Reliability of the Coimbra Reactive Agility Soccer Test (CRAST).

Agility is a fitness-skill-related component that should be a part of the standard physiological testing for soccer players and one of the key performance indicators in soccer. The present study aimed to assess the reliability of the CRAST as a research tool in the study of soccer skills. Twenty-one university soccer players (chronological age: 19.3 ± 1.4 years; body mass: 69.6 ± 8.2 kg; stature: 173.5 ± 6.5 cm; federated training experience: 9.7 ± 3.6 years) volunteered for the testing protocol. The CRAST requires players to complete random courses six times as quickly as possible. In addition, the CRAST requires players to control and dribble the markers (four different colors: green, yellow, blue, and red). The soccer players completed three trials, each separated by one week. The first trial accounted for familiarization; the second and third were considered for analysis. The correlation for overall performance was very strong. The reliability of the CRAST was slightly better for total time than that for the penalty score (0.95 vs. 0.93). The TEM and the associated CV range of 7.04%-7.54% were for the penalty score and the total time, respectively. For both measurements, the ICC values also represent excellent reliability, as both values were over 0.900. The CRAST is a reliable protocol for assessing agility in soccer players.

Knee and hip agonist-antagonist relationship in male under-19 soccer players.

The purpose of this study was to evaluate the strength of the knee flexors and extensors and hip abductor and adductor muscles in young soccer players. Twenty-three male under-19 soccer players participated in this study (age: 17.7 ± 0.2 years; height: 173.0 ± 1.1 cm; body mass: 66.1 ± 1.3 kg). Body composition was measured using a bioelectrical impedance (InBody770), and the dynamometry was performed by an isokinetic dynamometer (Biodex System 3) for knee flexion and extension, and by an isometric dynamometer (Smart Groin Trainer), for hip adduction and abduction. Comparisons were made between dominant members (D) vs. non-dominant members (ND) and adductors vs. abductors (ADD:ABD) using the Wilcoxon test. There were statistically significant differences in the peak torques between the dominant and non-dominant members in the flexion function (Z = -4.198, p < 0.01) and in the extension function (Z = -4.197, p < 0.01) of the knee in concentric muscular action, and the flexion (Z = -4.198, p < 0.01) and in the extension (Z = -4.198, p < 0.01) of the knee in eccentric muscular action. No statistically significant differences were obtained in the conventional ratio (Z = -0.456, p = 0.648) nor the functional ratio (Z = -0.335, p = 0.738) between D and ND members. There were no statistically significant differences between adductors and abductors at the moment of strength for absolute values (N). The reference absolute and normalized to the weight values and the ADD:ABD can be used as a guideline for classifying players in screening and comparison in return tests to sports practice after an injury.

Depressive Symptoms and Burnout in Football Players: A Systematic Review.

The purpose of this article was to systematically review and organise the available literature devoted to the topic of depressive symptoms and burnout in football players. A systematic search was conducted in Web of Science, Scopus, SPORTdiscus, PubMed, and Psychinfo for articles published up to June 2020. The searches yielded 1589 articles, and after the screening process, a total of 18 studies met the eligibility criteria and were included for review. Playing position and conflicts with coach/management seems to have a direct influence on the prevalence of depressive symptoms in current players as do the injuries and life events of former players. During the pre-competition phase, most of the athletes displayed reduced rates, indicating burnout. An exploration of the mental health of football players will help to create models of care and guide professionals so that they may help players achieve better performance while also having better wellbeing. Understanding how to prevent and cope with the emotional wellbeing of football players will be possible to guide players and coaches.

Biological maturation and muscular strength: mediation analysis in prepubescent girls / Maturação biológica e força muscular: análise de mediação em meninas pré-púberes / Maduración biológica y fuerza muscular: análisis de mediación en niñas prepúberes

