Clinical Outcomes After ACL Reconstruction in Soccer (Football, Futbol) Players: A Systematic Review and Meta-Analysis.

CONTEXT: The risk factors for anterior cruciate ligament (ACL) tear for athletes participating in pivoting sports includes young age and female sex. A previous meta-analysis has reported a reinjury rate of 15% after ACL reconstruction (ACLR) for athletes across all sports. To the best of the authors' knowledge, this is the first systematic review and meta-analysis of available literature reporting outcomes after ACLR in soccer players. OBJECTIVE: To review and aggregate soccer-specific outcomes data after ACLR found in current literature to help guide a more tailored discussion regarding expectations and prognosis for soccer players seeking operative management of ACL injuries. DATA SOURCES: A comprehensive search of publications was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SPORTDiscus databases. STUDY SELECTION: Inclusion criteria consisted of original studies, level of evidence 1 to 4, studies reporting clinical and patient-reported outcomes (PROs) after primary ACLR in soccer players at all follow-up length. STUDY DESIGN: The primary outcomes of interest were graft failure/reoperation rates, ACL injury in contralateral knee, return to soccer time, and PROs. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Search of literature yielded 32 studies for inclusion that involved 3112 soccer players after ACLR. RESULTS: The overall graft failure/reoperation rate ranged between 3.0% and 24.8% (mean follow-up range, 2.3-10 years) and the combined ACL graft failure and contralateral ACL injury rate after initial ACLR was 1.0% to 16.7% (mean follow-up range, 3-10 years); a subgroup analysis for female and male players revealed a secondary ACL injury incidence rate of 27%, 95% CI (22%, 32%) and 10%, 95% CI (6%, 15%), respectively. Soccer players were able to return to play between 6.1 and 11.1 months and the majority of PROs showed favorable scores at medium-term follow-up. CONCLUSION: Soccer players experience high ACL injury rates after primary ACLR and demonstrated similar reinjury rates as found in previous literature of athletes who participate in high-demand pivoting sports.

[Evaluation of the accuracy of different body composition prediction formulas, compared to dual energy X-ray absorptiometry, in soccer players of Colombian professional teams]. / Evaluación de la exactitud de distintas fórmulas de predicción de la composición corporal, comparadas con la absorciometría de energía dual de rayos X, en futbolistas de equipos profesionales colombianos.

INTRODUCTION: Introduction: professional soccer both in the local setting and in other countries is highly competitive, and those who practice must have specific morphological, anthropometric, and body composition characteristics, in addition to constant monitoring of nutritional and training interventions. Currently, the gold-standard criterion for the evaluation of body composition is Dual Energy X-ray Absorciometry (DXA), which is a costly laboratory method with limited use for many professionals. Knowing which field methods obtain similar results to this would allow a better interdisciplinary approach, which could have a positive impact on sports performance. The objective of this study was to evaluate the accuracy of different formulas for predicting fat percentage and fat mass, as compared to DXA, in Colombian soccer team players. Methods: a cross-sectional, analytical study using convenience sampling. A total of 79 professional male soccer players, belonging to 4 Colombian first and second division clubs, were included. Thirty anthropometric variables were measured, wherewith a descriptive analysis was performed using the SPSS v.21 program, and a procedure with analytical scope was carried out to establish concordance indices between different measurements using the Bland and Altman method. This statistical process was performed using the library (BlandAltmanLeh) of the statistical program "R". Results: average age was 23 ± 4.4 years, and the percentage of body fat was estimated using six equations: Jackson and Pollock (7.20 ± 2.58 %), Yuhasz as modified by Carter (7.52 ± 8.50 %), Reilly (10.04 ± 1.43 %), Faulkner (11.23 ± 11.90 %), Pariskova and Buskova (11.08 ± 16.06 %), and Durnin and Womersley (12.41 ± 20,10 %), in addition to the calculation of fat percentage for fat mass using the five-component method (13.17 ± 2.86 %). The percentage of body fat that showed the lowest intermethod difference was fractionation by five components (0.54 ± 3.56), followed by Durnin and Womersley (0.66 ± 3.52). Conclusion: the calculations of fat percentage using the fractionation of 5 components method and the Durnin and Womersley equation were closest to the results obtained by the gold-standard method (DXA) in soccer players of Colombian professional teams.

INTRODUCCIÓN: Introducción: el fútbol profesional, tanto a nivel nacional como internacional, es de alta competencia. Los futbolistas deben tener características antropométricas y de composición corporal específicas. El criterio de referencia para la evaluación de la composición corporal es la absorciometría de energía dual de rayos X (DXA), cuyo uso es limitado al ser un método de laboratorio y tener un elevado coste. Conocer qué métodos de campo obtienen resultados similares podría permitir mejores intervenciones nutricionales y de entrenamiento, repercutiendo positivamente en el rendimiento. El objetivo de este estudio fue evaluar la precisión de distintas fórmulas de predicción del porcentaje de grasa y masa adiposa, en comparación con la DXA, en futbolistas de equipos colombianos. Métodos: estudio analítico transversal con muestreo a conveniencia. Se evaluaron 79 futbolistas profesionales de 4 clubes colombianos. Se midieron 30 variables antropométricas y se realizó un análisis descriptivo en el SPSS v.21, así como un análisis de las correlaciones e índices de concordancia utilizando la prueba de Pearson o de Sperman y el método de Bland y Altman, respectivamente, ambos con el programa estadístico R. Resultados: se estimó el porcentaje de grasa corporal utilizando seis ecuaciones: Jackson y Pollock (7,20 ± 2,58 %), Yuhasz (7,52 ± 8,50 %), Reilly (10,04 ± 1,43 %), Faulkner (11,23 ± 11,90 %), Pariskova y Buskova (11,08 ± 16,06 %) y Durnin y Womersley (12,41 ± 20,10 %). Se calculó el porcentaje de grasa de la masa adiposa con el método de los cinco componentes (13,17 ± 2,86 %). El porcentaje de grasa corporal que presentó menor diferencia intermétodos (DIM) fue el de fraccionamiento por cinco componentes (0,54 ± 3,56), seguido del obtenido por la fórmula de Durnin y Womersley (0,66 ± 3,52). Conclusión: el cálculo del porcentaje de grasa a partir del fraccionamiento de 5 componentes y la ecuación de Durnin y Womersley fueron los más cercanos a los resultados obtenidos por el método de referencia, la DXA, en los futbolistas de equipos profesionales colombianos.

Assessment of diet quality and physical activity of soccer players aged 13 to 16, from the Principality of Asturias, Spain.

