Influence of lower-limb muscle power-related variables on the ippon-seoi-nage of elite judokas

This study investigated the influence of the lower-limb extension mechanical variables (strength variables) on the ippon-seoi-nage kinematic variables (technical variables) in elite judokas. Additionally, we studied the effect of performing ippon-seoi-nage with lower-limb flexion-extension action vs. without it, on the technical and strength variables, as well as on their relationship. Twenty-four male elite judokas were classified in two groups depending on the type of ippon-seoi-nage performed, i.e., with lower-limb flexion-extension action or without it. Mechanical outputs from an incremental loaded countermovement jump test were assessed, as well as kinematic variables transferred to the uke (person who is thrown) during an ippon-seoi-nage technique test. The strength parameters did not positively correlate with the technical ones, showing no transference between the variables studied. Furthermore, the judokas that performed the ippon-seoi-nage with lower-limb flexion-extension action presented lower times in the execution of the technique than the group that did not perform this action. Therefore, the transference from strength parameters to the performance of ippon-seoi-nage is not yet explained, even when considering different technical styles.This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness under Grant DEP2015-64350-P MINECO/FEDER and FPI pre-doctoral grant under Grant BES-2016-078035 awarded to one of the authors

Hormonal and Inflammatory Responses to Hypertrophy-Oriented Resistance Training at Acute Moderate Altitude

This research was funded by the Spanish Ministry of Science, Innovation and Universities, grant number PGC2018-097388-B-I00, by the Andalusian FEDER Operational Program, grant number A-SEJ-246-UGR18 and FPU pre-doctoral, grant number FPU18/00686 awarded to one of the authors.The authors thank the High Performance Center of Sierra Nevada, Spain and all the participants who volunteered for this investigation. The authors also thank Dymatize Europe for supplying the meal replacement supplements used in this study.This study investigated the effect of a traditional hypertrophy-oriented resistance training (R-T) session at acute terrestrial hypoxia on inflammatory, hormonal, and the expression of miR-378 responses associated with muscular gains. In a counterbalanced fashion, 13 resistance trained males completed a hypertrophic R-T session at both moderate-altitude (H; 2320 m asl) and under normoxic conditions (N; <700 m asl). Venous blood samples were taken before and throughout the 30 min post-exercise period for determination of cytokines (IL6, IL10, TNF alpha), hormones (growth hormone [GH], cortisol [C], testosterone), and miR-378. Both exercise conditions stimulated GH and C release, while miR-378, testosterone, and inflammatory responses remained near basal conditions. At H, the R-T session produced a moderate to large but nonsignificant increase in the absolute peak values of the studied cytokines. miR-378 revealed a moderate association with GH (r = 0.65; p = 0.026 and r = -0.59; p = 0.051 in N and H, respectively) and C (r = 0.61; p = 0.035 and r = 0.75; p = 0.005 in N and H, respectively). The results suggest that a R-T session at H does not differentially affect the hormonal, inflammatory, and miR-378 responses compared to N. However, the standardized mean difference detected values in the cytokines suggest an intensification of the inflammatory response in H that should be further investigated.Spanish Ministry of Science, Innovation and Universities PGC2018-097388-B-I00Andalusian FEDER Operational Program A-SEJ-246-UGR18FPU pre-doctoral FPU18/0068

Effect of training at moderate altitude on the technical and muscular performance in elite judokas Application to the technical learning process

