump (CMJ), aerobic endurance (VO 2 max), and body compos...

Introducción: Pocos estudios han sido encontrados donde se analicen los hábitos nutricionales, la composición corporal y la condición física de jóvenes futbolistas entre diferentes categorías y diferenciando entre chicos y chicas. Por tanto, el objetivo fue analizar las diferencias en los hábitos de consumo de alimentos, los parámetros de composici...

Growing evidence supports use of eccentric methods for strength development and injury prevention within elite soccer, yet uncertainty remains regarding practitioners’ application of flywheel (isoinertial) methods. The aims of this study were to investigate how the flywheel training literature is perceived and applied by elite soccer practitioners,...

Efectos de un programa de entrenamiento basado en nordic hamstring vs programa de entrenamiento basado en sprints en jugadores jóvenes de fútbol. Resumen: El objetivo del presente estudio es analizar el efecto de dos programas de entrenamiento, Nordic Hamstring (NH) y Sprint (SP) sobre la condición física en jugadores jóvenes de fútbol. Participaro...

This study aimed to analyze the influence of the different contextual factors (i.e., defensive style and game outcome) on the basketball players’ external load during games-based drills using ultrawideband (UWB) technology. Fourteen male professional basketball players belonging to an elite reserve Spanish Club (ACB) participated in this study. The...

Background Body composition is a strong indicator of nutritional and health status. Dual energy X-ray absorptiometry (DXA), multifrecuency bioelectrical impedance analysis (BIA), anthropometry and, skinfolds are non invasive methods to assess body composition with different levels of reliability. The validity of anthropometric and skinfolds to esti...

Introduction: Aging is associated with a reduction in physical activity levels, leading to a decrease in strength and muscle mass, and affecting the minimum functional capacity to maintain an independent life. The literature agrees that strength training is one of the most important strategies to curb the effects of age, since it has been shown to...

The aims of the current systematic review were to evaluate the current literature surrounding the chronic effect of flywheel training on the physical capacities of soccer players, and to identify areas for future research to establish guidelines for its use. Studies were identified following a search of electronic databases (PubMed and SPORTDiscus)...

Background: Plyometric jump training (PJT) can be used for improving balance through bilateral and unilateral jump-landing drills. Since the increased number of articles testing the effects of PJT on dynamic and static balance, it is relevant to summarize the evidence and determine the effects across different original articles. Objective: This sys...

The purpose of this study was to investigate the relationship between physical fitness and external load determined by local positioning system (LPS) in a simulated basketball game. Fourteen professional male basketball players performed a lane agility drill, 20-m maximal sprint speed, countermovement jump (CMJ), drop jump, and repeated sprint test...

Objetivo: Los objetivos del presente estudio fueron describir las características antropométricas y la capacidad cardiovascular de corredores amateurs de trail running de corta distancia y analizar si existe asociación entre las características antropométricas y la capacidad cardiovascular en los corredores de montaña. Método: A un grupo de 10 corr...

Small-sided games (SSGs) are a useful strategy to optimize the training process in soccer. The modification of some variables simultaneously implies several physical adaptations in soccer players. Thus, the aim of this study was to analyze the differences in the physical demands encountered by soccer players in different SSGs formats focusing on th...

The aim of this study was to analyze the effect of different supplementation conditions on the flywheel half-squat fatigue and performance. Sixteen active males participated in the experimental intervention during a 4-week period. Four experimental conditions were stablished in a double-blind manner as follows: placebo, caffeine (CAF), beetroot jui...

Background: Limited evidence exists comprehensively assessing physical fitness attributes, physical activity behaviors, nutritional habits, and nutritional knowledge according to sex in basketball players during early adolescence. Insight of this nature could be used to optimize the training process and lifestyles in young basketball players. Objec...

The aim of this study was twofold: 1) to test for differences on the external and internal responses encountered by youth soccer players during four bouts of 5-a-side small-sided game (SSG) across age categories and, 2) to analyze the external and internal responses attending to players’ sprinting and jumping profile within each age-category (i.e.,...

This systematic review with meta-analysis was conducted to assess the effects of small-sided games (SSG)-based training programs on bone mineral density (BMD) in untrained adults. The data sources utilized were Cochrane, Embase, Medline (PubMed), Scopus, SPORTDiscus, and Web of Science. The study eligibility criteria was: (i) Untrained adults (>18...

The objective of this study was to evaluate the effects of a combined plyometrics and sled training carried out two days a week for 8 weeks. 60 young male soccer players were distributed in 4 groups (Under U16) [Experimental Group (U16 Exp, n=15) and Control Group (U16 Cont, n=15); and (Under19) [U19 Exp, (n=15) and U19 Cont, (n=15)]. The jump with...

Background: The injury profile of each playing position in handball is a key factor in being able to improve the injury risk management process. Therefore, the aim of this study was to longitudinally analyze the differences in professional handball players’ injury profile according to their playing position (i.e., goalkeeper, back, wing and line)....

Purpose: To examine the effects of acute caffeine supplementation on physical performance during fitness testing and activity during simulated games in basketball players. Methods: A double-blind, counterbalanced, randomized, crossover study design was followed. A total of 14 professional male basketball players ingested a placebo (sucrose) and...

Background Football is the most popular sport among women; however, little is known about the injury profile in this population. This information would help design tailored injury risk mitigation strategies that may make football safer for women. Objective The aim of this study was to perform a systematic review and meta-analysis of epidemiologica...