INTRODUCTION: Diet and physical activity are factors that have key roles in childhood overweight and obesity prevention. Appropriate assessment of these factors is an essential task in public health. OBJECTIVE: The main aims of the study are to assess body composition, physical activity, and adherence to Mediterranean diet of soccer players, aged 13 to 16 years old in Asturias, Spain. It also aims to evaluate the relationships between diet, physical activity, body composition, and personal characteristics. METHODS: A cross-sectional descriptive survey approach was used involving children (n = 303) with a mean age of 14.15 years (SD = 1.06), and using the KIDMED and PAQ-A questionnaires to assess adherence to Mediterranean diet and level of physical activity, respectively. Body composition was represented using the participants' body mass index. RESULTS: Approximately 23.1% of the participants were overweight or obese. With regards to adherence to Mediterranean diet, 54.8% of the participants had medium adherence, while 8.9% had low adherence. PAQ-A mean score was 2.69 (SD = 0.47). Excess weight was associated with being a goalkeeper (P = .001), higher PAQ-A (P = .011), and lower KIDMED scores (P = .032). Correlation analysis showed an inverse association between age and PAQ-A score (r = -0.122), and a direct association between KIDMED and PAQ-A scores (r = 0.152). CONCLUSION: Participants had an adequate level of physical activity. However, they had an obesogenic profile similar to that of their age population, who were not soccer players. Actions to improve adherence to healthy diet practices are highly recommended.

Sex differences in mechanisms of head impacts in collegiate soccer athletes.

BACKGROUND: There has been growing interest in head impacts related to sports participation due to potential long- and short-term consequences of head injuries. Our purpose was to compare head impact magnitude and frequency between men's and women's intercollegiate soccer players based on head impact mechanism. METHODS: 28 collegiate soccer players (16 women: age = 19.94 (1.06) years, height = 163.75 (5.15) cm, mass = 61.21 (5.09) kg; 12 men: age = 20.25 (1.14) years, height = 180.34 (6.03) cm, mass = 74.09 (9.32) kg) wore xPatch (X2 Biosystems, Seattle, WA) head impact sensors. Each practice and game was video recorded in order to confirm head impacts. The independent variable was impact mechanism (head to head, head to body (other than head), head to ground, ball to head, goal to head, and combination). Sensors collected linear and rotational accelerations and frequency of head impacts per 1000 athlete exposures. FINDINGS: Men were more likely to sustain head impacts than women (IRR = 1.74, CI95 = 1.59-1.92). The highest head impact incidence rate for men was head to body (IR = 611.68, CI95 = 553.11-670.25) while the highest impact incidence rate for women was ball to head (IR = 302.29, CI95 = 270.93-333.64). The interaction between sex and mechanism was significant for rotational accelerations (F4, 1720 = 3.757, P = .005, ω2 = 0.013) but not for linear accelerations (F4,1720 = 0.680, P = .606, ω2 < 0.001, 1 - ß = 0.223). INTERPRETATION: To reduce the frequency of head impacts in men, perhaps rules governing player to player contact should be more strictly enforced as these data confirm frequent player-to-head contact during soccer practices and games. Prevention efforts for women should be focused on limiting the amount of purposeful heading (planned contact between the head and ball) occurring during play especially since these impacts had higher magnitudes compared to men.

The Impact of Covid-19 on Women's Experiences of and Through Football in Buenos Aires.

This research report explores the impact of Covid-19 on women's football in Buenos Aires. The suspension of all forms of football in Argentina as part of the country's hard lockdown measures threatens to undo significant gains made in women's football in recent years. By focussing on the experiences of key actors in a feminist Civil Society Organization (CSO) and a newly professional women's team, respectively, we examine what the pandemic has meant for women's football and for women football players at different levels of the game. We also consider the potential impact of the current situation on the future of women's football in Argentina, representative of wider social advances for women in the country.

Impact of football matches on number of visits to an emergency department. / Impacto de los partidos de fútbol en la frecuentación de pacientes a un servicio de urgencias.

OBJECTIVES: To analyze the impact of a local football team's matches on patient demand for hospital emergency department care in Bilbao, in the Spanish province of Biscay. MATERIAL AND METHODS: Retrospective analysis. We retrieved the number of patients coming to the emergency department on the days and hours of matches played by Bilbao's Athletic Club during the 2017-2019 and 2018-2019 seasons and compared the caseloads with those on the same days of the weeks before and after the matches (control days). RESULTS: Ninety-five match days were studied. Nineteen of the matches were considered key events. Visits by adults to the emergency department fell by a statistically significant 7.5% (95% CI, 4.6%-11.6%) when matches were being played in Bilbao. The decrease was 8.4% (95% CI, 5.3%-12.6%) when matches were played away. The decrease in pediatric emergencies was 32.7% (95% CI, 7.4%-68.3%) in the hours while important matches were played outside the city. CONCLUSION: The impact of football on the number of visits to our hospital emergency department was modest, except during important away matches.

OBJETIVO: Analizar el impacto que tienen los partidos de fútbol del equipo local en la frecuentación de pacientes al servicio de urgencias hospitalario (SUH) de Bilbao (Bizkaia). METODO: Estudio analítico retrospectivo. Se comparó la afluencia al servicio de urgencias durante los días y horas de partido del Athletic Club de Bilbao de las temporadas 2017/18 y 2018/19 con la de los mismos días de las semanas previas y posteriores a los eventos deportivos (controles). RESULTADOS: Fueron estudiadas 95 días de partido celebrados, donde 19 fueron considerados de alta relevancia. En pacientes adultos, cuando el partido se jugó en Bilbao se registró una disminución estadísticamente significativa del 7,5% (IC95% 4,6-11,6) en el número de urgencias y del 8,4% (IC95% 5,3-12,6) cuando el partido se celebró en otra ciudad. En pacientes pediátricos, se halló un descenso de la afluencia del 32,7% (IC95% 7,4-68,3) en las horas correspondientes al desarrollo del partido cuando este era relevante y se jugaba fuera de la ciudad. CONCLUSIONES: El fútbol tiene una limitada capacidad moduladora de la frecuentación de pacientes al SUH tan solo cuando se trata de partidos de alta relevancia.

[Anthropometric differences per playing position in Chilean professional footballers]. / Diferencias antropométricas por posición de juego en futbolistas profesionales chilenos.

INTRODUCTION: Introduction: given the characteristics of soccer, the tendency in the selection of these athletes and their allocation in certain game positions has been conditioned by the morphological characteristics that they present, so that the knowledge of anthropometric particularities by playing position is a relevant antecedent for the technical bodies of professional football. The objective of the present investigation is to identify and compare the anthropometric characteristics by playing position of Chilean professional soccer players. Methods: a total of 390 professional male soccer players, from 15 Chilean professional clubs, were evaluated morphologically by means of the measurement of 25 anthropometric variables, with which the body composition, the somatotype and the Z-score of Phantom were estimated. A Chi-square test with significance level of p < 0.05 was used to compare the variables between groups using SPSS software others players (greater adipose and muscular mass). As for a sample of active subjects, soccer players have a significantly different body composition, similarly occurs when compared to Phantom, where height, weight and muscle mass are greater and fat mass is lower. Conclusion: professional footballers differ by game position compared to other non-sports players and Phantom.

