Can the Supido Radar Be Used for Measuring Ball Speed during Soccer Kicking? A Reliability and Concurrent Validity Study of a New Low-Cost Device.

The aim was to analyze the reliability and validity of a low-cost instrument, based on a radar system, to quantify the kicking ball speed in soccer. A group of 153 male soccer players (under-13, n = 53; under-15, n = 54; under-18, n = 46) participated in this study. Each player performed three kicks on the goal in a standardized condition while the ball speed was measured with three different devices: one Radar Stalker ATS II® (reference criterion) and two Supido Radar® (Supido-front of the goal and Supido-back of the goal). The standard error of measurement (SEM) expressed as a coefficient of variation (CV) and the intraclass correlation coefficient (ICC) were employed for assessing the reliability of each instrument. Stalker and Supido-back showed very high absolute (CV = 4.0-5.4%) and relative (ICC = 0.945-0.958) reliability, whereas Supido-front resulted in moderate to low reliability scores (CV = 7.4-15%, ICC = 0.134-0.693). In addition, Lin's concordance correlation coefficient (CCC) values revealed an 'almost perfect' agreement between Stalker and Supido-back for the average (r = 0.99) and maximal (r = 0.98) ball speed, regardless of the ball speed range analyzed. However, Supido-front resulted in a poor degree of concordance (CCC = 0.688) and a high magnitude of error (17.0-37.5 km·h-1) with the reference Stalker radar gun. The Supido Radar® placed behind the goal could be considered a reliable and valid device for measuring ball speed in soccer.

Effects of fatigue induced by repeated-sprint on kicking accuracy and velocity in female soccer players.

The aim of this study was to investigate the effects of fatigue induced by repeated sprint in the kicking accuracy and velocity in female soccer players. Eighteen Under-23 female soccer players from a Spanish professional club were subjected to a fatigue protocol based on a repeated-sprint ability (RSA) test. Measurements of the kicking velocity (maximal ball velocity) and accuracy (Loughborough Soccer Shooting Test) were taken before and after fatigue induction. Correlations between the change in the maximal ball velocity/accuracy and the heart rate (HR), the fatigue index (FI), the sprint decrement (Sdec) and the rating of perceived exertion (RPE) were made. There was a significant difference between maximal ball velocity under fatigue conditions with respect to non-fatigue conditions (p = 0.001; ES = 0.89). However, despite a lower kicking accuracy punctuation with fatigue, this was not statistically significant (p = 0.433; ES = 0.22). Significant correlations were found between the maximal kicking velocity and the FI (r = 0.632, p < 0.01) and the Sdec (r = -0.554, p < 0.05) and between the kicking accuracy and the RPE (r = -0.506, p < 0.05). In conclusion, there was a significant reduction in the maximal kicking velocity, but not in the kicking accuracy, under fatigued conditions. The RSA-related FI and Sdec were the best predictors of the maximal kicking velocity and the RPE for the kicking accuracy.

Relationships between fitness test and kicking velocity in young soccer players.

BACKGROUND: To study the relation between fitness test and kicking velocity in young soccer players, which has not been previously studied in this group of age. METHODS: Ninety-eight Under-11 soccer players who belonged to two professional Spanish clubs and two amateur clubs were subjected to sprint test (15 and 30 meters), countermovement jump (CMJ), estimation of maximal oxygen intake (VO2max), kicking velocity test, fatigue index of jump height and anthropometrical measures. RESULTS: Kicking velocity was significantly correlated (P<0.05) with 15-m sprint (r=-0.554) and 30-m sprint (r=-0.587), CMJ height (r=0.479), VO2max (r=0.475), body mass (r=0.311) and height (r=0.529), but not with Body Mass Index (BMI) (r=-0.011) and Fatigue Index of jump height (r=-0.05). CONCLUSIONS: This study provides new data about correlations between kicking velocity and fitness test, establishing greater correlations between kicking velocity and other variables compared to other groups of age previously studied, suggesting high transferences between results in fitness test and kicking velocity.

Effects of Muscle Fatigue Induced by Countermovement Jumps on Efficacy Parameters of Instep Ball Kicking in Soccer.

The purpose was to study the effects of muscle fatigue induced by countermovement jumps (CMJ) on instep kick foot velocity in young male soccer players. Fifteen under-18 soccer players from a professional club performed maximal velocity instep kicks before and after a fatigue protocol that consisted of continuous CMJ. Foot velocity at impact without fatigue, foot velocity at impact with fatigue, CMJ height without fatigue, maximum jump height in fatigue test, and CMJ height change in fatigue test on a dynamometric platform were measured. There was a significant difference between jump height with and without fatigue (P = .00; ES = 0.8), but there were no significant differences between kicking with fatigue and without fatigue (P = .580, ES = 0.10). In conclusion, although the protocol was intense enough to generate fatigue in the muscles involved in CMJ, there were no significant differences in kicking velocity under fatigue conditions with respect to kicking without fatigue in the soccer players studied.

