Test-Retest Reliability of 3 Specific Strength Tests in Professional Handball Players.

CONTEXT: Current devices to assess strength performance in handball may not be sufficiently sports-specific and reliable methods. Functional electromechanical dynamometry is a new technology that allows the development of accurate strength tests in athletes. PURPOSE: To determine the absolute and relative reliability and to compare the reliability of the right and left side, and mean and peak force of 3 specific strength tests in handball players with a functional electromechanical dynamometer: unilateral pullover, standing lift, and step forward. METHODS: Fourteen male handball players of the first Spanish division (28.79 [4.81] y; 10.38 [4.63] y of professional experience) performed a repeated-measurement design. Three testing sessions were performed (one per week). The first measurement consisted of 4 isometric tests (right and left unilateral pullover, and right and left standing lift) to obtain isometric peak force, and in the second and third sessions, 6 incremental tests until failure (right and left unilateral pullover, and right and left standing lift, right and left step forward) were performed. RESULTS: The tests provided high reliability or acceptable reliability for mean and peak strength of unilateral pullover, standing lift and step forward (intraclass correlation coefficient = .83-.97; coefficient of variation = 3.90-11.57). Effect side was negligible in any of the parameters, except for a small effect side in the left peak force for unilateral pullover and a small effect side on the left side for a step forward. Significant differences in reliability (coefficient of variation ratio > 1.15) were found between the right and left sides and peak and mean force in all exercises except peak force in unilateral pullover and step forward. CONCLUSION: These results confirm that the tests could be applied to assess physical performance in handball at the same time as regular gym training. Moreover, this is an excellent opportunity to individualize the player's weekly load.

Influence of trunk rotator strength on rotational medicine ball throwing performance.

BACKGROUND: The strength of the trunk musculature plays an essential role in performance. The aims of this study were to analyze the relationship between the strength of the trunk rotation muscles with rotational medicine ball throwing velocity and distance, to study differences between sex in rotational medicine ball throwing and to compare the asymmetries of trunk rotational strength and rotational medicine ball throwing. METHODS: Thirty physically active college students participated on the study. Horizontal and low cable woodchop exercises were assessed with a functional electromechanical dynamometer and throwing was measured with a radar and a measuring tape. A Pearson's correlation coefficient was calculated for the relation between trunk rotational strength and rotational medicine ball throwing. Independent samples t-test was performed to determine the differences between sex in rotational medicine ball throwing and a paired samples t-test was performed to study the asymmetries. RESULTS: Large and very large correlations were obtained between trunk rotational strength and rotational medicine ball throwing (r=0.68-0.79). Significant differences and a large effect size were found between males and females for all throwing velocity and throwing distance variables (P<0.05; ES>0.90) and asymmetries in performance of mean velocity throwing (P=0.003; ES=-0.60) and peak velocity throwing (P=0.025; ES=-0.43). No significant differences were found between dominant and non-dominant side in any of the trunk rotator strength assessment conditions (P>0.05). CONCLUSIONS: There is a large or very large correlation between the STRM and the RMBT in all its modalities. Differences in strength were found between sexes, with no significant differences between dominant and non-dominant sides.

Reliability of a handball specific strength test battery and the association with sprint and throwing performance in young handball players.

BACKGROUND: A greater motivation for coaches to be more involved in assessment could be the development of specific strength tests closer to specific handball tasks. Therefore, the aims were to determine the reliability of a handball specific strength test battery in young handball players using a functional electromechanical dynamometer (FEMD) and to evaluate the association between the strength test battery and performance measurements. METHODS: Thirty-two young handball players (25% males and 75% females) performed a repeated-measurement design over four weeks. The players conducted one session per week, with each measurement consisting of two isometric tests to obtain isometric peak force, and four incremental tests. Moreover, performance handball tests (sprint and throwing velocity [TV]) were recorded. RESULTS: The reliability of the whole handball specific strength tests was very high for the peak and mean strength (ICC=0.70-0.85; CV=8.49-13.99; SEM=0.44-0.67 kg). The step forward had a moderate association with 5 to 10 meters' time. The highest correlation between TVmean was found with the peak strength of standing lift and between TVpeak with peak strength of unilateral throw. The sprint total time could be explained by Body Mass Index and peak strength of the standing lift in the 40% and the TVpeak could be explained by arm span and mean strength of the standing lift in the 68%. CONCLUSIONS: The high reliability for all exercises and the significant correlation with handball performance (sprint time and TV) allow us to include these tests in handball team evaluation and training.