INTRODUCCIÓN: Introducción: dadas las características del fútbol, la tendencia en la selección de estos deportistas y su asignación en determinadas posiciones de juego se han visto condicionadas por las características morfológicas que estos presenten, por lo que el conocimiento de las particularidades antropométricas por posición de juego es un antecedente relevante para los cuerpos técnicos del fútbol de élite. El objetivo de la presente investigación es identificar y comparar las características antropométricas por posición de juego de jugadores de fútbol profesional chileno. Métodos: un total de 390 futbolistas profesionales varones, pertenecientes a 15 clubes profesionales chilenos, fueron evaluados morfológicamente mediante la medición de 25 variables antropométricas, con las que se estimaron la composición corporal, el somatótipo y los Z-score de Phantom. Para la comparación de las variables entre los grupos se utilizó una prueba Chi-cuadrado con nivel de significancia de p < 0,05, utilizando el software SPSS versión 21. Resultados: se observan diferencias entre las posiciones de juego, especialmente entre los porteros y el resto de los jugadores (p < 0,001), quienes presentan más de 2 kg de masa muscular y más de 1,8 kg de masa adiposa, frente a las otras posiciones de juego. Respecto de una muestra se sujetos activos, los futbolistas presentan una composición corporal significativamente distinta; de igual manera ocurre al comparar con Phantom, donde la estatura, el peso y la masa muscular son mayores y la masa adiposa es menor. Conclusión: los futbolistas profesionales presentan diferencias por posición de juego y en comparación a otros sujetos no deportistas y a Phantom.

[Effect of contextual factors in body composition of professional soccer players. A retrospective study]. / Efecto de factores contextuales en la composición corporal de jugadores profesionales de fútbol. Un estudio retrospectivo.

INTRODUCTION: The requirements of physical demands in soccer have evolved in recent years, determining the need to investigate those aspects that condition athletic performance. The objective of this study was to describe the incidence of individualized training, company at meals, race, and demarcation on the anthropometric variables of professional soccer players since these four factors affect body composition, which is considered a predictor of performance and an indicator of lifestyle in these individuals. For this purpose, a retrospective study was developed in 51 professional players of the Spanish Football League Second Division B during the 2015/2016, 2016/2017, and 2017/2018 seasons. The anthropometric assessment was carried out under the technical standards of measurement recommended by the International Working Group of Kinanthropometry, adopted by the International Society for the Advancement of Kinanthropometry (ISAK). The results revealed that individualized training and company during meals were the factors that most influence exerted on the anthropometric variables that were collected. The values of fat mass and muscle mass, and the sum of fold measurements are sensitive to the effect of the intervention with these factors. The highest levels of interaction occurred between company during the meals and individualized training, and between demarcation and company during the meals. Considering body composition as an aspect to be taken into account in the development of performance, it should be considered that the application of certain training contents according to the individual characteristics and lifestyle of players are factors that may have a significant influence on professional soccer players.

INTRODUCCIÓN: La exigencia de las demandas físicas en el fútbol ha evolucionado en los últimos años, poniendo de manifiesto la necesidad de investigar sobre aquellos aspectos que condicionan el rendimiento deportivo. Es por esto que el objetivo de este estudio fue describir la incidencia del entrenamiento individualizado, la compañía en las comidas, la raza y la demarcación sobre las variables antropométricas en jugadores de fútbol profesional. Para ello se desarrolló un estudio retrospectivo sobre 51 jugadores profesionales de la Segunda División B española durante las temporadas de 2015/2016, 2016/2017 y 2017/2018. La valoración antropométrica se realizó bajo las normas técnicas de medición recomendadas por el International Working Group of Kinanthropometry, adoptadas por la International Society for the Advancement of Kinanthropometry (ISAK). Los resultados revelaron que el entrenamiento individualizado y la compañía en las comidas fueron los factores que más influyeron sobre las variables antropométricas. Los valores de masa grasa y de masa muscular, y el sumatorio de pliegues son sensibles al efecto de la intervención sobre dichos factores. Los mayores niveles de interacción se producen entre la compañía en las comidas y el entrenamiento individualizado, y entre la demarcación y la compañía en las comidas. Considerando la composición corporal como un aspecto a tener en cuenta en el desarrollo del rendimiento, se concluye que la aplicación de ciertos contenidos del entrenamiento según las características individuales y el estilo de vida de los jugadores es un factor que posee una influencia significativa sobre los futbolistas profesionales.

Pensando a prática no futebol de mulheres: a parceria entre Athletico Paranaense e Foz Cataratas (2019) / Thinking about women's soccer: the partnership between Athletico Paranaense and Foz Cataratas (2019) / Pensando en el fútbol femenino: la asociación entre Athletico Paranaense y Foz Cataratas (2019)

Este texto objetiva analisar as condições para atuação fu-tebolística das mulheres jogadoras da equipe Foz Cataratas após a associação realizada com o clube Athletico Paranaense em 2019. Para tanto optou-se por um estudo de caso realizado através de observações e entrevista semiestruturada aplicadas à quatorze jo-gadoras e ao dirigente. As narrativas foram analisadas com base na metodologia denominada Análise de Conteúdo (Bardim, 1979). Verificou-se que as ações fomentadas pelas entidades futebolísti-cas impactaram positivamente ao trazer oportunidades para um número maior de mulheres, mas não garantiu melhorias nas con-dições de atuação das jogadoras e não remeteu a profissionali-zação no futebol de mulheres, especialmente para equipes com baixo capital simbólico, localizadas fora dos centros futebolísticos.

The aim of this text is to analyze the conditions in which women players from the Foz Cataratas team can play football after the association with the Athletico Paranaense club in 2019. To this end, we opted for a case study carried out through observations and semi-structured interviews applied to fourteen female players and the manager. The narratives were analyzed using the methodology known as Content Analysis (Bardin, 1979). It was found that the actions promoted by soccer organizations had a positive impact by bringing opportunities to a greater number of women, but did not guarantee improvements in the playing conditions of the players and did not lead to the professionalization of women's soccer, especially for teams with low symbolic capital, located outside the soccer centers.

Este texto tiene como objetivo analizar las condiciones para el rendimiento futbolístico de las jugadoras del equipo Foz Cataratas después de la asociación con el club Athletico Paranaense en 2019. Para ello, optamos por un estudio de caso realizado a través de observaciones y entrevistas semiestructuradas con catorce jugadoras y el dirigente. Las narrativas fueron analizadas utilizando la metodología de Análisis de Contenido (Bardin, 1979). Se constató que las acciones promovidas por las organizaciones de fútbol tuvieron un impacto positivo al traer oportunidades a un mayor número de mujeres, pero no garantizaron mejoras en las condiciones de juego de las jugadoras y no condujeron a la profesionalización del fútbol femenino, especialmente para los equipos con bajo capital simbólico, localizados fuera de los centros futbolísticos.

