Coexistence of Distinct Performance Models in High-Level Women's Volleyball.

In performance analysis, and most notably in match analysis, generalizing game patterns in a sport or competition may result in formulating generic models and neglecting relevant variability in benefit of average or central values. Here, we aimed to understand how different game models can coexist at the same competitive level using social network analysis with degree centrality to obtain systemic mappings for six volleyball matches, one for each of the six national teams playing in the 2014 World Grand Prix Finals, guaranteeing a homogeneous game level and balanced matches. Although the sample was not recent, this was not relevant for our purposes, since we aimed to merely expose a proof of concept. A total of 56 sets and 7,176 ball possessions were analysed through Gephi Software, considering game actions as nodes and the interaction between them as edges. Results supported the coexistence of different performance models at the highest levels of practice, with each of the six teams presenting a very distinct game model. For example, important differences in eigenvector centrality in attack zones (ranging from 0 to 34) and tempos (20 to 38) were found between the six teams, as well as in defensive lines (20 to 39) and block opposition (22 to 37). This further suggests that there may be multiple pathways towards expert performance within any given sport, inviting a re-conceptualization of monolithic talent identification, detection and selection models. Future studies could benefit from standardizing the metrics in function of the number of ball possessions.

Pelvic Floor Muscle Training in Female Athletes: A Randomized Controlled Pilot Study.

The aim of this study was to investigate the effects of pelvic floor muscles training in elite female volleyball athletes and whether it is an effective therapy for stress urinary incontinence. Fourteen athletes, both continent and incontinent, between 18 and 30 years of age, were randomly assigned to an experimental group or a control group. The experimental group received a protocol for pelvic floor muscle training for 4 months. This consisted of three phases: awareness/stabilization, strength training and power. The control group was not subject to any intervention during the same period. Measures were collected at the initial and final phase for both groups. Maximum voluntary contractions were evaluated with a perineometer, involuntary urine loss with a Pad test and quality of life with the King's Health Questionnaire. Baseline sociodemographic and anthropometric characteristics were not significantly different. Comparing the two groups, the experimental group improved maximum voluntary pelvic contractions (p<0.001) and reduced urine loss (p=0.025), indicating the existence of significant differences between groups in the variation from the initial and final phases. The percentage of urine loss decreased in the experimental group, from 71.4-42.9%, suggesting that the protocol intervention for 16 weeks may help athletes with stress urinary incontinence.

Strength and power training improve skill performance in volleyball players

Abstract Aim: This study aimed to test the influence of functional improvements in volleyball skills performance. Methods: Twenty-eight amateur female volleyball players were assigned to Skill (S: n = 14, 19.5 ± 4.6 yrs; 169.7 ± 7.2 cm; 62.9 ± 12.7 kg) or Skill and Strength/Power (S+SP: n = 14; 18.6 ± 3.5 yrs; 169.7 ± 5.1 cm; 63.3 ± 9.2 kg). S+SP performed eight weeks of volleyball and conditioning training. S maintained only volleyball training. Functional variables (i.e. strength, power, and agility measures) and volleyball skills performance in a game-situation context were assessed before and after training. Results: 1-RM squat and bench press, time at modified agility T-test, peak power at bench throw and medicine-ball throw distance improved for the S+SP (p<0,05). S group increased only in medicine-ball throw distance (p<0.05). There were no differences between groups in the functional variables tested (p>0.05). The probabilities of a perfect set and an attack 'kill' in S+SP improved (¶>0.90). Changes from pre to post-training were higher in S+SP than in S for a perfect set, 'stuff block' and defense with displacement (¶>0.90). Conclusion: Our data suggest that functional improvements may positively affect volleyball skills performance. Although functional variables revealed only within-group changes, S+SP produced greater improvements in skill performance than S, supporting the use of conditioning training to improve volleyball performance.

Intervention with a combined physical exercise training to reduce oxidative stress of women over 40 years of age.

Exercise training has been shown to be one of the most important lifestyle factor for improving functional performance and health status. Nevertheless, and although some evidence exists about the effects of aerobic training on oxidative stress, there is scarce information concerning the effects of combined exercise training (aerobic and strength training) in oxidative stress. Considering this, the aim of this study was to verify the effects of a combined exercise training in oxidative stress parameters of women over 40 years of age. At baseline, 67 women enrolled in the study and were divided into three groups: younger group (YG, n = 28: 40 to 49 years), middle-aged group (MAG, n = 21: 50 to 59 years) and oldest group (OG, n = 18: above 60 years). These women engaged in a combined exercise training program for 16 weeks, 3 sessions of 60 min per week. At the end of the program, only 31 women (YG: 15; MAG: 8 and OG: 8) were remained in the study and were considered for analysis. Physical assessments (weight, height, body mass index and waist circumference), health and functional parameters (systolic and diastolic blood pressure, fitness tests: supine, latissimus, squat jump, 8 foot up and go test, 30 second chair stand test, and 6 min walk test) and measures of DNA damage (DNA SBs, DNA netFPG), lipid peroxidation (MDA), total antioxidant capacity (TAC) and catalase activity (CAT) were performed before and after the 16-week intervention with combined exercise. The results showed an improvement of overall physical and functional performance as well as a significant decrease in waist perimeter and systolic blood pressure after the exercise program intervention. Regarding the biochemical measures, the exercise training induced a significant decrease in oxidative damage, and a significant increase in the TAC (p < 0.05). The results indicate that combined exercise training induces benefits in functional capacity and reduce damage caused by oxidative stress.

