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Influence of Contextual Variables on Performance of the Libero Player in Top-Level Women’s Volleyball

Abstract

Sports performance changes dynamically according to multiple variables during a match. Contextual variables play an important role in complex situations and influence player’s performance depending on the player’s role. The aim of this study was to analyze performance of the libero player in terms of contextual variables in top-level women’s volleyball. The sample comprised 1,597 actions performed by libero players in 49 sets (13 matches) played in the Spanish Queen’s Cups from 2015 to 2017. The variables analyzed were: the game phase, the match period, the set period, match status, the type of the match, and action performance. The results revealed higher participation in the reception and digging, and top performance in reception and setting. The participation of the libero player decreased at the end of the match and the set as well as in advantage score situations, while performance got worse at the end of the set (especially in digs, p < .05) and improved in score advantage situations (especially in receptions, p < .05). Performance remained stable regardless of the type of the match (p > .05). These results may be useful to coaches in order to plan and design specific tasks coherent with libero competition demands and performance values.

Open access
Passing Network Analysis of Positional Attack Formations in Handball

Abstract

The aim of this study was to characterize handball from a social network analysis perspective by analyzing 22 professional matches from the 2018 European Men's Handball Championship. Social network analysis has proven successful in the study of sports dynamics to investigate the interaction patterns of sport teams and the individual involvement of players. In handball, passing is crucial to establish an optimal position for throwing the ball into the goal of the opponent team. Moreover, different tactical formations are played during a game, often induced by two-minute suspensions or the addition of an offensive player replacing the goalkeeper as allowed by the International Handball Federation since 2016. Therefore, studying the interaction patterns of handball teams considering the different playing positions under various attack formations contributes to the tactical understanding of the sport. Degree and flow centrality as well as density and centralization values were computed. As a result, quantification of the contribution of individual players to the overall organization was achieved alongside the general balance in interplay. We identified the backcourt as the key players to structure interplay across tactical formations. While attack units without a goalkeeper were played longer, they were either more intensively structured around back positions (7 vs. 6) or spread out (5 + 1 vs. 6). We also found significant differences in the involvement of wing players across formations. The additional pivot in the 7 vs. 6 formation was mostly used to create space for back players and was less involved in interplay. Social network analysis turned out as a suitable method to govern and quantify team dynamics in handball.

Open access
Physiological Responses and Swimming Technique During Upper Limb Critical Stroke Rate Training in Competitive Swimmers

Abstract

The aim of this study was to examine how arm stroke swimming with critical stroke rate (CSR) control would influence physiological responses and stroke variables in an effort to identify a new swimming training method. Seven well-trained male competitive swimmers (19.9 ± 1.4 years of age) performed maximal 200 and 400 m front crawl swims to determine the CSR and critical swimming velocity (CV), respectively. Thereafter, they were instructed to perform tests with 4 × 400 m swimming bouts at the CSR and CV. The swimming time (CSR test: 278.96 ± 2.70 to 280.87 ± 2.57 s, CV test: 276.17 ± 3.36 to 277.06 ± 3.64 s), heart rate, and rated perceived exertion did not differ significantly between tests for all bouts. Blood lactate concentration after the fourth bout was significantly lower in the CSR test than in the CV test (3.16 ± 1.43 vs. 3.77 ± 1.52 mmol/l, p < 0.05). The stroke rate and stroke length remained stable across bouts in the CSR test, whereas the stroke rate increased with decreased stroke length across bouts in the CV test (p < 0.05). There were significant differences in the stroke rate (39.27 ± 1.22 vs. 41.47 ± 1.22 cycles/min, p < 0.05) and stroke length (2.20 ± 0.07 vs. 2.10 ± 0.04 m/stroke, p < 0.05) between the CSR and CV tests in the fourth bout. These results indicate that the CSR could provide the optimal intensity for improving aerobic capacity during arm stroke swimming, and it may also help stabilize stroke technique.

