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This study focuses on certain characteristics of the jump take-offs in rhythmic gymnastics (RG). Rhythmic gymnasts always perform their jumps with the same preferred run-up technique, proceeded by a chassé-step in most of the cases. The overall idea was to analyse other step-techniques that could be performged on one-leg, which could prepare jumps. The aim of this study was to compare kinetic and kinematic variables between three-stag ring leaps with and without throwing-ball, performed using the glissade-step as a preparatory phase for take-off with one-leg these were as follows: glissade stag ring leap without-ball (GSWB), throw-ball glissade stag ring leap (TBGS) and glissade throw-ball stag ring leap (GTBS). Seven members of the Tunisian RG national team took part in this study. The technical elements were recorded in 2D using two-cameras on a specially designed floor carpet where a force-plate was integrated. The results showed that the three-leaps had significant impacts on the performance variables, especially on the force, the velocity and the flexibility. The GTBS was the most effective leap as the throw took place during the jump, which has increased its technicality and the applied physical variables, the vertical force, the rate of force development, the horizontal and vertical velocities and displacements. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study aims to analyze and compare the postural balance between two aquatic sports where vertical vs. horizontal body positions (i.e., windsurfing vs. swimming) are key techniques for both sports. SUBJECTS AND METHODS: Eight volunteer windsurfers and eight swimmers agreed to participate in this study. Each of the assessments was a 2D kinematic analysis of frontal and/or sagittal balance (i.e., in bipedal and/or unipedal stance) of the center of mass velocity on wobble board (Single Plane Balance Board) on hard and/or soft surface. Kinematic analysis was performed in 2D using two action-cams. Data were digitized using the video-based data analysis system SkillSpector. RESULTS: The results showed that the ANOVA, with repeated measures on 1 factor, showed a significant difference (p<0.001) between groups (i.e., swimmers and windsurfers) in all variables and in the interaction between ground (i.e., hard and foam) and group (p<0.01) in all tests in sagittal plane. Furthermore, for the ground*group interaction, a study (i.e., paired t-test) of the difference between balance (i.e., in frontal and/or sagittal plane) on hard and soft ground for each group showed that windsurfers had no difference in body sway in frontal and/or sagittal plane between hard and soft surface in bipedal stance. CONCLUSIONS: We concluded that the windsurfers showed better postural balance performances compared to swimmers in the bipedal posture on hard and soft ground. Also, the windsurfers presented a better stability level compared with the swimmers. [ABSTRACT FROM AUTHOR]

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The present investigation was conducted to evaluate the relative and absolute reliability and the minimal detectable change (MDC95%) of the karate specific aerobic test (KSAT) in male karate athletes. Sixteen subjects (age: 22.2±3.7 years, height: 175.7±6.7 cm, body mass: 72.7±7.2 kg and karate experience: 9.2±4.5 years) participated in this study and performed the KSAT twice (test-retest). Reliability of time to exhaustion (TE) was very good, with intraclass correlation coefficient ICC(3.1)>0.90, standard errors of measurement SEM<5% and 95% limits of agreement (LOA) -15.8 ± 74.7 s. The MDC95% of the KSAT was 81.42 s, rated as “satisfactory”. The dependent t test showed no significant difference between peak heart rate (HRpeak), peak lactate concentration (Lapeak) and rating of perceived exertion (RPE) between test and retest (P>0.05). Effect size for all variables was dz≤0.2, rated as trivial. Thus, when using the present test as a measure of aerobic fitness, a change greater than 9.4% (81.42 s) is necessary to be confident (at the 95% level) that the change in time to exhaustion reflects improvement and exceeds the measurement error. The KSAT is a reliable tool that can be used by practitioners for assessing aerobic fitness in experienced karate athletes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the immediate effect of video feedback on the regulation and control of the standing back tuck somersault in the absence of vision. Two groups of male parkour athletes performed the standing back tuck somersault under both open and closed eyes conditions. The first group received video feedback, while the second group received verbal feedback. Concurrent analysis, including kinetic data from a force plate (Kistler Quattro-Jump) and kinematic data in two-dimensional by Kinovea freeware, was employed for motion and technical performance analysis. The results indicate that the loss of vision during the standing back tuck somersault affected only the take-off and ungrouping angle, as well as the vertical velocity and displacement. These effects were consistent regardless of the type of feedback provided (i.e., video feedback or verbal feedback). Furthermore, a significant Vision × Feedback interaction was observed at the level of technical performance. This suggests that the use of video feedback enabled the parkour athletes to maintain a high level of technical performance both with and without vision (i.e., 13.56 vs. 13.00 points, respectively, p > .05 and d = 2.233). However, the verbal feedback group technical performance declined significantly under the no-vision condition compared with the vision condition (13.14 vs. 10.25 points, respectively, with and without vision, p < .001 and d = 2.382). We concluded that when the movement is proprioceptively controlled (i.e., without vision), the video feedback enables the athletes to globally assess the technical deficiencies arising from the lack of vision and to correct them. These findings are discussed based on parkour athletes' ability to evaluate the kinematic parameters of the movement.

Background: Changing from a static to a dynamic balance condition could affect the performance of a cognitive task such as mental rotation. Thus, the main goal of this study is to investigate aspects of visual-spatial cognition between two non-contact sports (i.e., badminton and volleyball) in different upright conditions (i.e., standing position, frontal balance, and sagittal balance)., Methods: Thirty-five volunteer female sports and physical education students, fourteen specialists in badminton and twenty-one specialists in volleyball agreed to participate in this study. Each of the assessments was a 3D cube mental rotation task with and/or without balance exercises (i.e., frontal and/or sagittal balance) on a wobble board. Five stimuli were used in the mental rotation task (i.e., 45°, 135°, 180°, 225° and 315° for objected-based cube condition with egocentric transformation) which included pairs of standard and comparison images., Results: The findings indicate that there was a notable decrease (p < 0.001; d = 1.745) in response time in both dynamic balance conditions (i.e., frontal and sagittal balance) compared to standing position condition. In addition, results revealed significant interaction between balance conditions (i.e., frontal and/or sagittal balance) and groups (i.e., badminton and volleyball) in the response time at 225° angle and in the error percentage., Conclusions: In sum, dynamic balance is also an activity that involves mental manipulation of objects in 3D space, which can enhance badminton and volleyball female players' ability to rotate 3D cube stimuli., (© 2024. The Author(s).)

Background: The present study aims to compare the mental rotation performance between two non-contact sports (i.e., badminton and volleyball) in different upright conditions (i.e., with and without dynamic balance)., Methods: Thirty-five female sports and physical education students voluntarily participated in the experiment, including fourteen specialists in badminton and twenty-one specialists in volleyball. The experiment involved a mental body rotation task with or without balance exercises on a wobble board., Results: Badminton players outperformed volleyball players in the mental rotation tasks regardless of balance. More interestingly, the results revealed an overall decrease in reaction times when participants performed balance exercises simultaneously with mental rotation., Discussion: Our findings suggest that introducing dynamic balance on a wobble board has immediate beneficial effects on the mental rotation performance of female badminton and volleyball players. These findings are discussed in the context of sport specificities and cognitive processing framework., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Amara, Al-Hadabi, El-Ashkar, Gmada, Habacha and Mkaouer.)