The Effects of 3-Month Skill-Based and Plyometric Conditioning on Fitness Parameters in Junior Female Volleyball Players.

PURPOSE: This study compared the effects of skill-based and plyometric conditioning (both performed in addition to regular volleyball training twice a week for 12 wk) on fitness parameters in female junior volleyball players. METHODS: The participants [n = 47; age: 16.6 (0.6) y; mass: 59.4 (8.1) kg; height: 175.1 (3.0) cm] were randomized into a plyometric (n = 13), a skill-based (n = 17), and a control (n = 17) groups. The variables included body height, body mass, calf girth, calf skinfold, corrected calf girth, countermovement jump, 20-m-sprint, medicine ball toss, and sit-and-reach test. RESULTS: Two-way analysis of variance (time × group) effects for time were significant (P < .05) for all variables except body mass. Significant group × time interactions were observed for calf skinfold [η2 = .14; medium effect size (ES)], 20-m sprint (η2 = .09; small ES), countermovement jump (η2 = .29; large ES), medicine ball (η2 = .58; large ES), with greater gains (reduction of skinfold) for plyometric group, and sit-and-reach (η2 = .35; large ES), with greater gains in plyometric and skill-based groups. The magnitude-based inference indicated positive changes in 1) medicine ball toss and countermovement jump for all groups; 2) sit-and-reach for the plyometric and skill-based groups; and 3) 20-m sprint, calf girth, calf skinfold, and corrected calf girth for plyometric group only. CONCLUSION: Selected variables can be improved by adding 2 plyometric training sessions throughout the period of 12 weeks. Additional skill-based conditioning did not contribute to improvement in the studied variables compared with regular volleyball training.

Training strategy of explosive strength in young female volleyball players.

OBJECTIVE: The aim of this study was to examine the effect of an 8-week combined jump and ball throwing training program in the performance of upper and lower extremities among young female volleyball players of the high school. MATERIALS AND METHODS: A total of 20 young female volleyball players playing at Scholar Sport in High School at the district level were divided in two groups: the experimental group (n=10; 14.0±0.0 years; 1.6±0.1 m; 52.0±7.0 kg and 20.7±2.4% body mass) and the control group (n=10; 13.8±0.4 years, 1.6±0.1 m; 53.5±4.7 kg and 20.3±1.7% body mass). The experimental group received additional plyometric and ball throwing exercises besides their normal volleyball practice. The control group underwent only their regular session of training. RESULTS: Strength performance in the experimental group significantly improved (medicine ball and volleyball ball throwing: P=0.00; and counter movement jump: P=0.05), with the improvement ranging from 5.3% to 20.1%. No significant changes in strength performance were observed in the control group (P>0.05). CONCLUSIONS: The 8-week combined jump and ball throwing training can significantly improve muscular performance in young female volleyball players. These findings may be useful for all physical education teachers and volleyball coaches.

Game-Related Volleyball Skills that Influence Victory.

The aim of the present study was to identify the volleyball skills that discriminate in favour of victory. Twenty-four games (n=24) from the Senior Men's Volleyball World Championship played in Italy in 2010 were chosen and analyzed with Data Volley software. The discriminating function was used to identify the discriminating variables, using a canonical structuring coefficient of |SC| ≥ .30. The results suggest that service points, reception errors, and blocking errors were the discriminating variables that identify the final outcome of the match (victory/defeat). Moreover, successful service points were the major variable most likely associated with match success (victory). In this sense, increasing the effectiveness of service should be a top priority in coaching elite volleyball teams.

Sex differences in discriminative power of volleyball game-related statistics.

To identify sex differences in volleyball game-related statistics, the game-related statistics of several World Championships in 2007 (N=132) were analyzed using the software VIS from the International Volleyball Federation. Discriminant analysis was used to identify the game-related statistics which better discriminated performances by sex. Analysis yielded an emphasis on fault serves (SC = -.40), shot spikes (SC = .40), and reception digs (SC = .31). Specific robust numbers represent that considerable variability was evident in the game-related statistics profile, as men's volleyball games were better associated with terminal actions (errors of service), and women's volleyball games were characterized by continuous actions (in defense and attack). These differences may be related to the anthropometric and physiological differences between women and men and their influence on performance profiles.