ABSTRACT Introduction: Biological maturation has been related to the level of physical activity and motor competence of children. Objectives: This study aimed to: 1) analyze the association between biological maturation and performance in muscular strength tests and 2) examine whether the relationship between maturation and performance in physical tests is mediated by anthropometric variables. Method: The sample was composed of 71 eight-year-old Brazilian girls. Anthropometry considered stature, body mass, waist circumference, estimated fat mass and fat-free mass. Biological maturation was assessed based on the percentage of predicted adult stature. The physical tests consisted of 2-kg medicine ball throw, handgrip strength, sit-ups and standing long jump. Pearson's correlation test was conducted between the study variables and the last stage consisted of a causal mediation analysis. Results: Biological maturation was significantly associated with the 2-kg medicine ball throw (r=0.52) and handgrip strength (r=0.42) tests. In the 2-kg medicine ball throw, the relationship with maturation was mediated by body mass (total mediation, Sobel's Test = 2.214, p<0.05) and by estimated lean mass (total mediation; Sobel's Test = 3.146, p<0.001). In the handgrip strength test, body mass was the only mediating variable (total mediation; Sobel's Test = 2.251, p<0.05). Conclusions: Advanced maturational status appears to contribute to the performance of prepubescent girls in muscular strength tests in which there is no translocation of total or partial body mass. It is recommended that studies be conducted in other age groups. Level of Evidence III; Study of nonconsecutive patients; without consistently applied reference ''gold'' standard.

RESUMO Introdução: A maturação biológica tem sido relacionada com o nível de atividades físicas e a competência motora das crianças. Objetivos: O presente estudo teve como objetivos: 1) analisar a associação da maturação biológica com o desempenho em testes de força muscular e 2) examinar se a relação entre o estado maturacional e o desempenho nos testes físicos é mediada por variáveis antropométricas. Método: A amostra foi composta por 71 meninas brasileiras com oito anos de idade. A antropometria considerou estatura, massa corporal, perímetro da cintura, estimativas de massa gorda e massa magra. A maturação biológica foi avaliada através do percentual da estatura matura predita. Os testes físicos aplicados consistiam em lançamento-2kg, preensão manual, abdominais e salto horizontal. A correlação de Pearson foi realizada entre as variáveis do estudo e, por último, a análise de mediação causal. Resultados: A maturação biológica associou-se significativamente à prova de lançamento-2kg (r=0,52) e preensão manual (r=0,42). No teste de lançamento-2kg, a relação com o estado maturacional foi mediada pela massa corporal (mediação total; Teste de Sobel=2,214, p<0,05) e pela estimativa de massa magra (mediação total; Teste de Sobel=3,146, p<0,001). Já no teste de preensão manual, a massa corporal foi a única variável mediadora (mediação total; Teste de Sobel=2,251, p<0,05). Conclusões: O estado maturacional avançado parece contribuir com o desempenho de meninas pré-púberes em testes de força muscular em que não há translocação da massa corporal total ou parcial. Recomenda-se que sejam realizados estudos em outras faixas etárias. Nível de Evidência III; Estudo de pacientes não consecutivos; sem padrão de referência "ouro" aplicado uniformemente.

RESUMEN Introducción: La maduración biológica ha sido relacionada con el nivel de actividades físicas y la competencia motora de los niños. Objetivos: El presente estudio tuvo como objetivos: 1) analizar la asociación de la maduración biológica con el desempeño en tests de fuerza muscular y 2) examinar si la relación entre el estado de maduración y el desempeño en los tests físicos es mediada por variables antropométricas. Métodos: La muestra fue compuesta por 71 niñas brasileñas con ocho años de edad. La antropometría consideró estatura, masa corporal, perímetro de cintura, estimaciones de masa grasa y masa magra. La maduración biológica fue evaluada a través del porcentual de la estatura madura predicha. Los tests físicos aplicados consistían en lanzamiento-2kg, prensión manual, abdominales y salto horizontal. La correlación de Pearson fue realizada entre las variables del estudio y, por último, el análisis de mediación causal. Resultados: La maduración biológica se asoció significativamente al test de lanzamiento-2kg (r = 0,52) y prensión manual (r = 0,42). En el test de lanzamiento-2kg, la relación con el estado de maduración fue mediada por la masa corporal (mediación total, Test de Sobel = 2,214, p<0,05) y por la estimativa de masa magra (mediación total, Test de Sobel = 3,146, P<0,001). Ya en el test de prensión manual, la masa corporal fue la única variable mediadora (mediación total, Test de Sobel = 2,251, p<0,05). Conclusiones: El estado de maduración avanzado parece contribuir con el desempeño de niñas prepúberes en tests de fuerza muscular en los que no hay translocación de la masa corporal total o parcial. Se recomienda que sean realizados estudios en otros grupos de edad. Nivel de Evidencia III; Estudio de pacientes no consecutivos; sin estándar de referencia "oro" aplicado uniformemente.