Adolescent female soccer players’ soccer-specific warm-up effects on performance and inter-limb asymmetries

No studies have assessed whether changes in physical performance and inter-limb asymmetries (ILA) can be achieved with the FIFA 11+ prevention programme in adolescent female soccer players. The aim of this study was to assess the effect of the FIFA 11+ programme compared with a standard warm-up on physical performance and ILA in adolescent female soccer players. Thirty-six adolescent female soccer players were randomly assigned to an experimental (EG; n = 19) or a control group (CG; n = 17). Unilateral/bilateral countermovement jump (CMJ), drop jump (DJ) and horizontal jump tests, two different change of direction tests, an ankle dorsiflexion test, the Y-Balance test (YBT) and inter-limb asymmetries were measured before and after 10 weeks of training. The results revealed no significant group-by-time interactions in the vast majority of variables (p>0.05). Paired t-test revealed significant improvements of the right [effect size (ES):0.56] and left (ES:0.49) CMJ, right (ES:0.74) and left (ES:0.54) DJ (ES:0.74), right (ES:1.27) and left (ES:1.26) posteromedial direction and right (ES:0.89) and left (ES:0.84) posterolateral direction in the YBT in the EG (p < 0.05). Right anterior direction in the YBT and V-cut test were significantly improved in both groups (p<0.05). For inter-limb asymmetry variables, no significant group-by-time interactions (ES:0 to 0.93) and an improvement between pre- and post-tests (ES:-0.76 to 0.49) were observed. Therefore, the FIFA 11+ programme led to improved unilateral jumping, dynamic balance and reduced lower extremity symmetries of several tests in adolescent female soccer players

Acute effect of repeated sprints on inter-limb asymmetries during unilateral jumping

The aim of the present study was to investigate the effects of multiple repeated sprints on unilateral jump performance and inter-limb asymmetries. Eighteen recreationally active males performed three single leg countermovement jumps (SLCMJ) as baseline data. The repeated sprint protocol was 6 x 40 m with 20 seconds of passive rest between each sprint. This protocol was conducted four times, each set separated by four minutes of rest. Within that rest period, subjects performed one SLCMJ on each limb after two minutes of rest. A one-way ANOVA showed significant reductions (p < 0.05; ES = -0.52 to -0.99) in jump height on both limbs after each set relative to baseline. Inter-limb asymmetries increased at each time point and ranged from 7.62-14.67%, with significant increases in asymmetry seen after sets three (p = 0.046) and four (p = 0.002). Significant increases in sprint time were shown between sprints one and six in each set (p ≤ 0.01). A fatigue index (%) was also calculated and showed an exponential increase from 5.74% (set one) to 13.50% (set four), with significant differences between all sets (p < 0.001) with the exception of sets three and four. Results from this study show that a 6 x 40 m repeated sprint protocol is a sufficient dose for implementing acute fatigue in recreationally active subjects. This was manifested by reductions in jump height at all time points and jump height asymmetries after the third and fourth sets. These findings indicate that jump height from unilateral jump testing may be a useful metric to use during the monitoring process in recreationally trained athletes

Post-activation potentiation: effects of different conditioning intensities on measures of physical fitness in male young professional soccer players

The aim of this study was to compare the effects of different warm-up conditioning intensities on the physical fitness (i.e., post-activation potentiation -PAP), of professional male field soccer players. Athletes (n = 10; age: 21.6 ± 3.2 years) completed a control warm-up and warm-ups aimed to induce PAP, in random and counterbalanced order. After control and experimental warm-up sessions participants completed a triple hop test with the dominant (H3Jd) and a non-dominant (H3Jnd) leg, a squat jump (SJ), a countermovement jump (CMJ), a change of direction ability (COD) test, a repeated sprint with a COD (RSCOD) test and a linear 30-m sprint test (S-30). The control warm-up (WU) protocol was designed according to athlete's regular warm-up practice. The experimental warm-ups included the same exercises as the WU, with addition of one set of half-back squats for 10 repetitions at 60%, 5 repetitions at 80%, and 1 repetition at 100% of 1RM (60%-1RM, 80%-1RM and 100%-1RM, respectively.) Threshold values for Cohen's effect sizes (ES) were calculated and used for group's comparison. Likely to most likely improvements were shown in H3Jd (ES = 0.52), H3Jnd (ES = 0.51), COD (ES = 0.38), fasted sprint (RSCODb) (ES = 0.58) and the total time of all sprints (RSCODt) (ES = 0.99) only after the 80%-1RM protocol in comparison to the WU. Conversely, 100%-1RM and 60%-1RM protocols, compared to WU, induced possibly to most likely poorer performance in all jumps, COD and RSCODb (ES = -0.07 to -1.03 and ES = -0.48 to -0.91, respectively). Possibly to most likely improvements were shown in all jumps, COD, RSCODb and RSCODt after the 80%-1RM warm-up protocol in comparison to the 100%-1RM and 60%-1RM warm-up protocols (ES = 0.35 to 2.15 and ES = 0.61 to 1.46, respectively). A moderate warm-up intensity (i.e., 80%-1RM back squat) may induce greater PAP, including improvements in jumping, repeated and non-repeated change of direction speed in male soccer players

