Gal Ziv

Physical attributes, physiological characteristics, on-court performances and nutritional strategies of female and male basketball players.

This article reviews a series of studies (n = 51) examining physical attributes, physiological characteristics, on-court performances and nutritional strategies of female and male elite basketball players. These studies included relevant information on physical and physiological variables, such as height, weight, somatotype, relative size, aerobic profile, strength, anaerobic power, agility and speed. Six main findings emerged from our review: (i) differences in physical attributes exist among playing positions and skill levels (e.g. guards tend to be lighter, shorter and more mesomorphic than centres); (ii) maximum aerobic capacity (V̇O2max) values of female and male players are 44.0–54.0 and 50–60mLO2/kg/min, respectively; (iii) male and female players of higher skill levels tend to have higher vertical jump values; (iv) the more skilled female and male players are faster and more agile than the less skilled players; (v) guards tend to perform more high-intensity movements during game play compared with forwards and centres; and (vi) a water deficit of 2% of bodyweight can lead to reduced physical and mental performance during an actual game. Five limitations associated with the testing protocols used in the studies are outlined, among them the lack of a longitudinal approach, lack of tests performed under physical exertion conditions, and lack of studies using a time-motion analysis. In addition, three practical recommendations for the basketball coach and the strength and conditioning coach are presented. It is concluded that the data emerging from these studies, combined with the knowledge already obtained from the studies on physical and physiological characteristics of elite basketball players, should be applied by basketball and strength and conditioning coaches when planning training programmes for elite basketball players.

Vertical jump in female and male basketball players--a review of observational and experimental studies.

The main purpose of this article was to review a series of studies (n=26; 15 observational and 11 experimental) examining vertical jump (VJ) performances in female and male basketball players. Information on the tests used in these studies and their specific protocols, and the training programs conducted to improve VJ ability in elite basketball players, was assessed. It was found that vertical jump values varied greatly, from 22 to 48 cm in female players and from 40 to 75 cm in male players. These large variations can be explained mostly by the differences in testing protocols (each VJ protocol examined different physiological pathways) and skill level of players. The variations in VJ values among studies were greatly reduced when they used the same protocol. In addition, short plyometric training sessions as part of the strength and conditioning program were found to enhance VJ performances in basketball players. Based on the reviewed studies, five limitations associated with the testing protocols and the strength and conditioning programs used in the studies were outlined, among them the use of multiple testing protocols and lack of experimental studies. Three recommendations for basketball and strength and conditioning coaches were suggested, for one of which was including plyometric training in the annual training program.

Physical and physiological attributes of female volleyball players--a review.

The main objective of this article was to review a series of studies (n = 31) on physical attributes, physiological attributes, and on-court performances of female volleyball players. Empirical and practical knowledge emerging from studies on training-related issues in volleyball, such as body mass, fat-free mass, aerobic profile, strength, and agility and speed, should be integrated and applied when planning annual training programs for volleyball players. Based on our review, it was found that (a) players of a higher skill level are taller, somewhat heavier, and have higher vertical jump values than players of a lower level; (b) the aerobic profile of female volleyball players is similar to that of female basketball players; (c) ballistic resistance training can increase vertical jump values in female volleyball players; and (d) preseason conditioning should be conducted to prevent fatigue and reduced performance at the beginning of the season. Among the research concerns discussed in the article are that there is a lack data for on-court performance and time-motion analysis in female volleyball players and that more experimental/manipulative studies are needed to examine the effectiveness of different training programs on physiological attributes of female volleyball players. Two practical implications are suggested for volleyball and strength and conditioning coaches: (a) functional and nonfunctional overreaching should be carefully monitored when planning strength and conditioning programs, and (b) volleyball programs should include ballistic-type training.