Comparison of the effect of repeated-sprint training combined with two different methods of strength training on young soccer players.

The aim of this study was to assess the effect of combining repeated-sprint training with 2 different methods of muscle strength training on physical performance variables in young players. Twenty-one soccer players with mean (± SD) age of 18.1 (± 0.8) years, weight 69.9 (± 6.5) kg, and height 177.1 (± 5.7) cm, and competing in U-19 category, were randomly assigned to 2 experimental groups: squat group (SG: n = 10) and take-off group (TG: n = 11). Intervention in both groups consisted of the combination of a weekly session of repeated-sprint training (the same for both groups), with 2 weekly sessions of strength training (different for each group), for 8 weeks in the final period of the season. The strength sessions for the SG consisted of conducting a series of full squats executed at maximum velocity in the concentric phase. Intervention in the TG was the performance of 2 specific strength exercises (take-offs and change of direction), with measurements taken before and after consideration of the following variables: repeated-sprint ability (RSA), yo-yo intermittent recovery test level 1 (YYIRT1), countermovement jump (CMJ), and average velocity in full squat progressive loads test. The SG improved CMJ height in 5.28% (p ≤ 0.05) and FS37.5-47.5-67.5 (p ≤ 0.05), whereas the TG improved FS17.5-27.5-37.5-47.5-67.5 (p ≤ 0.05). There were no significant changes in the values of RSA or YYIRT1 in either group. The results seem to show that the combination of a weekly session of repeated-sprint training with 2 weekly sessions of strength training could be an insufficient stimulus to improve RSA in the final period of the season.

Effect of phlebodium decumanum on the immune response induced by training in sedentary university students.

Exercise training is considered a good model to provoke different degrees of immune dysfunction affecting physical performance and some physiological responses related to oxidative stress and low grade inflammation. Phlebodium decumanum is a polypodiaceae may induce shown immunomodulating effects, specifically directed to the release of proinflammatory cytokines by macrophages in response to various stimuli, as reported different in vitro studies. The aim of this study was to evaluate the modulating effect of phlebodium decumanum, on the immune response induced by physical exercise. Thirty-one subjects (males only) were randomly divided into two groups: Group PD (n = 18); age: 22.1 ± 1.81, weight 74.21 ± 8.74 kg) that was treated with phlebodium decumanum; Group P (n = 13); age: 22.5 ± 1.63, weight 78 ± 12.5 kg) that was treated with a placebo. Before and after one month training program performed by both groups (three times a week), the following performance parameters and immune response variables were measured: Dynamic Maximum Force; Interval-Training; Tennis test; pro-inflammatory (TNF , IL6) and anti-inflammatory (TNFα-IIrs, IL1-ra) cytokines levels. Data were statistically analyzed with Mann- Whitney U test and Wilcoxon paired test (p < 0.05). Statistically significant differences were recorded within groups before and after the training program. PD group showed a significant improvement in the performance parameters (Strength Muscle Test: dorsal: p < 0.002; deltoids: p < 0.03; and pectorals: p < 0.07; Interval Training: p < 0.06; Tennis Test: p < 0.02). Cytokine levels resulted in a more positive profile in the PD group rather than in the P group, in which higher levels of IL-6 (p < 0.02) and a reduction of TNF-IIrs (p < 0.003) and IL1-ra (p < 0.03) were recorded. In this study the use of phlebodium decumanum demonstrated beneficial effects in the modulation of the immune response during physical performance. Key pointsPracticing sport or physical activity of medium-high intensity three times a week during 4 weeks induces changes in immune response indicators levels;The assumption of phlebodium decumanum induced a reduction in pro-inflammatory cytokines levels and a higher concentration of anti-inflammatory cytokines.Anti-inflammatory cytokines have a protective and modulating effect on the immune response.

Impedancia bioeléctrica como método para estimar cambios en los fluídos corporales en remeros / Bioelectric impedance analysis as method to estimate body fluid changes in rowers