Open access
The Potential Relationship Between Leg Bone Length and Running Performance in Well‐Trained Endurance Runners

Abstract

The present study aimed to determine the relationship between leg bone length and running performance in well-trained endurance runners. The lengths of the leg bones in 42 male endurance runners (age: 20.0 ± 1.0 years, body height: 169.6 ± 5.6 cm, body mass: 56.4 ± 5.1 kg, personal best 5000-m race time: 14 min 59 s ± 28 s) were measured using magnetic resonance imaging. The lengths of the femur and tibia were calculated to assess the upper and lower leg lengths, respectively. The total length of the femur + tibia was calculated to assess the overall leg bone length. These lengths of the leg bones were normalized with body height, which was measured using a stadiometer to minimize differences in body size among participants. The relative tibial length was significantly correlated with personal best 5000-m race time (r = -0.328, p = 0.034). Moreover, a trend towards significance was observed in the relative femoral length (r = -0.301, p = 0.053). Furthermore, the relative total lengths of the femur + tibia were significantly correlated with personal best 5000-m race time (r = -0.353, p < 0.05). These findings suggest that although the relationship between the leg bone length and personal best 5000-m race time was relatively minor, the leg bone length, especially of the tibia, may be a potential morphological factor for achieving superior running performance in well-trained endurance runners.

Open access
Short-Term Repeated-Sprint Training (Straight Sprint vs. Changes of Direction) in Soccer Players

Abstract

Repeated-sprint training (RST) is considered a critical training method in team sports. It is well known that RST effects may depend on several variables such as the duration of the protocol and repeated-sprint methodology. Few studies have evaluated very short-term protocols and compared different RST modalities. The aim of this study was to compare the effectiveness of 2 week RST including straight sprints or changes of direction (CODs) on physical performance in a sample of soccer players. This study used a randomised pre-post parallel group trial design. The participants were assigned to either an RST group using straight sprints (RST-SS = 18 players) or an RST group using CODs (RST-COD = 18 players). The protocols were: 3 sets of 7 x 30 m sprints for the RST-SS and 7 x 20 + 20 m (one COD of 180°) for the RST-COD, with 20 s and 4 min recovery between sprints and sets, respectively. The following evaluations were performed: 10 and 20 m sprint, agility test, repeated sprint test (RSTbest and RSTmean), and Yo-Yo Recovery Level 1. After the training period, the RST-SS did not report any performance variation, while the RST-COD showed improvements in the 10 m sprint and RSTbest (effect size = 0.70 and 0.65, respectively). The between-group analysis did not report any statistical difference between the RST-SS and the RST-COD. In conclusion, this study did not support the utilisation of a very short-term RST protocol with soccer players, however, the RST-COD presented some additional benefits in sprint performance compared to the RST-SS.

Open access
Technical-Tactical Analysis of The Players of the Left and Right Wing in Elite Soccer

Abstract

In today's soccer, teams are increasingly better trained both physically and tactically, hence different game styles can be identified and differences between them reduced. However, without an exhaustive analysis of reality, the view can lead to the extraction of erroneous conclusions, and what seems to be a team with a marked offensive profile is a mere illusion, resulting to be a team that develops a perfectly balanced game. In this paper, an analysis of technical-tactical performance of players who occupied both wings in an elite team was made, taking as reference the Spanish national soccer team as the model of international game to imitate in the last decade. The development of this paper was located within the observational methodology, using the polar coordinates technique for the analysis of the obtained data. The results showed how, despite identifying offensive profiles within technical-tactical performance of players that occupied the outer wings or lanes of the playing field, their tactical means and orientations diverged from each other. The results showed a more offensive profile and with higher technical complexity of players that occupied the left wing, while players that held the right wing showed a more defensive and recuperative profile, indicating a less vertical and complex style of play at a technical level with the forward as an offensive reference.

