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Antecedentes: La Asimetría Bilateral (AB) y el Déficit Bilateral (DBL) y su potencial relación negativa con el rendimiento físico es actualmente estudiada, aunque la relación con la velocidad del cambio de dirección (CODS) y el sprint lineal (5-M) en atletas de karate se desconoce. Objetivo: Examinar las correlaciones entre la AB y el DBL con el CODS y 5-M, así como entre el salto horizontal con el CODS y 5-M. Métodos: Diez atletas hombres de categoría cadetes participaron voluntariamente de este estudio. Entre las habilidades físicas evaluadas se incluyeron: salto horizontal bilateral (SBJ), salto horizontal unilateral derecho (RSBJ), salto horizontal unilateral izquierdo (LSBJ), CODS y 5-M. Posteriormente, la AB y el DBL fueron calculados. Resultados: Se reportó una baja AB (5.17 ± 3.61%) y presencia de DBL (-36.9 ± 6.2 %). Correlaciones moderadas entre la AB con CODS (r = -.38; R2 = .15%; p = .30) y 5-M (r = -.47; R2 = .22%; p = .19) y entre DBL con 5-M (r = .51; R2 = .26%; p = .16) y bajas con CODS (r = .20; R2 = .04%; p = .60). Correlaciones significativas (p < .05) entre CODS con RSBJ (r = -.92; R2 = .85%; p = .00), SBJ (r = -.87; R2 = .75%; p = .00) y LSBJ (r = -.82; R2 = .67%; p = .00). Conclusiones: La AB y el DBL se relacionarían negativamente con el CODS y 5-M. Aunque, el CODS se relaciona con la fuerza explosiva horizontal bilateral y unilateral. Background: Bilateral asymmetry (AB) and Bilateral Deficit (DBL) and their potential negative relationship with physical performance is currently studied, although the relationship with change of direction speed (CODS) and linear sprint (5-M) in karate athletes is unknown. Aim: To examine correlations between AB and DBL with CODS and 5-M, as well as between horizontal jump with CODS and 5-M. Methods: Ten male cadet athletes voluntarily participated in this study. The physical abilities assessed included: bilateral horizontal jump (SBJ), right unilateral horizontal jump (RSBJ), left unilateral horizontal jump (LSBJ), CODS and 5-M. Subsequently, AB and DBL were calculated. Results: Low AB (5.17 ± 3.61%) and presence of DBL (-36.9 ± 6.2 %) were reported. Moderate correlations between AB with CODS (r = -.38; R2 = .15%; p = .30) and 5-M (r = -.47; R2 = .22%; p = .19) and between DBL with 5-M (r = .51; R2 = .26%; p = .16) and low with CODS (r = .20; R2 = .04%; p = .60). Significant correlations (p < .05) between CODS with RSBJ (r = -.92; R2 = .85%; p = .00), SBJ (r = -.87; R2 = .75%; p = .00) and LSBJ (r = -.82; R2 = .67%; p = .00). Conclusions: AB and DBL would be negatively related to CODS and 5-M. However, CODS is related to bilateral and unilateral horizontal explosive strength.

Background. The kumite section or karate kumite is characterized by high-intensity activity, including explosive actions. Problem and Aim. Determine the magnitude of the effect on the physical performance of karate athletes of the application of two protocols: HIIT-SPRINT and HIIT-JUMP performed at the beginning of a training session (20 minutes) for six weeks. Methods. Both the HIIT-JUMP and HIIT-SPRINT group underwent a six-week HIIT program, while the CONTROL group continued with their regular karate training. The athletes performed the following tests: squat jump, countermovement jump, 5m and 10m line speed, change of direction, aerobic capacity and body composition. Results. Fat mass (kg) decreased in the HIIT-JUMP group (ES = -0.63), while the HIIT-SPRINT group reduced the percent of body fat (ES = -0.85). Jump height for the squat and countermovement jumps increased in the HIIT-SPRINT group (ES = 0.82 and 0.94, respectively) and 10-m test (ES = -1.14) and change in direction (ES = -0.60) times were reduced. The HIIT-JUMP group decreased their times for the 5-m and 10-m tests (ES = -0.97 and -1.07, respectively). The HIIT SPRINT group improved in the 5-m test compared to the CONTROL group (ES = 0.62). Conclusions. These results suggest that both HIIT modalities offer specific adaptations, and could be considered as complementary to the training of athletes.

Wrestling events included in the Olympic Games have different weigth classes. Most wrestlers reduce thir body weigth a few days before competition so they can enter the right weight category. Often they use irrational nutritional strategies to make the weight, sometimes even drastically reducing their water intake. The purpose of this study was the knowledge about influence of pre-competition level of hydration on mucle propperties in elite wrestlers.