La valoración de líquidos corporales en el deportista, agua corporal total (ACT), agua intracelular (AI) y agua extracelular (AE), es un factor de suma importancia para el entrenamiento y la competición. La impedancia bioeléctrica (BIA) es cada vez más utilizada en el ámbito de la salud y del deporte por ser un método simple y no invasivo. El objetivo de este estudio es analizar la capacidad de la BIA de última generación para detectar cambios en los fluidos corporales debidos a la deshidratación inducida por el ejercicio. Se estudiaron 19 remeros. Antes del ejercicio se valoró su composición corporal con método antropométrico como modelo de referencia y se estimaron el ACT, AI y AE con un aparato BIA segmental y multifrecuencia. Seguidamente se sometió a los deportistas a una sesión de entrenamiento sobre remoergómetro de 56 minutos de duración. Al finalizar fueron pesados nuevamente y sometidos a una segunda evaluación con BIA. La pérdida de líquido corporal inducida por el ejercicio y medida con balanza arrojó resultados significativos, siendo de 1,6 ± 0,36 kg. Sin embargo, las diferencias registradas por BIA, antes y después del ejercicio, para el ACT, AI yAE, no fueron significativas (p < 0,05).Tampoco se ha encontrado concordancia entre el método de balanza y el método BIA para estimar cambios en líquidos corporales y se ha hallado una media para las diferencias de 1,24 kg. Por lo tanto, concluimos que BIA no sirve para registrar cambios en los compartimentos acuosos corporales tras una sesión de ejercicio, ya que los niveles hídricos se registraron de forma cuantitativamente incorrecta (AU)

Evaluating the body fluids in athletes, as well as their total body water (TBW), intra (ICW) and extracelular water (ECW), is an important factor for the training and competition. Bioelectric Impedance Analysis (BIA) is becoming more and more useful in both heath and sport fields becauseit is a simple and non invasive method. The purpose of this study is to analyse the capability of state-of-the-art BIA devices in order to check any changes in body fluids due to de hydration as a consequence of exercise. The 19 rowers participating in this study. Before the exercise we evaluated their body composition with the anthropometric method as a reference model, and we estimated the TBW, ICW and ECW with a segmental and multifrequency BIA. Afterwards, subjects went through a 56-minutetraining session by ergo-rower. When finishing they we reweighed and subjected to a second evaluation. The loss of body fluids due to exercise and measured with the bascule provided us with significant results, 1.6 ± 0.4kg. However, the different values recorded by BIA, before and after the exercise for the TBW, ICW and ECW were not significant (p < 0.05).Concordance Bland-Altman analysis not confirmed good agreement between the bascule and the BIA methods, in order to estimate the change in body fluids. The average one for the estimation difference was 1.24 kg. Therefore we conclude that BIA is not used to record changes in body water compartments after a workout because water levels were recorded on a quantitatively incorrect (AU)

Análisis de la capacidad ergogénica del consumo de phlebodium decumanum en sujetos universitarios no entrenados / Evaluation of the ergogenic capacity of phlebodium decumanum in untrained universitary subjects

El objetivo de este estudio es demostrar si el aporte dietético de un preparado a base de Phlebodium Decumanum, tiene efectos ergogénicos sobre el rendimiento físico-deportivo. Para ello se sometió a 31 sujetos a un programa de acondicionamiento físico general. Se randonÍizó la muestra para obtener dos grupos, a uno de ellos se suplementó con el Phlebodium Decumanum (Grupo PD) (edad: 22.1+/- 1.81, peso 74.21+/-8.74 kg.), mientras que al otro se le administrÓ un placebo (Grupo P) (edad: 22.5+/-1.63, peso 78+/-12.5 kg.). Tras un mes de entrenamiento a razón de 3 sesiones semanales se controlaron variables de rendimiento físico y deportivo: Fuerza Máxima Dinámica, Interval- training, y test de tenis en cancha. Se recogieron medidas pre y postratamiento no encontrando diferencias significativas intergrupo en los contrastes de los pretest. Sin embargo, en los resultados obtenidos en los postest sí hallamos diferencias significativas en todas las variables estudiadas al comparar los grupos entre sí, mejorando en mayor medida el G.PD que el G.P: Test de Fuerza: Dorsales: G.P: 7.59 +/- 9.52 y G.PD: 22.35+/-19.11; p<0.002, hombros: G.P: 16.30 +/- 29.82 Y G.PD: 50.82 +/- 40.06; p

The aim of this study is to assess if the dietary dos e of a preparation from Phlebodium Decumanum, provides ergogenic effects over the sport performance.31 healthy subjects underwent a fitness training program including tennis practice. This sample was randomized in orderto obtain two groups: one (PD group; 22.1+/- 1.81 years, 74.21 +/- 8.74 kg) was supplemented with Phlebodium Decumanum and the other (Control group; 22.5 +/- 1.63 years, 78 +/- 12.5 kg ) toke a placebo. Before and after one month training with a frequency of 3 sessions a week, several variables of performance were assessed: maximal strengh, interval-training and an specific tennis test. In the previous measures there were no significant differences between groups. In the post-training results we found important differences between the two groups in all parameters in favor of PD group: dorsal strengh: G.P: 7.59 +/- 9.52 y G.PD: 22.35 +/- 19.11; p<0.002, shoulders strengh: G.P: 16.30 +/- 29.82 y G.PD: 50.82 +/- 40.06; p