Vitor Luiz de Andrade

Running-based Anaerobic Sprint Test as a Procedure to Evaluate Anaerobic Power

The aim of this study was to evaluate the use of the running anaerobic sprint test (RAST) as a predictor of anaerobic capacity, compare it to the maximal accumulated oxygen deficit (MAOD) and to compare the RASTs parameters with the parameters of 30-s all-out tethered running on a treadmill. 39 (17.0±1.4 years) soccer players participated in this study. The participants underwent an incremental test, 10 submaximal efforts [50-95% of velocity correspondent to VO(2MAX) (vVO(2MAX))] and one supramaximal effort at 110% of vVO(2MAX) for the determination of MAOD. Furthermore, the athletes performed the RAST. In the second stage the 30-s all-out tethered running was performed on a treadmill (30-s all-out), and compared with RAST. No significant correlation was observed between MAOD and RAST parameters. However, significant correlations were found between the power of the fifth effort (P5) of RAST with peak and mean power of 30-s all-out (r=0.73 and 0.50; p<0.05, respectively). In conclusion, the parameters from RAST do not have an association with MAOD, suggesting that this method should not be used to evaluate anaerobic capacity. Although the correlations between RAST parameters with 30-s all-out do reinforce the RAST as an evaluation method of anaerobic metabolism, such as anaerobic power.

Relationship of aerobic and anaerobic parameters with 400 m front crawl swimming performance

The aims of the present study were to investigate the relationship of aerobic and anaerobic parameters with 400 m performance, and establish which variable better explains long distance performance in swimming. Twenty-two swimmers (19.1±1.5 years, height 173.9±10.0 cm, body mass 71.2±10.2 kg; 76.6±5.3% of 400 m world record) underwent a lactate minimum test to determine lactate minimum speed (LMS) (i.e., aerobic capacity index). Moreover, the swimmers performed a 400 m maximal effort to determine mean speed (S400m), peak oxygen uptake (V.O2PEAK) and total anaerobic contribution (CANA). The CANA was assumed as the sum of alactic and lactic contributions. Physiological parameters of 400 m were determined using the backward extrapolation technique (V.O2PEAK and alactic contributions of CANA) and blood lactate concentration analysis (lactic anaerobic contributions of CANA). The Pearson correlation test and backward multiple regression analysis were used to verify the possible correlations between the physiological indices (predictor factors) and S400m (independent variable) (p < 0.05). Values are presented as mean ± standard deviation. Significant correlations were observed between S400m (1.4±0.1 m·s-1) and LMS (1.3±0.1 m·s-1; r = 0.80), V.O2PEAK (4.5±3.9 L·min-1; r = 0.72) and CANA (4.7±1.5 L·O2; r= 0.44). The best model constructed using multiple regression analysis demonstrated that LMS and V.O2PEAK explained 85% of the 400 m performance variance. When backward multiple regression analysis was performed, CANA lost significance. Thus, the results demonstrated that both aerobic parameters (capacity and power) can be used to predict 400 m swimming performance.

Efeito das cargas de treinamento sobre parâmetros fisiológicos de futebolistas

The aim of this study was to investigate the effects of three weeks of training with intensity monitored on the aerobic capacity of professional soccer players. Fourteen players, members of a first division Brazilian Championship team in 2010, aged 22.78 ± 3.06 years were evaluated pre and post three weeks of training. The anaerobic threshold intensity LAn was determined by bi-segmented method, for this four submaximal efforts of 800 meters with intensities 10, 12, 14 and 16 km/h were applied. Thirty three training sessions were quantified in zones according to heart rate related to the LAn (FCLAn): Z1 - 10% below, Z2 - 90-100% and Z3 - above the FCLAn. During training participants remained 31.17 ± 14.86%, 42.96% and 25.87 ± 14.90 ± 16.67% in Z1, Z2, and Z3 respectively. There were no significant differences in the LAn (pre = 13,29 ± 0,71 km∙h-1; post = 12,85 ± 0,90 km∙h-1), perceived exertion (pre = 11,53 ± 1,45 u.a; post = 11,23 ± 1,53 u.a) and FCLAn (pre = 166,64 ± 10,69 bpm; post = 174,50 ± 10,89 bpm) between conditions before and after training, indicating that three weeks of training are insufficient to generate positive changes in soccer players LAn.

