Sleep quality and regular physical activity in reducing cardiac risk.

BACKGROUND: Adolescents with sedentary behavior, spending many hours in front of the television and electronic devices, develop early involvement of cardiovascular disease and obesity. These sedentary behaviors increased significantly in this age group during the pandemic of 2020/2021. Sleep directly influences aspects of health, such as blood pressure and cardiac autonomic balance and exercise has a protective effect on these same physiological parameters. OBJECTIVE: This study aimed to examine whether or not physically active adolescents positively influence HRV and cardiovascular parameters despite poor sleep quality. METHODS: This is an analytic and transversal study. Sleep quality, physical activity levels, blood pressure, and heart rate variability (HRV) were measured. Two-way ANOVA and Tuckey post hoc test evaluated the difference between groups. RESULTS: Among 352 adolescents entrolled, mean age was 15.8 ± 0.24 years. It was observed that compared to the physically active group with poor sleep quality, the sedentary poor sleep quality group presented a more significant deficit in blood pressure and autonomic parameters such as pNN50, SD1, and HF. CONCLUSION: Adolescents who practiced physical activity regularly have shown better HRV and sleep quality compared with sedentary adolescents.

Brazilian South-South Scientific Collaboration and The Sustainable Development Goals.

We look at Brazilian collaboration in Scientific papers based on SciVal and Incites regarding the Sustainable Development Goals (SDGs) of the United Nations. Data were collected from InCites® and SciVal® (2012-2021). Groups of Global South countries were formed (ASEAN, Asia, Africa, BRICS, Caribbean, Central and Latin America). Analyses included Cluster (Author position, impact/citations, open access, journal quartil), principal component, path and analysis of variance to see the effect of region and SDGs in Brazilian publishing. Scopus data were analysed in Vosviewer® for creating country networks through publication, citation and bibliographic coupling, as well as keyword analysis. SDG 3 (Good Health and Well-Being) dominates all Brazilian scientific collaborations with the various country groups. While gender equality shows greater importance in ASEAN and African countries, Life Below Water (SDG14), on Land (SDG15), and Climate Action (SDG13), are important in all regions. SDGs 1, 8, 10, 12, and 16 show less importance in this collaboration overall. Brazil is relatively more active in Zero Hunger (SDG2) and Life on Land (SDG15) than worldwide. Brazil South-South collaboration in published documents shows higher impact than North South in some areas. Collaboration priorities vary by region and triangulation with countries is high depending on language and region.

Small-sided games in volleyball: A systematic review of the state of the art.

Studies on small-sided games (SSG) in team sports have increased in recent decades. However, the literature concerning this training strategy in volleyball is sparse. This study aims to summarize and analyse the scientific evidence on SSG in volleyball. For this purpose, electronic searches were conducted in August 2021 in PubMed, Scielo, ScienceDirect, Scopus, SPORTDiscus, and Web of Science databases. As result, a total of 22 studies (3 cross-sectional, 7 quasi-experimental, and 12 randomized controlled trial) that used SSG in volleyball were included in the qualitative synthesis after applying the eligibility criteria. Despite the few studies available for each outcome, our results suggest that the SSG can be used as a methodological resource for volleyball teaching and training of educational, recreational, and high-performance character. In conclusion, the use of SSG in volleyball is a pedagogical and training alternative with positive effects on populations with different levels of training (school and university students, recreational adult players, and athletes) considering instructional approaches, sport knowledge, participation in Physical Education classes, health markers, physical fitness, and physiological, psychological, and tactical-technical variables. However, more studies need to be carried out using SSG in volleyball in different contexts, with different manipulations and variables.

External and internal Load and their Effects on Professional Volleyball Training.

The purpose of this study was twofold: (i) characterize the external and internal training load of professional volleyball players with a focus on intra-week changes and (ii) test the relationships between internal and external load measures. Eight male professional players (age: 23.0±5.22 yo; body mass: 84.5 ± 7.58 kg; height: 193.0±9.71 cm; BMI: 22.0±0.02 kg/m2) were monitored daily over 15 weeks. The monitoring process included both internal (rate of perceived exertion [RPE] and session-RPE [s-RPE]) and external load variables, which were measured by an inertial measurement unit. Results revealed that, within-week variations revealed that RPE was significantly higher during MD-2 (d=0.59) and MD-3 (d=0.56) than MD-1. A significantly higher number of jumps was observed on MD-2 than MD-1 (d=0.69). Considering the relationships between internal and external load measures, small positive correlations were found between RPE and the number of jumps (r=0.17) and between s-RPE and the number of jumps (r=0.49). In conclusion, a tapering strategy was observed on the day before a match, as internal and external loads decreased. Both internal and external load measures are necessary to provide an accurate perception of the impact of training stimuli on players.

