Kinesiology

DETERMINANT FACTORS OF ATTACK EFFICACY IN HIGH-LEVEL MEN’S VOLLEYBALL: WHAT DOES DISTINGUISH THE MIDDLE-ATTACKER PERFORMANCE?

2021-04-19T10:42:09+02:00

This study aimed to identify determinant factors of attack efficacy considering the effects of reception, attack tempo, attack performance, setting type and attack type. Firstly, 19,454 offensive actions of complex I of the Brazilian Volleyball Men’s Super League were considered and analyzed separately from the middle, wing, and opposite attacker standpoints. The middle attack was the most effective, so the 5,259 offensive actions were analyzed considering the setting type and the attack direction. The independent variables were the quality of reception, type and direction of attack, whereas attack performance was the dependent variable. We found that the middle attack efficacy was related to excellent receptions, right tempo and left tempo (near the setter), and power attack. The results can afford coaches with the key information for better training plan designs and preparation for competition.

Key words: factors in sport performance, tactics, performance, attack efficacy

MONITORING EXTERNAL LOAD DURING REAL COMPETITION IN MALE HANDBALL PLAYERS THROUGH BIG DATA ANALYTICS: DIFFERENCES BY PLAYING POSITIONS

2024-02-01T18:48:53+01:00

The present study aimed to analyze the external load put on elite male handball players during the 2020 European Championship differentiated by playing positions. A system based on three phases was designed: 1) information capture of game events through sensor networks, LPS system and WebScraping techniques; 2) information processing based on Big Data Analytics; 3) extraction of results based on a descriptive analytics approach. Results showed that wings (Ws) and center backs (CBs) performed more accelerations and decelerations than the players in other positions in the entire match and attack. In defense, wings showed higher values than the rest of the players, followed by line players (LPs). In regard to body contacts, the positions that received more average number during the whole match were the CBs and LPs, with the CBs presenting the highest values in offense and the LPs in defense. Finally, backs were the ones performing more total jumps per game and in offense. In defense, LPs and left backs presented the highest values. It is necessary to monitor individual high intensity events to develop individual training programmes for different playing positions. High-intensity decelerations should be specially considered since they enlarge injury risks.

Keywords: accelerations, decelerations, body contacts, jumps, performance analysis

THE INFLUENCE OF SPORT-SPECIFIC FACTORS ON SLEEP QUALITY IN YOUNG ELITE ATHLETES: A COMPARATIVE STUDY

2023-07-13T12:50:03+02:00

Sleep is a crucial physiological process that promotes human health and well-being. Physical activity and sports participation are known to improve sleep quality in adolescents. The objective was to investigate how the characteristics of different sports affected this relationship in elite athletes. This cross-sectional study analyzed data from 1,831 young Spanish elite athletes (1,059 males and 772 females) from 11 to 20 years old who self-reported their sleep quality using the Pittsburgh Questionnaire and provided information on their sports practice. Technical sports reported significantly better sleep quality than team sports (p=.004, d =- 0.39, small). Additionally, individual competition sports reported better sleep quality than team competition sports (p=.033, d=-0.15, trivial). Differences by the type of metabolism were not statistically significant. Better sleep quality was reported in outdoors training environment sports compared to indoors training environment sports (p=.023, d=-0.11, trivial). The type of sports practiced may influence sleep quality in adolescents and highlights the importance of considering sport characteristics when promoting sleep health. Further research is necessary to explore the underlying mechanisms and to validate these findings across different age groups and populations.

Keywords: sleep quality, adolescents, elite sport, health, athletes

COMPARISON OF EXTERNAL LOAD DURING PRE-MATCH WARM-UP AMONG DIFFERENT AGE CATEGORIES FROM THE SAME FOOTBALL PROFESSIONAL CLUB

2023-06-09T16:53:32+02:00

The aim of the present study was to compare the external load (EL) of the football pre-match warm-up (WU) in absolute terms and as a percentage (%) of the individual match demands. A total of 96 football players from different age categories participated in the study: professional (PRO, n=26), reserve (RES, n=22), under-21 (U21, n=28) and U18 (n=20) teams. Eleven EL variables were obtained through global positioning system devices. The results show that there are differences among teams in total duration, total distance, number of accelerations and decelerations, acceleration load, distance covered at different speed ranges and the maximum velocity, both expressed absolutely and relative to the match demands. The EL of the WU represents a variable percentage depending on a particular variable with respect to the match, ranging from ≈5% for high-speed running or very high-speed running to ≈20% for acceleration-load. The conclusions were: 1) the WU load represents an important part of the EL on players in soccer matches, and 2) the PRO team presented a lower EL in most of the variables, being consistent in both absolute and relative terms to the match demand. The strength and conditioning coaches must be cautious not to cause fatigue in the players while guaranteeing an adequate set-up to dispute the match.