Variables biomecánicas del penalti en futbolistas de las categorías sub-12 y sub-17

Introducción: El estudio de los patrones del movimiento técnico deportivo implica analizar sus componentes biomecánicos, teniendo en cuenta el carácter multifactorial del rendimiento deportivo. Objetivo: Describir la mecánica del movimiento del tiro penalti en futbolistas categorías sub-12 y sub-17. Métodos: Estudio cuasi experimental de orden correlativo. Se estudiaron ocho variables biomecánicas: centro de gravedad en sus dos ejes, inclinación corporal, ángulos femorotibial antes del contacto, ángulos femorotibial luego del contacto, velocidad, aceleración y acierto. Se seleccionaron dos grupos independientes de 30 futbolistas del género masculino, se clasificaron por categorías sub-12 y sub-17, y se analizó su rendimiento mediante videoanálisis. Resultados: Hubo diferencias significativas a favor de la categoría sub-17 en las variables centro de gravedad en el eje X (p = 0,000), en inclinación corporal (p = 0,000), en velocidad (p = 0,000), y en aceleración y acierto (p = 0,000); y diferencias no significativas en el resto (centro de gravedad eje Y: p = 0,267; ángulos femorotibial antes del contacto: p = 0,459; ángulos femorotibial luego del contacto: p = 0,446; y aciertos: p = 0,226). Conclusiones: Todos los rangos promedios sobresalieron en la categoría sub-17, excepto en la variable aciertos, lo que implicó una mayor velocidad y aceleración del pie durante la ejecución del tiro a penal. Sin embargo, la precisión, como componente coordinativo, resultó fundamental en la efectividad del disparo.

Introduction: The study of the patterns of technical sports movement involves analyzing its biomechanical components, taking into account the multifactorial nature of sports performance. Objective: To describe the mechanics of the movement of the penalty kick in U-12 and U-17 football players. Methods: Quasi-experimental study of a correlative order. Eight biomechanical variables were studied: center of gravity in its two axes, body inclination, femorotibial angles before contact, femorotibial angles after contact, speed, acceleration and success. Two independent groups of 30 male footballers were selected, classified by U-12 and U-17 categories, and their performance was analysed through video analysis. Results: There were significant differences in favor of the sub-17 category in the variables center of gravity on the X axis (p = 0.000), body inclination (p = 0.000), speed (p = 0.000), and acceleration and accuracy (p = 0.000); and non-significant differences in the rest (center of gravity Y-axis: p = 0.267; femorotibial angles before contact: p = 0.459; femorotibial angles after contact: p = 0.446; and correct answers: p = 0.226). Conclusions: All the average ranges stood out in the U-17 category, except in the variable hits, which implied a greater speed and acceleration of the foot during the execution of the penalty kick. However, accuracy, as a coordinating component, was fundamental in the effectiveness of the shot.

Pensando a prática no futebol de mulheres: a parceria entre Athletico Paranaense e Foz Cataratas (2019) / Thinking about women's soccer: the partnership between Athletico Paranaense and Foz Cataratas (2019) / Pensando en el fútbol femenino: la asociación entre Athletico Paranaense y Foz Cataratas (2019)

Este texto objetiva analisar as condições para atuação futebolística das mulheres jogadoras da equipe Foz Cataratas após a associação realizada com o clube Athletico Paranaense em 2019. Para tanto optou-se por um estudo de caso realizado através de observações e entrevista semiestruturada aplicadas à quatorze jogadoras e ao dirigente. As narrativas foram analisadas com base na metodologia denominada Análise de Conteúdo (Bardim, 1979). Verificou-se que as ações fomentadas pelas entidades futebolísticas impactaram positivamente ao trazer oportunidades para um número maior de mulheres, mas não garantiu melhorias nas condições de atuação das jogadoras e não remeteu a profissionali-zação no futebol de mulheres, especialmente para equipes com baixo capital simbólico, localizadas fora dos centros futebolísticos (AU).

Anthropometric profile at u-15 to professional on brazilian national team soccer players / Perfil antropométrico de jugadores sub-15 a profesionales de la selección brasileña de fútbol / Perfil antropométrico de jogadores sub-15 a profissionais da seleção brasileira de futebol

ABSTRACT Introduction: Although competitiveness rises progressively increases according to age groups, players must stand out in their playing position at all ages to win a spot on their National Teams. The differences among match physical and technical demands could also influence which anthropometrical aspects would be most importantly considered for National Team selection. Objectives: This study aimed describe and compare the anthropometric profile of soccer players from U15 to professional categories of the Brazilian National Soccer Team. Methods: The sample consisted of 673 players from the categories U15, U17, U20, U23 and PRO. Measurements of height, body mass, and sum of seven skinfolds from the Brazilian Football Confederation database between 2013 and 2021 were used to describe the players' anthropometric profile. Players were grouped according to categories, playing position, and those who were selected or not selected. Results: As expected, the results indicate that body mass increases with age and stabilizes from category U23 onwards. Body mass and the sum of seven skinfolds increase within the U15 category (U15.1 vs. U15.2), while height and body mass increase within the U17 category (U17.1 vs. U17.2). Defenders and fullbacks stabilize body mass and stature prior to U17, while midfielders, strikers, and goalkeepers stabilize body mass later, with midfielders and strikers at U20, and goalkeepers at U23. Goalkeepers and defenders were the players with the greatest height and body mass compared to the other positions in all categories. The selected and non-selected players in the different categories had similar anthropometric profiles. Conclusion: From the results, there is a diversity in anthropometric profile within the positions and a difference in maturation according to the players' positions. This study can be used by coaches, physical trainers and sport scientists as normative data about the anthropometric profile of Brazilian men's soccer teams, establishing a benchmark. Level of Evidence III; Retrospective and Comparative Study.