Analysis of grip specificity on force production in grapplers and its effect on bilateral deficit grip specificity and bilateral deficit in force production among grapplers.

The use of strength training is important for athletes in combat sports such as judo and jiu-jitsu. Specificity is key when prescribing strength training programs for athletes, considering maximal strength, muscular power and strength-endurance. Grappling combat sports require grip control, which is necessary to execute throwing techniques and groundwork. The aim of this study was to verify the bilateral strength deficit in general and in grappling combat sport-specific action in the control group and grapplers. A sample of 73 subjects, divided into 2 groups, was used: the Student Group (15 females and 16 males) and the Grappler Group (29 males and 13 females). The male and female participants attended four laboratory sessions over a 48-hour interval, the first two to familiarize themselves with the Electromechanical Functional Dynamometer (EMFD), and the last two to collect maximal isometric strength data, using a standard grip and a judo/jiujitsu specific grip. Significant differences in mean and peak forces (p < 0.001) were found, with high performance combat sport athletes having greater maximal isometric strength compared to students both bilaterally and unilaterally (p < 0.001). All comparisons also indicated higher values for males compared to females (p < 0.001). The results suggest that specific training in combat sports as well as sex differences play a significant role in maximal isometric strength performance. The type of grip used affects the application of force in the upper limb isometric strength tests, finding a main effect of grip type (p < 0.001), with the standard grip obtaining higher levels. However, the dominance between hands remains constant. More research is needed on specific judogi/jiu-jitsu-gi grips and their impact on maximal isometric strength with the EMFD.

The cognitive benefits of basketball training compared to a combined endurance and resistance training regimen: a four-month intervention study.

Neurocognitive function, especially executive functioning, is positively associated with better fitness or higher levels of physical activity (PA). Previous research suggests that combined endurance and resistance (AER+R) training leads to greater improvements than training in either modality separately. Dynamic team sports with cognitive dimensions, such as basketball (BAS), may be an excellent context for improving cognition. This study compared the effects of following a four-month PA training program in BAS versus AER+R on executive functions along with a control group with low PA. Fifty participants completed the training period and were randomly distributed into three groups: BAS (16 participants), AER+R (18), and control (16). Participants in the BAS group showed improved inhibition and working memory and those in the AER+R group showed improved inhibition and cognitive flexibility, while inhibition deteriorated in the control group. There were significant differences between groups only in inhibition. It appears that following a four-month PA training program is enough to enhance executive functioning, and improvements in inhibition are more evident when the program includes an open sport such as BAS.

The Role of the Specific Strength Test in Handball Performance: Exploring Differences across Competitive Levels and Age Groups.

The aim of this study was to determine if specific physical tests are sufficiently discriminant to differentiate players of similar anthropometric characteristics, but of different playing levels. Physical tests were conducted analyzing specific strength, throwing velocity, and running speed tests. Thirty-six male junior handball players (n = 36; age 19.7 ± 1.8 years; 185.6 ± 6.9 cm; 83.1 ± 10.3 kg; 10.6 ± 3.2 years of experience) from two different levels of competition participated in the study: NT = 18 were world top-level elite players, belonging to the Spanish junior men's national team (National Team = NT) and A = 18 players of the same age and anthropometric conditions, who were selected from Spanish third league men's teams (Amateur = A). The results showed significant differences (p < 0.05) between the two groups in all physical tests, except for two-step-test velocity and shoulder internal rotation. We conclude that a battery combining the Specific Performance Test and the Force Development Standing Test is useful in identifying talent and differentiating between elite and sub-elite players. The current findings suggest that running speed tests and throwing tests are essential in selecting players, regardless of age, sex, or type of competition. The results shed light on the factors that differentiate players of different levels and can help coaches in selecting players.

Effects of post-tetanic potentiation induced by whole-body electrostimulation and post-activation potentiation on maximum isometric strength.