Keywords: GPS, soccer, team sport, elite, training load, age-group

THE EFFECTS OF ATTENTIONAL FOCUS INSTRUCTIONS ON THE PERFORMANCE OF A PERSISTENT FORM-BASED SKILL IN GYMNASTICS

2023-12-18T12:57:04+01:00

External relative to internal focus instructions have been shown to be more effective for enhancing optimal performance across various motor tasks that do not rely on movement quality or movement form. The aim of this study was to examine the effects of an external versus an internal focus of attention on the motor performance of a gymnastic skill that requires static strength and movement form. Participants with previous experience in aerobic gymnastics were asked to perform an L-support task for 4 seconds in three attentional focus conditions: internal focus, external focus, and control, with the order counter-balanced across focus conditions. Two pieces of yellow tape (2×9 cm) were attached to the gymnasts’ feet on the inner side of the navicular bones. Two pieces of red tape (2×9 cm) were wrapped around the distal phalanx of the big toes of the right and left foot. All participants performed four trials in the external focus (focus on keeping red tape below the yellow tape), internal focus (focus on pointing your toes), and control (no-focus) conditions. The results showed that execution faults were smaller in the external focus condition compared to the internal focus and control conditions. No difference was found between the internal focus and control condition. The findings of this study indicate that the external focus is more beneficial than the internal focus and no-focus control condition for enhancing the performance of a static gymnastic skill that requires static strength and movement form.

Keywords: focus of attention, movement form, motor performance, gymnastics

QUANTIFYING WITHIN-MATCHES TACTICAL BEHAVIORS USING POSITION DATA AND NOTATIONAL ANALYSIS IN SOCCER: THE EFFECT OF GOAL SCORING

2023-09-11T23:03:15+02:00

This study aimed to compare the collective and individual tactical positional behavior before the first goal was scored or conceded in official soccer matches. The sample comprised 50 players and 27 official matches played in Brazil during the 2020 and 2021 U-20 seasons. Global Positioning System devices were used to monitor the players’ positional data. Collective – width, length, length per width ratio, and stretching index, and individual – spatial exploration index, variables were calculated and compared between the contextual scenarios by a one-way ANOVA. Results indicated a reduction in the width after scoring a goal (p=.006) and a lower spatial exploration after conceding a goal (p<.001) compared with the draw condition. Therefore, it is concluded that goal-scoring affects the tactical positional responses of the players. Specifically, a higher width concentration, characteristic of defensive tactical behavior, is observed after scoring a goal to keep the current match status. On the other hand, players present difficulties in exploring the space after conceding a goal. The knowledge of these intrinsic game dynamics is helpful for coaches in preparing the strategies to explore changes due to goal scoring in official matches.

Keywords: football, youth sport, GPS devices, ecological dynamics

TRAINING LOAD AND PLAYERS’ READINESS MONITORING METHODS USED IN VOLLEYBALL: A SYSTEMATIC REVIEW

2023-07-12T17:12:02+02:00

Monitoring workloads during training and competition and players’ readiness seems to be key to increasing performance, reducing injury incidence and avoiding overtraining. We systematically reviewed the methods used to measure workloads and athletes’ readiness in volleyball to help coaches make the best decision when selecting monitoring methods. Databases Web of Science, Scopus, SPORTDiscus and PubMed were searched from inception to the 21st of February 2022. All peer-reviewed original research in English, Spanish, Portuguese and Italian, longitudinally monitoring loads and athlete readiness in indoor volleyball team settings of any level, gender and age were included. The quality of evidence was evaluated with a modified risk of bias assessment used in previous research by Castellano et al. (2014). This study has been registered in PROSPERO ID CRD42022316313. Out of 1774 records identified, 78 were screened of which 55 full texts were added for systematic review. For internal workload, the session rating of perceived exertion (sRPE) seems to be the “golden standard” used from 2010 to 2022 across all the studies. External workload has mainly been researched through quantified jumps. Even with technological advances and the introduction of microsensors in 2017, the use of video analysis is still present nowadays. Players’ readiness studies mainly used the total quality recovery scale (TQR) and wellness questionnaires in most research. New technological advances offer coaches more extensive and real-time data on external load. However, the use of the sRPE, TQR/WB, CMJ would create a monitoring system sufficient for teams at developmental stages and are of a reduced cost.