The influence of resistance training under hypoxic conditions (RTH) on the development of strength and muscle mass is a research area of current interest. However, there is no consensus on the beneficial influence of hypoxic training conditions on muscle functional and physiological adaptations, especially when real altitude is used. Specifically, the influence of hypobaric hypoxia on power-oriented resistance training (RT) remains unexplored, as well as its effects on technical and physical adaptations in judokas, or the evolution of those effects on athletes after returning to sea level. Moreover, transference from physical improvements to technical performance in judo has not been examined before. Therefore, the main goal of this thesis was to analyze the effect of a power-oriented RT program at moderate altitude on the leg extension capacity, on the ippon-seoi-nage performance and on the relationship between them in elite judokas. A longitudinal design, with intra- and inter-group measurements, was used to compare the effect of a lower-limb power-oriented RT at moderate altitude (hypobaric hypoxia) or sea level (normoxia) on leg extension capacity, on kinematic variables of the ippon-seoi-nage and on the relationship between them in elite judokas. Twenty-four male judokas from the Spanish Judo Training Center of Valencia, all international medalists, participated in this study. Participants were randomly assigned to a group that performed a 3-week training program at hypobaric hypoxia (at the High Performance Center of Sierra Nevada, 2320 m; HT; n = 13) or normoxia (at the Spanish Judo Training Center of Valencia, 15 m; NT; n = 11). Testing sessions were conducted under normoxic conditions at 4 time-points: pre-test (N1), post-test (N2), one and two weeks after training (N3 and N4, respectively). The HT undertook an additional testing session in acute hypoxia (H1) conditions immediately after the ascent to altitude. An additional intra-group design was used to assess the effect of an acute exposure to moderate altitude on the same variables (N1 vs. H1). Testing sessions comprised 1) a body composition assessment that included anthropometrical and bioelectrical impedance analysis variables, 2) an incremental countermovement jump (CMJ) test to determine leg extension load-velocity and forcevelocity profile and 3) an ippon-seoi-nage test to assess the kinematic variables transferred to the uke during this technique. The 3-week power-oriented training program applied included a physical conditioning session in the morning and a judo session in the afternoon, from Monday to Saturday morning. Physical conditioning training included 3 power-oriented RT sessions per week alternated with 3 metabolic sessions. The content of the physical conditioning sessions was designed and supervised by the research team, while judo sessions were designed by the coaches. Each power-oriented RT session included 1) a velocity-based training (4-6 sets of 6 CMJ with the load associated to a mean propulsive velocity (MPV) of 1.2 m·s-1 calculated in the pre-test, on Wednesdays and Fridays, and with the load associated to a MPV of 1.2 m·s-1 adjusted each Monday at the corresponding condition, with 4 minutes of rest) and a 2) contrast training (3-4 sets of 2 repetitions of a moderate to high-load RT exercise followed by 6 repetitions of ipponseoi- nage throws at maximal intended velocity, with 4 minutes of rest). Acute hypoxia caused small increases in leg extension peak velocity (PV) (3.67%; p < 0.05), while no changes in the kinematic variables of the ippon-seoi-nage were observed. Ippon-seoi-nage kinematic variables show a great individual reliability, which contrasts with the low reliability observed when the whole group is considered. The coefficient of variation ratio (H1/N1) of the time needed to reach the leg extension during the technique performance increased. There was a RT effect on the leg extension PV, jump height (JH) and maximal theoretical force (F0, determined using mean values of force and velocity) (p < 0.05), both at moderate altitude and sea level. PV and JH also displayed a time × altitude interaction effect (p < 0.05). A detailed analysis of this interaction showed a higher magnitude of change in PV, JH and F0 in HT than NT, which was achieved one week earlier (HT-N2 vs. NT-N3: 8.78 vs. 5.58% for PV; 8.20 vs. 1.41% for JH; 11.76 vs. 7.61% for F0; p < 0.05). The force-velocity profile of both groups displayed important imbalances due to lower current values in F0 (p < 0.001, η2 p = 0.889) and higher values in maximal theoretical velocity (V0) (p < 0.001, η2 p = 0.844) compared with the optimal expected. Although no significant differences were found between the imbalances of both groups at all time-points, complementary results showed a trend for a moderate reduction of this imbalance from N1 to N2 in HT and from N1 to N3 in NT (- 11.96% and -7.88%, respectively, p < 0.10). An altitude main effect was registered for ippon-seoi-nage variables (p < 0.05), with the HT displaying a 22.95% smaller increase in the acceleration of the leg extension phase than NT (p = 0.03) and an increase in the time to reach the horizontal position while a decrease was observed in NT (difference between HT and NT = 18.68%, p = 0.003). The training period did not induce any changes in anthropometrical and bioelectrical impedance analysis variables, nor did the altitude condition affect these variables (p > 0.05). There was no association between the leg extension mechanical variables and the acceleration or angular velocity transferred to the uke, nor did acute exposure to hypoxia or training at different altitude conditions affect this association. These results show an increase in the leg extension capacity from the first exposure to altitude, which is in accordance with the literature. Later, after a poweroriented RT period, moderate altitude seems to increase and accelerate peak performance. A detailed analysis of the time × altitude interaction effect showed that HT achieved the highest leg extension PV and JH compared to NT and achieved it earlier (in N2 vs. N3) (p < 0.05). The technical performance variables did not show changes due to acute exposure to moderate altitude, while an impairment was observed after altitude training, due to a rise in the times and accelerations transferred to the uke. Changes in physical condition, together with changes in the space-time pattern of the technique induced by altitude exposure, confirm the need to adjust and stabilize the technique during and after an altitude training period in sports with complex technical skills. Finally, differences between individual and within-groups coefficient of variation confirm that each judoka adapts the technique to his characteristics, always performing it in the same way. Nevertheless, the absence of association between the leg extension capacity and ipponseoi- nage performance could indicate that, at least in the sample studied, the legs implication during the ippon-seoi-nage was not sufficient according to the technical gold standard. Future studies are needed to further analyze the technique, the nature of the strength adaptations and its transference to the technical performance as consequence of hypoxic exposure and training.La influencia del entrenamiento de fuerza en condiciones de hipoxia (RTH) sobre el desarrollo de la fuerza y masa muscular se está convirtiendo en un área de investigación de gran interés. Sin embargo, no existe consenso sobre el efecto positivo del entrenamiento en hipoxia sobre las adaptaciones funcionales y fisiológicas, especialmente en el caso de la altitud real. Son escasos los estudios sobre la influencia de la hipoxia hipobárica en el entrenamiento orientado a la potencia muscular, así como sobre sus efectos en las adaptaciones técnicas y físicas de los judokas y la evolución de estos efectos después del regreso a nivel del mar. Además, la transferencia de las mejoras condicionales al rendimiento técnico nunca ha sido estudiada. Así, el objetivo principal de este estudio fue analizar el efecto de un programa de entrenamiento orientado a la potencia muscular en altitud moderada sobre la capacidad de extensión de piernas, el rendimiento del ippon-seoi-nage y la relación entre ambos en judokas de élite. Se utilizó un diseño longitudinal, con medidas intra- e inter-grupo, para comparar el efecto de un entrenamiento orientado a la potencia de piernas en altitud moderada (hipoxia) o a nivel del mar (normoxia) sobre la capacidad de extensión de piernas, las variables cinemáticas del ippon-seoi-nage y la relación entre ambos en judokas de élite. Participaron en este estudio 24 judokas del Centro de Entrenamiento Nacional de Judo de Valencia, todos medallistas internacionales. Los participantes fueron aleatoriamente asignados a un