RESUMEN Introducción: Aunque la competitividad aumenta progresivamente según los grupos de edad, los jugadores deben destacar en su posición de juego a todas las edades para ganarse un puesto en sus selecciones nacionales. Las diferencias entre las exigencias físicas y técnicas de los partidos también pueden influir en qué aspectos antropométricos serían más importantes para la selección nacional. Objetivos: Este estudio tuvo como objetivo describir y comparar el perfil antropométrico de futbolistas masculinos de menores de 15 años a categorías mayores de las selecciones brasileñas de fútbol. Métodos: La muestra estuvo compuesta por 673 jugadores de las siguientes categorías: Sub 15 (U15), Sub 17 (U17), Sub 20 (U20), Sub 23 (U23) y Profesional (PRO). Se utilizaron medidas de estatura, masa corporal y la suma de 7 pliegues cutáneos de la base de datos de la Confederación Nacional de Fútbol de Brasil entre 2013 y 2021 para describir el perfil antropométrico de los jugadores. Los jugadores se agruparon según los tramos de edad oficiales, la posición de juego y los seleccionados y no seleccionados. Resultados: Como era de esperar, los resultados indican que la masa corporal aumenta con la edad y se estanca a partir de la categoría U23. La masa corporal y la suma de 7 pliegues cutáneos aumentan dentro de la categoría U15 (U15.1 vs. U15.2), mientras que la estatura y la masa corporal aumentan dentro de la U17 (U17.1 vs. U17.2). Los defensas centrales y los laterales estabilizan antes la masa corporal y la estatura a partir de la U17, mientras que los mediocampistas, delanteros y porteros estabilizan la masa corporal más tarde, con los mediocampistas y delanteros en la U20 y los porteros en la U23. Los porteros y defensas centrales fueron los grupos que mostraron mayor estatura y masa corporal respecto a otras posiciones en todos los tramos de edad. Los jugadores seleccionados y no seleccionados en diferentes tramos de edad tienen un perfil antropométrico similar. Conclusión: Con base en los resultados, existe diversidad en el perfil antropométrico dentro de las posiciones de juego y diferencia en la maduración según la posición de los jugadores. Este estudio puede ser utilizado por entrenadores, preparadores físicos y científicos del deporte como dato normativo sobre el perfil antropométrico de las selecciones masculinas de fútbol de Brasil, estableciendo un punto de referencia. Nivel de Evidencia III; Estudio Retrospectivo Comparativo.

RESUMO Introdução: Embora a competitividade aumente progressivamente de acordo com as faixas etárias os jogadores devem se destacar em sua posição de jogo em todas as idades para conquistar uma vaga em suas equipes nacionais. As diferenças entre as exigências físicas e técnicas dos jogos também podem influenciar quais aspectos antropométricos seriam mais importantes para a seleção da equipe nacional. Objetivo: Este estudo teve por objetivo descrever e comparar o perfil antropométrico de jogadores de futebol da categoria sub 15 ao profissional da Seleção Brasileira de Futebol. Métodos: A amostra consistiu de 673 jogadores das seguintes categorias: sub 15 (U15) sub 17 (U17) sub 20 (U20) sub 23 (U23) e profissional (PRO). Medidas da estatura massa corporal e soma das sete dobras cutâneas do banco de dados da Confederação Brasileira de Futebol entre 2013 e 2021 foram utilizadas para descrever o perfil antropométrico dos jogadores. Os jogadores foram agrupados de acordo com as categorias posição de jogo e aqueles que foram selecionados ou não selecionados. Resultados: Como esperado os resultados indicam que a massa corporal aumenta com a idade e estabiliza a partir da categoria U23. A massa corporal e a soma das sete dobras cutâneas aumentam dentro da categoria U15 (U15.1 vs. U15.2) enquanto a estatura e a massa corporal aumentam dentro da categoria U17 (U17.1 vs. U17.2). Os zagueiros e laterais estabilizam a massa corporal e a estatura antes do U17 enquanto os meio campistas atacantes e goleiros estabilizam a massa corporal posteriormente com os meio campistas e atacantes no U20 e goleiros no U23. Os goleiros e os zagueiros foram os jogadores que apresentaram maior estatura e massa corporal comparados às outras posições em todas as categorias. Os jogadores selecionados e não-selecionados nas diferentes categorias apresentam perfil antropométrico semelhante. Conclusão: Baseando-se nos resultados há uma diversidade no perfil antropométrico dentro das posições e uma diferença na maturação de acordo com as posições dos jogadores. Este estudo pode ser utilizado por treinadores preparadores físicos e cientistas do esporte como dados normativos sobre o perfil antropométrico das seleções masculinas do futebol brasileiro estabelecendo um benchmark. Nível de Evidência III; Estudo Retrospectivo Comparativo.

Em busca de más emoción: reflexiones sobre las apuestas deportivas / Em busca de mais excitação: reflexões acerca das apostas esportivas / In search of more excitement: reflections on sports bets

Resumo O objetivo deste ensaio é refletir acerca das apostas esportivas a partir da base teórica de Norbert Elias e Eric Dunning. Além disso, como suporte, analisa-se a estrutura dos sites de apostas esportivas e os estudos produzidos acerca do assunto. Assim, diante dos referenciais apresentados, conclui-se que os indivíduos que apostam no esporte estão em busca de mais excitação para além do que a assistência dessa atividade proporciona. Logo, se as apostas eram condimento para a excitação a fim de assistir uma luta, como apresentado por Elias no passado, hoje, certamente, diante da expansão do mercado das apostas esportivas, os indivíduos têm procurado cada vez mais esse condimento, ou seja, estão em busca de mais excitação.

Abstract The objective of this essay is to reflect on sports betting from the theoretical basis of Norbert Elias and Eric Dunning. Additionally, this essay analyzes the structure of sports betting websites and the studies produced on the subject. Based on the references presented, it is concluded that individuals who bet on sports are seeking more excitement beyond what the mere spectating of the activity provides. If betting was a condiment for the excitement of watching a fight, as Elias presented in the past, today, with the expansion of the sports betting market, individuals are undoubtedly seeking this condiment even more, that is, they are looking for increased excitement.

Resumen El objetivo de este ensayo es reflexionar sobre las apuestas deportivas desde la base teórica de Norbert Elias y Eric Dunning. Además, como apoyo, se analiza la estructura de los sitios de apuestas deportivas y los estudios producidos sobre el tema. Basándose en los referentes presentados, se concluye que los individuos que apuestan en deportes buscan más emoción que la que proporciona la mera asistencia a la actividad. Si las apuestas eran un condimento para la emoción de ver una pelea, como lo presentó Elias en el pasado, hoy, ante la expansión del mercado de las apuestas deportivas, los individuos sin duda buscan cada vez más este condimento, es decir, buscan más emoción.

