Sequencing Effects of Neuromuscular Training on Physical Fitness in Youth Elite Tennis Players

[EN] The aim of the present study was to analyze the effects of a 5-week neuromuscular training (NMT) implemented before or after a tennis session in pre-pubertal players on selected components of physical fitness. Sixteen elite and well-trained tennis players with a mean age of 12.9 ± 0.4 years participated in this study, and were assigned to either a training group performing NMT before tennis specific training (BT; n=8) or a group that conducted NMT after tennis specific training (AT; n=8). Pre and post-tests included: speed (5,10 and 20 m); modified 5-0-5 agility test; countermovement jump (CMJ); overhead medicine ball throw (MBT); and serve velocity (SV). Results showed that the BT group achieved positive effects from pre- to post-test measures in speed (d = 0.52, 0.32 and 1.08 for 5, 10 and 20 m respectively) 5-0-5 (d = 0.22), CMJ (d = 0.29), MBT (d = 0.51) and SV (d = 0.32), while trivial (10 m, 20 m, CMJ, SV, MBT) or negative effects (d = -0.19 and -0.24 for 5 m and 5- 0-5 respectively), while trivial or negative effects were reported for the AT group. The inclusion of a NMT session before the regular tennis training led to positive effects from pre- to post-test measures in performance-related variables (i.e., jump, sprint, change of direction capacity, as well as upper body power), while conducting the same exercise sessions after the regular tennis training was not accompanied by the same improvements

Bariatric surgery, weight loss and the role of physical activity: a systematic review

P. 145-160La obesidad se ha convertido en uno de los mayores problemas de salud en la sociedad actual, hasta tal punto de ser considerada como una epidemia. Para personas con obesidad mórbida (Índice de Masa Corporal (IMC) ≥ 40 kg·m-2) que no consiguen reducción de peso por métodos convencionales se recurre a cirugía bariátrica. Existe cierta controversia entre la relación de la actividad física y la pérdida de peso posterior a la intervención bariátrica, por lo que, el objetivo de este trabajo es el de revisar y describir los distintos trabajos que existen al respecto. Se realizó una búsqueda bibliográfica en las bases de datos Medline y Scopus. De un total de 128 trabajos y tras los criterios de exclusión se procedió a la lectura exhaustiva de 24 artículos completos, 21 de ellos observacionales y 3 experimentales. Encontramos que la práctica actividad física se correlaciona de manera positiva con la pérdida de peso, no obstante, aunque no existen diferencias significativas entre realizar ejercicio o no realizarlo a corto plazo (primeros seis meses), sí que se empiezan a hacer palpables a medio o largo plazo (+ 9 meses)S

Acute effects of dynamic versus foam rolling warm-up strategies on physical performance in elite tennis players.

To date, there is a lack of information about the optimal conditions of the warm-up to lead to a better performance in elite tennis players. The aim of this study was to compare the effects of two different warm-up protocols (dynamic vs. self-myofascial release with foam rolling) on neuromuscular variables associated with physical determinants of tennis performance. Using a crossover randomised experimental design, eleven professional men tennis players (20.6 ± 3.5 years) performed either a dynamic warm-up (DWU) or a selfmyofascial release with foam rolling (SMFR) protocol. DWU consisted of 8 min of dynamic exercises at increasing intensity and SMFR consisted of 8 min of rolling on each lower extremity unilaterally. Just before (baseline) and after completing warm-up protocols, players performed a countermovement jump (CMJ), the 5-0-5 agility test, a 10-m sprint test and the Straight Leg Raise and Thomas tests to assess range of motion. Compared to baseline, the DWU was more effective to reduce the time in the 5-0-5 test than SMFR (-2.23 vs. 0.44%, respectively, p = 0.042, ηp2 = 0.19). However, both warm-up protocols similarly affected CMJ (2.32 vs. 0.61%, p = 0.373, ηp2 = 0.04) and 10-m sprint time changes (-1.26 vs. 1.03%, p = 0.124, ηp2 = 0.11). Changes in range of motion tests were also similar with both protocols (p = 0.448–1.000, ηp2 = 0.00–0.02). Overall, both DWU and SMFR were effective to prepare well-trained tennis players for highly demanding neuromuscular actions. However, DWU offered a better preparation for performing change of direction and sprint actions, and hence, in high-performance tennis players, the warm-up should include dynamic exercises.post-print402 K

On-Court Change of Direction Test: An Effective Approach to Assess COD Performance in Badminton Players