It is currently unknown the most effective potentiation protocol to increase maximum strength. Hence, we investigated the separated and combined effects of post-tetanic potentiation (PTP) induced by whole-body electrostimulation (WB-EMS) and post-activation potentiation (PAP) induced by voluntary maximum isometric contractions on maximum isometric strength. Ten trained males were randomly evaluated on four occasions. In session A, maximum isometric strength (split squat) was measured in minutes 1, 4, and 8. In session B, the measurements were taken in minutes 2, 6, and 10. In session C, a WB-EMS protocol was applied to elicit PTP and the measurements were performed in minutes 1, 4, and 8. In session D, the same WB-EMS protocol was applied and the measurements were taken in minutes 2, 6, and 10. No significant differences in maximum isometric strength were observed between: (i) the control and WB-EMS in minutes 1 vs. 1 and 2 vs. 2; (ii) the control and PAP in minutes 1 vs. 4, 1 vs. 8, 2 vs. 6, and 2 vs. 10; and (iii) the PAP and WB-EMS plus PAP in minutes 4 vs. 4, 8 vs. 8, 6 vs. 6, and 10 vs. 10. In contrast, the WB-EMS plus PAP revealed a significant increase of 54% (~450 N) compared to the WB-EMS in minutes 4 and 8 compared to the minute 1 (p < 0.001), but not between minutes 2 vs. 6 and 2 vs. 10. The present results showed that PTP induced by WB-EMS in isolation or combined with PAP induced by voluntary maximum isometric contractions did not produce a significant increase in maximum isometric strength compared to the control and PAP alone, respectively.

Throwing performance by playing positions of male handball players during the European Championship 2020.

The aim of this study was to analyze the throwing velocity and effectiveness of elite male handball players during the European Championship 2020. A local positioning system was used for the first time in a European Championship to collect 6568 throw events from 337 players of 24 national teams during 65 matches. ANOVA (F = 80.8, p < 0.01, η2  = 0.058) revealed that back players throws were significantly faster (24.3-26.5 m/s) than the rest of the players (22.2-22.5 m/s). Similarly, throws made from the central zone showed the highest speed values of 28.0 m/s (F = 43.2, p < 0.01, η2  = 0.050). In regard to the goal hit zone, higher speeds were shown for throws in side zones (24.9-26.8 m/s) compared to central zones (23.0-23.8 m/s) (F = 49.0, p < 0.01, η2  = 0.063). Effectiveness was higher in wing players (62%-64%) than the rest (45%-56%) (F = 30.9, p < 0.01, η2  = 0.023). Interestingly, the two higher velocity categories (>22 m/s) showed similar effectiveness (~60%), which were higher than the preceding slower category of 17-22 m/s (39.7%) (F = 175.1, p < 0.01, η2  = 0.074). Regarding court zones, throws from first-line zones (48%-60%), were more effective than from second line (38%-43%) (F = 13.1, p < 0.01, η2  = 0.016). With respect to the goal hit zone, effectiveness was higher in side (72%-77%) than in central zones (58%-64%) (F = 523.2, p < 0.01, η2  = 0.418). Coaches should improve the throwing velocity of players but also train at submaximal velocities (effective velocity) to save energy and reduce the potential risk of injury. Finally, training should be specialized according to the performance shown by players from different throwing zones, rather than from playing positions.

Changes in bench press performance and throwing velocity after strength-oriented and ballistic resistance training programs.

BACKGROUND: This study aimed to compare the effect of two upper-body resistance training programs (strength-oriented vs. ballistic) on bench press (BP) performance and handball throwing velocity (HTV). METHODS: Thirty resistance-trained males were randomly assigned to a strength-oriented training group (STG) or a ballistic training group (BTG). The study consisted of 11 sessions: 2 pre-tests (week 1), 8 training sessions (weeks 2-5), and 1 post-test (week 6). The STG performed the BP at the 70-90% of the one-repetition maximum (1RM), and the BTG the BP throw at the 40% of 1RM. BP performance (BP 1RM and maximum velocity achieved against 20 kg [BP20]) and HTV were assessed before and after training. RESULTS: The STG enhanced BP 1RM (effect size [ES]=0.24) but not BP20 (ES=0.21) or HTV (ES=0.10). The BTG enhanced BP20 (ES=0.63) but not BP1RM (ES=0.27) or HTV (ES=0.02). HTV was not significantly correlated with the BP 1RM (r≤0.181) or BP20 (r≤0.220). CONCLUSIONS: These results indicate that a short-term RT program based exclusively on the BP exercise performed against either heavy (strength-oriented) or light loads (ballistic) is not effective to increase HTV in resistance-trained men with little handball experience.

