Principios y métodos para el entrenamiento de la fuerza muscular

Comprender la fuerza como fenómeno fisiológico y mecánico es un elemento fundamental para aumentar el conocimiento de las técnicas y métodos de entrenamiento muscular basados en distintas formas de aplicar cargas de trabajo. En este sentido la fuerza muscular debe ser considerada como una cualidad física básica físico, de generar desplazamiento de los segmentos corporales o de vencer una resistencia se considera parte fundamental del Fitness físico, ya que se ha demostrado dentro de la evidencia científica sus beneficios para mantener y mejorar la condición de salud de las personas. El texto está divido en dos partes: la primera, presenta aspectos fisiológicos y mecánicos básicos del sistema músculo esquelético y la segunda, se centra en los distintos métodos de entrenamiento muscular; basados en esta propuesta conceptual lo estudiantes de pregrado podrán comprender de una manera sencilla los principios y métodos de entrenamiento de la fuerza.

Valoración del rendimiento físico de jóvenes futbolistas en función de la edad cronológica.

Resumen tomado de la publicación

Prueba de campo específica de valoración de la resistencia en tenis : respuesta cardiaca y efectividad técnica en jugadores de competición.

Resumen tomado de la publicación

La estética del toreo.

Si la lidia es arte no se entiende por qué los estetas clásicos , al proceder así, han pasado por alto elementos esenciales de lo dado como son la lidia y sus bellezas y, esta mutilación de lo bello les llevó a concepciones incompletas sobre el arte y su expresión esencial.. De ahí, que todas las grandes teorías estéticas coincidan en un punto: en considerar el arte como una actividad que, a nivel práctico, se caracteriza por ser inútil. La estética tradicional, tanto la metafísica como la científica y positivista, reposa en la concepción de la utilidad de la obra artística y de su falta de verdadera realidad. A tal punto, que reduce la belleza a puro simulacro, a imitación, a finalidad sin fin, a simple apariencia, a pura forma. Pero existe un arte, la lidia, en donde la belleza es realidad auténtica y cuya creación reporta utilidad positiva a quien la crea. De ahí que juzguemos incompleta la estética tradicional e indispensable ampliarla con retoques sustanciales para que comprenda todas las manifestaciones de lo bello. Más nada se logra afirmando que la lidia es arte bello; precisa demostrar su belleza, porque sólo la demostración de su elevado valor estético ha de convencer a los cultos de la necesidad de ampliar las teorías sobre la esencia del arte y la belleza en nombre de las corridas de toros.

Educación y sociedad en la Rioja Republicana 1931-1936.

