The Good Behaviour Game: Maintaining students' physical distancing in physical education classes during the COVID-19 pandemic.

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.

Resisted sprint training with partner towing improves explosive force and sprint performance in young soccer players - a pilot study.

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.

Prediction of Gymnastics Physical Profile Through an International Program Evaluation in Women Artistic Gymnastics.

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.

Effects of Different Plyometric Training Frequencies on Measures of Athletic Performance in Prepuberal Male Soccer Players.

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.

Validity and Reliability of a New Test of Planned Agility in Elite Taekwondo Athletes.

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.

Evaluating the physical and basic gymnastics skills assessment for talent identification in men's artistic gymnastics proposed by the International Gymnastics Federation.

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/m²) 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.

Agility in Young Athletes: Is It a Different Ability From Speed and Power?

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.

Physical and Physiological Attributes of Wrestlers: An Update.

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.

Effects of Plyometric Training on Components of Physical Fitness in Prepuberal Male Soccer Athletes: The Role of Surface Instability.

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.

Acute static vibration-induced stretching enhanced muscle viscoelasticity but did not affect maximal voluntary contractions in footballers.

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.

Acute Effect of Video Feedback on Self-Regulation and Proprioceptive Control of Standing Back Tuck Somersault in the Absence of Vision.

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.

Does dynamic balance affect cube mental rotation task in badminton vs. volleyball female players?

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.

Effects of eliminating visual cues on kinetic and kinematic parameters in back tuck somersault: A comparison between artistic gymnasts and parkour athletes.

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.

Validity of a new sport-specific endurance test in artistic gymnastics.

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 (VO2max) 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 (HRmax), 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., VO2max, MAS, HRmax, 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 VO2max, MAS, BLa, and RER was good (smallest worthwhile change [SWC0.2] > TEM), except HRmax (SWC0.2 < TEM). Additionally, results showed a nearly perfect association between the VO2max 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.

Kinetic and Kinematic Analysis of Landing during Standing Back Somersault Using Three Technical Arm Swings in Artistic Gymnastics.

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., SBS270°, SBS180°, and SBS90°) 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 SBS90° arm-swing resulted in the closest angle to the vertical. Additionally, the SBS90° arm-swing technique induced the lowest horizontal and vertical force values upon landing compared to the other arm-swing techniques (SBS270°: p = 0.023 and 0.009, respectively; SBS180°: 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 SBS90° arm-swing technique. However, the best opening angle was observed during the SBS270° technique, since it presented the best vertical displacement. In conclusion, the SBS with a SBS90° 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.

Effect of dynamic balance on human mental rotation task in female badminton vs. volleyball players.

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.

Reliability and construct validity of the karate-specific aerobic test.

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.

The effect of three run-up techniques on kinetic and kinematic variables of the stag ring leap with throw-catch of the ball in rhythmic gymnastics.

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.

Immediate Effect of Self-Modelling with Internal Versus External Focus of Attention on Teaching/Learning Gymnastics Motor-Skills.

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.

Age and clinical signs as predictors of COVID-19 symptoms and cycle threshold value.

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 (SpO2)) 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 SpO2, 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 SpO2, 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 SpO2 (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 SpO2, but there was no relation between viral load and age.