Influence of Grip Width and Anthropometric Characteristics on the Bench-Press Load-Velocity Relationship.

PURPOSE: To compare the load-velocity (L-V) relationship between bench-press exercises performed using 4 different grip widths, to determine the association between the anthropometric characteristics and L-V profile, and to explore whether a multiple linear-regression model with movement velocity and subjects' anthropometric characteristics as predictor variables could increase the goodness of fit of the individualized L-V relationship. METHODS: The individual L-V relationship of 20 men was evaluated by means of an incremental loading test during the bench-press exercise performed on a Smith machine using narrow, medium, wide, and self-selected grip widths. Simple and multiple linear-regression models were performed. RESULTS: The mean velocity associated with each relative load did not differ among the 4 grip widths (P ≥ .130). Only body height and total arm length were correlated with the mean velocity associated with light and medium loads (r ≥ .464). A slightly higher variance of the velocity attained at each relative load was explained when some anthropometric characteristics were used as predictor variables along with the movement velocity (r2 = .969 [.965-.973]) in comparison with the movement velocity alone (r2 = .966 [.955-.968]). However, the amount of variance explained by the individual L-V relationships was always higher than with the multiple linear-regression models (r2 = .995 [.985-1.000]). CONCLUSIONS: These results indicate that the individual determination of the L-V relationship using a self-selected grip width could be recommended to monitor relative loads in the Smith machine bench-press exercise.

Reliability of isometric and isokinetic trunk flexor strength using a functional electromechanical dynamometer.

AIM: To determine the absolute and relative reliability of functional trunk tests, using a functional electromechanical dynamometer to evaluate the isokinetic strength of trunk flexors and to determine the most reliable assessment condition, in order to compare the absolute and relative reliability of mean force and peak force of trunk flexors and to determine which isokinetic condition of evaluation is best related to the maximum isometric. METHODS: Test-retest of thirty-seven physically active male student volunteers who performed the different protocols, isometric contraction and the combination of three velocities (V1 = 015 m s-1 , V2 = 0.30 m  s-1, V3 = 0.45 m s-1) and two range of movement (R1 = 25% cm ; R2 = 50% cm) protocols. RESULTS: All protocols to evaluate trunk flexors showed an absolute reliability provided a stable repeatability for isometric and dynamic protocols with a coefficient of variation (CV) being below 10% and a high or very high relative reliability (0.69 < intraclass correlation coefficient [ICC] > 0.86). The more reliable strength manifestation (CV = 6.82%) to evaluate the concentric contraction of trunk flexors was mean force, with 0.15 m  s-1 and short range of movement (V1R1) condition. The most reliable strength manifestation to evaluate the eccentric contraction of trunk flexors was peak force, with 0.15 m  s-1 and a large range of movement (V1R2; CV = 5.07%), and the most reliable way to evaluate isometric trunk flexors was by peak force (CV = 7.72%). The mean force of eccentric trunk flexor strength with 0.45 m  s-1 and short range of movement (V3R1) condition (r = 0.73) was best related to the maximum isometric contraction. CONCLUSION: Functional electromechanical dynamometry is a reliable evaluation system for assessment of trunk flexor strength.

Efecto agudo de un protocolo de Complex Training sobre la velocidad del lanzamiento de la granada en pentatletas militares / Acute effect of Complex Training protocol on grenade throwing velocity on military pentathletes