Asociación entre la composición corporal y el rendimiento en 30-15 Intermittent Fitness Test en futbolistas profesionales adultas de Chile / Association between Body Composition and Performance in the 30-15 Intermittent Fitness Test in Adult Female Professional Soccer Players in Chile

Resumen Antecedentes: La participación de las mujeres en el fútbol se ha incrementado exponencialmente en los últimos años, por lo que integrar antecedentes basados en la evidencia en esta población, permite una mejor compresión y análisis del desempeño deportivo de atletas femeninas. Objetivo: Determinar el nivel de asociación entre los indicadores de composición corporal y el rendimiento en test 30-15 IFT en futbolistas mujeres de primera división. Métodos: Participaron 29 jugadoras profesionales de un equipo de primera división de Chile. Se evaluó el test 30-15, se analizó la velocidad final alcanzada (VIFT) y se estimó el consumo máximo de oxígeno (VO2máx). La composición corporal (CC) fue estimada a través de antropometría y se analizó la talla, masa corporal, índice de masa corporal (IMC), masa adiposa absoluta (MA) y relativa (PMA), masa muscular absoluta (MM) y relativa (PMM) y sumatoria de 6 pliegues (S6P). Para analizar el nivel de asociación, se utilizó el coeficiente de correlación de Pearson (r) con un alfa de 0.05. Resultados: Se encontraron correlaciones negativas débiles entre MA con VIFT (r = -0.384 y p = 0.04) y VO2máx (r = -0.375 y p = 0.45); correlaciones negativas moderadas entre S6P con VIFT (r = -0.476 y p = 0.009) y VO2máx (r=0.454 y p=0.013); correlaciones negativas moderadas entre IMC con VIFT (r = 0.401 y p = 0.031) y VO2máx (r = -0.379 y p = 0.043). No se hallaron correlaciones entre MM y PMM con VIFT o VO2máx. Conclusión: Es posible concluir que el rendimiento en el 30-15IFT presenta asociación con la composición corporal, específicamente con la MA, S6P e IMC en las jugadoras evaluadas.

Abstract Background: The participation of women in football has increased exponentially in recent years, so integrating evidence-based background in this population allows a better understanding and analysis of the sporting performance of female athletes. Objective: Determine the level of association between body composition indicators and performance in the 30-15 IFT test in first division female football players. Methods: 29 professional female players from a first division team in Chile participated. The 30-15 test was evaluated, the final velocity achieved (VIFT) was analyzed, and the maximum oxygen consumption (VO2máx) was estimated. Body composition (CC) was estimated through anthropometry and height, body mass, body mass index (BMI), absolute (AM) and relative (RM) adipose mass, absolute (MM) and relative (RMM) muscle mass, and 6-fold sum (S6P) were analyzed. Pearson's correlation coefficient (r) with an alpha of 0.05 was used to analyze the level of association. Results: Weak negative correlations were found between MA with VIFT (r = -0.384 and p = 0.04) and VO2máx (r = -0.375 and p = 0.45); moderate negative correlations between S6P with VIFT (r = -0.476 and p = 0.009) and VO2máx (r = 0.454 and p = 0.013); moderate negative correlations between BMI with VIFT (r = 0.401 and p = 0.031) and VO2máx (r = -0.379 and p = 0.043). No correlations were found between MM and PMM with VIFT or VO2máx. Conclusion: It is possible to conclude that performance in the 30-15IFT is associated with body composition, specifically with MA, S6P, and BMI in players evaluated.

Prevalence of labrum and articular cartilage injuries of the hip on 3T magnetic resonance imaging of asymptomatic elite soccer players. / Prevalencia de lesiones del labrum y del cartílago articular de la cadera en imagen por resonancia magnética simple 3 T de futbolistas profesionales asintomáticos.

OBJECTIVE: To establish the prevalence of lesions of the labrum and articular cartilage of the hip in asymptomatic elite soccer players by performing 3T magnetic resonance imaging. METHODS: Eighty-four asymptomatic hips of 42 professional soccer players were evaluated. Male subjects older than 18 years were included. Cam and pincer deformity were defined as an alpha angle greater than 55 degrees and a lateral centre edge angle greater than 39 degrees, respectively. Labral injuries were classified with the Czerny classification and cartilage damage was classified with the Outerbridge classification. Specific statistical tests were used to establish the relationship between anatomical variances of the hip and the presence of chondral and labral injuries. RESULTS: FAI morphology prevalence was 25%. Abnormalities such as cam (22.5%) and labral injuries (33.8%) were found. Those cases with reported labral injury were predominantly intrasubstance damage (18.8%). Anatomical features of FAI were found to be related to lesions of the femoral cartilage (P<.001), chondrolabral damage (P=.042), or both injuries (P<.001). CONCLUSION: Asymptomatic labral or cartilaginous injuries of the hip were reported in 25% of the included professional soccer players. These injuries were associated with anatomical features of FAI.

La táctica como fundamento esencial en el proceso de preparación del futbolista

El fútbol es un deporte de oposición, cooperación, donde se interrelacionan las estructuras y las funciones específicas que lo rigen, de carácter eminentemente táctico y de ahí la necesidad que tienen los jugadores de relacionarse para organizarse colectivamente con eficacia en las situaciones ofensivas, defensivas, y las transiciones de ambas acciones, las cuales van a surgir el resto de capacidades técnicas, físicas, de teóricas y psicológicas según las necesidades de la idea de juego. Esta investigación, enmarcada en el proceso de preparación táctica de la selección provincial de fútbol de mayores de Pinar del Río, tuvo objetivo determinar el estado en que se encuentra la preparación táctica de los jugadores según el modelo de juego planificado para enfrentar el torneo nacional y definir la metodología de entrenamiento sustentada en los sistemas modernos de preparación fundamentado en el componente táctico como dimensión rectora en el proceso. Con la utilización de métodos teóricos, empíricos, y de nivel estadístico, se guía todo el proceso de la investigación a través de observaciones a entrenamientos, entrevistas y mediciones del comportamiento táctico en partidos oficiales, con lo cual se pudo corroborar en los resultados alcanzados una serie de insuficiencias y limitaciones tácticas en las dimensiones e indicadores valorados que denota que problemas en la preparación para la competencia.

O futebol é um esporte de oposição, cooperação, onde as estruturas e funções específicas que o regem estão inter-relacionadas, de natureza eminentemente tática e daí a necessidade de os jogadores se relacionarem entre si para se organizarem coletivamente de forma eficaz em situações ofensivas e defensivas, e as transições de ambas as ações, que darão origem ao resto das capacidades técnicas, físicas, teóricas e psicológicas de acordo com as necessidades da ideia de jogo. Esta pesquisa, enquadrada no processo de preparação tática da equipe de futebol sênior provincial de Pinar del Río, teve como objetivo determinar o estado da preparação tática dos jogadores de acordo com o modelo de jogo planejado para enfrentar o torneio nacional e definir a metodologia de treinamento com base nos modernos sistemas de preparação baseados no componente tático como uma dimensão orientadora no processo. Com a utilização de métodos teóricos, empíricos e estatísticos, todo o processo da pesquisa foi orientado por meio de observações em sessões de treinamento, entrevistas e medições do comportamento tático em jogos oficiais, com os quais foi possível corroborar nos resultados alcançados uma série de insuficiências e limitações táticas nas dimensões e indicadores avaliados que denotam problemas na preparação para a competição.