Contribuir desde el conocimiento de la dinámica del pasado a la planificación y reforma socioeducativa en el presente de una Comunidad Autónoma. Se trata de considerar el estudio de la escolarización como ámbito de investigación interdisciplinar, interrelacionado con el específico interés educativo, las aportaciones de las distintas modalidades historiográficas sobre el tema para poder explicar cómo se configuran y transforman las estructuras y mentalidades colectivas, objetivo fundamental de un enfoque totalizador de la historia. En concreto, partiendo de la Rioja como espacio geopolítico y sociocultural, mostrar si se produce, un paralelo a lo que acontece en el contexto republicano nacional, un cambio significativo de mentalidad y tendencia social que se concreta en la institucionalización de un ciclo de especial significación pedagógica. Describir, comprender y explicar, por tanto, el papel que la provincia de la Rioja desarrolla en la estructura Pedagógica-Educativa, cultural y social de la segunda república, sus proyectos y realizaciones educativas y culturales, su contribución al modelo republicano y a una sociedad que se debate ante importantes problemas sociales, políticos y culturales. Archivos públicos y privados de la Rioja. El proyecto Pedagógico Republicano, centrado en un nuevo sistema inspirado en el ideal de la escuela unificada, laica y activa, no puede considerarse alcanzado de forma plena, a tenor de las planificaciones que se proyectan en la Rioja. No obstante, la normativa educativa emanada del Ministerio, ámpliamente debatida, contó con una actitud generalizada de apoyo especialmente en instancias organizativas, como la inspección, los consejos provinciales y locales de proyección escolar y los claustros de las instituciones docentes, así como por la mayor parte del movimiento asociativo del magisterio. Se evidencian determinados canales personales e institucionales que manifiestan un alto nivel de concienciación profesional de las personas implicadas en el sistema educativo, así como un conocimiento de la nueva pedagogía, con claras alusiones, sobre todo a través de las páginas del boletín de educación provincial, al movimiento Paidológico, a la corriente higienista y en general a la escuela nueva. A través de la prensa local y de la documentación que producen las propias instituciones educativas y los ayuntamientos Riojanos se observa un claro avance en orden a conseguir una renovación de la escuela. Los ayuntamientos fueron los principales ejecutores de las gestiones encaminadas a la correcta aplicación y eficacia de las medidas reformistas. La política educativa republicana mantuvo una especial sensibilidad hacia la Primera Enseñanza, patentizada en la creación de escuelas públicas, en su decidida opción por mejorar sus condiciones materiales y pedagógicas, en la promoción de una política definida por el apoyo y defensa de la escuela a través de instituciones circumescolares y la reducción de categorías en el escalafón de maestros, sus incrementos salariales y las corridas de escala. En Segunda Enseñanza se vivió con intensidad el cambio de planes de estudio y se produjo un incremento del número de Institutos. El ideal de la escuela laica tuvo dos efectos en la Rioja: por una parte, dio origen a un tenso debate social en el que se aprecia un movimiento confesional muy intenso y, por otra, no se llegó a materializar la sustitución. La reforma del magisterio tuvo una clara repercusión en la Rioja. La campaña de alfabetización, a pesar de las dificultades, produjo una proliferación de actividades de extensión y dinamización cultural.

Estudo comparativo dos níveis de aptidão física dos alunos dos 11 aos 14 anos com e sem prática de atividades físicas extracurriculares ao longo do ano letivo 2010/2011 : estudo caso

O estudo apresentado tem como objetivo avaliar os níveis de Aptidão Física de crianças e jovens dos 11 aos 14 anos da Freguesia de Bobadela, estabelecendo uma comparação entre aqueles que praticam Atividade Física somente através da Disciplina de Educação Física e os que para além desta realizam Atividades Físicas Extracurriculares. A amostra é constituída por 321 alunos de ambos os géneros, da Escola Básica Integrada de Bobadela, distrito de Lisboa, com idades compreendidas entre os 11 e os 14 anos. Tendo em conta os objetivos do estudo, a amostra foi dividida em dois grupos distintos, sendo que 148 alunos praticam Atividade Física Extracurricular, 81 do género masculino e 67 do género feminino, com uma média de 12,43 anos de idade, e 173 alunos que só praticam Atividade Física durante as aulas de Educação Física, 90 do género masculino e 83 do género feminino, com uma média de idades de 12,31 anos. Para a realização do estudo foi aplicada a bateria de testes do Fitnessgram de modo a avaliar a Aptidão Física das Crianças na dimensão motora (Flexibilidade – senta e alcança; Força Média – abdominal; Resistência – Vaivém e um questionário de prática desportiva fora do contexto escolar). A recolha de dados teve lugar entre 22 de Setembro e 26 de Maio de 2011. A apresentação dos resultados foi efetuada através do uso da estatística descritiva: media, desvio padrão, amplitude; e o teste T-Student. Concluímos que: 1 - No início do ano letivo não existem diferenças estatisticamente significativas entre géneros, em todas as capacidades motoras consideradas; 2- Em termos de evolução da NZSAF para a ZSAF, verifica-se uma melhoria das capacidades motoras em todas as faixas etárias de ambos os grupos, à exceção das raparigas não praticantes no teste da Força Média. A Flexibilidade dos Membros Inferiores foi mais acentuada nas raparigas de 11 anos, não praticantes (3.6%) e praticantes (4.5%). 3 – A percentagem mais elevada de evolução ocorre ao nível da Capacidade Aeróbia (nos rapazes (3.7%) e raparigas (3%) de 12 anos). 4 - Comparando o grupo de Praticantes e de Não Praticantes (rapazes e raparigas) com os valores de referência do Fitnessgram verificou-se que em relação à Aptidão Física, os Praticantes apresentaram maiores percentagens dentro do intervalo da Zona Saudável para todos os testes realizados.