Physical characteristics, physiological attributes, and on-court performances of handball players: A review

Abstract The main purpose of this article was to review a series of studies (n=23) on physical characteristics, physiological attributes, throwing velocity and accuracy, and on-court performances of male handball players – amateur players, experienced players, professional players, and players on the national team. Five main findings emerged from our review: (1) Elite players are heavier and have higher fat-free mass than amateur players. (2) The maximal oxygen uptake of male players is between 50 and 60 ml · kg−1 · min−1. (3) Throwing velocity is higher by as much as 9% in elite male players compared with amateur male players. (4) Heart rates can rise above 160 beats · min−1 in male players during a game. (5) On-court distance covered in a game averaged approximately 4 km and ranged between 2 and 5 km, depending on playing position. Our methodological concerns based on the reviewed studies are: (a) a lack of on-court physiological data; (b) a lack of experimental/manipulative studies; (c) limited data on throwing accuracy; and (d) a lack of longitudinal studies. The practical implications include: (a) strength and power exercises should be emphasized in conditioning programmes, as they are associated with both sprint performance and throwing velocity; (b) speed and agility drills should also be implemented in conditioning programmes; and (c) specificity of training based upon the position of the player is of great importance when planning strength and conditioning programmes.

Physical Characteristics and Physiological Attributes of Female Volleyball Players - The Need for Individual Data

Abstract Nikolaidis, PT, Ziv, G, Arnon, M, and Lidor, R. Physical characteristics and physiological attributes of female volleyball players—The need for individual data. J Strength Cond Res 26(9): 2547–2557, 2012—The purpose of this study was twofold: (a) to profile physical characteristics and physiological attributes of adolescent and adult Greek female volleyball players (n = 61) who were members of the A (the best league for female volleyball players) and B (the second-best league for female volleyball players) Series clubs in Greece and (b) to examine the intraindividual variability among these players in all physical and physiological measurements that were undertaken in the study. The participants were divided into 3 age groups––under 14, 14–18, and over 18 years. They underwent a series of physical (e.g., height, body mass, and percentage of body fat) and physiological (e.g., aerobic profile, flexibility, and vertical jumping ability) tests. Three main findings emerged from the data analysis: (a) differences in physical characteristics and physiological attributes existed between the 3 age groups. For example, fat-free mass was lower in players under the age of 14 years (41.57 ± 6.06 kg) compared with that in players between the ages of 14–18 years (50.24 ± 6.96 kg) and players over the age of 18 years (52.03 ± 3.39 kg). In addition, the relative peak power as measured in the Wingate Anaerobic Test was the highest in the over-18 group (9.72 ± 0.65 W·kg−1), lower in the 14–18 group (8.95 ± 0.7), and the lowest in the under-14 group (8.32 ± 0.78 W·kg−1), (b) large intraindividual variability existed in most physical characteristics and physiological attributes measured in the study, and (c) the intraindividual variability was observed in all the 3 groups. These findings emphasize the need for coaches to examine the intraindividual variability within the players on their teams and to use this information when designing training programs and strength and conditioning programs.

The effects of using aversive training methods in dogs—A review

ABSTRACT The purpose of this study was to review a series of studies (N = 17) regarding the effects of using various methods when training dogs. The reviewed studies examined the differences between training methods (e.g., methods based on positive reinforcement, positive punishment, escape/avoidance, et cetera) on a dogs physiology, welfare, and behavior toward humans and other dogs. The reviewed studies included surveys, observational studies, and interventions. The results show that using aversive training methods (e.g., positive punishment and negative reinforcement) can jeopardize both the physical and mental health of dogs. In addition, although positive punishment can be effective, there is no evidence that it is more effective than positive reinforcement–based training. In fact, there is some evidence that the opposite is true. A few methodological concerns arose from the reviewed studies. Among them are small sample sizes, missing data on effect size, possible bias when coding behavior in observational studies, and the need to publish case reports of bodily damage caused by aversive training methods. In conclusion, those working with or handling dogs should rely on positive reinforcement methods and avoid using positive punishment and negative reinforcement as much as possible.

