José M. Palao

Effects of three types of resisted sprint training devices on the kinematics of sprinting at maximum velocity.

Resisted sprint running is a common training method for improving sprint-specific strength. For maximum specificity of training, the athletes movement patterns during the training exercise should closely resemble those used when performing the sport. The purpose of this study was to compare the kinematics of sprinting at maximum velocity to the kinematics of sprinting when using three of types of resisted sprint training devices (sled, parachute, and weight belt). Eleven men and 7 women participated in the study. Flying sprints greater than 30 m were recorded by video and digitized with the use of biomechanical analysis software. The test conditions were compared using a 2-way analysis of variance with a post-hoc Tukey test of honestly significant differences. We found that the 3 types of resisted sprint training devices are appropriate devices for training the maximum velocity phase in sprinting. These devices exerted a substantial overload on the athlete, as indicated by reductions in stride length and running velocity, but induced only minor changes in the athletes running technique. When training with resisted sprint training devices, the coach should use a high resistance so that the athlete experiences a large training stimulus, but not so high that the device induces substantial changes in sprinting technique. We recommend using a video overlay system to visually compare the movement patterns of the athlete in unloaded sprinting to sprinting with the training device. In particular, the coach should look for changes in the athletes forward lean and changes in the angles of the support leg during the ground contact phase of the stride.

Determining the optimal load for resisted sprint training with sled towing.

Alcaraz, PE, Palao, JM, and Elvira, JLL. Determining the optimal load for resisted sprint training with sled towing. J Strength Cond Res 23(2): 480-485, 2009-An excessive load in resisted sprint training can produce changes in running patterns. Therefore, load control is essential to ensure the specificity of these training methods. The most common way to control it is through the percentage of velocity lost in relation to maximum velocity. The present paper describes a study that aimed to establish the load for sprint training with sled towing. The study developed a regression equation for calculating the load in the maximum velocity phase. The calculation was done with 26 athletes from the Spanish and French national levels on a synthetic track surface and with spikes. The regression equation obtained was % body mass = (−0.8674 × % velocity) + 87.99. The equation, although specific for type of surface used and sled towing characteristics, is useful in establishing the optimal load for acceleration and maximum velocity training with sled towing.

Techniques used and efficacy of volleyball skills in relation to gender

The purposes of this study were to determine reference values for the techniques used and assess the efficacy of these techniques in relation to gender in volleyball. Twenty-two matches from the XVth Mediterranean Games of Almeria 2005 (38 sets for males and 39 sets for females) were analyzed. A descriptive, correlational, and transversal design was done. The variables analyzed were gender, type of technique, and efficacy of technique. The serve most used by males was the power jump serve and by females it was the standing serve. The serve was more effective for females than for males, while serve reception was more effective for males. The overhand set was the most used set for both males and females. When the set was done after a dig, the forearm contact was also used. Males had more effective sets than females. The standard attack technique was the most used attack. Attack efficacy was similar for both genders. The dig technique most often used was the forearm contact. Dig efficacy was similar for both genders. The data found show that use of the techniques and their efficacy are different for males and females; therefore, training methods should also be different.

Relationship between the use of commit-block and the numbers of blockers and block effectiveness.

The purpose of this paper is to find out the effect of the use of the commit block on the number of players in the block and block effectiveness in the side-out phase and counter-attack phase, and give reference values on the utilization of the commit and reading block. The sample was made up of four male national teams (Portugal, Japan, Cuba and Yugoslavia). The actions of the teams where analyzed in 549 sequences corresponding to 25 sets of the World League 2001. The variables studied were: game phase, usage of the commit block against first tempo, block effectiveness, and spike opponent’s error. The results show that the use of the commit block difficult the formation of double and triple blocks in the wings and does not increase the block effectiveness or the opponent’s error in spike.

Quantity and quality of practice: interrelationships between task organization and student skill level in physical education.

In terms of planning and achieving student learning in physical education, important variables that influence this goal include task organization, quantity and quality of practice, task structure, communication with students or feedback, appropriateness of the skills, and motivational climate (for reviews, see Pièron, 2005; Silverman, 2005; & Solmon, 2003). Judy Rink gave an eloquent summary of research on effective instruction with the maxim that “students who spend more time in good practice learn more” (Rink, 2003, p. 167). Interestingly, since the descriptive studies of the 1980s and 1990s (e.g., Ashy, Lee, & Landin, 1988; Silverman, 1985, 1990) showing the importance of total practice trials and the quality of that practice, there has been sparse examination of practice conditions in physical education. With respect to this construct of quality practice trials, goal achievement depends largely on how the teacher organizes his or her students (Pièron, 1996). While a number of studies highlighted the importance of task planning and strict control over the tasks to enhance learning (Rink, 2003; Silverman, 1985; Silverman, Kulinna, & Crull, 1995; Silverman, Subramaniam, & Woods, 1998; Silverman, Tyson, & Krampitz, 1992; Silverman, Tyson, & Marrs, 1988), little is known about student outcomes when they participate in different organizational formats within lessons. Consequently, the purpose of this study was to investigate the impact of various forms of task organization (lines, circuits, and game-like activities) on the quantity and quality of closed skills practice in physical education classes. In this study, those skills were the track and field events of hurdles, high jump, and shot put (representing one run, one jump, and one throw).