Preliminary results on organization on the court, physical and technical performance of Brazilian professional futsal players: comparison between friendly pre-season and official match

The main aim of this study was to verify possible differences between a friendly pre-season match (FM) and an official in-season match (OM) regarding physical, technical, and organizational performances of a professional Brazilian futsal team. Ten professional futsal athletes participated in this study. The matches were monitored with video cameras (30 Hz) and athlete trajectories obtained with automatic tracking. The values obtained for distance covered per minute, percentage of distance covered at moderate intensity, team coverage area, spread, passes, possessions, ball touches and successful passes per minute were greater for the OM than FM. On the contrary, percentage of distance covered, standing and walking was greater for the FM than OM. We concluded that physical, technical, and tactical performances are different between a FM and an OM in futsal and also these parameters mutually influenced each other distinctly. Future studies should verify whether pre-season tournaments reproduce similar demands to a regular season official match.

Influência da aptidão aeróbia no running anaerobic sprint test (RAST)

El objetivo de este estudio fue investigar la posible influencia de los diferentes niveles de aptitud aerobica (VO2MAX) en los parametros del running anaerobic sprint test (RAST). Trinta y ocho pacientes (edad = 18,1 ± 2,5 anos, altura = 173 ± 1 cm y masa corporal = 65,1 ± 6,5 kg) fueron clasificados en dos grupos, de baja y alta potencia aerobica (BPA: n = 22 y APA: n = 16). El VO2MAX se determino mediante un test de ejercicio progresivo realizado hasta el agotamiento. El RAST se compone de seis esfuerzos maximos de 35m separadas por 10s de recuperacion pasiva. El VO2MAX fue significativamente diferente entre los grupos (BPA = 51,7 ± 1,9 mL.kg-1.min-1; APA = 58,6 ± 3,1 mL.kg1.min-1). La potencia media (MP) fue significativamente mayor en el BPA (552.7 ± 132.1 W) en relacion con el grupo APA (463.6 ± 132.8 W). El impulso (ImP) se correlaciono significativamente con el VO2MAX en APA. Se puede concluir que no hay una indicacion de que el metabolismo aerobico ejerce una influencia sobre la finalizacion de RAST.