Embodied social capital and geographic perspectives: performing the habitus

This paper reopens debates of geographic theorizations and conceptualizations of social capital. I argue that human geographers have tended to underplay the analytic value of social capital, by equating the concept with dominant policy interpretations. It is contended that geographers could more explicitly contribute to pervasive critical social science accounts. With this in mind, an embodied perspective of social capital is constructed. This synthesizes Bourdieu's capitals and performative theorizations of identity, to progress the concept of social capital in four key ways. First, this theorization more fully reconnects embodied differences to broader socioeconomic processes. Second, an exploration of how embodied social differences can emerge directly from the political-economy and/or via broader operations of power is facilitated. Third, a path is charted through the endurance of embodied inequalities and the potential for social transformation. Finally, embodied social capital can advance social science conceptualizations of the spatiality of social capital, by illuminating the importance of broader sociospatial contexts and relations to the embodiment of social capital within individuals.

Comparison of white metal and resin socket terminations for wire ropes

Previously the authors have presented both theoretical and experimental work discussing the operating mechanism of a wire rope held in a tapered socket by means of a cast resin cone. The work reported here extends the investigation to address the question of whether the same socket fabricated with white metal operates in the same manner. To date, previous investigations have compared the operational efficiency of resin and white metal in terms of both strength and/or fatigue endurance. Some other work has analysed the operation of resin sockets or specific cast metal terminations. This paper seeks to draw the results from this work together, and, in addition to a theoretical analysis, presents experimental data obtained from a direct comparison of the operation mechanism for the same sockets filled with resin or white metal. Results show that white metal terminations have a very different distribution of stresses along the length of the socket basket from resin terminations, and a smaller but still significant amount of socket draw. For both types of termination the socket draw develops high frictional gripping forces which can transfer the load from the rope to the socket. The different stress distributions mean that the consequences of termination fabrication defects may not be the same for resin and white metal terminations.

Torsional interactions between mooring line components

Six strand ropes generate torque under tension. This can lead to transfer of twist to other mooring line components, either permanently, or dynamically. The effects of this imposed twist can seriously affect strength and fatigue endurance. In order to predict the torsional interactions between components it is necessary to quantify the tension/torsion behavior of all the different categories of mooring line component, not just the six strand rope. This paper discusses the problems of torsional interaction and presents results of measurements of tension/torsion behavior of six strand rope, stud link chain and a PET fiber rope.

A comparison of two time-domain analysis procedures in the determination of VO2 kinetics by pseudorandom binary sequence exercise testing

The purpose of this study was to apply and compare two time-domain analysis procedures in the determination of oxygen uptake (VO2) kinetics in response to a pseudorandom binary sequence (PRBS) exercise test. PRBS exercise tests have typically been analysed in the frequency domain. However, the complex interpretation of frequency responses may have limited the application of this procedure in both sporting and clinical contexts, where a single time measurement would facilitate subject comparison. The relative potential of both a mean response time (MRT) and a peak cross-correlation time (PCCT) was investigated. This study was divided into two parts: a test-retest reliability study (part A), in which 10 healthy male subjects completed two identical PRBS exercise tests, and a comparison of the VO2 kinetics of 12 elite endurance runners (ER) and 12 elite sprinters (SR; part B). In part A, 95% limits of agreement were calculated for comparison between MRT and PCCT. The results of part A showed no significant difference between test and retest as assessed by MRT [mean (SD) 42.2 (4.2) s and 43.8 (6.9) s] or by PCCT [21.8 (3.7) s and 22.7 (4.5) s]. Measurement error (%) was lower for MRT in comparison with PCCT (16% and 25%, respectively). In part B of the study, the VO2 kinetics of ER were significantly faster than those of SR, as assessed by MRT [33.4 (3.4) s and 39.9 (7.1) s, respectively; P<0.01] and PCCT [20.9 (3.8) s and 24.8 (4.5) s; P < 0.05]. It is possible that either analysis procedure could provide a single test measurement Of VO2 kinetics; however, the greater reliability of the MRT data suggests that this method has more potential for development in the assessment Of VO2 kinetics by PRBS exercise testing.