Introducción: El Complex Training se ha utilizado para lograr la potenciación post-activación (PAP) de las capacidades físicas y, al hacerlo, mejorar el rendimiento deportivo de los atletas. Sin embargo pocos estudios han considerado una activación con intensidades en zonas de potencia. Objetivo: Determinar el efecto agudo de un protocolo de Complex Training en press banca sobre la velocidad del lanzamiento de la granada en pentatletas militares. Método: Diecinueve pentatletas militares fueron parte del estudio. El estudio tuvo un diseño cuasi experimental intrasujeto. El protocolo de Complex Training consistió en: 4 series de 5 repeticiones al 30% de 1RM + 4 repeticiones al 60% de 1RM + 3 lanzamientos de granada separada por 15 segundos. Las variables medidas fueron: velocidad máxima (Vmax) y promedio (Vpro) del lanzamiento de la granada a través de un Radar Gun, las potencias máximas (Pmax) y promedio (V pro) en press banca a través de un encoder lineal y concentraciones de lactato [La] post esfuerzo. Para el análisis estadístico se utilizó ANOVA de medias repetidas y para el tamaño del efecto la prueba Eta Cuadro Parcial. Resultados: La Vmax, Vpro y Pmax no presentaron modificaciones significativas entre la serie control y las cuatro series experimentales (p = 0,90; p = 0,94; p = 0,06). Sin embargo las Ppro de press banca y las [La] sufrieron un descenso significativo (p = 0,002; p = 0,001). Conclusiones: Los resultados del estudio no mostraron efectos positivos del protocolo de Complex Training sobre las velocidades de lanzamiento de la granada en pentatletas militares, por lo tanto no se consiguió PAP en la musculatura involucrada en el lanzamiento del proyectil. También se observó fatiga general y local durante la aplicación del protocolo. Se sugiere seguir indagando las cargas de activación realizando cambios en la intensidad y pausas de las cargas

Introduction: Complex Training (CT) has been used to achieve Post-activation Potentiation (PAP) of physical capabilities and, in doing so, improve athletes’ sports performance, however few studies have taking into account an activation with intensities in power zones. Objective: To determine the acute effect of Complex Training on bench press on grenade throwing velocity on military pentathletes. Method: Nineteen military pentathletes were part of the study. The study had a quasi-experimental intra-subject design. The Complex Training protocol consisted of 4 sets of 5 repetitions at 30% one Repetition Maximum (1RM) + 4 repetitions at 60% 1RM + 3 grenade throws with a 15-second rest. The measured variables were: maximum velocity and grenade throw average through a Radar Gun, peak power and bench press average through a lineal encoder and post-effort Lactate [La]. For the statistical analysis repeated measures of ANOVA was used, and for the size of the effect an Eta-squared test was used. Results: The maximum velocity, average velocity and peak power did not show significant modifications between the control series and the 4 experimental series (p = 0.90; p = 0.94; p = 0.06). However, the average power of bench press and [La] showed a significant fall (p = 0.002: p = 0.001). Conclusions: The results of the study did not show effects in Complex Training on maximum and average velocity of grenade throwing in military pentathletes; hence, Post Activation Potentiation was not reached in the muscles involved in the projectile throwing. General and local fatigue was also observed during the application of the protocol. It is recommended to continue researching on activation loads, performing changes in the intensity and pauses of each load

Efecto de la resistencia variable sobre la potenciación post activación: una revisión sistemática / Effect of variable resistance on post-activation potentiation: a systematic review

Introducción: Tanto la Resistencia Variable (RV) como la Potenciación Post Activación (PAP) han sido utilizadas como metodologías de entrenamiento para mejorar la fuerza explosiva en deportistas, pero hasta el momento no se sabe cuántas investigaciones existen en las principales bases de datos que relacionen ambas variables. Objetivo: Investigar cuáles fueron los métodos de RV utilizados para generar PAP entre enero de 2011 y enero de 2016. El objetivo secundario fue visualizar las intensidades de estimulación y los cambios en los niveles de fuerza explosiva reportados en cada uno de los estudios consultados. Método: El diseño corresponde a una Revisión Sistemática de los estudios previamente publicados que relacionaron la RV con PAP. La búsqueda sistemática incluyó artículos publicados desde enero de 2011 a enero de 2016 en Web of Science (WOS), Scopus, Sport Discuss, PubMed y Medline. Para la selección de los estudios, se identificaron sólo aquellos artículos que usaron RV como metodología de entrenamiento para generar PAP. Resultados: Se identificaron nueve artículos, los cuales fueron estratificados según el entrenamiento que realizaban: (i) Resistencia variable intra-sesión (n = 3), (ii) Resistencia variable intra-repetición (n =1) y (iii) Resistencia variable intra-serie (n = 5). Por otro lado, ocho de los nueve estudios consultados estuvieron centrados en los miembros inferiores y ninguno de forma específica en los miembros superiores. También se pudo observar, que todos aquellos estudios que reportaron cambios significativos en la fuerza explosiva trabajaron sobre el 80 % de 1RM. Conclusiones: No existe evidencia suficiente para conocer el verdadero efecto de la RV sobre la PAP, más aún en los miembros superiores. Sin embargo, hay indicios que la resistencia variable intra-serie puede generar cambios agudos en los niveles de fuerza explosiva trabajando sobre un 80 % de 1RM