EFEITO DO TREINO NEUROMUSCULAR NA ROTAÇÃO DO JOELHO DURANTE A ATERRISSAGEM EM MULHERES

Introduction: The high rate of injuries of the anterior cruciate ligament (ACL) without involving contact in women is a source of curiosity among scientists, because drop landing assessments may suggest a predisposition to the risk of this injury. In these sense, several training protocols have been used as an intervention and achieved mixed results in the change of this risk factor. Objective: The aim of this project was to evaluate the possible changes of rotation knee in single-leg drop landing after the intervention of a neuromuscular training program. Methods: The study included 18 women aged between 18 and 51 years, who were divided into two groups: neuromuscular training group (NTG) (n=11) and control group (CG) (n=7). In addition, they did not have musculoskeletal injury or pain in the lower limbs. Each participant completed five valid single-leg drop landings from a platform of 40 cm. The motion capture process was carried out with 12 infrared cameras of the OptiTrackTM system to obtain three-dimensional coordinates of markers fixed in the anatomical points of interest. The local coordinate systems of the thigh and leg were defined by means of the respective markers set in the anatomical points. Thus, the knee rotation angles in the sagittal, frontal, and transverse planes were calculated through the sequence of Euler angles and the angular velocities were calculated using the formulations of quaternions. Results: The results showed an increase in the knee rotation speed after the neuromuscular training. Conclusion: We conclude that neuromuscular training resulted in faster rotation at the knee in the 40 milliseconds succeeding the single-leg landing.Introduccion: El gran numero de lesiones del ligamento cruzado anterior sin que implique un contacto en las mujeres es motivo de curiosidad entre los cientificos porque las evaluaciones de aterrizaje pueden sugerir predisposicion al riesgo de esta lesion. En este sentido, varios protocolos de entrenamiento se han utilizado como intervencion y lograron resultados mixtos en el cambio de este factor de riesgo. Objetivo: El objetivo de este proyecto fue evaluar los posibles cambios de rotacion de la rodilla en el aterrizaje unipodal despues de la intervencion de un programa de entrenamiento neuromuscular. Metodos: El estudio incluyo a 18 mujeres de edades comprendidas entre 18 y 51 anos, que fueron divididas en dos grupos: grupo de entrenamiento neuromuscular de ocho semanas (GEN) (n = 11) y grupo control (GC) (n = 7). Ademas, no tenian lesion musculoesqueletica o dolor en las extremidades inferiores. Cada participante realizo cinco aterrizajes unipodales validos desde una plataforma de 40 cm. El proceso de captura de movimiento se llevo a cabo con 12 camaras infrarrojas del sistema OptiTrack(tm) para obtener las coordenadas tridimensionales de los marcadores fijados a los puntos anatomicos de interes. Los sistemas de coordenadas locales del muslo y la pierna se definieron por medio de los respectivos marcadores establecidos en los puntos anatomicos. De esa manera, fueron calculados los angulos de rotacion de la rodilla en los planos sagital, frontal y transversal utilizando las secuencias de los angulos de Euler, y las velocidades angulares utilizando las formulaciones de cuaterniones. Resultados: Los resultados mostraron un aumento en la velocidad de rotacion de la rodilla despues del entrenamiento neuromuscular. Conclusion: Se concluye que el entrenamiento neuromuscular resulto en mayor velocidad de rotacion en la rodilla en los 40 milisegundos posteriores al aterrizaje unipodal.

EFECTO DEL ENTRENAMIENTO NEUROMUSCULAR EN LA ROTACIÓN DE LA RODILLA DURANTE EL ATERRIZAJE EN LAS MUJERES

Introduction: The high rate of injuries of the anterior cruciate ligament (ACL) without involving contact in women is a source of curiosity among scientists, because drop landing assessments may suggest a predisposition to the risk of this injury. In these sense, several training protocols have been used as an intervention and achieved mixed results in the change of this risk factor. Objective: The aim of this project was to evaluate the possible changes of rotation knee in single-leg drop landing after the intervention of a neuromuscular training program. Methods: The study included 18 women aged between 18 and 51 years, who were divided into two groups: neuromuscular training group (NTG) (n=11) and control group (CG) (n=7). In addition, they did not have musculoskeletal injury or pain in the lower limbs. Each participant completed five valid single-leg drop landings from a platform of 40 cm. The motion capture process was carried out with 12 infrared cameras of the OptiTrackTM system to obtain three-dimensional coordinates of markers fixed in the anatomical points of interest. The local coordinate systems of the thigh and leg were defined by means of the respective markers set in the anatomical points. Thus, the knee rotation angles in the sagittal, frontal, and transverse planes were calculated through the sequence of Euler angles and the angular velocities were calculated using the formulations of quaternions. Results: The results showed an increase in the knee rotation speed after the neuromuscular training. Conclusion: We conclude that neuromuscular training resulted in faster rotation at the knee in the 40 milliseconds succeeding the single-leg landing.Introduccion: El gran numero de lesiones del ligamento cruzado anterior sin que implique un contacto en las mujeres es motivo de curiosidad entre los cientificos porque las evaluaciones de aterrizaje pueden sugerir predisposicion al riesgo de esta lesion. En este sentido, varios protocolos de entrenamiento se han utilizado como intervencion y lograron resultados mixtos en el cambio de este factor de riesgo. Objetivo: El objetivo de este proyecto fue evaluar los posibles cambios de rotacion de la rodilla en el aterrizaje unipodal despues de la intervencion de un programa de entrenamiento neuromuscular. Metodos: El estudio incluyo a 18 mujeres de edades comprendidas entre 18 y 51 anos, que fueron divididas en dos grupos: grupo de entrenamiento neuromuscular de ocho semanas (GEN) (n = 11) y grupo control (GC) (n = 7). Ademas, no tenian lesion musculoesqueletica o dolor en las extremidades inferiores. Cada participante realizo cinco aterrizajes unipodales validos desde una plataforma de 40 cm. El proceso de captura de movimiento se llevo a cabo con 12 camaras infrarrojas del sistema OptiTrack(tm) para obtener las coordenadas tridimensionales de los marcadores fijados a los puntos anatomicos de interes. Los sistemas de coordenadas locales del muslo y la pierna se definieron por medio de los respectivos marcadores establecidos en los puntos anatomicos. De esa manera, fueron calculados los angulos de rotacion de la rodilla en los planos sagital, frontal y transversal utilizando las secuencias de los angulos de Euler, y las velocidades angulares utilizando las formulaciones de cuaterniones. Resultados: Los resultados mostraron un aumento en la velocidad de rotacion de la rodilla despues del entrenamiento neuromuscular. Conclusion: Se concluye que el entrenamiento neuromuscular resulto en mayor velocidad de rotacion en la rodilla en los 40 milisegundos posteriores al aterrizaje unipodal.