Introduction: General and particularly sport-specific testing is an integral aspect of performance optimization in artistic gymnastics. In artistic gymnastics, however, only non-specific field tests have been used to assess endurance performance (e.g., Multistage Shuttle Run Test; Cooper's Test)., Methods: This study aimed to examine the validity of a new sport-specific endurance test in artistic gymnastics. Fourteen elite-level gymnasts (i.e., eight males and six females) participated in this study. The newly developed artistic gymnastics-specific endurance test (AGSET) was conducted on two different occasions seven days apart to determine its reliability. To assess the concurrent validity of AGSET, participants performed the multistage shuttle run test (MSRT). Maximum oxygen uptake (VO 2max ) and respiratory exchange ratio (RER) were directly assessed using a portable gas analyzer system during both protocols. Additionally, the total time maintained (TTM) during the AGSET, maximum heart rate (HR max ), maximal aerobic speed (MAS), and blood lactate concentration (BLa) during the two protocols were collected., Results: The main findings indicated that all variables derived from the AGSET (i.e., VO 2max , MAS, HR max , BLa, and RER) displayed very good relative (all intraclass correlation coefficients [ICC] > 0.90) and absolute (all typical errors of measurement [TEM] < 5%) reliability. Further, results showed that the ability of the AGSET to detect small changes in VO 2max , MAS, BLa, and RER was good (smallest worthwhile change [SWC 0.2 ] > TEM), except HRmax (SWC 0.2 < TEM). Additionally, results showed a nearly perfect association between the VO 2max values derived from the AGSET and MSRT ( r  = 0.985; coefficient of determination [R²] = 97%) with no statistically significant differences ( p >0.05). The mean (bias) ± 95% limits of agreement between the two protocols were 0.28 ± 0.55 mlminkg-1., Discussion: AGSET seems to present very good reliability and concurrent validity for assessing endurance performance in elite artistic gymnastics. In addition, the newly developed protocol presents a good ability to detect small changes in performance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Mkaouer, Amara, Bouguezzi, Ben Abderrahmen and Chaabene.)

Background: Maintaining physical distancing is one of the most important steps to enforce in educational institutions to reduce the risk of transmission of COVID-19. However, close proximity and physical contact between students are often considered 'normal' during physical education (PE) classes, making it challenging for PE teachers to ensure physical distancing., Objectives: The aim of this study was to assess the effect of the implementation of the Good Behaviour Game (GBG) in maintaining physical distancing in PE settings in times of the COVID-19 pandemic., Method: In a quasi-experimental design, two groups were separately designated as an experimental group (20 classes involving 220 students) and a control group (20 classes involving 231 students). They were all enrolled in the eighth grade of the Tunisian education system. In the experimental group, the PE teacher managed physical distancing by administering the GBG. Physical distancing was evaluated by direct observation of videos of filmed PE sessions using a code grid. It was measured twice for the two groups using Kinovea software., Results: Quantitative data analyses showed that the level of maintaining physical distancing increased after the GBG intervention in the experimental group ( p  < .001). Furthermore, greater percent changes between pre- and post-intervention were identified in the experimental group compared to the control group (120% vs 1%, respectively)., Conclusion: The GBG was effective in ensuring students' physical distancing when implemented in PE settings., (© The Author(s) 2023.)

Objective: This study aims to analyze and compare the postural balance between two aquatic sports where vertical vs. horizontal body positions (i.e., windsurfing vs. swimming) are key techniques for both sports., Subjects and Methods: Eight volunteer windsurfers and eight swimmers agreed to participate in this study. Each of the assessments was a 2D kinematic analysis of frontal and/or sagittal balance (i.e., in bipedal and/or unipedal stance) of the center of mass velocity on wobble board (Single Plane Balance Board) on hard and/or soft surface. Kinematic analysis was performed in 2D using two action-cams. Data were digitized using the video-based data analysis system SkillSpector., Results: The results showed that the ANOVA, with repeated measures on 1 factor, showed a significant difference (p<0.001) between groups (i.e., swimmers and windsurfers) in all variables and in the interaction between ground (i.e., hard and foam) and group (p<0.01) in all tests in sagittal plane. Furthermore, for the ground*group interaction, a study (i.e., paired t-test) of the difference between balance (i.e., in frontal and/or sagittal plane) on hard and soft ground for each group showed that windsurfers had no difference in body sway in frontal and/or sagittal plane between hard and soft surface in bipedal stance., Conclusions: We concluded that the windsurfers showed better postural balance performances compared to swimmers in the bipedal posture on hard and soft ground. Also, the windsurfers presented a better stability level compared with the swimmers.

The crucial criteria when assessing technical performance in artistic gymnastics is the higher elevation of the gymnast's body and a stable landing (i.e., stick-landing). The purpose of this study was to compare kinetic and kinematic parameters during the landing phase of standing back somersaults (SBS) following three technical arm-swing performed during the preparatory phase in high-level male gymnasts. The three different arm-swing pertain to three "gymnastics schools", i.e., Russian, Chinese, and Romanian. Six high-level male gymnasts participated in this study. Three arm-swing with different angles (i.e., SBS 270° , SBS 180° , and SBS 90° ) were randomly performed. A 3D kinetic and kinematic analysis was conducted. Results showed significant variation in the landing angle ( p = 0.009) across the three arm-swing techniques. The SBS 90° arm-swing resulted in the closest angle to the vertical. Additionally, the SBS 90° arm-swing technique induced the lowest horizontal and vertical force values upon landing compared to the other arm-swing techniques (SBS 270° : p = 0.023 and 0.009, respectively; SBS 180° : p = 0.004 and 0.080, respectively). The same was noted for the horizontal velocity ( p = 0.021) with the lowest values noted for the SBS 90° arm-swing technique. However, the best opening angle was observed during the SBS 270° technique, since it presented the best vertical displacement. In conclusion, the SBS with a SBS 90° arm-swing seems to favor a better absorption of the ground reaction force upon landing by reducing the intensity of the impact with the ground and by affording a landing angle closer to the vertical in high-level male gymnasts.