[EN] The aim of this research was to assess the reliability of a specific change of direction test (i.e., “On-Court COD test”) in youth badminton players, evaluate the effect of age on On-Court COD performance, and examine its correlations with linear speed, change of direction speed, and vertical jump tests. Forty-two young badminton players (27 males and 15 females; age: 17.3±1.6 years, body height: 170.3±7.5 cm, body mass: 59.0±9.7 kg) were divided into two age groups (Under 17 years and under 19 years). Tests included: linear sprints (5, 10, and 20-m), bilateral/unilateral countermovement jumps, a hexagon test, traditional and modified 505 change of direction tests; and On-court COD. Results showed an excellent intraclass correlation coefficient score (0.90) and a very low coefficient of variation values (1.6%) for the On-Court COD test. Comparing age groups, under 19 players were significantly faster in linear sprints (i.e., 5, 15 and 20-m; small to moderate effect sizes) and in all change of direction tests (moderate to large effect sizes). Moreover, the On-Court COD test showed moderate to large (r=.513-.779) relationships with both acceleration and COD abilities in under 17 players, and with linear sprints, COD, and jump performances in under 19 players. These data indicate that the On-Court COD test is a useful and reliable means to assess COD performance in youth badminton players and it is associated with acceleration, sprint and jump performance

Does the length used in the 30-15 International Fitness Test (40-vs 28-m) influence the maximal running speed achieved by under- 18 players from different sports?

The maximal running speed (MRS) achieved in the 30-15 International Fitness Test (30-15 IFT) is widely used to prescribe high-intensity interval training (HIIT). The 30-15 IFT can be performed in either 40-(30-15 IFT-40) or 28-meters (30-15 IFT-28) length. Objectives: The aim of this study was to evaluate the MRS archieved in the 30-15 IFT-40 and the 30-15 IFT-28. Methods: Fifty U-18 players from different sports (handball: n=19, soccer: n=19, tennis n=12) attended two testing sessions. Results: MRS did not differ between the 30-15 IFT-40 and the 30-15 IFT-28 in either handball or soccer players. However, tennis players showed significantly greater MRS values in the 30-15 IFT-28 than in the 30-15 IFT-40 (20.80±1.87 vs 20.05±2.09 km·h-1;p = 0.030; ES = 0.38). In addition, tennis player showed significant greater MRS in the 30-15 IFT -28 (20.80±1.87 km·h-1) than both handball (18.58±1.13 km·h-1; p< 0.001;ES = 1.53) and soccer players (18.74±0.93 km·h-1; p=0.001;ES = 1.47). Conclusions: The different MRS values in the 30-15 IFT-40 and the 30-15 IFT-28, entail significant ractical implications for HIIT prescription in tennis players

Comparison of six weeks eccentric overload training between bilateral and unilateral squat in basketball players

Basketball is a team sport in which strength and power in the lower limb are key variables. The use of eccentric overload devices has augmented in the past years, and several studies have shown the benefits of this methodology to improve physical parameters. The aim of the present study is to compare the effects of bilateral and unilateral squat during eccentric overload training. Ten players from a same team participated in a six weeks of two session per week eccentric overload training. Participants were divided in two groups according to their performance in pretest. Test measured in pre and postest situation were a power test in flywheel, CMJ, triple hop test and T-Test. Training consisted in 4 sets of 8 repetitions of bilateral or unilateral squat. After treatment both groups improve their performance in T-Test and power test in flywheel device. Trends of improve were observed for triple hop test, with a greater ES for unilateral group. Results shown as eccentric overload training of bilateral or unilateral squat can be a good choice to improve physical performance, with different benefits according to the type of execution.El baloncesto es un deporte de equipo en el que la fuerza y la potencia del tren inferior son aspectos claves. El uso de dispositivos de sobrecarga excéntrica se ha incrementado en los últimos años, y varios estudios han mostrado los beneficios de esta metedología para desarrollar parámetros físicos. El objetivo del presente estudio es comparar los efectos del entrenamiento con sobrecarga excéntrica en acciones de sentadilla bipodal y monopodal. Diez jugadores de un mismo equipo participaron en un programa de entrenamiento de sobrearga excéntrica durante seis semanas, realizando dos sesiones semanales. Los participantes fueron divididos en dos grupos en función de su rendimiento durante las test previos al entrenamiento. Los test pre y post tratamienot fueron un test de potencia en el dispositivo de sobrecarga excéntrica, CMJ, test de triple salto y test de agilidad T-Test. Las sesiones de entrenamiento consistieron en 4 series de 8 repeticiones de squat bipodal o monopodal en función del grupo de entrenamiento. Tras la intervención, ambos grupos mejoraron su rendimiento en T-test y en el test de potencia con sobrecarga excéntrica. Se observó una tendencia de mejora en los valores para el triple salto, con tamaños del efecto mayores para el grupo que entrenó de manera monopodal. Los resultados muestran como el entrenamiento con sobrecarga excéntrica ejecutado de manera bipodal o monopodal puede ser una buena opción para mejorar el rendimiento físico en jugadores de baloncesto, con diferentes beneficios acorde al tipo de ejecución