Efecto del programa FIFA11+ sobre el rendimiento físico en jugadoras adolescentes de fútbol: Estudio piloto

El FIFA 11+ ha sido desarrollado como un programa de calentamiento estructurado dirigido a prevenir las lesiones más frecuentes en el fútbol. Se ha evaluado si el FIFA 11+ era capaz de mejorar el rendimiento físico en jugadores de fútbol, sin embargo no existen datos referentes al efecto de dicho programa sobre el rendimiento físico de jugadoras de fútbol femenino de categoría U-16. Este estudio investigó el efecto del FIFA 11+ en el rendimiento físico de un grupo de chicas futbolistas entre 12-15 años. Se les valoró el salto horizontal y vertical unilateral y bilateral, la amplitud del movimiento y los cambios de dirección mediante diferentes pruebas en campo, además se halló la asimetría entre extremidades inferiores. Se calculó el tamaño de efecto en las variables de fuerza, equilibrio y agilidad. Se encontraron mejoras en la mayoría de variables cuando se comparó a ambos grupos con la evaluación inicial, pero no se observaron diferencias significativas entre grupos. Como conclusión, el FIFA 11+ no logra un estímulo suficiente como para mejorar el rendimiento de las futbolistas adolescentes, pero sí el equilibrio dinámico y funcional y la potencia unilateral de extremidades inferiores, así como la asimetría de dichas variables, lo que incide positivamente en la prevención de lesiones

Evaluación del rendimiento físico y asimetrías funcionales en jugadoras de fútbol adolescentes Evaluation of physical performance and functional asymmetries in adolescent female soccer players

El fútbol femenino ha tenido un crecimiento espectacular en la última década, lo que ha supuesto un aumento del número de investigaciones en esta población. Dichos estudios se han llevado a cabo, principalmente, en jugadoras adultas, sin embargo, hay una carencia considerable de estudios con jugadoras adolescentes. Además, en los últimos años, se ha observado que la asimetría entre extremidades inferiores, a parte de detectar jugadoras con alto riesgo de lesión, podría tener también un papel relevante en el rendimiento. Se han llevado a cabo diversos programas de intervención para mejorar las capacidades físicas y asimetrías funcionales aunque existen ciertas discrepancias en cuáles son los mejores ejercicios para mejorar el rendimiento de las jugadoras adolescentes debido al escaso número de estudios presentes en la literatura científica. Por otro lado, la fiabilidad y la sensibilidad de los test que se utilizan para valorar las capacidades físicas en jugadoras adolescentes de fútbol prácticamente no se han evaluado. De este modo, sería necesario analizar tales cuestiones para conocer si los diferentes test evalúan lo que quieren evaluar y si son capaces de detectar cambios relevantes tras una intervención. El principal objetivo de esta Tesis Doctoral es analizar la fiabilidad y la sensibilidad de diferentes test físicos, así como analizar la influencia de diferentes programas de entrenamiento y la maduración en la fuerza, la velocidad lineal, el cambio de dirección (CD) y las asimetrías funcionales en jugadoras de fútbol adolescentes.En primer lugar, el artículo I trata de contextualizar y mostrar el estado actual de la literatura científica en cuanto al CD y el rendimiento en jugadoras de fútbol adolescentes. El artículo II utiliza una muestra de 68 jugadoras adolescentes para analizar la fiabilidad y sensibilidad de diferentes test de fuerza, velocidad lineal y CD. En el artículo III y IV se exponen los resultados de un entrenamiento neuromuscular y un entrenamiento combinado de fuerza y potencia en extremidades inferiores de 8-10 semanas (2 veces/ semana) en 38 jugadoras de fútbol adolescentes, mientras que un grupo control compuesto por 35 futbolistas adolescentes proseguían su rutina de entrenamiento de fútbol. Por último, en el artículo V se muestra un estudio que examina la asociación entre variables antropométricas y de maduración biológica con el rendimiento en la velocidad lineal. Los resultados principales de la presente Tesis Doctoral muestran que la fiabilidad de los test de CD depende de los instrumentos utilizados, la superficie o el nivel de las jugadoras de fútbol. Además, los resultados de las pruebas de CD deben interpretarse con precaución, ya que pueden estar influenciados por el periodo de crecimiento y la maduración del sujeto, la posición de la jugadora y el momento de la temporada. El estudio de fiabilidad y sensibilidad muestra que los test de salto (CMJ y salto horizontal), velocidad lineal y CD (180ºCD y test V-cut) pueden ser fiables y sensibles a los cambios inducidos por el entrenamiento a corto y medio plazo en jugadoras de fútbol adolescentes. En nuestros estudios longitudinales, el entrenamiento neuromuscular durante 10 semanas produjo efectos positivos en la fuerza, la potencia y el equilibrio dinámico, así como redujo la asimetría entre extremidades inferiores, mientras que el entrenamiento combinado de fuerza y potencia sólo mostró efectos beneficiosos en la velocidad lineal y el CD. Finalmente, el peso corporal guarda una relación significativa con el rendimiento de la velocidad lineal en jugadoras de fútbol adolescentes.<br /