Effects of a physical activity and nutritional intervention in overweight and obese children through an educational and recreational camp.

BACKGROUND:: Educational camps have hosted millions of children around the world. However, few studies have described their benefits on weight control and health promotion for overweight and obese children. AIM:: To investigate the impact of a health educational program for children composed of 5 days of camp and a 12-week follow up on the physical activity level, sedentary behaviour, anthropometric data and food intake in overweight and obese children. METHODS:: 12 children attended the Health Educational Program for Children divided into two phases. Phase 1 consisted of pre-assessments and Phase 2 corresponded to 12 weeks of follow up. Physical activity level, sedentary behaviour and food intake were assessed throughout the questionnaire. RESULTS:: After the follow up, 25% of the children became active (>1500 and <3000 Metabolic Equivalent of Tasks per week). In contrast, the number of sedentary children (<600 Metabolic Equivalent of Tasks per week) decreased by 15% and insufficiently active (600-1500 Metabolic Equivalent of Tasks per week) increased by 15%. The physical activity level of leisure time increased significantly throughout weekdays (26.0%) and weekends (14.1%) after the follow up compared to before the camp. Sedentary behaviour showed a significant reduction of 177.14 and 41.43 minutes on weekdays and weekends, respectively. Before the camp, the consumption of sugar and sweets was out of control (100% inadequate), and after the intervention, 58.4% started to consume these foods in a balanced way. CONCLUSIONS:: The Health Educational Program for Children (5-day camp and the 12 weeks of follow up) contributed to an increase in the physical activity level and a reduction in the sedentary behaviour and anthropometric measures in overweight and obese children.

Space and players' number constrains the external and internal load demands in youth futsal.

Introduction: The aim of this study was to analyze the effects of space and number of players manipulation on the external and internal load demands of youth futsal athletes. Methods: Forty-two male U17 players (age = 15.62 ± 0.58 years) from three futsal teams participated in the study. In this cross-sectional study that lasted 8-week, the player's sample practiced six futsal tasks (T1-T6) and a futsal game played under the official rules (T7). From T1-T6, two task constraints were manipulated: (i) the number of players and, (ii) the space of play. The WIMU PRO™ Ultra-Wideband (UWB) tracking system was used to measure the external and internal load during the futsal tasks. External load was quantified using kinematic and mechanical variables extracted from positional data and, the internal load was quantified using Heart rate (HR) and rating of perceived exertion (RPE). Repeated measures ANOVA was used for comparison purposes. Results: In general, the results showed high external (total distance, distance 18.1-21, above 21 Km/h, and high intensity acceleration and deceleration, p < 0.001) and internal load (heart rate average and rating of perceived exertion, p < 0.001) in the tasks with low number of players and high area. In relation to the match, the tasks with small relative area per player (GK + 2 vs. 2 + GK and GK + 3 vs. 3 + GK in 20 × 20 m) promoted low external load. Conclusion: It was concluded that increasing the relative area by reducing the number of players involved in the tasks in the form of small-sided games (GK + 2 vs. 2 + GK and GK + 3 vs. 3 + GK), in relation to the futsal game (GK + 4 vs. 4 + GK), can be considered a pedagogical strategy to increase the external and internal load demands of young futsal players.

Is There a Relationship Between Birth Quartile and Vertical Jump Performance Among Young Male Elite Volleyball Athletes?

Vertical jump is an important skill that influences volleyball performance. In this study, we analyzed the relationship between vertical jump performance and birth quartile of Brazilian male youth volleyball players. We calculated chi-square goodness-of-fit tests to compare the athletes' birthdate distributions in quarters of their birth years (Q1, Q2, Q3, and Q4) according to player age categories (U17, U18, U19, and U21). We calculated one-way ANOVAs to compare spike jump and block jump heights of players born in different quarters of the same year. Overall, we found a relative age effect (i.e., more players with birth dates early in the birth year) in U17 (p < .001), U18 (p < .001), U19 (p < .001), and U21 (p = .04). Regarding vertical jump performance, U18 athletes born in Q2 reached higher spike jump heights (p = .006) and block jump heights (p = .002) than athletes born in Q4, and U19 athletes born in Q1 reached higher block jump heights than athletes born in Q3 (p = .049). There were no significant differences in vertical jump performance across birth quartiles among U17 and U21 athletes. Thus, a relative age effect was present in all age categories but not always reflected in vertical jump performance. Volleyball coaches and policymakers are still advised to employ strategies to ensure fairer opportunities for players born later in the year of their eligibility dates, as we found RAE to be sometimes, but not always, related to higher spike or block jump heights even among these older adolescents and young adult athletes.