Purpose: The aim of this study was to compare the effect of vision (i.e., open and closed eyes) on the kinetic and kinematic parameters of the standing back tuck somersault (SBTS) in artistic gymnasts and parkour athletes., Methods: Eleven male parkour athletes (age 22.53 ± 2.36 years; height 1.72 ± 0.08 m; weight 69.58 ± 3.72 kg) and seven male artistic gymnasts (age 21.96 ± 2.64 years; height 1.62 ± 0.02 m; weight 63.54 ± 1.35 kg) participated in this study. Each subject was asked to perform the SBTS in the same condition (i.e., first open-eyes then closed-eyes). 2D kinetic and kinematic analysis was conducted., Results: The results showed significant interaction (i.e., vision and sport) obtained at the take-off angle (p <0.05 and d = 1.992), horizontal displacement (p <0.05 and d = 1.906) and technical execution (p < 0.05 and d = 1.972). This interaction indicates that when vision is permitted, artistic gymnasts and parkour athletes were similar in all kinetic and kinematic parameters, and technical execution (p > 0.05). However, the elimination of vision during SBTS only affected parkour athletes (i.e., landing angle, ground reaction force, vertical velocity and technical execution, p < 0.05 and d > 1.20) while artistic gymnasts remain unchanged., Conclusion: We conclude that the specificity of the practice in each of the two sports disciplines influences the kinetic and kinematic control of the SBTS and suggests that with closed-eyes, the integration of afferent information relating to the vestibular and proprioceptive systems is different and specific to each discipline's goal. Artistic gymnasts seem to be better skilled in the mechanical and technical control of the SBTS than parkour athletes.

Background: The circadian clock regulates the function of the immune system, the replication of viruses, and the magnitude of infections. The aim of this study was to analyse whether hospital attendance in Coronavirus disease 2019 (COVID-19) patients presents a diurnal variation., Methods: Data from the electronic medical records of 1094 COVID-19 patients who presented to a Health Centre in Qatar during the month of July 2020 was retrospectively analysed. The following demographic (i.e. time of day (TOD), sex, age), clinical (i.e. cycle threshold (CT), temperature, oxy-haemoglobin saturation and resting heart-rate), biochemical (i.e. uraemia, glycaemia and albuminia) and haematological (i.e. leukocytes, erythrocytes ad platelets) parameters were collected., Results: Univariate analysis showed a significant effect of TOD on hospital admission ( p  < 0.001), with patients attending the health care centre more during the active behavioural phase (08h00-00h00) compared to the resting phase (00h00-08h00). COVID-19 infection blunted the circadian rhythms of core body temperature, neutrophils and leukocytes family and shifted the circadian rhythms of resting heart-rate and uraemia. Correlation analysis showed a near perfect negative correlation between the age of patients and the TOD ( r =-0.97), with older patients attending the care centre earlier during the day., Conclusion: COVID-19 infection affected the circadian rhythms of the host through disrupting the circadian rhythms of core temperature and innate immunity mediators. Old patients attend the health care centre earlier compared to younger ones. However, CT during polymerase chain reaction-test was unaffected by the TOD, which limits the conclusion that COVID-19 viral infection exhibits diurnal variation.

Many COVID-19 infected people remain asymptomatic, and hence the diagnosis at first presentation remains a challenge. Assessment at a presentation in primary care settings is usually done by visual triaging and basic clinical examination. This retrospective study involved investigating the medical e-records of COVID-19 positive patients who presented to a COVID-19 centre in Qatar for July 2020. The presence (symptomatic group) or the absence (asymptomatic group) of symptoms along with objective vital examination ( ie ; heart-rate (HR), temperature, haemoglobin saturation (SpO 2 )) were analysed and linked to the viral load ( ie ; cycle threshold (Ct)) of COVID-19 positive patients. Four hundred eighty-one symptomatic (230 males) and 216 asymptomatic (101 males) patients were included. Compared to the asymptomatic male group, the symptomatic male group was older, had lower Ct value and SpO 2 , and higher temperature and HR. Compared to the females asymptomatic group, the symptomatic females group had lower Ct value, and higher temperature. Compared to the asymptomatic group, the symptomatic group had lower Ct value and SpO 2 , and higher temperature and HR. Compared to the asymptomatic group, the symptomatic group had lower Ct values (age groups [21-30], [31-40], [41-50] and [51-60]), higher temperature (age groups [21-30] and [31-40], Ct ranges [20.01-25.00] and [25.01-30.00]), higher HR (age groups [21-30] and [31-40], Ct range [15.01-20.00]); and lower SpO 2 (age groups [41-50] and [51-60], Ct ranges [15.01-20.00] and [35.01-40.00]). Compared with asymptomatic patients, symptomatic patients with COVID-19 are most likely to be febrile, tachycardic, hypoxic and having higher viral load. Higher viral load was associated with higher HR, higher temperature, lower SpO 2 , but there was no relation between viral load and age.

The aim of this study was to identify the immediate effect of self-modelling with different focus of attention strategies (i.e., internal vs. external) on the teaching/learning of gymnastics motor-skills. Fifty-nine non-gymnast students participated in this study and were divided into three groups (i.e., an external focus group (EF), an internal focus group (IF), and a control group (CG)). Each participant's performance of the back dismount in the parallel bars was assessed before the experiment (i.e., base-score), and each participant was asked to provide a self-evaluation of their performance and their efficiency percentage. Afterwards, participants received a specific learning session (i.e., self-modelling with external focus, self-modelling with internal focus, or traditional learning with verbal instruction) and performed the back dismount in the parallel bars again immediately after (i.e., final score). Four international judges evaluated performance of our participants. The results showed that the EF and IF outperformed the CG in the final score. Importantly, a significant difference between the base and the final score was observed in the EF and IF, but not in the CG. In addition, the EF showed the highest percentage of improvement (Δ-score) and self-estimation scores compared to the two other groups. In conclusion, this study supports the adoption of external focus of attention for teaching/learning gymnastics motor-skills., (© 2022 Asma Amri-Dardari, Bessem Mkaouer, Samiha Amara, Sarra Hammoudi-Nassib, Hamdi Habacha, Fatma Zohra BenSalah, published by Sciendo.)

Objective: This study aimed to systematically review and meta-analyze the effect of flywheel resistance training (FRT) versus traditional resistance training (TRT) on change of direction (CoD) performance in male athletes. Methods: Five databases were screened up to December 2021. Results: Seven studies were included. The results indicated a significantly larger effect of FRT compared with TRT (standardized mean difference [SMD] = 0.64). A within-group comparison indicated a significant large effect of FRT on CoD performance (SMD = 1.63). For TRT, a significant moderate effect was observed (SMD = 0.62). FRT of ≤2 sessions/week resulted in a significant large effect (SMD = 1.33), whereas no significant effect was noted for >2 sessions/week. Additionally, a significant large effect of ≤12 FRT sessions (SMD = 1.83) was observed, with no effect of >12 sessions. Regarding TRT, no significant effects of any of the training factors were detected (p > 0.05). Conclusions: FRT appears to be more effective than TRT in improving CoD performance in male athletes. Independently computed single training factor analyses for FRT indicated that ≤2 sessions/week resulted in a larger effect on CoD performance than >2 sessions/week. Additionally, a total of ≤12 FRT sessions induced a larger effect than >12 training sessions. Practitioners in sports, in which accelerative and decelerative actions occur in quick succession to change direction, should regularly implement FRT.