Equine anthelmintics: survey of the patterns of use, beliefs and attitudes among horse owners in the UK

An online survey was conducted to establish horse owners' beliefs, attitudes and practices relating to the use of anthelmintic drugs. Out of a total of 574 respondents, 89 per cent described themselves as ‘leisure riders’, most of whom took part in a variety of activities including eventing, show jumping, dressage, hunter trials, hunting, driving, endurance and showing. Overall, respondents were generally aware and concerned about the issue of anthelmintic resistance. Less than 60 per cent of all respondents were comfortable with their existing anthelmintic programme, and 25 per cent would like to reduce the use of anthelmintics in their horses. Of all the respondents, 47 per cent used livery, and 49 per cent of those reported that the livery imposed a common anthelmintic programme for horses kept on the premises; 45 per cent of these respondents were not entirely happy with the livery yard's programme. Less than 50 per cent of all respondents included ‘veterinary surgeon’ among their sources of advice on worming.

Muscular weakness in the mdx mouse.

mdx mice are believed to be virtually free from neuromuscular symptoms, despite the presence of a degenerative/regenerative process that involves all skeletal muscles. We analyzed both the spontaneous motility and treadmill motor activity of mdx mice aged 15 days to 6 months. Our results indicate that there is an early period, between the end of the second and up to the fifth week of life, when mdx mice experience extreme weakness. After this critical period, both spontaneous motility and endurance of mdx mice, although lower than those of controls, do not show statistically significant differences up to 6 months of age. We also carried out a detailed histological analysis of proximal and distal muscle groups in mdx mice during this early critical motility period. The occurrence of extensive necrosis followed by regeneration and involving proximal muscles before distal ones was documented in mice as young as 16-17 days of age and reached a peak at day 18. We conclude that dystrophin deficiency induces muscle degeneration and significant weakness in mdx mice, but only in an early period. Later on, during development, mdx mice adapt to the lack of this protein and do not show detectable in vivo functional muscle impairment up to 6 months of age.

Effect of short-term creatine supplementation on markers of skeletal muscle damage after strenuous contractile activity

The protective effect of short-term creatine supplementation (CrS) upon markers of strenuous contractile activity-induced damage in human and rat skeletal muscles was investigated. Eight Ironman triathletes were randomized into the placebo (Pl; n = 4) and creatine-supplemented (CrS; n = 4) groups. Five days prior to the Ironman competition, the CrS group received creatine monohydrate (20 g day(-1)) plus maltodextrin (50 g) divided in two equal doses. The Pl group received maltodextrin (50 g day(-1)) only. The effect of CrS (5 g day(-1)/kg body weight for 5 days) was also evaluated in a protocol of strenuous contractile activity induced by electrical stimulation in rats. Blood samples were collected before and 36 and 60 h after the competition and were used to determine plasma activities of creatine kinase (CK), lactate dehydrogenase (LDH), aldolase (ALD), glutamic oxaloacetic acid transaminase (GOT), glutamic pyruvic acid transaminase (GPT), and C-reactive protein (CRP) level. In rats, plasma activities of CK and LDH, muscle vascular permeability (MVP) using Evans blue dye, muscle force and fatigue were evaluated. Activities of CK, ALD, LDH, GOT, GTP, and levels of CRP were increased in the Pl group after the competition as compared to basal values. CrS decreased plasma activities of CK, LDH, and ALD, and prevented the rise of GOT and GPT plasma activities. In rats, CrS delayed the fatigue, preserved the force, and prevented the rise of LDH and CK plasma activities and MVP in the gastrocnemius muscle. CrS presented a protective effect on muscle injury induced by strenuous contractile activities.