Using inertial measurement units for quantifying the most intense jumping movements occurring in professional male volleyball players.

The purpose of this study was to use an inertial measurement unit (IMU) to analyze variations in the jump outcomes concerning weekly training days, and the dependencies between the number of jumps per minute and the jump height. An experimental research design was adopted across three weeks of the final play-off of a volleyball championship. Through an IMU, the external load of seven male elite volleyball athletes of a top rating team from Portuguese 1st Division (age: 30.5 ± 3.5 years; height: 200.2 ± 6.3 cm; body mass: 93.0 ± 8.1 kg; BMI: 23.1 ± 2.3 kg/m2) was monitored. Repeated measures ANOVA was executed to compare the outcomes between training days. It was observed a similar density of jumps during the week. However, when comparing MD-1 to MD-2, a more significant average number of jumps per minute was observed in MD-1 (1.3 ± 0.2 vs. 1.0 ± 0.2). Additionally, a positive, large and significant correlation was registered between the number of jumps and the height of the jump. Those results highlight the benefits of the specific training, leading to greater stimulation and improvement, in a game-like context, of the stretching-shortening cycle, observed in every jump action in volleyball.

Does Relative Age Effect Exist in Paralympic Sport? A Study With Brazilian Paralympic Swimmers.

A Relative Age Effect (RAE), by which young athletes with birthdates early in a calendar year have experienced a team selection advantage that persists throughout their careers, has been found to be prevalent in many sports. However, this phenomenon has not been investigated in the Paralympic sports context. Thus, we aimed to investigate the prevalence of RAE among male and female Brazilian Paralympic swimmers. Data from 694 ranked athletes were collected from the 2021 Brazilian Paralympic Swimmers National rankings. Athletes' birthdates were divided into four quarters (Q1, Q2, Q3, and Q4) according to their month of birth. Chi-Square (χ2) goodness-of-fit tests were used to compare the observed and expected distributions of athletes born in each quarter, based on sex (male and female), impairment type (physical, visual, and intellectual), and swim stroke competition (freestyle, medley, backstroke, butterfly, and breaststroke). The observed birthdates distributions were different from expected in males (χ2 = 11.647; p = 0.009) and females (χ2 = 8.899; p = 0.031), for athletes with physical impairments (χ2 = 10.443; p = 0.015); and for athletes who competed in freestyle (χ2 = 16.683; p = 0.001), medley (χ2 = 12.343; p = 0.006) and backstroke (χ2 = 8.025; p = 0.045) races. Even though our results demonstrated asymmetric distributions of Brazilian Paralympic swimmers' birthdates in many of the analyses, we could not establish the classical prevalence of athletes born at the beginning of the year that defines RAE. Therefore, the selection process of Brazilian Paralympic swimmers does not seem to be influenced by the athletes' time of birth.

The Relative Age Effect in Male and Female Brazilian Elite Volleyball Athletes of Varied Competitive Levels.

Volleyball is a popular sport in Brazil, and the relative age effect (RAE) is known to occur within it; but less is known of how RAE relates to elite Brazilian volleyball players' age, sex, and competitive levels. We aimed to investigate RAE prevalence with data from two seasons of play among players in the Superliga A (2020/2021 and 2021/2022 seasons), and Superliga B (2021 and 2022 seasons) made available from the Brazilian Volleyball Confederation (CBV), the club's official website, or direct consultation with the CBV. After removing duplicate data, we grouped these 1,063 athletes by their dates of birth, sex, and competition level (Superliga A or B). We divided players' birth dates into quarters (Q1: January-March, Q2: April-June, Q3: July-September and Q4: October-December) and into semesters, and we performed chi-square (χ2) tests to investigate RAE prevalence according to the players' sex and competitive level. RAE was prevalent overall (χ2 = 33.198; p < .001), among males (χ2 = 24.48; p < .001) and females (χ2 = 11.23; p < .011). Regarding competition level, RAE was evident among males in both Superliga A (χ2 = 14.581; p = 0.002), and B (χ2 = 13.985; p = 0.003), and among females in Superliga B (χ2 = 9.204; p = 0.027), but not Superliga A (χ2 = 4.012; p = 0.26). Thus, the RAE phenomenon operated differently for male and female Brazilian volleyball players according to their competitive level. We discuss the implications of these findings.