The purpose of this study was to examine the effects of non-resisted (NRS) and partner-towing resisted (RS) sprint training on legs explosive force, sprint performance and sprint kinematic parameters. Sixteen young elite soccer players (age 16.6 ± 0.2 years, height 175.6 ± 5.7 cm, and body mass 67.6 ± 8.2 kg) were randomly allocated to two training groups: resisted sprint RS (n = 7) and non-resisted sprint NRS (n = 9). The RS group followed a six-week sprint training programme consisting of two "sprint training sessions" per week in addition to their usual soccer training. The NRS group followed a similar sprint training programme, replicating the distances of sprints but without any added resistance. All players were assessed before and after training: vertical and horizontal jumping (countermovement jump (CMJ), squat jump (SJ), and 5-jump test (5JT)), 30 m sprint performance (5, 10, and 20 m split times), and running kinematics (stride length and frequency). In the RS group significant (p < 0.05) changes were: decreased sprint time for 0-5 m, 0-10 m and 0-30 m (-6.31, -5.73 and -2.00%; effect size (ES) = 0.70, 1.00 and 0.41, respectively); higher peak jumping height (4.23% and 3.59%; ES = 0.35 and 0.37, for SJ and CMJ respectively); and 5JT (3.10%; ES = 0.44); and increased stride frequency (3.96%; ES = 0.76). In the NRS group, significant (p < 0.05) changes were: decreased sprint time at 0-30 m (-1.34%, ES = 0.33) and increased stride length (1.21%; ES = 0.17). RS training (partner towing) for six weeks in young soccer players showed more effective performances in sprint, stride frequency and lower-limb explosive force, while NRS training improved sprint performance at 0-30 m and stride length. Consequently, coaches and physical trainers should consider including RS training as part of their sprint training to ensure optimal sprint performance., Competing Interests: There are no conflicts of interest concerning this paper., (Copyright © Biology of Sport 2021.)

Purpose: The aim of this study was to compare the effect of three run-up steps on the kinetic and kinematic variables of the stag ring leap, with throw-catch of the ball, in high-level rhythmic female gymnasts. The three run-up steps used are a chassé step, glissade, and assemblé., Methods: Seven high-level rhythmic female gymnasts participated in this study. Three run-up steps (i.e., chassé step, glissade and assemblé) were used randomly to perform a stag ring leap with throwing a ball on the jump take-off. 2D kinetic and kinematic analysis was conducted., Results: The results indicated that the assemblé step used in the run-up technique generated greater values of the rate of force development, the highest values of vertical velocity, and the best vertical displacement. In addition, the assemblé step allows for the best opening angle of the split leap and the best closest angle of the ring leg. The same was noted for the front leg's angular velocity., Conclusion: We concluded that the assemblé step used in the run-up technique appears to favor a greater stag ring leap that meets the Code of Points' condition for admitting the jump, as well as numerous studies that focus on improving jumping abilities in rhythmic gymnastics.

The aim of this study was to compare the effects of vibration (Vib versus noVib) during a maximal graded cycling exercise on hormonal response, precisely on cortisol (C) and testosterone (T). Twelve active males (25 ± 5yrs; 181 ± 5cm; 80.7 ± 11.1kg) randomly performed two maximal incremental cycling tests on two separate days and at the same time of the day (09:00). The protocol consisted of incremental steps of 3 min duration performed on a PowerBIKETM that induces vibration cycling. The study was a repeated measures design and participants performed the test with and without vibration. Gas exchange and heart rate (HR) were continuously assessed and blood lactate (Bla) was recorded at the end of each incremental stage. Saliva samples were collected before and immediately after the test, and analysed for (C) and (T). The results show that C and T increased in both cycling conditions; however, the C's magnitude of change was significantly higher by 83% after Vib cycling in comparison to the no Vib (p = 0.014), whereas the T's magnitude of change were not statistically different between trials (p = 0.715). Vibration induced a decrease of the T/C ratio (p = 0.046) but no significant changes were observed following noVib (p = 0.476). As a conclusion, the investigation suggests that adding mechanical vibration to cycling may potentiate a catabolic exercise-induced state, which could have potential clinical implications in rehabilitation and injury treatment. Sport experts should take this message home to carefully plan the recovery process and time during training and competitions., Competing Interests: The authors have declared that no competing interests exist.

Bouguezzi, R, Chaabene, H, Negra, Y, Ramirez-Campillo, R, Jlalia, Z, Mkaouer, B, and Hachana, Y. Effects of different plyometric training frequencies on measures of athletic performance in prepuberal male soccer players. J Strength Cond Res 34(6): 1609-1617, 2020-This study aimed to compare the effects of 1 vs. 2 sessions of equal-weekly volume plyometric training (PT) across 8 weeks on measures of athletic performance (i.e., sprint time, change of direction [CoD], jumping ability, and muscle strength) in prepuberal male soccer players. Thirty participants were randomly assigned either to 1 session PT group (1SPT [n = 15]) or 2 sessions PT group (2SPT [n = 15]). Plyometric training was integrated into their regular soccer training routine. Pretraining and posttraining tests for the assessment of sprint time (e.g., 5, 10, 20, and 30-m), CoD (e.g., T-test and modified Illinois change of direction test [MICODT]), jumping ability (e.g., standing long jump [SLJ], countermovement jump [CMJ], and squat jump [SJ]), muscle strength (reactive strength index [RSI]), and kicking distance were conducted. Results showed a main effect of time for 5-m sprint-time performance (F(1,56) = 4.00, effect size [ES] = 0.53 [medium], p = 0.05), T-test (F(1,56) = 23.19, ES = 1.28 [large], p < 0.001), MICODT (F(1,56) = 5.72, ES = 0.94 [large], p = 0.02), SLJ (F(1,56) = 16.63, ES = 1.09 [large], p < 0.001), CMJ (F(1,56) = 15.43, ES = 1.04 [large], p < 0.001), SJ (F(1,56) = 20.27, ES = 1.20 [large], p < 0.001), RSI (F(1,56) = 26.26, ES = 1.36 [large], p < 0.001), and kicking distance (F(1,56) = 47.19, ES = 1.83 [large], p < 0.001). There were no training group × time interactions in all the measured outcomes. In conclusion, when an equated moderate volume of jumps is performed, higher PT frequency across 8 weeks has no extra effects on prepuberal male soccer players' measures of athletic performance. The present findings may help optimizing PT interventions dedicated to prepuberal male soccer players.