grupo que realizaba un entrenamiento de tres semanas en hipoxia hipobárica (en el Centro de Alto Rendimiento de Sierra Nevada, 2320 m; HT; n = 13) o en normoxia (en el Centro de Entrenamiento Nacional de Judo de Valencia, 15 m; NT; n = 11). Los test se realizaron en normoxia en 4 momentos distintos: pre-test (N1), posttest (N2), una y dos semanas post-entrenamiento (N3 y N4, respectivamente). El HT realizó un test adicional en hipoxia aguda (H1), inmediatamente después del ascenso. Se usó un diseño intra-grupo adicional para analizar el efecto de la exposición aguda a la altitud moderada sobre las mismas variables (N1 vs. H1). Los tests incluían 1) un análisis de la composición corporal a través de antropometría y análisis de impedancia bioeléctrica, 2) un test incremental de countermovement jump (CMJ) para determinar el perfil fuerza-carga-velocidad en la extensión de piernas y 3) un test de ippon-seoi-nage para estudiar las variables cinemáticas transferidas al uke durante la ejecución de esta técnica. El programa de entrenamiento incluía una sesión de acondicionamiento físico por la mañana y una sesión de judo por la tarde, de lunes a sábado por la mañana. El programa de acondicionamiento físico incluía 3 sesiones semanales de entrenamiento orientado a la potencia muscular alternadas con 3 sesiones metabólicas. El contenido del programa de acondicionamiento físico fue diseñado y supervisado por el equipo de investigación, mientras que las sesiones de judo fueron diseñadas por los entrenadores. Cada sesión de entrenamiento orientado a la potencia muscular incluía dos partes: 1) entrenamiento basado en la velocidad (4-6 series de 6 CMJ, los miércoles y viernes con una carga asociada a 1.2 m·s-1 de la velocidad media propulsiva (MPV) del pre-test, y cada lunes con una carga asociada a 1.2 m·s-1 de la MPV ajustada a cada condición en ese momento, con 4 minutos de descanso) y 2) entrenamiento de contraste (3-4 series de 2 repeticiones de un ejercicio de fuerza con una carga moderada-alta seguido de 6 proyecciones de ippon-seoi-nage ejecutadas a máxima velocidad, con 4 minutos de descanso). La exposición aguda a la hipoxia causó pequeños incrementos en la velocidad pico (PV) de extensión de piernas (3.67%; p < 0.05), mientras que no se verificaron cambios en las variables cinemáticas del ippon-seoi-nage. Las variables cinemáticas del ippon-seoi-nage mostraron una gran fiabilidad individual que contrasta con la baja fiabilidad grupal observada. Finalmente, la ratio del coeficiente de variación (H1/N1) del tiempo necesario para alcanzar la extensión de piernas durante la ejecución de la técnica aumentó. Se ha verificado un efecto del entrenamiento orientado a la potencia en la PV, altura de salto (JH) y fuerza máxima teórica (F0, calculada a partir de valores medios de fuerza y velocidad) de extensión de piernas (p < 0.05), en altitud moderada y a nivel del mar. La PV y la JH mostraron un efecto de interacción momento × altitud (p < 0.05). El análisis pormenorizado de esta interacción mostró una mayor magnitud de cambio en la PV, JH y F0 del HT que del NT y que el HT la ha alcanzado una semana antes (HT-N2 vs. NT-N3: 8.78 vs. 5.58% para la PV; 8.20 vs. 1.41% para la JH; 11.76 vs. 7.61% para la F0; p < 0.05). Se han observado importantes desequilibrios en el perfil de fuerzavelocidad de ambos grupos, causados por valores actuales de F0 bajos (p < 0.001, η2 p = 0.889) y por valores actuales de velocidad máxima teórica (V0) altos (p < 0.001, η2 p = 0.844) comparados con el perfil óptimo estimado. A pesar de que no existen diferencias significativas entre los desequilibrios presentados por ambos grupos en cada momento, resultados complementarios mostraron una tendencia moderada a reducir el desequilibrio de N1 a N2 en el HT y de N1 a N3 en el NT (-11.96% y -7.88%, respectivamente, p < 0.10). Se ha registrado un efecto de la altitud sobre las variables del ippon-seoi-nage (p < 0.05). Así, la aceleración de la fase de extensión de piernas aumentó un 22.95% menos en HT que en NT (p = 0.03). Además, el tiempo hasta alcanzar la horizontal del uke aumentó en HT y disminuyó en NT (diferencia entre HT y NT = 18.68%, p = 0.003). El período de entrenamiento no provocó cambios en las variables de