The Decision-Making of High-Level Volleyball Setters in the 2021-2022 Volleyball Men's Superliga: Does the Opponent Matter?

Our primary objective in this study was to investigate the offensive strategies employed in the attack phase of men's volleyball, specifically focusing on side-out as stratified by the type of confrontation that was determined by the opponent's team performance. We analyzed 5524 attacking actions during 22 games of the 12 teams that participated in the Volleyball Men's Superliga (season 2021-2022). Based on their final rankings in the championship, we classified these teams into three tiers: high-performance, intermediate-performance, and low-performance. Subsequently, we examined the dynamics of these matches using Social Network Analysis. We found that the opponent teams' performance levels did not influence the game dynamics. Notably, the eigenvector values were prominently higher for Attack Zones 2 and 4, wherein the middle-blocker jumped to attack close to the setter across all networks. Thus, setters opted for traditional and low-risk strategies to minimize errors, disregarding available information about the skill level of the opposing team, making their offensive tactics predictable.

Inter e intra-variability of the best ranked teams: A network analysis in male high-level volleyball.

The present research objective was to analyze the offensive phase from Complex I in high-level male volleyball teams in a macro- and micro-level view, through the inter e intra-team variability analysis of eight best teams of the 2018 Men's Volleyball World Championship over the social network analysis and eigenvector centrality. The sample consisted of 22 matches and 2,743 offensive actions, resulting in 8 sub-networks with 368 nodes and 6221 edges. The results showed from macro view the variables that presented highest centrality values were Attack Zone 4 (range 0.56-0.90), Attack Tempo 2 (0.65-0.87), Power Attack (0.62-0.94), No Touch Block (0.61-1), Attack Effect Continuity (0.59-0.94), and Middle Blocker Centralized (0.60-0.95). In a micro view, Reception Effect, Play Position, Reception Zone, and Block Composition showed high variability in each sub-network. The intra- and inter-team variability presented the importance of to respect each team idiosyncrasies and to consider the different approaches to the game and success.

Construct Validity Evidence in the Motor Coordination Test with Ball - MCTB.

Our purpose with this study was to analyze construct validity evidence for the Motor Coordination Test with Ball (MCTB). Our participant sample included 1620 students (741 girls; 879 boys) aged between 10-12 years. Evidence for construct-validity of the four tasks using exploratory factor analysis (EFA) and adequacy indices confirmed a good fit of a final two-dimensional model (BTS = .000; KMO = .83; loading .53 to .91; communalities ranging from .31 to .86; explained variance of 63.5%; goodness-of-fit index (GFI) = .99; adjusted GFI (AGFI) = .97; RMSR = .03), and confirmatory factor analysis (CFA) (X2/df = 4.9; GFI = .97; comparative fit index (CFI) = .92; TLI = .90; Root-Mean-Square Error of Aproximation (RMSEA) = .03). We concluded that, in a Brazilian sample, the MCTB has good construct validity for motor coordination tests with balls; this helps qualify this test for use in schools and in the sports context.

Within-Week Variations and Relationships between Internal and External Intensities Occurring in Male Professional Volleyball Training Sessions.