NEUROMUSCULAR TRAINING EFFECT ON KNEE ROTATION DURING DROP LANDING IN WOMEN

Introduction: The high rate of injuries of the anterior cruciate ligament (ACL) without involving contact in women is a source of curiosity among scientists, because drop landing assessments may suggest a predisposition to the risk of this injury. In these sense, several training protocols have been used as an intervention and achieved mixed results in the change of this risk factor. Objective: The aim of this project was to evaluate the possible changes of rotation knee in single-leg drop landing after the intervention of a neuromuscular training program. Methods: The study included 18 women aged between 18 and 51 years, who were divided into two groups: neuromuscular training group (NTG) (n=11) and control group (CG) (n=7). In addition, they did not have musculoskeletal injury or pain in the lower limbs. Each participant completed five valid single-leg drop landings from a platform of 40 cm. The motion capture process was carried out with 12 infrared cameras of the OptiTrackTM system to obtain three-dimensional coordinates of markers fixed in the anatomical points of interest. The local coordinate systems of the thigh and leg were defined by means of the respective markers set in the anatomical points. Thus, the knee rotation angles in the sagittal, frontal, and transverse planes were calculated through the sequence of Euler angles and the angular velocities were calculated using the formulations of quaternions. Results: The results showed an increase in the knee rotation speed after the neuromuscular training. Conclusion: We conclude that neuromuscular training resulted in faster rotation at the knee in the 40 milliseconds succeeding the single-leg landing.Introduccion: El gran numero de lesiones del ligamento cruzado anterior sin que implique un contacto en las mujeres es motivo de curiosidad entre los cientificos porque las evaluaciones de aterrizaje pueden sugerir predisposicion al riesgo de esta lesion. En este sentido, varios protocolos de entrenamiento se han utilizado como intervencion y lograron resultados mixtos en el cambio de este factor de riesgo. Objetivo: El objetivo de este proyecto fue evaluar los posibles cambios de rotacion de la rodilla en el aterrizaje unipodal despues de la intervencion de un programa de entrenamiento neuromuscular. Metodos: El estudio incluyo a 18 mujeres de edades comprendidas entre 18 y 51 anos, que fueron divididas en dos grupos: grupo de entrenamiento neuromuscular de ocho semanas (GEN) (n = 11) y grupo control (GC) (n = 7). Ademas, no tenian lesion musculoesqueletica o dolor en las extremidades inferiores. Cada participante realizo cinco aterrizajes unipodales validos desde una plataforma de 40 cm. El proceso de captura de movimiento se llevo a cabo con 12 camaras infrarrojas del sistema OptiTrack(tm) para obtener las coordenadas tridimensionales de los marcadores fijados a los puntos anatomicos de interes. Los sistemas de coordenadas locales del muslo y la pierna se definieron por medio de los respectivos marcadores establecidos en los puntos anatomicos. De esa manera, fueron calculados los angulos de rotacion de la rodilla en los planos sagital, frontal y transversal utilizando las secuencias de los angulos de Euler, y las velocidades angulares utilizando las formulaciones de cuaterniones. Resultados: Los resultados mostraron un aumento en la velocidad de rotacion de la rodilla despues del entrenamiento neuromuscular. Conclusion: Se concluye que el entrenamiento neuromuscular resulto en mayor velocidad de rotacion en la rodilla en los 40 milisegundos posteriores al aterrizaje unipodal.