Inflammation and adipose tissue: effects of progressive load training in rats

Introduction: Cytokines (IL-6, IL-10 and TNF-alpha) are increased after exhaustive exercise in the rat retroperitoneal (RPAT) and mesenteric adipose tissue (MEAT) pads. On the other hand, these cytokines show decreased expression in these depots in response to a chronic exercise protocol. However, the effect of exercise with overload combined with a short recovery period on pro-and anti-inflammatory cytokine expression is unknown. In the present study, we investigated the regulation of cytokine production in the adipose tissue of rats after an overtraining-inducing exercise protocol. Methods: Male Wistar rats were divided into four groups: Control (C), Trained (Tr), Overtrained (OT) and recovered overtrained (R). Cytokines (IL-6, TNF-alpha and IL-10) levels and Toll Like Receptor 4 (TLR4), Nuclear Factor kBBp65 (NF-kBp65), Hormone Sensitive Lipase (HSL) and, Perilipin protein expression were assessed in the adipose tissue. Furthermore, we analysed plasma lipid profile, insulin, testosterone, corticosterone and endotoxin levels, and liver triacylglycerol, cytokine content, as well as apolipoprotein B (apoB) and TLR4 expression in the liver. Results: OT and R groups exhibited reduced performance accompanied by lower testosterone and increased corticosterone and endotoxin levels when compared with the control and trained groups. IL-6 and IL-10 protein levels were increased in the adipose tissue of the group allowed to recover, in comparison with all the other studied groups. TLR-4 and NF-kBp65 were increased in this same group when compared with both control and trained groups. The protein expression of HSL was increased and that of Perilipin, decreased in the adipose in R in relation to the control. In addition, we found increased liver and serum TAG, along with reduced apoB protein expression and IL-6 and IL-10 levels in the of R in relation to the control and trained groups. Conclusion: In conclusion, we have shown that increases in pro-inflammatory cytokines in the adipose tissue after an overtraining protocol may be mediated via TLR-4 and NF-kBp65 signalling, leading to an inflammatory state in this tissue.

Effects of Low-Level Laser Therapy (LLLT) in the Development of Exercise-Induced Skeletal Muscle Fatigue and Changes in Biochemical Markers Related to Postexercise Recovery

STUDY DESIGN: Randomized crossover double-blinded placebo-controlled trial. OBJECTIVE: To investigate if low-level laser therapy (LLLT) can affect biceps muscle performance, fatigue development, and biochemical markers of postexercise recovery. BACKGROUND: Cell and animal studies have suggested that LLLT can reduce oxidative stress and inflammatory responses in muscle tissue. But it remains uncertain whether these findings can translate into humans in sport and exercise situations. METHODS: Nine healthy male volleyball players participated in the study. They received either active LLLT (cluster probe with 5 laser diodes; A = 810 nm; 200 mW power output; 30 seconds of irradiation, applied in 2 locations over the biceps of the nondominant arm; 60 J of total energy) or placebo LLLT using an identical cluster probe. The intervention or placebo were applied 3 minutes before the performance of exercise. All subjects performed voluntary elbow flexion repetitions with a workload of 75% of their maximal voluntary contraction force until exhaustion. RESULTS: Active LLLT increased the number of repetitions by 14.5% (mean +/- SD, 39.6 +/- 4.3 versus 34.6 +/- 5.6; P = .037) and the elapsed time before exhaustion by 8.0% (P = .034), when compared to the placebo treatment. The biochemical markers also indicated that recovery may be positively affected by LLLT, as indicated by postexercise blood lactate levels (P<.01), creatine kinase activity (P = .017), and C-reactive protein levels (P = .047), showing a faster recovery with LLLT application prior to the exercise. CONCLUSION: We conclude that pre-exercise irradiation of the biceps with an LLLT dose of 6 J per application location, applied in 2 locations, increased endurance for repeated elbow flexion against resistance and decreased postexercise levels of blood lactate, creatine kinase, and C-reactive protein. LEVEL OF EVIDENCE: Performance enhancement, level 1b. J Orthop Sports Phys Ther 2010;40(8):524-532. doi:10.2519/jospt.2010.3294