Abstract Introduction: The development of strength has shown to be beneficial to sports performance and health. However, during strength training, they also produce alterations in muscle fatigue indicators, leading to a decrease in the ability to generate strength. Despite this, there is still not enough knowledge about the levels of muscle fatigue generated by different methods of strength training and how this information can be integrated into sports planning. Review and analyze the studies existing between January 2009 and January 2019 that have used indicators of muscle fatigue established in the search terms during and after strength training as measurement variables. Evidence acquisition: The study corresponds to a systematic review of previously published studies, following the PRISMA model. Articles published between 2009 and 2019 that measured muscle fatigue indicators during and after strength training were evaluated. The electronic search was conducted through Web of Science, Scopus, Sport Discus, PubMed, and Medline. We included all articles that used a strength protocol and also measured indicators of muscle fatigue and its possible effect on physical performance. Evidence synthesis: A total of 39 articles were found, which were stratified according to the protocol used: (i) plyometric training, (ii) Bodypump® training, (iii) occlusion training, (iv) variable resistance training, (v) conventional strength training, (vi) eccentric strength training, (vii) rest times in strength training and (viii) concurrent training. Conclusion: At the end of the systematic review, it was shown that the different training methodologies for strength development generate increases in muscle fatigue indicators, and the increase generated in the different muscle fatigue indicators depends both on the methodology used and on the type of population, sex, level of training and type of sport. The most-reported indicators are [La], HR and RPE, DOM, MR variation, and ammonium.

Resumo O aumento nos níveis de ansiedade e estresse tem sido relacionado na maioria das vezes a efeitos negativos no desempenho de atletas, de modo que o uso de habilidades psicológicas como a autodiálogo tem sido utilizado para gerenciar a ansiedade e o estresse para obter melhor desempenho esportivo. Este artigo apresenta uma revisão sistemática focada em intervenções que utilizaram o autodiálogo como método de treinamento mental para controle 2 níveis de ansiedade e estresse em tenistas. Foram encontrados apenas três estudos que investigaram o método de autodiálogo em variáveis psicológicas e apenas um estudo que avaliou o efeito sobre a ansiedade. Por essa razão, sugere-se mais pesquisas que abordem as variáveis mencionadas.

Abstract The increase in levels of anxiety and stress have been related most of the time to negative effects on the performance of athletes, so the use of psychological skills such as self-talk has been used to manage anxiety and stress to obtain better sports performance. This article presents a systematic review focused on interventions that used self-talk as a method of mental training to control levels of anxiety and stress in tennis players. We found only 3 studies that investigated the method of self-talk in psychological variables and only one study that evaluate the effect on anxiety. For that reason, more research is suggested to addresses these variables.

Resumen El incremento en los niveles de ansiedad y estrés se han relacionado la mayoría de las veces con efectos negativos para el desempeño de atletas, por lo que la utilización de habilidades psicológicas como el autodiálogo se han usado para manejar la ansiedad y el estrés para obtener un mejor rendimiento deportivo. Este artículo presenta una revisión sistemática centrada en intervenciones que utilizaron el autodiálogo como método de entrenamiento mental para controlar niveles de ansiedad y estrés en jugadores de tenis. Se encontraron solamente 3 estudios que investigaron el método de autodiálogo en variables psicológicas y apenas un estudio que evaluó el efecto sobre la ansiedad. Por esta razón, se sugieren más investigaciones que aborden las variables mencionadas.

Abstract Introduction: A plyometric training based on HIIT that would improve the strength parameters in lower limbs of teenager soccer players has never been completely studied before. Objective: To analyze the effect of a HIIT based plyometric exercise program on muscle strength in Under-17 male soccer players. Materials and methods: Twenty-four Under-17 male soccer players were divided into two groups (Experimental Group [GE] n=12 and Control Group n=12.) The variables used were: The jump (h) height and the Peak power (Pp) through the Sargent Jump Test. The protocol used was a HIIT based plyometric exercise program. The Student’s T Test and the Effect Size were used for statistical analysis and the results were calculated with a Cohen’s D. Results: Post intervention, only the GE (p < 0.0001; Effect Size = 0.763). showed a significant increase in the h of the Sargent Jump Test. In terms of the Pp, only the GE presented a significant increase post intervention (p < 0.0001; Effect Size = 0.413). Conclusions: The results revealed that a HIIT based plyometric exercise program is an effective tool to improve the height and the Pp in h of Under-17 male soccer players.

Resumen Introducción: Un entrenamiento pliométrico basado en HIIT que mejore la potencia muscular en futbolistas adolescentes, aún no ha sido del todo estudiado. Objetivo: Analizar el efecto de un entrenamiento pliométrico basado en HIIT sobre la potencia muscular en futbolistas Sub-17. Materiales y métodos: Veinticuatro futbolistas divididos en dos grupos fueron parte del estudio (Grupo Experimental [GE] n = 12 y Grupo Control n = 12). Las variables fueron: altura (h) de salto y Pico de potencia (Pp) a través del Test de Sargent. El protocolo utilizado fue un entrenamiento pliométrico basado en HIIT. Para el análisis estadístico se utilizó la prueba t de Student y el tamaño del efecto fue calculado con la prueba d de Cohen. Resultados: La h en el Test de Sargent presentó un aumento significativo post intervención sólo para el GE (p < 0.0001; Tamaño del Efecto = 0.763). En relación a los Pp, sólo el GE presentó un aumento significativo post intervención (p < 0.0001; Tamaño del Efecto = 0.413). Conclusiones: Los resultados dejaron en evidencia que el entrenamiento pliométrico basado en HIIT es una herramienta efectiva para incrementar la h de salto y Pp en futbolistas adolescentes Sub-17.