Kinematic, strength, and stiffness adaptations after a short-term sled towing training in athletes.

One of the most frequently used methods for training the sprint-specific strength is the sled towing. To date, no studies have been conducted to explore the effects of this method after a training period in well-trained athletes. The purpose of this study was to determine the effects of 4 weeks of resisted sprint training with sled towing. Twenty-two trained athletes experienced in the use of weighted sled (WS) participated in the study. They conducted the same 3-week training to level their initial condition. After that they were distributed in two groups, unresisted (UR) and WS training. They carried out the same 4-week, 2 days/week sprint-specific training, only differing in that the experimental group performed sprints with a (WS) which caused a reduction of 7.5% of their maximum velocity. Pre- and posttest were conducted which included the measurement of sprint kinematics, muscular strength (including isoinertial, isokinetic, and jump measurements), and sprinting stiffness (leg and vertical). Results show different adaptations in the groups although no interaction effect was found. The WS group improved the velocity in the transition phase, while the UR group improved the velocity in the maximum velocity phase. No improvements in the height of the jump tests were found.

Validity of the standing spike test as a monitoring protocol for female volleyball players.

THE PURPOSE OF THIS PAPER WAS: a) to provide reference values for the standing spike test for female volleyball players and b) to study whether the standing spike test is valid for assessing the theoretical differences between female volleyball players. The sample included 83 players from the first nine teams of the Spanish women's first volleyball division (52 Spanish players and 31 from other nationalities). The variables studied were the ball speed of the standing spike test, the age of the players, the player's role (outside hitter, opposite, middle-blocker, libero, or setter), height, and nationality of the players (Spanish or foreign). The results demonstrate the ranges for the standing spike among female performance volleyball players (70-82 km · h(-1)). The differences regarding nationality, player role, height, and age seem to indicate that the test is a valid instrument for monitoring the performance of female volleyball players.

Height, weight, Body Mass Index, and age in beach volleyball players in relation to level and position.

AIM: This study tried to find out the height, weight, Body Mass Index (BMI), and age of peak performance beach volleyball players with regard to their level of play and their role. METHODS: The men's and women's pairs that classified in the World Tour and in the Olympic Games during seasons 2000-2006 were analyzed (625 males and 617 females). A descriptive, correlational, and longitudinal design was used. The variables studied were: height, weight, age, BMI, level (World Tour ranking), and player role (blocker, defense specialist, or no specialization). The data were obtained from the webpage of the International Federation of Volleyball. RESULTS: The average characteristics for males were 1.93 m, 88-89 kg, a BMI of 23.8-24.1, and an age range of 29-31 years, and for females, they were 1.77-1.79 m, 66-68 kg, a BMI of 19.2-21.1, and an age range of 27-29 years. CONCLUSION: Beach volleyball players are older and have smaller anthropometric characteristics when compared to indoor volleyball players. Male players present similar values for age and height across rankings. For both genders, with regard to weight and BMI, the higher the level, the larger the value. For women, the players at a higher level presented higher values of age, height, weight, and BMI. With regard to role, the blocking specialists were taller than the defense specialists. The pairs that share the blocking and defense responsibilities have intermediate values.