Keywords: workload, monitoring methods, wellness, readiness, performance

CASE STUDY: CARBOHYDRATE SUPPLEMENTATION IMPROVES ULTRA-ENDURANCE PERFORMANCE IN A KETO-ADAPTED INDIVIDUAL

2023-09-16T15:25:55+02:00

Ketogenic dietary interventions cause a dramatic increase in fat oxidation, with a growing body of research indicating prolonged ketogenic diets do not impair exercise performance. However, there is neither strong evidence in support of such a strategy. Over prolonged endurance events, the need for carbohydrates becomes increasingly important to prevent glycogen depletion and hypoglycaemia. A case study methodology was used to examine the response of an ultra-endurance runner with experience of events ranging from 60 to 161km (age: 37; stature: 184cm; mass: 80.2±0.8kg; V ˙ O 2max 56.5ml/kg/min; mean training volume 37km/week) to three identical 67km field tests following an 8-week ketogenic dietary intervention. Supplementation protocols comprised an acute carbohydrate feeding on the day of competition (74g carbohydrate [0.92g/kg pre-race], 310g [3.85g/kg] during race), in addition to a condition comprising an acute feed as well as a two day of carbohydrate feed (200g carbohydrate [2.5g/kg] in two day feed, 44g carbohydrate [0.54g/kg pre-race], 310g [3.85g/kg] during race), prior to the event and these were compared to baseline event where no carbohydrate was consumed, within race feeding restricted to low carbohydrate options. Compared to baseline (05:58:47 [hours:minutes:seconds]), the 67km time trial improved in both carbohydrate feeding conditions, with greater performance improvements after acute consumption compared to the two-day feed (05:36:59 vs. 05:42:01). Rate of fat oxidation during 0-15km and 40-45km of the acute condition time trial decreased compared to baseline (0.95±0.32g/min, 0.42±0.24g/min vs. 1.20±0.34g/min, 0.89±0.02g/min), and was greatest during the two-day feed condition (1.52±0.30g/min, 1.37±0.34g/min). Carbohydrate feeding impacted substrate metabolism and improved time to complete ultra marathon performance in a ketogenic athlete emphasising the importance of carbohydrates as a fuel for exercise performance. More research is required to determine the efficacy of this strategy within ketogenic athletic populations, as well as investigating optimal ketogenic dietary practices and carbohydrate supplementation protocols.

Keywords: fat oxidation, RER, carbohydrate feeding, carbohydrate oxidation

THE EFFECTS OF CORE TRAINING ON ENDURANCE IN DIFFERENT TRUNK MOVEMENTS: A SYSTEMATIC REVIEW AND META-ANALYSIS

2024-01-01T15:58:37+01:00

Core muscle endurance involves the trunk muscles’ capability to maintain a particular position for as much time as possible. It is essential to know how specific training aimed at this area affects endurance of different trunk movements performance and to what extent. The objective was to assess the effects of trunk training on different core muscle endurance measurements in flexion, extension, and right and left lateral flexion. A literature search was performed using different databases. The studies included: (a) cohorts of healthy people or subjects with chronic low back pain; (b) a core training intervention; (c) pre-post intervention parameters of interest; (d) a minimum of four out of 10 on the PEDro scale, and (e) randomised controlled trials. A random-effects model for meta-analyses was used. Fifteen studies were selected for the systematic review and 11 for the meta-analysis, comprising 1,213 participants. Compared to the control condition, core training induced a moderate effect on trunk flexion endurance (ES = 0.67), right-lateral trunk flexion endurance (ES = 0.77), left-lateral trunk flexion endurance (ES = 0.94), and a small effect on trunk extension endurance (ES = 0.49). To back up the results presented in this study, more research into the effects of trunk training on core muscle endurance is needed to confirm these results significantly. Core training improves core muscle endurance in four trunk movements. Core training is more effective in participants with pre-intervention poor results.