antropometría y de análisis de impedancia bioeléctrica en ambos grupos (p > 0.05). No se han observado correlaciones entre las variables mecánicas de la extensión de piernas y la aceleración o velocidad angular transferida al uke. Esta asociación no se vio afectada por la exposición aguda o el entrenamiento en altitud. En concordancia con la literatura, nuestros resultados muestran un incremento en la capacidad de empuje de piernas desde el primer momento de exposición a la altura. Posteriormente, tras un periodo de entrenamiento orientado de potencia muscular, la altitud moderada parece incrementar el pico de rendimiento y acelerar el momento en que este se alcanza. El análisis pormenorizado del efecto de interacción momento × altitud indica que el mayor rendimiento en la velocidad de extensión de piernas y en la altura de salto se obtuvo en HT (alcanzado en N2) con respecto al de NT (alcanzado en N3) (p < 0.05). Los parámetros de rendimiento de la técnica analizada no sufrieron cambios en exposición aguda a la altitud moderada y empeoraron tras el periodo de entrenamiento, incrementando los tiempos y reduciendo las aceleraciones producidas en el uke. Los cambios en la condición física, junto a los del propio patrón espacio-temporal que puede inducir la exposición a la altitud, ponen de manifiesto la necesidad de ajustar y estabilizar la técnica tanto durante como después de un periodo de entrenamiento en altitud en aquellas disciplinas que incorporen acciones de coordinación compleja. Finalmente, las diferencias entre el coeficiente de variación individual y grupal confirman que cada judoca adapta la ejecución del ippon-seoi-nage a sus características, ejecutándolo siempre de la misma manera. No obstante, la ausencia de asociación entre la capacidad de extensión de piernas y la performance del ippon-seoi-nage podrían indicar que, por lo menos en la muestra estudiada, la implicación de las piernas durante la ejecución del ippon-seoi-nage no fue suficiente de acuerdo con el gold standard de la técnica. Estudios futuros son necesarios para profundizar en el análisis de la técnica y en la naturaleza de las adaptaciones de la fuerza y su transferencia al gesto deportivo como consecuencia de la exposición y entrenamiento en hipoxia.Tesis Univ. Granada

Altitude alters the effects of a power-oriented resistance training on the force-velocity relationship of elite judokas

This study investigated the effects of a 3-week power-oriented resistance training program performed at moderate altitude on the lower-limb maximal theoretical power and force-velocity (F-V) imbalance of elite judokas. Twenty-two elite male judokas were randomly assigned to either a hypobaric hypoxia or normoxia group. Mechanical outputs from an incremental loaded countermovement jump test were assessed at sea level, before and after training, and 1 week later. Results indicated an increase in the maximal theoretical force and a reduction in the F-V imbalance both at moderate altitude and sea level. Altitude training induced additional benefits when compared to sea level for F-V imbalance (8.4%; CI: 0.3, 17.3%), maximal theoretical power (2.09 W·kg-1; CI: 0.13, 4.52 W·kg-1) and force (1.32 N·kg-1; CI: -0.12, 2.96 N·kg-1), jump height (3.24 cm; CI: 2.02, 4.80 cm) and optimal maximal theoretical force (1.61 N·kg-1; CI: 0.06, 3.60 N·kg-1) and velocity (0.08 m·s-1; CI: 0.00, 0.17 m·s-1) after the training period. The hypoxia group achieved their best results immediately after the training period, while the normoxia group achieved them one week later. These results suggest that a power-oriented resistance training program carried out at moderate altitude accelerates and improves the gains in leg push capacity while minimizing lower-limb imbalances. Therefore, it seems appropriate to compete immediately after the return to sea level and/or use altitude training as a tool to improve muscle power levels of athletes without tapering goals, especially in highly trained power athletes, since their window of adaptation for further power enhancement is smaller.Spanish Ministry of Economy, Industry and Competitiveness under Grant DEP2015-64350-P MINECO/FEDERFPI pre-doctoral grant under Grant BES-2016-078035 awarded to one of the author