Background Study Aim: Brazilian Jiu Jitsu (BJJ) is gaining thousands of practitioners in all countries; however, there is a lack of scientific research related to this sport. We wanted to establish the parameters approached by BJJ athletes to sporting excellence, which is the reason why we divided the subjects into two groups: experts and novices. Additionally, the aim of this study was to measure body composition, and to compare the performance of BJJ athletes focusing on two variables: isometric hand grip and explosive strength legs. Material Methods: Fifty six BJJ players, who were contestants in the European Open Jiu-Jitsu Championship 2013 in Lisbon (Portugal), took part in this study. Novice group (n=24; age: 29.9±5.8 yrs), Expert group (n=32; age: 30.5±4.7 yrs). Body mass was measured with Bioimpedance, and handgrip strength was measured with a dynamometer. Explosive strength leg was measured from a force platform with the Countermovement Jump (CMJ) test. Differences between experts and novices were established with the t Student?s test or Mann-Whitney U test for the parametric and non-parametric variables respectively. Results: Experts obtained significant differences over novices on isometric hand grip strength in both hands; as for the variables of CMJ, significant differences were found in Height of jump, peak power, velocity at peak power and average power. Conclusions: BJJ athletes with higher experience, training, and level (expert group) have more adaptations and improvements than the novice group. This can be seen by their higher records in isometric handgrip and the higher explosive strength in their legs. Keywords: Brazilian jiu jitsu, Countermovement jump, isometric handgrip, body composition, sport performance, force platform.

JOURNAL OF STRENGTH AND CONDITIONING RESEARCH , núm. 27 issue 11, pág. 2946-2951, 2013, Suarez-Arrones, L, Portillo, LJ, García, JM, Calvo-Lluch, A, Roberts, SP, and Mendez-Villanueva, A. Running demands and heart rate response in rugby union referees. J Strength Cond Res 27(11): 2946?2951, 2013?The aim of this study was to examine the match physical demands and exercise intensity associated with men rugby union refereeing using global positioning system technology. Ten male rugby union referees (age, 37.1 ± 5.9 years; body mass, 83.7 ± 4.8 kg; height, 175.5 ± 6.2 cm) were analyzed 2?4 times during a total of 30 national level matches. The average total distance covered by the referees throughout the game was 6,322.2 ± 564.9 m. As a percentage of total distance, 37.3% (2,356.9 ± 291.3 m) was spent walking, 24.1% (1,524.4 ± 229.4 m) jogging, 10.4% (656.2 ± 130.7 m) running at low intensity, 17.6% (1,110.3 ± 212.2 m) at medium intensity, 5.5% (347.1 ± 27.1 m) at high intensity, and 5.2% (328.1 ± 230.3 m) at sprint. A significant decrease (p < 0.05) in running performance was observed between the first and the second halves in the last 3 speed zones. When the total distance traveled during consecutive 10-minute periods was compared, there was a significantly greater distance covered in the first 10 minutes of the game (876.3 ± 163 m) compared with 50?60 minutes (679.8 ± 117.6 m), 60?70 minutes (713.03 ± 122.3 m), and 70?80 minutes (694.2 ± 125.7 m; all p < 0.05). The average heart rate responses were similar (p > 0.05) in the first (157 ± 7 b·min−1; 85% HRmax) and second half (155 ± 7 b·min−1; 84% HRmax). This study provides evidence of reduced high-intensity running toward the end of the game. These findings offer important information to design better training strategies adapted to the requirements and demands of rugby union refereeing.

El objetivo del presente estudio fue comprobar, que cambios se producen sobre la velocidad con cambio de dirección, al aplicar en jóvenes futbolistas un entrenamiento específico de potencia, compuesto por la asociación de trabajos con cargas individualizadas y saltos pliometricos; para ello se reclutaron a cuarenta jugadores juveniles españoles con una media de edad de (17.29 ± 0.791) pertenecientes a las categorías preferente y autonómica; se formaron dos grupos, un grupo experimental GEX (P+F) asociaba un entrenamiento especial destinado a elevar los niveles de potencia junto al realizado habitualmente en su club. El programa se diseño con cargas especificas de carácter individual (después de realizar una evaluación para identificarlas mediante el mejor valor de potencia media con el dispositivo Isocontrol 5.2); los ejercicios realizados fueron cargada colgado, media sentadilla, salto cargado y saltos continuos de 40 -50cm; se formó un segundo grupo denominado GC (F) que solo realizó su trabajo de futbol habitual en campo. Las variables evaluadas fueron: la velocidad con cambio de dirección en 30m (VCD30); se estableció un nível de significación de p

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Física Aplicada. Fecha de lectura: 23-10-2012

En el presente trabajo se analiza las manifestaciones de la fuerza en judokas y no judokas

El artículo analiza las diferencias atencionales y condicionales entre judokas de categoría internacional y judokas en puerta de serlo