Keywords: muscle strength, resistance training, athletic performance, exercise therapy, motor activity, physical fitness

COMPARATIVE STUDY OF POSITIONING AND TECHNICAL-TACTICAL INDICATORS BETWEEN TEAMS OF DIFFERENT PERFORMANCE LEVELS IN THE QATAR 2022 FIFA WORLD CUP

2024-01-31T19:22:43+01:00

The aim of the study was to identify the technical-tactical indicators and differentiate collective positioning between the qualified teams and teams non-qualified for the final phase of the FIFA World Cup Qatar 2022, considering effective playing time. The aim was also to understand the interaction of variables that significantly increased the likelihood of being qualified in the analysed championship. We conducted a comparative analysis that covered all matches played (N=64), evaluating 93 technical-tactical indicators, 24 collective positional indicators and six hybrid indicators. The absolute technical-tactical indicators were normalised based on the effective playing time of each team in each match. We used t-tests and binary logistic regression (R2 Nagelkerke = .738 – AUC = .955) to analyse differences and determine their statistical significance (p<.05). Our analysis revealed significant differences in 33 indicators, suggesting that certain technical-tactical aspects played a crucial role in teams’ performance. Furthermore, through multivariate analysis, we were able to identify that offensive efficiency in set pieces, the height of the defensive line during the offensive phase, and the ability to reduce the available playing space for the opposing team during the defensive phase emerged as the main indicators that allowed us to classify the teams’ performance. These findings enable coaches to use the identified key indicators as performance predictors to devise match strategies aimed at enhancing the effectiveness of their teams.

Keywords: FIFA World Cup, key performance indicators, multivariate analysis, match analysis

EFFECTS OF SHORT AND LONG INTER-SET REST ON MAXIMAL ISOKINETIC STRENGTH AT SLOW AND FAST ANGULAR VELOCITIES IN TRAINED YOUNG MALES AFTER EIGHT WEEKS OF RESISTANCE TRAINING

2024-01-05T16:09:20+01:00

Resistance training is a widely used method to enhance muscle strength, with acute program variables influencing muscle adaptations. This study focused on the often-neglected variable of inter-set rest interval duration and its impact on muscle strength gains. Existing literature presents conflicting findings, with some studies advocating for longer rest intervals, while the others show comparable strength increases with shorter rests. Methodological differences in prescription and sample groups contributed to these inconsistencies. This study investigated the effect of short and long inter-set rests on maximal isokinetic strength gains of the upper and lower extremities during slow and fast angular velocities after eight weeks of resistance training. The research involved 26 healthy strength-trained males (age=20±1 year, body mass=81.5±8.8 kg, body height=184.4±6.1 cm) randomly assigned to G1m (1-minute rest) or G3m (3-minute rest). The resistance training programs were matched for all acute program variables, emphasizing the rest interval as the primary difference. Isokinetic dynamometry pre- and post-training assessed knee and elbow extensor and flexor maximal strength at 60º/s and 120º/s. The training program consisted of seven exercises performed at 70% 1RM until muscle failure three times per week over eight weeks. The most important result was that G3m, in contrast to G1m, led to a higher increase in peak torque of the knee (p=.037) and elbow extensors (p=.007) as well as the elbow flexors (p=.045) at 60º/s. Furthermore, G3m and G1m similarly increased the peak torque of the knee and elbow extensors and flexors at 120º/s and of the knee flexors at 60º/s (p>.138). In conclusion, the study suggests that strength training with longer inter-set rest intervals may lead to similar strength gains as strength training with shorter inter-set rest intervals. Nonetheless, individuals who prioritize maximizing their strength gains are advised to utilize longer rest intervals. However, shorter rest intervals may still yield significant strength enhancements, particularly for those who are limited by time.