The purpose of the study was to test the within-week variations of the internal and external training intensity outcomes organized by days of the week. An 8-month observational period was conducted during the 2020-2021 season. The training sessions and matches of an elite volleyball team were monitored daily. The data comes from 14 players (two setters, five middle blockers, five outside hitters, and two opposites) of an elite team from the Portuguese 1st League (age: 21.7 ± 4.19 years of age; experience: 6.2 ± 3.8 years; body mass: 85.7 ± 8.69 kg; height: 192.4 ± 6.25 cm; BMI: 23.1 ± 1.40 kg/m2). The CR10 Borg scale was applied daily to measure the training intensity. The rate of perceived exertion (RPE) and the session-RPE were extracted as the internal outcomes. The external intensity was measured using an inertial measurement unit (IMU). The number of jumps, height average of jumps (JHA), minimum jump (MJ), maximal jump (MXJ), range jump (RJ), number of jumps (NJ), and training session density (D) were extracted as external intensity outcomes. The results showed that there was a difference between RPE and S-RPE (F (1.98) = 6.31, p = 0.01, η2 = 0.36, and F (1.73) = 28.30, p = 0.001, η2 = 0.72), as well as JHA and NJ (F (2.14) = 4.76, p = 0.02, η2 = 0.30, and F (1.77) = 4.77, p = 0.02, η2 = 0.30) within the microcycle. When analyzing the correlations between internal and external intensity, it was observed that there was a negative correlation between the Maximum Jump (4, 3, and 1 days before the Match day) (r2 = 0.34, r2 = 0.40, r2 = 0.41, respectively) and the Range Jump (3 and 1 days before the Match day (r2 = 0.33, r2 = 0.38, respectively) with the RPE (4 days before the Match day) and Maximum Jump (5, 4, 3, and 1 days before the Match day (r2 = 0.35, r2 = 0.39, r2 = 0.44, r2 = 0.34, respectively) and Range Jump (5, 4, 3, and 1 days before the Match day) (r2 = 0.34, r2 = 0.35, r2 = 0.40 and r2 = 0.36, respectively) with S_RPE (4 days before the Match day). Such findings show that higher internal intensities are correlated with lower external intensities in sessions further away from the game day. Such results could be an important tool for coaches to reflect, plan, monitor, and execute the training unit according to the temporal distance to the competition.

Within-week differences in external training load demands in elite volleyball players.

PURPOSE: The aim of this study was to analyze the within-week differences in external training intensity in different microcycles considering different playing positions in women elite volleyball players. METHODS: The training and match data were collected during the 2020-2021 season, which included 10 friendly matches, 41 league matches and 11 champions league matches. The players' position, training/match duration, training/match load, local positioning system (LPS) total distance, LPS jumps, accelerations, decelerations, high metabolic load distance (HMLD), acute and chronic (AC) mean and AC ratio calculated with the rolling average (RA) method and the exponentially weighted moving average (EWMA) method, monotony and strain values were analyzed. RESULTS: All the variables except strain, Acc/Dec ratio and acute mean (RA) showed significant differences among distance to match days. Regarding the players' positions, the only difference was found in the AC ratio (EWMA); in all microcycles, the middle blocker player showed workload values when compared with the left hitter, setter and libero. CONCLUSION: Overall, the analysis revealed that the intensity of all performance indicators, except for strain, acc/dec and acute mean load (RA), showed significant differences among distance to match day with moderate to large effect sizes. When comparing players' positions, the middle blocker accumulated the lowest loads. There were no significant differences among other positions.

Did the Absence of Crowd Support During the Covid-19 Pandemic Affect the Home Advantage in Brazilian Elite Soccer?

This study aimed to investigate the impact of crowd absence due to the COVID-19 pandemic on home advantage in Series A and B of professional Brazilian male soccer. Moreover, we sought to compare the home advantage between different competitive levels. Data from 2018 to 2020 Brazilian professional soccer championships (Series A and B) were analyzed, consisting of 2280 matches. The effect of home advantage was calculated in relation to the number of points won, the number of wins, goals scored and goals conceded. Our results indicated that home advantage was reduced in Serie A. Specifically, the 2020 (absence of the crowd) and 2019 seasons showed smaller home advantage compared to the 2018 season. On the other hand, Serie B analyses indicated no changes in home advantage over the seasons analyzed. The comparison of home advantage between competitive levels indicated higher home advantage in Serie A, exclusively in the 2018 season. In addition to the absence of fans, other changes occurred in elite sports due to the pandemic, such as changes in rules and the calendar. Considering that home advantage is affected by multiple interacting factors, it is important to investigate specific sports leagues across the world to determine which factors had the greatest impact on the advantage of playing home matches.

Prevalence of the Relative Age Effect in Elite Brazilian Volleyball: An Analysis Based on Gender, the Playing Position, and Performance Indicators.