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.

Match Duration and Number of Rallies in Men’s and Women’s 2000–2010 FIVB World Tour Beach Volleyball

Abstract After the 2000 Olympic Games, the Fédération Internationale de Volleyball (FIVB) modified the scoring system used in beach volleyball from side-out to a rally point system. The goal was to facilitate the comprehension of the game and to stabilize match duration. The purpose of this study was to assess the duration and number of rallies in men´s and women´s beach volleyball matches (2000-2010 FIVB World Tour). Data from 14,432 men´s matches and 14,175 women´s matches of the 2000-2010 World Tour were collected. The variables studied were: match duration, total rallies per set and match, number of sets, team that won the set and match, type of match (equality in score), and gender. The average match duration in beach volleyball is stable, ranging from 30 to 64 minutes, regardless of the number of sets, the stage of the tournament (qualifying round or main draw), or gender. The average number of rallies per match were 78-80 for two-set matches and 94-96 for three-set matches. Matches from the main draw are more balanced than matches from the qualifying round. More balanced matches (smaller point difference between teams) have longer durations. It is not clear why there is no relationship between the number of rallies and match duration. Future studies are needed to clarify this aspect. The results can serve as a reference to guide beach volleyball training (with regard to duration and number of rallies) and to help understand the effect of the rule change.

Relationship between laterality of foot strike and shot zone on penalty efficacy in specialist penalty takers

The purpose of this paper was to study the relationship between laterality of foot strike and shot zone on penalty efficacy in professional penal-tytaking specialist football players. A total of 514 penalty shots of national (Spanish) and international competitions in the 2004-2005 and 2005-2006 seasons were analyzed. A descriptive and correlative intra- and inter-group design was used. The variables studied were: shot efficacy (goals, saves by the goalkeeper, hitting the goal post, and misses), foot used for strike, and shot zone. Descriptive and inferential analyses (Chi-Square Test and likelihood ratio) of the data were done. The following conclusions can be established from the results obtained: a) No significant differences in shot efficacy in relation to foot used in specialists were found; b) The specialist penalty takers obtained a goal in eight out of ten penalty shots; c) There was a tendency in right-footed players to shoot to a zone right of the goalkeeper and a tendency in left-footed players to shoot to a zone left of the goalkeeper; and d) There was a tendency in both right-footed and left-footed players to shoot to the low zones of the goal.

The Impact of Video Technology on Student Performance in Physical Education

The purpose of this study was to assess the effectiveness of the use of video feedback on student learning in physical education, while also examining the teacher’s responses to the innovation. Three classes from one Spanish high school participated in different conditions for learning hurdles in a track and field unit. These conditions compared the use of video feedback (either from the teacher or from peers) with no video. The ‘video and teacher feedback’ condition provided the most positive overall results, with statistically significant improvements in skill execution, technique, and knowledge learning, as well as the highest level of practice. Nonetheless, while acknowledging the utility of video feedback as an instructional tool, the teacher felt overwhelmed by the demands of the technology on both his time commitments and in terms of his own technology competencies.

Game statistical system and criteria used by Spanish volleyball coaches

The aim of this paper was to study the game analysis used by Spanish volleyball coaches. The sample included 22 coaches from the first and second divisions of the men’s and women’s Spanish competition. The variables studied were: criteria used to evaluate technical and tactical actions, mathematical calculations used to analyse the data, reference values used, adaptations done in the statistical analysis, and situation in which performance is monitored. Descriptive and inferential analyses of the data were done. The use of game statistics is high in volleyball. It is used in practice, competition, opponent scouting, and post-analysis. Volleyball coaches use a category scale to monitor players’ and team’ actions based on the effect on the rally and/or the following game actions. Coaches make adaptations to this scale to fit their needs, perspective, goals, etc. This adaptation varies with regard to type of actions. The types of calculation most used for data analysis and establishing reference values are simple (total values and percentages), probably due to the high number of aspects to monitor or because coaches share the results of the monitoring with players. Coaches individualise their technical-tactical analysis to their needs in order to practice and compete properly.