Keywords: strength training, rest intervals, muscle strength, isokinetic dynamometry

IMPACT OF CARRYING HEAVY LOADS ON POSTURAL SWAY AND RELATIVE GROUND REACTION FORCES DURING QUIET STANCE IN INTERVENTION POLICE OFFICERS

2024-05-03T17:38:40+02:00

Although carrying heavy loads impacts gait characteristics in military personnel, less studies have examined whether a gradually load increase affects foot parameters during quiet standing in the different population of intervention police officers. Therefore, the main purpose of the study was to examine differences in postural sway and ground reaction force characteristics during a quiet stance while carrying progressively heavier equipment. Ninety-six elite intervention male police officers were assessed under four conditions: (i) ‘no load’, (ii) ‘a 5 kg load’, (iii) ‘a 25 kg load’, and (iv) ‘a 45 kg load’. Foot characteristics during standing were assessed with the Zebris pedobarographic pressure platform. Heavier loads increased 95% confidence ellipse area (p=.012, η2=0.028), the center of pressure path length (p=.010, η2=0.029) and average velocity (p=.011, η2=0.029), and length of the minor (p<.001, η2=0.040) and major axis (p=.004, η2=0.035). No significant changes in relative ground reaction forces beneath the forefoot and hindfoot regions of both feet were observed (p>.05). The findings suggest that spatial and temporal foot parameters may be more prone to change while carrying heavy loads, especially the center of pressure characteristics.

Keywords: special population, foot characteristics, center of pressure, statics, equipment, changes

DEVELOPMENT AND VALIDATION OF SPORTS SUPERSTITION ATTITUDE SCALE: EXAMINING THE INFLUENCES OF SUPERSTITION ON ATHLETES’ BEHAVIOR

2024-01-03T10:35:16+01:00

Superstition exists in every culture, and particularly in sports. This study aimed to develop a reliable and valid Sports Superstition Attitude Scale (SSAS) and test the influences of superstition on athletes’ behavior. Study #1 developed an initial SSAS draft and examined content validity and reliability. Study #2 examined SSAS factorial structure and construct validity. Study #3 tested hypothesized relationships among athletic identity, locus of control, superstition, and fear of failure. Results found by SSAS comprised three components: ritual and taboo, lucky charms, and folk culture, and showed appropriate construct validity and reliability. Theoretical model examination found that athletic identity and external control interact with superstition to predict fear of failure. We concluded that the 15-item three-factor SSAS is a reliable and valid sport-specific superstition measure that can be used in future studies. We suggest future studies examine how psychosocial factors influence athletes’ behavior and superstition. Limitations and suggestions for future study are also discussed.

Keywords: supernatural beliefs, misattribution, athletic identity, lucky charms, uncertainty hypothesis

ELITE BASKETBALL GAME EXTERNAL LOAD VARIES BETWEEN DIFFERENT TEAMS AND COMPETITION

2023-12-22T10:07:13+01:00

Understanding the external load demands of basketball games is fundamental information for training planning and programming. However, there is a scarcity of information about external load during official games at high-level basketball. The purpose of this research was to investigate basketball game external load differences between two elite basketball teams involved in separate competitions. External load demands experienced by forty-six elite basketball players (from two teams) were analyzed using inertial devices during official basketball games. External load was expressed with calculated (PlayerLoad, PL, averaged and in different time epochs) and inertial movement analysis variables (acceleration, deceleration, change of direction and jump). The results showed that the Euroleague team had a higher peak PL in epochs of 30-s (p<.001) and 60-s (p=.02) with moderate and small effect sizes compared to the Eurocup team. The Eurocup team had a significantly higher number of low and moderate accelerations and changes of direction with effect sizes from 0.34 to 1.15. In conclusion, external load demands in basketball vary depending on the team and league therefore practitioners should consider the specific level and style of play when comprising a training plan. Furthermore, practitioners should rely on their own team’s external load values for training load management, rather than attempting to adhere to standards established by external sources.