Comparison of the Kinematic Patterns of Kick Between Brazilian and Japanese Young Soccer Players.

Background Kicking performance is the most studied technical action in soccer and lower limbs kinematics is closely related to success in kicking, mainly because they are essential in imparting high velocity to the ball. Previous studies demonstrated that soccer leagues in different countries exhibit different physical demands and technical requirements during the matches. However, evidencewhether nationality has any influence in the kinematics of soccer-related skills has not yet been reported. The nationality of the players is an aspect that might be also relevant to the performance in kicking. Objectives The aim of this study was to compare the lower limbs kinematic patterns during kicking, between Brazilian and Japanese young top soccer players. Patients and Methods Seven Brazilian (GA) and seven Japanese (GB) U-17 players performed 15 side-foot kicks each, with a distance of 20 m away from the goal, aiming a target of 1 × 1 m in upper corner, constrained by a defensive wall (1.8 × 2 m). Four digital video cameras (120 Hz) recorded the performance for further 3D reconstruction of thigh, shank and foot segments of both kicking and support limbs. The selected kicking cycle was characterized by the toe-off of the kicking limb to the end of the kicking foot when it came in contact with the ball. Stereographical projection of each segment was applied to obtain the representative curves of kicking as function of time for each participant in each trial. Cluster analysis was performed to identify the mean GA and GB curves for each segment. Silhouette coefficient (SC) was calculated, in order to determine the degree of separation between the two groups’ curves. Results Comparison between the median confidence intervals of the SC showed no differences between groups as regards lower limb patterns of movements. Task accuracy was determined by the relative frequency that the ball reached the target for all attempts and no differences were found (GA: 10.48 ± 14.33%; GB: 9.52 ± 6.51%; P = 0.88). Conclusions We conclude that lower limb kinematic patterns, in support and ball contact phases, are similar in young Brazilian and Japanese soccer players during free kicks when adopting the side-foot kick style.

Comparisons between predictive equations of resting metabolic rate and indirect calorimetry in obese teenagers

Objective: To measure the accuracy of predictive equations of resting metabolic rate (RMR) in obese teenagers in relation to indirect calorimetry (IC). Methods: This study was conducted with 116 obese teenagers (60 males; 13.7±1.1 years). The RMR was calculated from Harris and Benedict, Schofield, WHO, Henry and Rees equations. The RMR was measured by the QUARK-RMR system. The comparison between predictive equations and IC was by the Student’s t test. The reliability of data between predictive equations and IC was verified by the typical error of measu rement (TEM) and the coefficient of variation (CV%). Results: Henry’s equation was significantly different from IC (p<0.02). The CV% found for each equations compared to IC turned was low. However, when the TEM was measured it was considered high in absolute values which can cause errors when estimating the RMR. Therefore, it is important that specific predictive equations are developed for Brazilian obese teenagers.