Reliability and usefulness of half-squat 1RM estimation through movement velocity in U18 soccer players

Assessment of strength in youth athletes using as afety , time-efficient and reliable test is crucial for strength and conditioning professionals . The purpose of this study was to examine the reliability of the one-repetition maximum (1RM) estimation through movement velocity in youth soccer players . In addition, the relations hips between 1RM estimation with peak power (PP), jumping and sprinting performance were checked. Material and methods : Twenty-two youth soccer players (16.8±0.6 years ) took part in the study . Participants completed a 1RM estimation in thehalf-squat, squat jump (SJ), counter movement jump (CM J) and 30m s print in three different occasions . Results : The 1RM estimation showed good absolute (SEM 0.7) reliability scores. The estimated 1RM value was significantly lower in the trial 1 compared to the trials 2 and 3. The estimated 1R M and the PP output showed significant correlations (r =0.538-0.560) with jumping and sprinting performance. Discussion: These data suggest the necessity to performat leas to ne familiarizations es s io n to obtain a reliable 1R M estimation through movement velocity in youth soccer players . Once youth soccer players are familiarized with the 1R M estimation protocol, coaches could use this evaluation to obtain a reliable measure of player s ' maximal strength in a time-efficient wayLa evaluación de la fuerza en los deportistas mediante el uso de un test seguro , eficiente y fiable es crucial para los profesionales del acondicionamiento físico . El objetivo de este estudio fue examinar la fiabilidad de la estimación de la repetición máxim a (1R M ) a través de la velocidad de movimiento en jóvenes jugadores de fútbol. Además , se analizó las relaciones entre la estimación de 1R M con el pico de po tencia (PP), la altura de salto y el sprint. Material y métodos : Veintidós jóvenes jugador es de fútbo l (16,8 ± 0,6 año s ) participaron en el es tudio . Los participantes completaron un tes t de 1R M en media sentadilla, squat jump (SJ), salto en contra movimiento (CM J) y sprint de 30 m en tres ocasiones diferentes . Resultados : La estimación del 1R M mostró buenos valores de fiabilidad absoluta (SEM 0.7) . El valor estimado de 1R M fue significativamente menor en la prueba 1 en comparación con las pruebas 2 y 3. La estimación del 1R M y PP mostraron correlaciones significativas (r=0.538-0.560) con el rendimiento en saltos y sprint. Discusión: Estos datos sugieren la necesidad de realizar al menos una sesión de familiarización par a obtener una estimación fiable d el 1R M a través de la velocidad de movimiento en jugadores de fútbol juveniles . Una vez que los jugadores de fútbol juveniles estén familiarizados con el pro toco lo de estimación 1RM , los entrenadores podrían usar esta evaluación para obtener una medida fiable de la fuerza máxima de los jugadores de una mane a eficiente en el tiempo

Does handball throwing velocity increase after an eccentric overload-induced postactivation potentiation?