Introduction: The Variable Resistance (VR), as well as the Post-Activation Potentiation (PAP) have been used as training methodologies to improve the explosive strength in athletes. By the moment, there is no specific knowledge of the number of investigations connecting both variables that exist in the main data bases. Objective: The aim of this study was to find out which were the VR methods used to generate PAP between January 2011 and January 2016. The secondary aim was to visualize the stimulus intensity and the variations in the explosive strength levels recounted in every one of the studies consulted for this research. Method: the design is a systematic revision of the studies previously published that connected VR with PAP. The systematic research included articles published since January 2011 until January 2016 in the Web of Science (WOS), Scopus, Sport Discuss, PubMed, and Medline. For the studies selection, only those articles using VR as a training methodology to generate PAP were identified. Results: Nine articles were identified, which were stratified according to the training performed: (i) Intra-Session Variable Resistance (n = 3), (ii) Intra-Repetition Variable Resistance (n = 1), and (iii) Intra-Set Variable Resistance (n = 5). On the other hand, eight out of nine studies were focused on the lower limbs and none of them focused specifically on the upper limbs. It was also observed that all those studies showing significant variation in explosive strength worked with over 80 % 1RM. Conclusions: There is no conclusive evidence to identify the real effect of VR over PAP, and clearly not for the upper limbs. However, there are indicators that the Intra-Set Variable Resistance can generate acute changes in the explosive strength levels working over 80 % 1RM

Efectos de la actividad física sobre las funciones ejecutivas en una muestra de adolescentes / Effects of physical activity on executive function in a sample of adolescents

El propósito de este trabajo fue analizar los efectos de un programa de actividad física, con una duración de 8 semanas y basado en juegos reducidos, sobre diversas variables cognitivas vinculadas al constructo funciones ejecutivas como memoria de trabajo, inhibición y flexibilidad cognitiva. Los participantes fueron 54 adolescentes, físicamente inactivos, de la ciudad de Priego (Córdoba, España), con edades entre los 15 y 16 años (M= 15.35; DT= .48). Se empleó un diseño pre-post con dos grupos aleatorizados, control y experimental. Los instrumentos utilizados para evaluar las habilidades cognitivas fueron el test Dígitos y el test Letras y Números, de la Escala de Inteligencia de Wechsler para Niños (WISC-IV), el Trail Making Test y el Test Stroop. Se realizó un análisis de la varianza mixta 2x2 para determinar los efectos del tratamiento. Los resultados indicaron efectos positivos del programa de actividad física sobre la memoria de trabajo y la flexibilidad cognitiva, aunque con un tamaño del efecto bajo. Se propone incrementar el tiempo de intervención y aplicar diferentes programas para observar el impacto del tipo de actividad en futuras investigaciones

The aim of this study was to analyse the effects of a physical activity program, eight-week and based on small sided games, on some variables associated to executive functions construct such as working memory, inhibition and cognitive flexibility. The participants in the study were 54 adolescents, who were physically inactive, from the city of Priego (Córdoba, Spain), whose age ranged between 15 and 16 years old (M=15.35; SD= .48). The study was based on a quasi-experimental pre-post design with two randomized groups, control and experimental. The instruments used to evaluate the cognitive skills were Digits and Letters and Numbers tests of the Wechsler Intelligence Scale for Children (WISC-IV), the Trail Making Test (A and B) and the Stroop Test. It was realized an analysis of the mixed variance 2x2 to determine the effects of the treatment. Results showed positive effects of the physical activity program on working memory and cognitive flexibility, although the effect size was weak. It is proposed to increase the time of intervention and apply different treatments to observe the impact of type of activity for future research