Athletes born closer to an arbitrary cut-off date are more likely to reach an elite level in sport, which is supported by a phenomenon called the relative age effect (RAE). It is important to determine whether this phenomenon is present in a sport to minimize this selection bias. This study aimed to investigate the prevalence of RAE in elite volleyball athletes, considering the influence of gender, the playing position (Setter, Middle, Libero, Opposite, and Outside Hitter) and the performance level (attack points, aces, and block points). The sample comprised 203 male and 193 female athletes competing in the Superliga A in the 2020/2021 season, which was equivalent to all of the teams of the championship. The data collection was performed during May and June, 2021. Athletes were organized according to gender, the playing position, and performance in the Superliga. For performance variables, athletes were separated based on the median value (90.0), and classified as high- or low-performance. Chi-squared tests were performed to verify differences between birth date distributions in relation to the aforementioned variables. Results indicated overrepresentation of relatively older male athletes (Q1 = 35.96%; Q2 = 27.59%; Q3 = 19.21%; Q4 = 17.24%), especially in Middles, Opposites, and Outside Hitters, regardless of their performance level. Considering females, no differences were found. Our findings suggest that RAE operates differently for men and women in elite Brazilian volleyball. The characteristics of the games played by male and female elite athletes may lead to different talent selection processes, affecting the likelihood of RAE prevalence.

Differences in visual search behavior between expert and novice team sports athletes: A systematic review with meta-analysis.

Background: For a long time, in sports, researchers have tried to understand an expert by comparing them with novices, raising the doubts if the visual search characteristics distinguish experts from novices. Therefore, the aim of the present study was to review and conduct a meta-analysis to evaluate the differences in visual search behavior between experts and novices in team sports athletes. Methods: This systematic review with meta-analysis followed the PRISMA 2020 and Cochrane's guidelines. Healthy team athletes were included, which engaged in regular practice, from any sex or competitive level, specifically classified a priori as expert or novice in the original research (i.e., if they were classified after the experiment, based on one of the tests, the study would be excluded). We considered only research published in peer-reviewed journals, with no limitations regarding date or language. It was considered healthy team sport athletes engaged in regular practice. The scenarios could be in situ or film-based. The databases of EBSCO (Academic Search Complete, Academic Search Ultimate, APA PsycArticles, and APA PsycINFO), PubMed, Scopus, SPORTDiscus, and Web of Science were used to perform the searches. The risk of bias was calculated through the RoBANS tool. Results: From a total of 6,257 records, of which 985 were duplicates, titles and abstracts of 5,272 were screened, and 45 required full-text analysis. Of those, 23 were excluded due to not fulfilling the eligibility criteria regarding participants. In the end, 22 studies were selected, however, as two studies were part of the same trial and were analyzed conjointly. Discussion: Experts showed to be older and with more years of practice. The ability to distinguish experts from novices was not so clear regarding the variables analyzed. This could be due to the strategies chosen in each study, which were specific to each scenario, and when grouping all together, it was lost information within non-representative averages. The distinction between experts and novices was not clear, showing a lot of heterogeneity in the included studies. The expert classification itself may have been the conditioning aspect for these results, retaining the doubt and the need for more studies in the field. Systematic review registration: The protocol was pre-registered in OSF (project https://osf.io/3j4qv/, register https://osf.io/dvk2n).

Effects of Congested Fixture on Men's Volleyball Load Demands: Interactions with Sets Played.

The purpose of this study was to compare the external load, internal load, and technical efficacy between the first and the second matches (M1 and M2) occurring in congested fixtures (two matches in two days) using the number of sets as a moderating factor. An observational analytic research design was adopted. Data from official volleyball matches were collected during the first competitive period of the championship, comprising 14 competitive games within 10 weeks. Ten male elite volleyball athletes (age: 21.7 ± 4.19 years of age; experience: 6.2 ± 3.8 years; body mass: 85.7 ± 8.69 kg; height: 192.4 ± 6.25 cm; BMI: 23.1 ± 1.40 kg/m2) participated in this study. Players were monitored for external load (number of jumps and height of jumps) and internal load (using the rate of perceived exertion-RPE). Additionally, notational analysis collected information about attack efficacy and receptions made during matches. The mixed ANOVA revealed no significant interaction between time (M1 vs. M2) and number of sets for number of jumps per minute (p = 0.235; ηp2 = 0.114), mean jump height (p = 0.076; ηp2 = 0.193), RPE (p = 0.261; ηp2 = 0.106), attack efficacy (p = 0.346; ηp2 = 0.085), Positive reception (p = 0.980; ηp2 = 0.002) and Perfect reception (p = 0.762; ηp2 = 0.022). In conclusion, congested fixtures do not seem to affect the performance of volleyball players negatively.

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.