Post-activation performance enhancement (PAPE) has been defined as an increase in performance of voluntary movements after a high-intensity voluntary task. This phenomenon can be achieved through different strategies. However, the relationship between a conditioning eccentric overload (EO) exercise and PAPE in the upper extremities is scarce. The aim of this work was to study the application of PAPE to improve handball throwing velocity using EO, and to compare it with a traditional resistance training exercise. Material and methods: Fourteen team handball players carried out two sessions with different PAPE protocols. One of the sessions consisted of performing a PAPE protocol through a set of three repetitions at 90% of RM in the bench press (BP). In the other session, a set of three maximal-effort repetitions of one-handed horizontal press was carried out using a conical pulley (CP) with a 0.16 kg•m2 inertial load. Throwing velocity was measured pre and post both protocols. Results: Both protocols showed a non-significant handball throwing velocity after the application of PAPE protocols (effect size = 0.24 and 0.20 for CP and BP respectively). Conclusions: None of the procedures obtained the expected PAPE phenomenon for the improvement of handball throw velocity. Future studies need to assess different EO protocols to elicit PAPE in complex sport-related actions.La elevación del rendimiento posterior a la activación (PAPE) se ha definido como un aumento en el rendimiento de los movimientos voluntarios después de una tarea voluntaria de alta intensidad. Este fenómeno se puede lograr a través de diferentes estrategias. Sin embargo, la relación entre un ejercicio de sobrecarga excéntrica condicionada (EO) y el fenómeno de PAPE en las extremidades superiores ha sido poco estudiada . El objetivo de este trabajo fue estudiar la aplicación de PAPE para mejorar la velocidad de lanzamiento de balonmano mediante un protocolo de EO, y compararlo con un ejercicio tradicional de entrenamiento de fuerza. Material y métodos: Catorce jugadores de balonmano realizaron dos sesiones con diferentes protocolos PAPE. Una de las sesiones consistió en realizar un protocolo PAPE que consistía en tres repeticiones al 90% de RM en el press de banca (BP). En la otra sesión, se realizó una serie de tres repeticiones de máxima intensidad del ejercicio de press horizontal a una mano utilizando una polea cónica (CP) con una carga inercial de 0.16 kg • m2. La velocidad de lanzamiento se midió antes y después de ambos protocolos. Resultados: Ninguno de los protocolos consiguió un aumento significativo de la velocidad de lanzamiento después de la aplicación de ambos protocolos PAPE (tamaño del efecto = 0.24 y 0.20 para CP y BP respectivamente). Conclusiones: Ninguno de los procedimientos obtuvo el fenómeno PAPE esperado para la mejora de la velocidad de lanzamiento de balonmano. Futuros estudios necesitan evaluar diferentes protocolos de EO para obtener PAPE en acciones complejas vinculadas con el rendimiento deportivo

Eccentric-Overload Production during the Flywheel Squat Exercise in Young Soccer Players: Implications for Injury Prevention

This study aimed to evaluate the differences in power production between movement phases (i.e., concentric and eccentric) during the execution of resistance exercises with a flywheel device, differentiating between execution regimes (i.e., bilateral, unilateral dominant leg and unilateral non-dominant leg). Twenty young elite soccer players (U&minus;17) performed two sets of six repetitions of the bilateral half-squat (inertia 0.025 kg&middot;m&minus;2) and the lateral-squat exercise (inertia 0.010 kg&middot;m&minus;2) on a flywheel device. During the testing sessions, mean and peak power in concentric (MPcon) and eccentric (MPecc) phases were recorded. The non-dominant leg showed higher values in all power variables measured, although substantial differences were only found in MPecc (ES = 0.40, likely) and PPcon (ES = 0.36, possibly). On the other hand, for both exercises, MPcon was higher than MPecc (ES = &minus;0.57 to &minus;0.31, possibly/likely greater), while only PPecc was higher than PPcon in the dominant lateral-squat (ES = 0.44, likely). These findings suggest that young soccer players have difficulty in reaching eccentric-overload during flywheel exercises, achieving it only with the dominant leg. Therefore, coaches should propose precise preventive programs based on flywheel devices, attending to the specific characteristics of each limb, as well as managing other variables to elicit eccentric-overload

Valoración de la intensidad del entrenamiento de fuerza a través de la velocidad en el aula

El entrenamiento de fuerza ha recabado gran interés por la literatura científica en los últimos años, dada su importancia en campos tan dispares como el rendimiento deportivo, la calidad de vida en la tercera edad, o la mejora de patologías que se reflejan en la incapacidad funcional de los pacientes. Desde el punto de vista de la valoración y la planificación del entrenamiento de fuerza son distintas las variables claves que lo definen, ocupando especial relevancia la intensidad de dicho entrenamiento de fuerza. La cuantificación de la intensidad del entrenamiento de fuerza se ha realizado clásicamente desde el punto de vista de la cantidad de carga que el sujeto moviliza en el ejercicio. Sin embargo, en los últimos años la bibliografía nos ha mostrado como los efectos del entrenamiento de fuerza pueden ser muy diferentes cuando una misma carga se moviliza a distintas velocidades. El desarrollo de instrumentales, que a través de la acelerometría permiten el control de la velocidad de ejecución del movimiento de fuerza, está permitiendo que los profesionales cuenten con herramientas más accesibles para que los alumnos o deportistas y puedan conocer la influencia de la velocidad en el control del entrenamiento de fuerza. El objetivo del presente trabajo es presentar las bandas PushTM para el registro de la velocidad de ejecución y su posible aplicación para explicar contenidos propios de la titulación de Ciencias del Deporte