Nassib, SH, Mkaouer, B, Riahi, SH, Wali, SM, and Nassib, S. Prediction of gymnastics physical profile through an international program evaluation in women artistic gymnastics. J Strength Cond Res 34(2): 577-586, 2020-The purpose of this study was to investigate the most appropriate aptitudes for top-level sporting results to identify physical profile of talent identified women's artistic gymnastics (WAG). Forty-eight women's artistic gymnasts in the provincial team (age 11.12 ± 1.22 years; height 1.35 ± 0.04 m; body mass 28.5 ± 4.04 kg) voluntarily participated in this study. Anthropometrics measures and the WAG battery physical tests were used to ensure a systematic approach for the WAG development worldwide. The present findings revealed that the strength (static strength, speed strength, and endurance strength), power and flexibility seem to be important and essential for good performance. Another characteristic that emerged from the results of the physical domain is coordination. This motor skill may seem relevant to gymnastics, they are applicable to the gymnasts' ability to perform all apparatus and more generally they relate to the ability to accurately perform whole-body skills supported by the leg on the floor, balance beam, and vault. Therefore, athletic performance can be boosted using combination of several characteristics that seems to be important for an elite gymnast. This reinforcing the view that systematic approach for the development and mufti-dimensional profile seems promising.

The aim of this study was to compare the physiological responses between a vibration induced cycling step protocol (Vib) and normal cycling (without vibration, no-Vib). Eighteen moderate trained males (age 24.1 ± 4.3 years; weight 76.5 ± 10.5 kg; height 178.0 ± 6.4 cm) have participated in this study. They randomly performed two gradual maximal exercise tests on two separate days using a new bike that automatically induces vibration cycling and the Corival cycle ergometer. The choice of two different bikes was made because of the impossibility to recreate the same power output without altering the cycling cadence on the vibration Bike. Both protocols were matched for power output and cycling cadence incrementations. Oxygen uptake (VO 2 ), carbon dioxide production (VCO 2 ), ventilation (VE), heart rate (HR), blood lactate and rating of perceived exertion (RPE) during each stage were continuously recorded. No statistical differences were founded for all variables when comparing the Vib to no-Vib trials, except a higher ventilation during the vibration trial at submaximal levels. The results of this study do not confirm those of previous studies stated that Vib increased metabolic demands during cycling exercise. Added vibration stimulus to an incremental cycling protocol does not affect physiological parameters.

This study aimed to determine the specific physical and basic gymnastics skills considered critical in gymnastics talent identification and selection as well as in promoting men's artistic gymnastics performances. Fifty-one boys from a provincial gymnastics team (age 11.03 ± 0.95 years; height 1.33 ± 0.05 m; body mass 30.01 ± 5.53 kg; body mass index [BMI] 16.89 ± 3.93 kg/m ² ) regularly competing at national level voluntarily participated in this study. Anthropometric measures as well as the men's artistic gymnastics physical test battery (i.e., International Gymnastics Federation [FIG] age group development programme) were used to assess the somatic and physical fitness profile of participants, respectively. The physical characteristics assessed were: muscle strength, flexibility, speed, endurance, and muscle power. Test outcomes were subjected to a principal components analysis to identify the most representative factors. The main findings revealed that power speed, isometric and explosive strength, strength endurance, and dynamic and static flexibility are the most determinant physical fitness aspects of the talent selection process in young male artistic gymnasts. These findings are of utmost importance for talent identification, selection, and development., Competing Interests: There is no conflict of interest including any financial, personal or other relationships with other people or organizations that have influenced the performance of this work.

Chaabene, H, Negra, Y, Capranica, L, Bouguezzi, R, Hachana, Y, Rouahi, MA, and Mkaouer, B. Validity and reliability of a new test of planned agility in elite taekwondo athletes. J Strength Cond Res 32(9): 2542-2547, 2018-This study aimed to examine the validity, reliability, and sensitivity of a new test of planned agility in elite taekwondo athletes and to establish its relationship with sprint-time, jumping ability, and dynamic balance. Twenty-seven (20 males and 7 females) taekwondo athletes participated in this study. They performed taekwondo-specific agility test (TSAT) in 2 occasions (i.e., test-retest). In addition, they performed jumping ability (i.e., squat jump, countermovement jump, standing long jump, and 3-hop jump), sprint-time (5- and 20-m dash), and dynamic balance (i.e., Y-test) tests along with a planned agility test (i.e., T-test). To establish TSAT's construct validity, 2 subgroups were identified based on their international and national taekwondo results: top elite (9 males and 2 females) and elite (11 males and 2 females). Taekwondo-specific agility test showed high relative and absolute reliability as well as a good ability to detect small and meaningful performance change. Top-elite athletes showed greater (p < 0.001) TSAT performances (4.5 ± 0.4 seconds) compared with their elite (5.3 ± 0.4 seconds) counterparts. Receiving operating characteristic (ROC) analysis showed that TSAT was able to discriminate athletes of different competitive level as revealed by an area under the ROC curve of 0.94 (95% confidence interval: 0.76-0.99). Taekwondo-specific agility test demonstrated significant association with the T-test (r = 0.71; shared variance = 50%), which is considered as a gold-standard planned agility test. In addition, results showed moderate-to-large associations between TSAT and jumping ability, sprint-time, and dynamic balance tests. The TSAT might be considered as a valid and reliable test to evaluate specific agility of taekwondo athletes.

The rotation sequence-order differs from a gymnast to another according to the draw at the time of the qualifying competitions in men's artistic gymnastics. Only the six best gymnasts start on the floor exercises, the others could start on any of the other five apparatuses. It has been demonstrated that some gymnastics events are physiologically less taxing than others; hence some gymnasts could experience lower and/or higher levels of cardiovascular and metabolic stress compared to others, depending on the apparatus they start with. In this regard, the objective of this investigation was to compare cardiovascular and metabolic variables between two different types of Olympic rotation-order; one began with the floor exercises and the other began with the pommel horse. Six elite male gymnasts took part in this investigation. Heart rates, synchronized with real-time video acquisition, as well as capillary lactate concentration following each apparatus routine were monitored. Cardiovascular and metabolic stresses were significantly higher when gymnasts started their rotation with the pommel horse in all apparatuses except the pommel horse. The floor exercises' score was significantly affected when gymnasts ended up their competition on this apparatus. As a conclusion, starting gymnastics' competition on the floor exercises implicates less cardiovascular and metabolic stress associated with better performance compared with the other rotation order. As a matter of fact, best gymnasts who start on this apparatus could have a slight advantage compared with the other athletes.

