Javier Sanchez-Sanchez

Efecto de la motivación del entrenador sobre la carga interna y el rendimiento físico de un juego de fútbol reducido

Los juegos reducidos de futbol son una estrategia de entrenamientomuy empleada en la actualidad. Manipulando sus parametros configuradores,el entrenador puede conseguir diferentes propositos. El objetivo del trabajofue analizar la influencia de la motivacion del entrenador sobre la intensidad de un juego reducido (JR) de 3 contra 3 y su efecto sobre el rendimiento fisico de jugadores de categoria alevin. Doce futbolistas realizaron el mismo juego reducido con motivacion del entrenador (JME) y sin motivacion del tecnico(JSME). La carga interna de cada tarea fue cuantificada mediante el registro de la frecuencia cardiaca. Antes y despues del JR los jugadores realizaron un test de velocidad (sprint de 30-m), un test de fuerza explosiva de piernas (testtriple Hop) y un test de agilidad (test de Illinois). La participacion motivante del entrenador provoca una frecuencia cardiaca media, expresada como porcentaje de la frecuencia cardiaca maxima, significativamente mayor quela obtenida sin la motivacion del entrenador (89.12±4.29% vs. 82.15±3.12%respectivamente). Ademas, se ha observado una perdida significativa de rendimiento en el test de velocidad (5.15±0.21s pre-test y 5.43±0.27 s post-test),agilidad (20.25 ± 0.86s pre-test y 21.01±0.99s post-test) y salto con pierna habil (4.88±0.43 m pre-test y 4.58±0.41 m post-test) tras realizar el JME.El JSME solo provoca un descenso significativo del rendimiento en el testde velocidad (5.28±0.27s pre-test y 5.51±0.22s post-test). La motivacion delentrenador aumenta la intensidad del JR 3 contra 3

Specific Changes in Young Soccer Player's Fitness After Traditional Bilateral vs. Unilateral Combined Strength and Plyometric Training

The aim of this study was to compare changes in young soccer players fitness after traditional bilateral vs. unilateral combined plyometric and strength training. Male athletes were randomly divided in two groups; both received the same training, including strength training for knee extensors and flexors, in addition to horizontal plyometric training drills. The only difference between groups was the mode of drills technique: unilateral (UG; n = 9; age, 17.3 ± 1.1 years) vs. bilateral (TG; n = 9; age, 17.6 ± 0.5 years). One repetition maximum bilateral strength of knee muscle extensors (1RM_KE) and flexors (1RM_KF), change of direction ability (COD), horizontal and vertical jump ability with one (unilateral) and two (bilateral) legs, and limb symmetry index were measured before and after an 8-week in-season intervention period. Some regular soccer drills were replaced by combination of plyometric and strength training drills. Magnitude-based inference statistics were used for between-group and within-group comparisons. Beneficial effects (p < 0.05) in 1RM_KE, COD, and several test of jumping performance were found in both groups in comparison to pre-test values. The limb symmetry index was not affected in either group. The beneficial changes in 1RM_KE (8.1%; p = 0.074) and 1RM_KF (6.7%; p = 0.004), COD (3.1%; p = 0.149), and bilateral jump performance (from 2.7% [p = 0.535] to 10.5% [p = 0.002]) were possible to most likely beneficial in the TG than in the UG. However, unilateral jump performance measures achieved likely to most likely beneficial changes in the UG compared to the TG (from 4.5% [p = 0.090] to 8.6% [p = 0.018]). The improvements in jumping ability were specific to the type of jump performed, with greater improvements in unilateral jump performance in the UG and bilateral jump performance in the TG. Therefore, bilateral strength and plyometric training should be complemented with unilateral drills, in order to maximize adaptations.

Heart Rate, Technical Performance, and Session-RPE in Elite Youth Soccer Small-Sided Games Played With Wildcard Players

Abstract Sanchez-Sanchez, J, Hernández, D, Casamichana, D, Martínez-Salazar, C, Ramirez-Campillo, R, and Sampaio, J. Heart rate, technical performance, and session-RPE in elite youth soccer small-sided games played with wildcard players. J Strength Cond Res 31(10): 2678–2685, 2017—The aim of this study was to compare heart rate (HR), rating of perceived exertion (RPE), and technical-tactical actions during small-sided games (SSGs) played without (CTR), with internal (IW), and with IW and external (IEW) wildcard players. A total of 22 young male soccer players (age 17.2 ± 0.9 years) randomly completed six 4vs4 SSG situations. The control conditions occurred with goals scored without goalkeeper (4vs4-NO) and with goalkeeper (4vs4-GK). During the experimental conditions, the situations incorporated 2 IW (4vs4+2IW-NO, 4vs4+2IW-GK) and 2 IEW (4vs4+2IW+2IEW-NO, 4vs4+2IW+2IEW-GK). Processed results did not include data from goalkeepers, IW, and IEW players. The HR was divided in intensity-zones (Z1, Z2, and Z3, for <80%, 80–90%, and >90% of maximal HR, respectively) and the analyzed technical-tactical actions were the pass, dribbling, collective success, and pause. The effects of IW and IEW were analyzed through repeated measures analysis of variance. During 4vs4+2IW+2IEW-NO, greater time was recorded in Z1 (p ⩽ 0.05) compared with 4vs4-NO and 4s4+2IW-NO. During 4vs4+2IW+2IEW-GK, greater time was recorded in Z1 and less in Z3 (p ⩽ 0.05) compared with 4vs4-GK. Greater RPE was reported in 4vs4-NO (p < 0.01) and 4vs4+2IW-NO (p < 0.01) compared with 4vs4+2IW+2IEW-NO, and during 4vs4-GK (p < 0.01) than 4vs4+2IW+2IEW-GK. Greater number of dribbling situations were recorded during 4vs4-NO (p ⩽ 0.05) compared with 4vs4+2IW+2IEW-NO. In conclusion, compared with the control condition of 4vs4, the incorporation of IEW reduced HR, RPE, and dribbling actions.

Validity of the RSA-RANDOM Test for Young Soccer Players

The present study aimed to examine the reliability, usefulness, responsiveness, age-related differences and construct validity of a novel decision-making RSA test (RSA-RANDOM test) in young soccer players. Twenty-five young male soccer players performed the RSA-RANDOM test on 2 occasions separated by 5-7 days to assess test-retest reliability and determine a priori usefulness. Furthermore, the same players executed the RSA-RANDOM test 4 times throughout the season to analyse responsiveness. Forty-five players (U-13 to U-17) were evaluated in such test to examine age-related differences. Finally, 9 players were used to determine the construct validity of the test. Reliability scores showed a high intraclass correlation coefficient (ICC=0.88 to 0.90) and low coefficient of variation (CV=1.0-1.2%). The responsiveness of the RSA-RANDOM test was good, as the typical short- (1.2-1.9%), mid- (1.4-2.4%) and long-term (2.3-3.2%) changes in RSA-RANDOM performance were higher than the CV. Age-related differences analysis showed better RSA-RANDOM performance as age increased in young soccer players. Low (r=-0.50) to moderate (r=-0.75) relationships were found between the RSA-RANDOM test variables (RSA best and mean times) with high-intensity and total distance covered, respectively. A novel decision-making RSA test (RSA-RANDOM) has shown to be reliable and valid in young soccer players.