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

[EN] The aim of this study was to compare changes in young soccer player’s 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.S

Enhancing high-intensity actions during a basketball game after a strength training program with random recovery times between sets

To examine the effects of a strength training program with random recovery times between sets in consideration of several physical parameters, high-intensity actions (HIA), and spatial exploration index during a simulated basketball game. Twenty male basketball players (age: 19.45 ± 4.36 years) were assigned randomly, either to strength training group (n = 10), or a control group (n = 10). The strength training included: parallel back squat and bench press exercises, twice a week for the duration of 10 weeks, with two blocks of 5 sets × 5 repetitions interspersed with variable passive recovery (range = 15–35 sec.) between sets, and constant passive recovery (3-min) between blocks with the load that maximized propulsive power output. The pre- and post-test assessments included jumping (bilateral and unilateral), change-of-direction, straight sprinting, and a 5-on-5 full-court situation. The external training load was assessed using the local positioning system, and the internal load was recorded with the use of individual heart rate monitors. A significant interaction effect (group x time) was observed on countermovement jump (CMJ), unilateral right hops, high-intensity accelerations and decelerations, and peak accelerations and decelerations in the 5-on-5 full-court situation. Relative improvements observed and recorded in the training group on unilateral right hops, accelerations, and decelerations were correlated. Similar results were observed on 0–25m sprints, high-intensity decelerations, peak accelerations, and decelerations. Strength training paired with random recovery times enhanced physical and game-related aspects in the observed basketball players

Are change of direction speed and agility different abilities from time and coordinative perspectives?

This study aimed to test whether agility and change of direction speed (COD) are independent capacities using the same movement pattern (1) in terms of the completion time and (2) the entropy. Seventeen semi-professional female football players participated in the study. The agility task consisted of a Y-shaped (45° COD) task with three possible exit options (center, right and left) performed pre-planned or in reaction to the movement of two testers (i.e., blocking exit gates). Players’ acceleration was measured using an inertial measurement unit. Entropy was calculated from the acceleration signal and completion time was extracted using a magnet-based timing system. Significantly greater times and lower entropy (p&lt;0.001) were found during agility runs to pre-planned COD runs. Furthermore, weak to moderate correlations were found between COD and agility for both completion time (r = 0.29, p&lt;0.001) and entropy (r = 0.53, p&lt;0.001, r2 = 28.1%). These results highlight that COD speed and agility are independent capacities and skills, and as such, should be tested and trained as distinct, separate qualities. Modifying task constraints including a reactive stimulus (i.e., cognitive factors), is essential for increasing task complexity by altering the biomechanical and coordinative aspects of the action.</jats:p

Effects of high-intensity training with one versus three changes of direction on youth female basketball players’ performance

To compare the effects of high-intensity interval training (HIT) with one versus three changes of direction (COD) on young (age, 17.2±1.1 years) female basketball players’ performance, six weeks of regular basketball training (control period) was followed by six weeks of high-intensity training added to regular training , two times per week, with a random allocation of athletes to either HIT with one (HIT-COD1; n=6) or three COD (HIT-COD3; n=6). Before and after the control and HIT-COD training periods athletes performed repeatedsprint ability test (RSA), modified agility T-test (MAT), V-cut, triple standing dominant (TS-D) and nondominant (TS-ND) jump, TS-D and TS-ND with COD tests, and 30-15 Intermittent Fitness Test (30-15IFT). With the exception of a substantial improvement in V-cut in both groups, no substantial changes occurred during the control period. Both HIT-COD training programs improved V-cut, although only HIT-COD3 substantially improved RSA mean time (RSAm), MAT and the final speed reached in 30-15IFT (VIFT). The between-group comparison revealed greater improvements in RSAm and VIFT in HIT-COD3 than in HITCOD1. In conclusion, supplementation of basketball training with HIT-COD drills adds improvements to young female basketball player’s performance, especially when 3 COD are incorporated into HIT