Negra, Y, Chaabene, H, Sammoud, S, Bouguezzi, R, Mkaouer, B, Hachana, Y, and Granacher, U. Effects of plyometric training on components of physical fitness in prepuberal male soccer athletes: the role of surface instability. J Strength Cond Res 31(12): 3295-3304, 2017-Previous studies contrasted the effects of plyometric training (PT) conducted on stable vs. unstable surfaces on components of physical fitness in child and adolescent soccer players. Depending on the training modality (stable vs. unstable), specific performance improvements were found for jump (stable PT) and balance performances (unstable PT). In an attempt to combine the effects of both training modalities, this study examined the effects of PT on stable surfaces compared with combined PT on stable and unstable surfaces on components of physical fitness in prepuberal male soccer athletes. Thirty-three boys were randomly assigned to either a PT on stable surfaces (PTS; n = 17; age = 12.1 ± 0.5 years; height = 151.6 ± 5.7 cm; body mass = 39.2 ± 6.5 kg; and maturity offset = -2.3 ± 0.5 years) or a combined PT on stable and unstable surfaces (PTC; n = 16; age = 12.2 ± 0.6 years; height = 154.6 ± 8.1 cm; body mass = 38.7 ± 5.0 kg; and maturity offset = -2.2 ± 0.6 years). Both intervention groups conducted 4 soccer-specific training sessions per week combined with either 2 PTS or PTC sessions. Before and after 8 weeks of training, proxies of muscle power (e.g., countermovement jump [CMJ], standing long jump [SLJ]), muscle strength (e.g., reactive strength index [RSI]), speed (e.g., 20-m sprint test), agility (e.g., modified Illinois change of direction test [MICODT]), static balance (e.g., stable stork balance test [SSBT]), and dynamic balance (unstable stork balance test [USBT]) were tested. An analysis of covariance model was used to test between-group differences (PTS vs. PTC) at posttest using baseline outcomes as covariates. No significant between-group differences at posttest were observed for CMJ (p > 0.05, d = 0.41), SLJ (p > 0.05, d = 0.36), RSI (p > 0.05, d = 0.57), 20-m sprint test (p > 0.05, d = 0.06), MICODT (p > 0.05, d = 0.23), and SSBT (p > 0.05, d = 0.20). However, statistically significant between-group differences at posttest were noted for the USBT (p < 0.01, d = 1.49) in favor of the PTC group. For most physical fitness tests (except RSI), significant pre-to-post improvements were observed for both groups (p < 0.01, d = 0.55-3.96). Eight weeks of PTS or PTC resulted in similar performance improvements in components of physical fitness except for dynamic balance. From a performance-enhancing perspective, PTC is recommended for pediatric strength and conditioning coaches because it produced comparable training effects as PTS on proxies of muscle power, muscle strength, speed, agility, static balance, and additional effects on dynamic balance.

Chaabene, H, Negra, Y, Bouguezzi, R, Mkaouer, B, Franchini, E, Julio, U, and Hachana, Y. Physical and physiological profile of wrestler athletes: a short review. J Strength Cond Res 31(5): 1411-1442, 2017-Wrestling is one of the oldest combat sports, disputed since the ancient Greek Olympic Games. This combat sport discipline has caught the attention of scientists since 1943 which is the date that matches the appearance of the first scientific research dealing with wrestling. The current short review aimed to summarize and critically analyze the scientific literature related to wrestling's physical and physiological attributes and to provide practical recommendations for testing/training together with new perspective and areas of future scientific research. Regardless of sex and wrestling styles, an optimal level of cardiorespiratory fitness is important to help sustaining effort throughout the duration of the match and to stimulate the recovery process between periods. With regard to the anaerobic power and capacity, the available studies were in agreement about their critical importance toward reaching high-level wrestling success since these variables have discriminated well between successful and less-successful wrestlers regardless of age, weight classes, and wrestling styles. Physical fitness parameters such as maximal dynamic strength, isometric strength, explosive strength, and strength endurance are closely related to high-level wrestling performance. However, flexibility level seems not to be one of the key fitness variables that help to reach high-level wrestling success. Overall, to achieve high-level wrestling performance, training should be directed to develop anaerobic power and capacity, aerobic power, maximal dynamic and isometric strength, explosive strength, and strength endurance.

Negra, Y, Chaabene, H, Hammami, M, Amara, S, Sammoud, S, Mkaouer, B, and Hachana, Y. Agility in young athletes: is it a different ability from speed and power? J Strength Cond Res 31(3): 727-735, 2017-Agility is an important physical attribute for successful participation in team sports events. Illinois agility test (IAT) and T-test have been widely used within adult team sports players to assess agility performance. The purposes of this investigation are (a) to study the reliability and the sensitivity of both IAT and T-test scores and (b) to explore to what extend the agility is an independent physical ability from speed time and jumping ability. Competitive-level young soccer (n = 95) and handball players (n = 92) participated in this study (i.e., approximately 12 years old). Reliability analyses were established by determining intraclass correlation coefficient (ICC(3,1)) and typical error of measurement (TEM). The sensitivity of agility tests was revealed by comparing TEM to the value of the smallest worthwhile change (SWC). The second aim was examined by means of the principal component analysis. Results revealed that the scores of both IAT and T-test showed a high reliability (all ICC(3,1) > 0.90 and TEM < 5%) and sensitivity (all TEM < SWC). Principal component analysis resulted in one significant component for the soccer and handball group each that explained 72.18 and 80.16% of the total variance, respectively. Significant relationships were recorded between all the selected tests (r = -0.72 to 0.85, p < 0.001). Based on the results of this study, it was concluded that both IAT and T-test provided reliable and sensitive scores. Therefore, these tests could be strongly recommended to evaluate agility within young male competitive-level team sports athletes. In addition, it seems that agility, speed time, and jumping ability assess the same physical attribute in young competitive-level team sports players.

Background: Determining the physiological profile of athletes in boxing match is important for defining aspects of physical performance that are important to competitive performance. Therefore, examination of the energy pathway of high-level boxers' athletes can be very helpful for optimizing training and then improving boxing physical fitness and performance. The aim of the present study was to assess the physiological and cardiovascular responses during boxing matches and subsequent recovery., Methods: Fifteen male international level boxers (mean age 19.56±3.6 years; mean body mass 72.46±11.86 kg; mean height 176.50±7.22 cm) participated in this study. Blood samples were drawn from the antecubital vein before and after the boxing matches (T1: pre-match rest measure around 11:00 a.m., T2: measure at 3 minutes of post-match recovery; T3: measure at 60 minutes of recovery; T4: measure at 24 hours post-match - the match started around 11:30 a.m.). An analysis of glucose, triglycerides, lactate, cholesterol, creatinine, uric-acid, high density lipoprotein, and low density lipoprotein concentrations was performed for each sample. Participants did perform a maximal incremental test to measure maximal heart rate (HRmax). Heart rate responses to the matches were measured and expressed in percentage of HRmax., Results: The average HR recorded during the match corresponded to 93±3.26% of HRmax. The levels of glucose, lactate, and cholesterol increased significantly from T1 to T2. Likewise, creatinine levels increased significantly from T1 to T2 and T3. However, the cholesterol level decreased significantly at T3 in comparison with T1. Moreover, 24-hour post-match creatinine levels were significantly lower and triglyceride levels were significantly higher compared with T1., Conclusions: The main results of this study revealed that the boxing matches stress the lipid metabolism system during boxing and post-match (for at least 24 hours) even if it is widely recognized boxing being mainly composed of repeated short-duration anaerobic efforts.