Physiological Characteristics of the Preferred Transition Speed in Racewalkers

PURPOSE The preferred transition speed (PTS) at which humans change their gait from walking to running was found to be lower than their energetically optimal transition speed (EOTS). This phenomenon has not been examined in racewalkers. The purpose of this study was to evaluate the PTS and the EOTS in racewalkers compared with controls. METHODS Eleven racewalkers and 13 control subjects participated in this study. Subjects arrived at the laboratory on three occasions. Visit I: determination of PTS. Subjects walked at a slow speed that was increased by 0.2 km x h every 30 s until they felt it was easier to run. Then, subjects ran at a high speed and the treadmill speed was reduced by 0.2 km x h every 30 s until they felt it was easier to walk. Visits II and III: subjects walked and ran at PTS - 1 km x h, PTS - 0.5 km x h, PTS, PTS + 0.5 km x h, and PTS + 1 km x h. At each stage, physiological measurements were recorded. RESULTS PTS was 7.33 +/- 0.33 km x h in controls and 8.20 +/- 0.54 km.h in racewalkers (P < 0.001), and EOTS was 8.00 +/- 0.48 km x h in controls and 8.46 +/- 0.55 km x h in racewalkers (P = 0.039). There was a trend for a smaller difference between PTS and EOTS in racewalkers. V O2 was higher during running at the PTS in both groups (F1, 22 = 5.972, P = 0.023), and there was a trend for a group interaction (F1, 22 = 3.442, P = 0.077). HR and V E were higher at the PTS in racewalkers compared with controls. CONCLUSION Racewalkers have a higher PTS and EOTS compared with controls. There is a trend for the difference between the PTS and the EOTS to be smaller in racewalkers compared with controls.

Predicting team rankings in basketball: The questionable use of on-court performance statistics

Statistics on on-court performances (e.g. free-throw shots, 2-point shots, defensive and offensive rebounds, and assists) of basketball players during actual games are typically used by basketball coaches and sport journalists not only to assess the game performance of individual players and the entire team, but also to predict future success (i.e. the final rankings of the team). The purpose of this correlational study was to examine the relationships between 12 basketball on-court performance variables and the final rankings of professional basketball teams, using information gathered from seven consecutive seasons and controlling for multicollinearity. Data analyses revealed that (a) some on-court performance statistics can predict team rankings at the end of a season; (b) on-court performance statistics can be highly correlated with one another (e.g. 2-point shots and 3-point shots); and (c) condensing the correlated variables (e.g. all types of shots as one category) can lead to more stable regressional models. It is recommended that basketball coaches limit the use of individual on-court statistics for predicting the final rankings of their teams. The prediction process may be more reliable if on-court performance variables are grouped into a large category of variables.

Inter-individual Variability in Soccer Players of Different Age Groups Playing Different Positions

Abstract The purpose of this study was twofold: (a) to profile physical characteristics and motor abilities of three age groups of soccer players - under 14 years, 14-17, and over 17, playing different positions - goalkeepers, defenders, midfielders, and forwards; and (b) to examine the inter-individual variability among the players in each age group in all physical and physiological measurements performed in the study. In addition, anthropometric, power, strength, and flexibility tests were administered. Findings showed large inter-individual variability in all three age groups and in all playing positions. Differences between playing positions were found only in the 14-17 group (body mass) and in the over-17 group (body height, body mass, fat-free mass, and mean power in the Wingate Anaerobic Test). Due to the observed large inter-individual variability, it was concluded that the findings obtained in the physical and physiological tests should be interpreted with caution when attempting to differentiate between successful and unsuccessful soccer players, as well as when trying to predict future success in soccer.

Focusing attention instructions, accuracy, and quiet eye in a self-paced task—an exploratory study

The purpose of this exploratory study was twofold: (a) to examine the effectiveness of internal (INT; focusing on the swinging motion of the arms) and external (EXT; focusing on the pendulum motion of the club head) focus of attention instructions on the performance of a golf-putting task under non-distracted and distracted (noisy) conditions, and (b) to examine the relationship between attentional focus instructions and gaze behaviour under these two conditions. A two-phase study was conducted. In Phase 1 participants performed the task under non-distracted conditions, while in Phase 2 they performed the task under both non-distracted and distracted conditions. Performance and gaze behaviour were measured in both non-distracted and distracted conditions in three groups: INT focus, EXT focus, and control (C). Two main findings emerged from the current study: (a) under non-distracted conditions, quiet eye (QE) durations were longer in the EXT participants than in the INT and C participants; however, accuracy and consistency of the golfing performance did not improve in the EXT participants; and (b) under distracted conditions, higher performance was observed in both the INT and EXT attentional focus participants than in the C participants. To further determine the relationship between EXT focusing instructions and QE, additional studies should be conducted.