Keywords: team sport, workload, inertial technology, physical load management

PACING STRATEGIES IN MEN’S AND WOMEN’S WORLD RECORD MARATHON PERFORMANCES AND OLYMPIC GAMES AND WORLD CHAMPIONSHIP’S WINNING PERFORMANCES

2024-05-08T21:15:47+02:00

The aims of this study were to compare marathon pacing profiles between major championships winning races and world record (WR) races in men’s and women’s long-distance runners. Percentages of mean race speeds (%RS) for each 5 km section and last 2,195 m were compared between the latest 12 men’s and 8 women’s marathon WRs and the most recent 14 men’s and 14 women’s performances leading to either World Championship or Olympic Games (championships) gold medals, and between sexes in championships, through analysis of variance. Additionally, the coefficient of variation in pace (%CV) was compared through independent samples t-tests. %RS during the first 5 km was greater in WRs than championships in men (p=.010, d = 1.07), with a subsequent even pacing profile. More negative pacing profiles were adopted in championships than WRs in men (p<.001, d = 2.07). Women’s WR and championship performances were characterized by even and negative pacing profiles, with different %CV (p<.001, d = 1.89). Whereas marathon WRs are characterized by fast, even and sustained paces, slower paces and more negative pacing approaches with fast endspurts are adopted during winning major championship performances. These fast endspurts are specially used by women in championships.

Keywords: behavior, competition, endurance, running, tactics

ARE AEROBIC CAPACITY, ANAEROBIC THRESHOLD, AND RESPIRATORY COMPENSATION VALUES DETERMINANTS FOR THE TIME OF USEFUL CONSCIOUSNESS AT 25000 FEET?

2024-05-06T22:25:18+02:00

The higher the altitude, the higher the risk of hypoxia exposure. Good fitness status or aerobic capacity (AC) of persons with the military or civil aviation sector and those interested in high altitude sports have been thought of great importance to encounter hypoxic risk. It is unclear whether a difference in maximal oxygen consumption (VO2max) capacity would result in differential tolerance in hypoxia responses. The present study aims to determine the relationship between AC, anaerobic threshold (AT), respiratory compensation (RC), and time of useful consciousness (TUC) of people working in the military or civil aviation sector and those interested in high-altitude sports. Eighty-seven healthy males were recruited on a volunteer basis (age = 24.2 ± 1.6 years; height = 177.0 ± 5.1 cm; weight = 76.4 ± 8.1 kg). The 25000 feet test was applied to the participants in the hypobaric chamber. During the test, participants’ TUC levels were recorded. The Bruce protocol was used for the VO2max test, and the maximal oxygen consumption value, AT, and RC regions were recorded. Participants were divided into four groups according to their VO2max values. AT and RC values were higher in the group with high VO2max, although not significant (p>.05). There was no statistically significant difference between the TUC levels of the groups. There was no statistically significant difference between the groups’ TUC level, peripheral oxygen saturation (SpO2), and heart rate levels (p>.05). The results clearly show that there is no significant relationship between VO2max determined on the treadmill with a gas analyzer and TUC determined in the hypobaric chamber at 25000 feet. For future studies, the relationship between anaerobic capacity and hypoxia or studies in which different physical and physiological characteristics are evaluated together in the same participants may contribute to the literature.

Keywords: effective performance time, oxygen consumption, hypoxia, aviation

STRATEGIES FOR A SELF-SELECTED UNANTICIPATED CHANGE OF DIRECTION MANEUVER AND THE RISK FOR ACL INJURY: FINDINGS FROM HAIE STUDY

2023-12-11T12:56:51+01:00

The purpose of the study was twofold: 1) to qualitatively investigate the different change of direction (COD) strategies used by females in an ecological situation; and 2) to evaluate the knee internal adduction moment and knee flexion during the first 30% of support as risk factors for anterior cruciate ligament (ACL) injury during these strategies. Ninety-four females, classified in ACTIVE and NON-ACTIVE groups performed five trials of a COD maneuver that were subsequently qualitatively evaluated. Kinematic and ground reaction force data were analyzed in the first 30% of support. To assess differences between strategies, we used a two-way repeated measures analysis of variance. Four strategies of 45° COD maneuvers were found. The different strategies involved either a cross-over with the right or left leg or had no cross-over. The statistical analysis revealed significant differences with a lesser knee internal adduction moment (p<.05) and a greater knee flexion angle during the strategies with a cross-over of the right foot compared to the other strategies (p<.05). Therefore, it is important to consider the potential effect of different strategies on ACL injury risk factors, as ACL injury risk factors may vary depending on the specific directional technique used.

Keywords: knee moment, knee flexion, change of direction, COD strategies, anterior cruciate ligament