Soccer is a sport of opposition and cooperation, where the specific structures and functions that govern it are interrelated, of an eminently tactical nature and hence the need for players to relate to organize themselves collectively effectively in offensive, defensive, and the transitions of both actions, from which the rest of the technical, physical, theoretical and psychological capacities will emerge according to the needs of the game idea. This research, framed in the tactical preparation process of the provincial senior soccer team of Pinar del Río, had the objective of determining the state of the tactical preparation of the players according to the game model planned to face the national tournament and define the training methodology supported by modern preparation systems based on the tactical component as a guiding dimension in the process. With the use of theoretical, empirical, and statistical methods, the entire research process is guided through observations of training, interviews, and measurements of tactical behavior in official matches, with which it was possible to corroborate in the results achieved a series of insufficiencies and tactical limitations in the valued dimensions and indicators that denote problems in preparation for the competition.

Impacto de ejercicios bilaterales y unilaterales en la potenciación aguda del salto horizontal en futbolistas profesionales / Impact of Bilateral and Unilateral Exercises on Acute Enhancement of Horizontal Jump Performance in Professional Soccer Player / Impacto dos Exercícios Bilaterais e Unilaterais no Aumento Agudo do Desempenho do Salto Horizontal em Jogadores Profissionais de Futebol

Resumen Objetivo: Analizar el efecto de una activación realizada a través de ejercicios de fuerza y pliometría ejecutados de forma bilateral o unilateral sobre el rendimiento en salto horizontal. Metodología: En el estudio participaron 15 futbolistas masculinos, altamente entrenados (edad, 24.7 ± 3.1 años; altura, 181.2 ± 4.7 cm; peso, 79.7 ± 3.4 kg) pertenecientes al mismo equipo, que competía en liga nacional. Su rutina de entrenamiento regular constaba de 4 sesiones y 1 partido competitivo por semana. Los participantes llevaron a cabo 1 protocolo control (CON) y 3 protocolos de activación, siguiendo un diseño contrabalanceado, basados en ejercicios específicos de fútbol (SIN), ejercicios de fuerza y pliometría ejecutados de forma bilateral (BIL) y unilateral (UNI). Después de cada protocolo los jugadores realizaron la prueba de salto horizontal (HZB). Resultados: Los resultados de la prueba ANOVA de medidas repetidas mostraron efectos positivos significativos sobre el HZB de los protocolos SIN (p<0.01; dif = 2.95(2.00)%), BIL (p<0.01; dif = 3.22(2.61) %); y UNI (p<0.01; dif = 6.80(3.40) %) con respecto a CON. Además, HZB fue, significativamente, mayor después del protocolo UNI que del SIN (p<0.01; dif = 3.74(2.62) %) y BIL (p<0.01; dif = 3.47(1.94) %). El análisis de la respuesta individual reflejó efectos positivos en HZB de los protocolos SIN, BIL y UNI respecto al CON, mientras que el 89 % de los jugadores tuvieron mejor rendimiento en HZB después de UNI que de BIL. Conclusiones: Una activación que incorpora estímulos de fuerza y pliometría ejecutados, de forma unilateral, tiene un efecto positivo mayor sobre la capacidad de salto horizontal, que una activación que involucra ejercicios generales, específicos de fútbol y de ejecución bilateral.

Abstract Objective: To analyze the effect of activation through bilateral or unilateral strength and plyometric exercises on horizontal jump performance. Methodology: The study involved 15 highly trained male soccer players (age, 24.7 ± 3.1 years; height, 181.2 ± 4.7 cm; weight, 79.7 ± 3.4 kg) from the same team competing in the national league. Their regular training routine consisted of 4 sessions and 1 competitive match per week. Participants performed 1 control protocol (CON) and 3 activation protocols following a counterbalanced design based on specific soccer exercises (SIN), bilateral (BIL), and unilateral (UNI) strength and plyometric exercises. After each protocol, players underwent the horizontal jump test (HZB). Results: The repeated measures ANOVA revealed significant positive effects on HZB for the SIN (p<0.01; diff = 2.95(2.00) %), BIL (p<0.01; diff = 3.22(2.61) %), and UNI (p<0.01; diff = 6.80(3.40) %) protocols compared to CON. Furthermore, HZB was significantly higher after the UNI protocol than after SIN (p<0.01; diff = 3.74(2.62) %) and BIL (p<0.01; diff = 3.47(1.94) %). Individual response analysis reflected positive effects on HZB for SIN, BIL, and UNI compared to CON, while 89 % of players showed better HZB performance after UNI than after BIL. Conclusions: Activation incorporating unilateral strength and plyometric stimuli has a greater positive effect on horizontal jump capacity than activation involving general, soccer-specific, and bilateral exercises.

Resumo Objetivo: Analisar o efeito da ativação por meio de exercícios de força e pliométricos bilaterais ou unilaterais no desempenho do salto horizontal. Metodologia: O estudo envolveu 15 jogadores de futebol masculinos altamente treinados (idade, 24.7 ± 3.1 anos; altura, 181.2 ± 4.7 cm; peso, 79.7 ± 3.4 kg) da mesma equipe competindo na liga nacional. Sua rotina de treinamento regular consistia em 4 sessões e 1 jogo competitivo por semana. Os participantes realizaram 1 protocolo de controle (CON) e 3 protocolos de ativação seguindo um desenho contrabalanceado com base em exercícios específicos de futebol (SIN), exercícios de força e pliométricos bilaterais (BIL) e unilaterais (UNI). Após cada protocolo, os jogadores foram submetidos ao teste de salto horizontal (HZB). Resultados: A ANOVA de medidas repetidas revelou efeitos positivos significativos no HZB para os protocolos SIN (p<0.01; diff = 2.95(2.00) %), BIL (p<0.01; diff = 3.22(2.61) %) e UNI (p<0.01; diff = 6.80(3.40) %) em comparação com CON. Além disso, o HZB foi significativamente maior após o protocolo UNI do que após SIN (p<0.01; diff = 3.74(2.62) %) e BIL (p<0.01; diff = 3.47(1.94) %). A análise de resposta individual refletiu efeitos positivos no HZB para SIN, BIL e UNI em comparação com CON, enquanto 89 % dos jogadores mostraram melhor desempenho de HZB após UNI do que após BIL. Conclusões: A ativação incorporando estímulos de força e pliométricos unilaterais tem um efeito positivo maior na capacidade de salto horizontal do que a ativação envolvendo exercícios gerais, específicos do futebol e bilaterais.

Somatic Maturity and Physical Performance in Male Youth Players from a Professional Soccer Academy / Madurez Somática y Rendimiento Físico en Jugadores Juveniles Masculinos de una Academia de Fútbol Profesional

SUMMARY: The aim was to analyze the relationship between somatic maturation and physical performance in male youth soccer players belonging to a professional Mexican academy. In 121 male soccer aged 11 to 16 years from a professional academy the peak height velocity (PHV), percentage of adult height (PAS), jump capacity, sprint, intermittent speed and muscle mass were estimated. ANOVA was conducted to compare performance variables among maturity somatic categories and percentiles were calculated based on maturity offset using LMS method. Furthermore, a general linear model was employed to determine the explanatory variables for performance. Post-PHV soccer players demonstrated superior physical performance across several tests compared to Pre-PHV (p<0.001) and Circa-PHV (p<0.001) players. The smoothed percentile values of performance tests, based on somatic maturation, indicated progressive performance enhancement as individuals approached PHV (-2 to 2 years from PHV) (p<0.005). PHV was associated with jump capacity (p<0.001) and intermittent speed (p=0.007) while PAS was associated with time in sprint (p=.0004). In conclusion PHV and PAS explained better performance than chronological age, body composition characteristics, injuries, or training factors.