Open access
The Evaluation of Cohesion in the Sports Groups within a Romanian City

Abstract

We propose to conduct an analysis, by studying the influences exercised by certain variables (the biological gender, the ranking and the sociomotor space) on the level of cohesion among the sports teams in the municipality of Iaşi, Romania, evolving in the first leagues. A questionnaire was conducted on a number of 158 athletes (55 females, 103 males) who practice basketball, soccer, handball, rugby, volleyball. The responders answered the questionnaire regarding the group environment (GEQ). Factor analysis groups the items on two factors at the level of the Romanian subjects. The homogeneity of the instrument was evaluated for the entire scale, as well as independently for each of the two factors. The gender variable does not influence the level of social cohesion and the one of task cohesion among the sports teams taken into account. The ranking does not influence task cohesion among the teams studied. Both the ranking and the level of sociomotor space, as independent variables, determine significant differences regarding the level of social cohesion among the teams studied. The sociomotor space variable determines at the level of the teams sportive studied significant differences also regarding task cohesion.

Open access
Motivation for Participation in Sports Based on Athletes in Team and Individual Sports

Abstract

There are many reasons why individuals are motivated to participate in sports. For athletes to participate in and keep up exercise, investigating the participation motivation of athletes is necessary. The aim of this study was to compare sport participation motivation of athletes in team and individual disciplines. The sample consisted of 265 athletes including four teams from football, volleyball, basketball, and handball and two individual disciplines of kung fu and taekwondo which were randomly selected. The 30-item sports participation motivation questionnaire (PMQ) was used. Analysis of data was conducted by the use of independent-samples t-test. The results showed that there is a significant difference between the sports participation motivation of athletes in a team and individual sports as well as between male and female athletes. But, among the components of the sports participation motivation, only the aspect of achievement in a team and individual sports and the aspect of finding friendship in male and female athletes existed, no other significant difference was observed. The results of this study show that sports discipline and the athlete’s gender is effective in motivating athletes’ continuation and commitment to a physical activity.

Open access
Motivation Psychological Characteristics of Canoe-Kayak Sprint Elite Youth Athletes

Abstract

The objective of the current study was the investigation of anxiety and satisfaction levels among Elite Greek Youth athletes of Canoe-Kayak Sprint. Additionally, whether elements such as gender, age, athletic experience, and weekly practice-time, differentiated the sample. 122 athletes, (61 males and 61 females) between the ages of 15-17 yrs. old, who competed in the Hellenic Federation’s Canoe-Kayak Sprint National Championships. Study participants were invited to complete two questionnaires: a) the Greek version of “CSAI-2” (Stavrou, Zervas, Kakkos, & Psichoundaki, 1998), and b) the Greek version of the “Athlete Satisfaction” scale (Bebetsos & Theodorakis, 2003). Results of the conducted study revealed that the sample differentiated: a) on somatic, and cognitive anxiety, according to their athletic experience, and b) on somatic, and cognitive anxiety, self-confidence, leadership, and personal outcome, according to their weekly practice-time. Finally, no sex differences were found in any questionnaire variable. In conclusion, the survey results highlighted the importance of the psychological factors tested on Canoe-Kayak Sprint athletes’ performance. Knowing and understanding athletes’ psychological state, can help them out (the athletes) in identifying aspects such as stress and satisfaction that directly affect their racing performance.

Open access
The Acute Effects of High‐Intensity Cycling Exercise on Arterial Stiffness in Adolescent Wrestlers

Abstract

The aim of this study was to determine the acute effects of high‐intensity cycling exercise on the variables of carotid artery compliance, distensibility and beta stiffness index in elite adolescent wrestlers. The subjects were elite athletes competing in national, European and World Championships, who attended a training camp in the province of Kahramanmaras organized by the Turkish Centre for Olympic Preparation. The study sample comprised 31 male elite wrestlers with a mean age of 15.90 ± 0.87 years, body height of 165.97 ± 9.7 cm and body mass of 66.3 ± 18.45 kg. The arterial stiffness variables of the wrestlers were measured with high‐resolution Doppler ultrasonography before and 5 min after 30 s of high‐intensity cycling exercise (the Wingate Anaerobic Cycling test). The results showed a statistically significant correlation between mean power performance and carotid artery compliance at the 5th min after a single cycling sprint exercise (p < 0.05). No correlation was determined between peak power and the arterial stiffness variables (p > 0.05). The study results indicate that acute changes in arterial stiffness variables are associated with the performance level of high‐intensity cycling exercise in a group of elite adolescent wrestlers.

Open access