Background: Karate is one the most popular combat sports in the world. Physical fitness assessment on a regular manner is important for monitoring the effectiveness of the training program and the readiness of karatekas to compete., Objectives: The aim of this research was to examine the criterion related to validity of the karate specific aerobic test (KSAT) as an indicator of aerobic level of karate practitioners., Patients and Methods: Cardiorespiratory responses, aerobic performance level through both treadmill laboratory test and YoYo intermittent recovery test level 1 (YoYoIRTL1) as well as time to exhaustion in the KSAT test (TE'KSAT) were determined in a total of fifteen healthy international karatekas (i.e. karate practitioners) (means ± SD: age: 22.2 ± 4.3 years; height: 176.4 ± 7.5 cm; body mass: 70.3 ± 9.7 kg and body fat: 13.2 ± 6%)., Results: Peak heart rate obtained from KSAT represented ~99% of maximal heart rate registered during the treadmill test showing that KSAT imposes high physiological demands. There was no significant correlation between KSAT's TE and relative (mL/min kg) treadmill maximal oxygen uptake (r = 0.14; P = 0.69; [small]). On the other hand, there was a significant relationship between KSAT's TE and the velocity associated with VO2max (vVO2max) (r = 0.67; P = 0.03; [large]) as well as the velocity at VO2 corresponding to the second ventilatory threshold (vVO2 VAT) (r = 0.64; P = 0.04; [large]). Moreover, significant relationship was found between TE's KSAT and both the total distance covered and parameters of intermittent endurance measured through YoYoIRTL1., Conclusions: The KSAT has not proved to have indirect criterion related validity as no significant correlations have been found between TE's KSAT and treadmill VO2max. Nevertheless, as correlated to other aerobic fitness variables, KSAT can be considered as an indicator of karate specific endurance. The establishment of the criterion related validity of the KSAT requires further investigation.

Boxing is one of the oldest combat sports. The aim of the current review is to critically analyze the amateur boxer's physical and physiological characteristics and to provide practical recommendations for training as well as new areas of scientific research. High-level male and female boxers show a propensity for low body fat levels. Although studies on boxer somatotypes are limited, the available information shows that elite-level male boxers are characterized by a higher proportion of mesomorphy with a well-developed muscle mass and a low body fat level. To help support the overall metabolic demands of a boxing match and to accelerate the recovery process between rounds, athletes of both sexes require a high level of cardiorespiratory fitness. International boxers show a high peak and mean anaerobic power output. Muscle strength in both the upper and lower limbs is paramount for a fighter's victory and is one of the keys to success in boxing. As boxing punches are brief actions and very dynamic, high-level boxing performance requires well-developed muscle power in both the upper and lower limbs. Albeit limited, the available studies reveal that isometric strength is linked to high-level boxing performance. Future investigations into the physical and physiological attributes of boxers are required to enrich the current data set and to help create a suitable training program.

The aim of this study was to compare the effects of acute vibration-enhanced static stretching and/or static stretching alone on the strength and flexibility of the hamstrings and quadriceps muscles. Twenty-one male footballers participated in this study (21.9 ± 1.8 years; 75.54 ± 7.3 kg; 178.7 ± 6.5 cm). The experiment started with 5 minutes standardized warm-up followed by (a) baseline flexibility pretest (Split Test); (b) maximal voluntary flexion and extension (isokinetic strength) of the knee; (c) Treatment or Sham involving 45-second stretch with or without vibration for the hamstring and quadriceps muscle groups with 10-second rest between; and (d) posttest repeating the measures of the pretest. Each player randomly performed both trials on separate occasions. The vibration device operated at 35 Hz with 2 mm amplitude. Stretching with vibration statistically increased hamstring flexibility by 7.8% (p ≤ 0.05) when compared with stretching without vibration. No statistical differences for hamstring or quadriceps strength were noted between treatment conditions. There was no statistical correlation between flexibility and strength measurements. In conclusion, flexibility increased with vibration-enhanced static stretching; however, no change was evident in the maximal voluntary contractions of the knee flexors and extensors.

Arms swing during standing back somersaults relates to three different "gymnastics schools", each is considered "optimal" by its adepts. In the three cases, technical performance, elevation and safety differ. Therefore, the aim of this study was to compare the mechanical variables of three different arms swing techniques in the performance of a standing back tucked somersault. Five high-level male gymnasts (age: 23.17±1.61 yrs; body height: 1.65±0.05 m; body mass: 56.80±7.66 kg) randomly performed standing somersaults under three conditions, each following a different arms' swing technical angle (270°, 180° and 90°). A force plate synchronized with a three dimensional movement analysis system was used to collect kinetic and kinematic data. Significant differences were observed between somersaults' performance. The back somersault performed with 270° arms swing showed the best vertical displacement (up to 13.73%), while the back somersaults performed with 180° arms swing showed a decrease in power (up to 22.20%). The back somersault with 90° arms swing showed the highest force (up to 19.46%). Considering that the higher elevation of the centre of mass during the flight phase would allow best performance and lower the risk of falls, this study demonstrated that optimal arms' swing technique prior to back tucked somersault was 270°.

Purpose: The aim of this study was to measure and compare physiological and time-motion variables during karate fighting and to assess eventual differences between winners and defeated elite karatekas in an ecologically valid environment., Methods: Fourteen elite male karatekas who regularly participated in national and international events took part in a national-level competition., Results: There were no significant differences between winners and defeated karatekas regarding all the studied variables. Karatekas used more upper-limb (76.19%) than lower-limb techniques (23.80%). The kisami-zuki represented the most frequent technique, with 29.1% of all used techniques. The duration of each fighting activity ranged from <1 s to 5 s, with 83.8% ± 12.0% of the actions lasting less than 2 s. Karatekas executed 17 ± 7 high-intensity actions per fight, which corresponded to ~6 high-intensity actions per min. Action-to-rest ratio was about 1:1.5, and high-intensity-action- to-rest ratio was ~1:10. The mean blood lactate response at 3 min postcombat (Lapost) elicited during karate fighting was 11.18 ± 2.21 mmol/L (difference between Lapre and Lapost = 10.01 ± 1.81 mmol/L). Mean heart rate (HR) was 177 ± 14 beats/min (91% ± 5% of HRpeak). Karatekas spent 65% of the time exercising at HR >90% of the individual HRpeak., Conclusion: Karatekas predominantly use upper-limb karate techniques. Karate's nature is intermittent, with fighting activities representing ~6% of total combat's duration and ~84% of actions lasting less than 2 s, with ~21-s mean time interval in between. Kumite combat sessions induced high La and near-maximal cardiovascular strain. Other key success factors should be investigated to properly discriminate winners and defeated athletes.