El objetivo fue analizar la relación entre la maduración somática y el rendimiento físico en futbolistas juveniles masculinos pertenecientes a una academia profesional mexicana. Métodos. En 121 futbolistas masculinos de 11 a 16 años de una academia profesional se estimó la velocidad máxima en altura (VPH), porcentaje de altura adulta (PAS), capacidad de salto, sprint, velocidad intermitente y masa muscular. Se realizó ANOVA para comparar variables de desempeño entre categorías somáticas de madurez y se calcularon percentiles en función de la compensación de madurez utilizando el método LMS. Además, se empleó un modelo lineal general para determinar las variables explicativas del desempeño. Los jugadores de fútbol post-PHV demostraron un rendimiento físico superior en varias pruebas en comparación con los jugadores Pre-PHV (p<0,001) y Circa-PHV (p<0,001). Los valores percentiles suavizados de las pruebas de rendimiento, basados en la maduración somática, indicaron una mejora progresiva del rendimiento a medida que los individuos se acercaban al PHV (-2 a 2 años desde el PHV) (p<0,005). PHV se asoció con la capacidad de salto (p<0,001) y velocidad intermitente (p=0,007) mientras que PAS se asoció con el tiempo en sprint (p=0,0004). En conclusión PHV y PEA explicaron un mejor rendimiento que la edad cronológica, las características de composición corporal, las lesiones o los factores de entrenamiento.

O mercado das escolinhas de futebol em belo horizonte / The market for football schools in belo horizonte / El mercado de las escuelas de fútbol en belo horizonte

Resumo Este estudo analisa a quantidade e a distribuição territorial das escolinhas de futebol em Belo Horizonte. O objetivo é examinar quantos estabelecimentos desse tipo existem na cidade, onde estão localizados e quais critérios seus proprietários empregam para essa decisão. Para isso, utilizamos dados quantitativos e qualitativos, baseados, respectivamente, em informações sobre a localização desses estabelecimentos e dados censitários, de um lado, e entrevistas semiestruturadas realizadas com proprietários de escolinhas de futebol da cidade, de outro. Nossa interpretação geral é a de que escolinhas de futebol se distribuem aleatoriamente pela cidade em razão de circunstâncias que impõem uma lógica oportunista na tomada de decisão acerca da abertura de um estabelecimento comercial desse tipo.

Abstract The study analyzes the quantity and geographical distribution of "football schools" in Belo Horizonte. The objective is to examine how many of these establishments exist in the city, where they are located and what criteria their owners use to make this decision. For this, we used quantitative and qualitative data, based on information about the location of these establishments and census data, on the one hand, and semi-structured interviews with owners of soccer schools in the city, on the other. Our general interpretation is that football schools are distributed randomly throughout the city due to circumstances impose an opportunistic logic on decision-making.

Resumen Este estudio analiza la cantidad y la distribución territorial de las "escuelas de fútbol" en Belo Horizonte. El objetivo es examinar cuántos establecimientos de este tipo existen en la ciudad, dónde están ubicados y qué criterios utilizan sus propietarios para esta decisión. Para ello, se utilizaron datos cuantitativos y cualitativos, basados en información sobre la ubicación de estos establecimientos y datos censales, por un lado, y entrevistas semiestructuradas a propietarios de escuelas de fútbol de la ciudad, por otro. Nuestra interpretación general es que las escuelas de fútbol se distribuyen aleatoriamente por la ciudad debido a circunstancias que imponen una lógica de opotunismo en la toma de decisiones sobre la apertura de un establecimiento comercial de este tipo.

Valores cardiorrespiratorios de árbitros de fútbol profesional de Pichincha

Introducción: La capacidad de resistencia física es uno de los indicadores del rendimiento profesional en el fútbol, no estando exceptos los profesionales del arbitraje, los cuales requieren entrenamientos especializados en función de sus aptitudes físicas; por lo cual, es útil conocer sus desempeños. Objetivo: determinar los parámetros reales de aptitud cardiorrespiratoria al esfuerzo máximo progresivo, de árbitros de fútbol de Pichincha. Métodos: se estudia a 25 árbitros hombres seleccionados intencionalmente, de la asociación de árbitros de fútbol profesional de Pichincha. Luego de un reconocimiento de salud previo, de realizó una prueba de esfuerzo progresivo sobre una banda sinfín, con un lector de consumo de oxígeno. Los árbitros tienen una experiencia media de 11 años, entrenan 3-4 días a la semana, y arbitran partidos oficiales 1-2 veces por semana. Resultados: el valor medio global de consumo máximo de oxígeno (VO2máx.) relativo de los árbitros evaluados en el presente estudio es: (= 52.00 ml·kg-1·min-1, similar al obtenido en otros estudios internacionales sobre la valoración de la capacidad física en árbitros, que describen unos valores relativos de vo2máx de 46-51 ml·kg-1·min-1 para hombres. Conclusiones: las competencias profesionales del arbitraje ecuatoriano son similares en la capacidad de resistencia que sus homólogos extranjeros. Se sugiere una implementación de contenidos del entrenamiento basados en mejorar la aptitud cardiorrespiratoria en el arbitraje, así como su control sistemático.

Introduction: Physical endurance capacity is one of the indicators of professional performance in soccer, not excepting referee professionals, who require specialized training based on their physical capabilities; Therefore, it is useful to know their performances. Objective: Determine the real parameters of cardiorespiratory fitness at maximum progressive effort, of soccer referees from Pichincha. Methods: 25 male referees intentionally selected from the Pichincha professional soccer referee association are studied. After a previous health examination, a progressive stress test was performed on a treadmill, with an oxygen consumption reader. Referees have an average experience of 11 years, train 3-4 days a week, and referee official matches 1-2 times a week. Results: The overall average value of relative maximum oxygen consumption (VO2max) of the referees evaluated in the present study is: (= 52.00 ml·kg-1·min-1, similar to that obtained in other international studies on the capacity physics assessment in referees, who describe relative vo2max values of 46-51 ml·kg-1·min-1 for men. Conclusions: the professional skills of Ecuadorian arbitration are similar in resistance capacity to their foreign counterparts. An implementation of training content based on improving cardiorespiratory fitness in refereeing, as well as its systematic control, is suggested.