Purpose: This study aimed to compare physiological responses and time-motion analysis between official and simulated karate combat., Methods: Ten high-level karatekas participated in this study, which included official and simulated karate combat., Results: Karatekas used more upper-limb attack techniques during official combat compared to simulated ones (6±3 vs 3±1; P=0.05, respectively). For official and simulated karate matches, the numbers of high-intensity actions (i.e. offensive and defensive fighting activity) were 14±6 and 18±5, respectively (P>0.05), lasting from <1s to 5s each. Total fighting activity phase was lower during official compared to simulated matches (21.0±8.2s vs 30.4±9.9s, P<0.01, respectively). Effort (10.0±2.8s) to rest (11.9±2.7s) ratio (E:R) was 1:1 and high-intensity actions (1.6±0.3s) to rest (11.9±2.7s) ratio was higher than 1:7 during simulated combat. During official karate match, the activity and rest duration were 10.0±3.4s and 16.2±4.1s, respectively (E:R ratio 1:1.5), while high-intensity actions were 1.5±0.3s, resulting in an E:R ratio of 1:11. Blood lactate concentration was higher during official (11.14±1.82 mmol.l(-1)) compared to simulated karate combat (7.80±2.66 mmol.l(-1)) (P<0.05). Subjective perceived exertion differed significantly between official and simulated combat (14±2 vs. 12±2; P<0.05, respectively). The majority of karatekas' perceived exertion was higher in the lower limb muscle groups irrespective of the karate combat condition., Conclusion: Official and simulated matches differ considerably, therefore coaches should create new strategies during training sessions to achieve the same effort and pause profile of competitive matches and/or that athletes should be submitted to frequent competitions to adapt themselves to the profile of this event.

Back swing connections during gymnastics acrobatic series considerably influence technical performance and difficulties, particularly in the back somersault. The aim of this study was to compare the take-off's kinetic and kinematic variables between two acrobatic series leading to perform the backward stretched somersault (also called salto): round-off, flic-flac to stretched salto versus round-off, tempo-salto to stretched salto. Five high level male gymnasts (age 23.17 ± 1.61 yrs; body height 1.65 ± 0.05 m; body mass 56.80 ± 7.66 kg) took part in this investigation. A force plate synchronized with a two dimensional movement analysis system was used to collect kinetic and kinematic data. Statistical analysis via the non-parametric Wilcoxon Rank-sum test showed significant differences between the take-offs' variables. The backswing connections were different in the take-off angle, linear momentum, vertical velocity and horizontal and vertical displacements. In conclusion, considering that the higher elevation of the centre of mass in the flight phase would allow best performance and lower the risk of falls, particularly when combined to a great angular momentum, this study demonstrated that the optimal connection series was round-off, flic-flac to stretched salto which enabled the best height in the somersault. Analysis of the results suggests that both connections facilitate the performance of single and double (or triple) backward somersaults with or without rotations around the longitudinal axis. Gymnasts could perform these later while gaining height if they chose the round-off, flic-flac technique or gaining some backward displacement if they choose the round-off, salto tempo.

ABThe aim of this study was to examine absolute and relative reliabilities and external responsiveness of the Karate-specific aerobic test (KSAT). This study comprised 43 male karatekas, 19 of them participated in the first study to establish test-retest reliability and 40, selected on the bases of their karate experience and level of practice, participated in the second study to identify external responsiveness of the KSAT. The latter group was divided into 2 categories: national-level group (G(n)) and regional-level group (G(r)). Analysis showed excellent test-retest reliability of time to exhaustion (TE), with intraclass correlation coefficient ICC(3,1) >0.90, standard error of measurement (SEM) <5%: (3.2%) and mean difference (bias) ± the 95% limits of agreement: -9.5 ± 78.8 seconds. There was a significant difference between test-retest session in peak lactate concentration (Peak [La]) (9.12 ± 2.59 vs. 8.05 ± 2.67 mmol·L(-1); p < 0.05) but not in peak heart rate (HRpeak) and rating of perceived exertion (RPE) (196 ± 9 vs. 194 ± 9 b·min(-1) and 7.6 ± 0.93 vs. 7.8 ± 1.15; p > 0.05), respectively. National-level karate athletes (1,032 ± 101 seconds) were better than regional level (841 ± 134 seconds) on TE performance during KSAT (p < 0.001). Thus, KSAT provided good external responsiveness. The area under the receiver operator characteristics curve was >0.70 (0.86; confidence interval 95%: 0.72-0.95). Significant difference was detected in Peak [La] between national- (6.09 ± 1.78 mmol·L(-1)) and regional-level (8.48 ± 2.63 mmol·L(-1)) groups, but not in HRpeak (194 ± 8 vs. 195 ± 8 b·min(-1)) and RPE (7.57 ± 1.15 vs. 7.42 ± 1.1), respectively. The result of this study indicates that KSAT provides excellent absolute and relative reliabilities. The KSAT can effectively distinguish karate athletes of different competitive levels. Thus, the KSAT may be suitable for field assessment of aerobic fitness of karate practitioners.

This review focuses on the most important physical and physiological characteristics of karate athletes from the available scientific research. It has been established that karate's top-level performers require a high fitness level. Top-level male karate athletes are typified by low body fat and mesomorphic-ectomorphic somatotype characteristics. Studies dealing with body composition and somatotype of females are scarce. Aerobic capacity has been reported to play a major role in karate performance. It prevents fatigue during training and ensures the recovery processes during rest periods between two subsequent bouts of fighting activity within a fight and between two consecutive matches. It has been established that there is no significant difference between male and female kata (forms) and kumite (sparring/combat) athletes with regard to aerobic performance. Nevertheless, further studies are needed to support these findings. Concerning anaerobic performance, there is a difference in maximal power explored by the force-velocity test between national and international level karatekas (karate practitioners) but, for the maximum accumulated oxygen deficit test there is no difference between them. Muscle explosive power plays a vital role in a karateka's capacity for high-level performance. However, it has been revealed that vertical jump performance, maximal power and maximal velocity differed between national- and international-level karatekas. Moreover, it has been reported that karate performance relies more on muscle power at lower loads rather than higher ones. Thus, karate's decisive actions are essentially dependent on muscle explosive power in both the upper and lower limbs. With regard to dynamic strength, limited research has been conducted. The maximal absolute bench press, half-squat one-repetition maximum and performance of isokinetic tasks differed significantly between highly competitive and novice male karatekas. Studies on female karate athletes do not exist. Concerning flexibility, which is important for the execution of high kicks and adequate range of action at high speeds, it has been demonstrated that karate athletes' ranges of bilateral hip and knee flexion are greater compared with non-karate athletes. Finally, reaction time is a crucial element in karate because high-level performance is based essentially on explosive techniques. A significant difference in the choice reaction time between high-level and novice karatekas exists. Further research is needed concerning the physiological characteristics of female karatekas, the differences between kata and kumite athletes and variations based on weight categories.