Technical variation in a sample of high level judo players

Variability Analysis in Judo Para Athletes With Visual Impairments: Match-Outcome Performance in the Tokyo 2020 Paralympic Games With Evidence From the New Classification System

Match-related performance analysis in judo Para athletes with visual impairments is important to coaches and staff to identify technical-tactical profiles of their athletes and opponents but also to identify whether there are similar characteristics in each visual class. Thus, this study explores the match-related performance in judo Para athletes and verifies the relationship between performance using the old and new classification systems. The match-derived variables were analyzed using different statistical methods considering a total of 182 matches from the Tokyo 2020 Paralympic Games. The results indicated that performance was affected by sex and degree of impairment. The new classification system seems suitable for grouping Para judo athletes, as it differentiates performance between the two proposed classes (J1 and J2), since athletes from each group compete separately. Furthermore, different variability index measures were correlated with competitive performance, demonstrating a specific performance profile for each sport class in judo.

A New Developmental Approach for Judo Focusing on Health, Physical, Motor, and Educational Attributes

Judo is currently the most practiced combat sport in the world. There is no doubt of its importance for children, adolescents, adults, and seniors. However, due to its inherent complexity, coaches tend to place greater or lesser emphasis only on one of its multiple domains during the judoka formative years. The present study presents a novel developmental approach signaling Judo as an excellent way for physical, motor, educational, and health development across the lifespan. In this study, we consulted 23 Judo coaches, aiming to clarify the relevance and adequacy of the domains (Competitive, Health, Technical-Tactical, and Philosophical-Educational) and phases of the proposed model. Our findings showed that the model contents-physical, motor, educational, and health-are entwined with its four domains, which were considered of utmost importance by experts in the development of judokas. We, therefore, contend that our model is essential to better understand the growth and development of young judokas. Also, it may be a useful tool for Motor Development experts.

Diurnal variation in Uchikomi fitness test performance: Influence of warm-up protocols

Performance is judged using a variety of methods to ensure uniformity between competitions. Uchikomi Fitness Test (UFT) could accomplished between morning qualifying and evening finals. The purpose of this study is to investigate the impact of different warm-up protocols on UFT at different times of the day in female judokas. Ten volunteer women who had been practising judo on a regular basis for more than 5 years and actively competed in international tournaments took part in this study. Judokas completed UFT, either after no-warm-up (NWU), specific warm-up (SWU), and linear+lateral warm-up (FWU) protocols for two times a day in the morning: 09:00-11:00 and in the evening: 16:00-18:00, on non-consecutive days. In conclusion, there was a significant increase in UFT scores (F = 9.89; p = 0.002), a + b (F = 4.42; p = 0.04) and heart rate (F = 28.99; p < 0.001) in the early evening compared to the morning. Increases in UFT performance were observed in the SWU protocol compared to the NWU and FWU protocols (p < 0.05). However, the interaction between time of day and warm protocol was not significant (p > 0.05). The UFT performance revealed diurnal variation, and the judokas' performances may be favourably affected more in the late hours, particularly following SWU procedures.

Effects of Sodium Bicarbonate Ingestion on Recovery in High-Level Judokas

BACKGROUND

The aim of this study was to examine the sodium bicarbonate (NaHCO3) effect on recovery in high-level judokas.

METHODS

The sample of participants consisted of 10 male judokas (Age = 20 ± 2.1 years) who are judo masters (black belt holders) with a minimum of 10 years of training and competition experience. The study was designed as a double-blinded crossover design with the order of treatments being randomly assigned. The washout period was 72 h. All subjects received a dose of sodium bicarbonate (0.3 g/kg body weight) or a placebo 120 min before the fatigue caused by the special judo fitness test (SJFT). Lactate concentration (LC), countermovement jump (CMJ), hand grip strength and degree of perceived fatigue on Borg's scale (RPE) were tested two times before SJFT and four times after SJFT.

RESULTS

There was no interaction between groups and type of recovery at any time during the two types of recovery for RPE, grip strength, VJ and lactate concentration (p > 0.05). However, there was a main effect of time for dominant grip strength (F_(1,8)= 3.3; p = 0.01; η² = 0.25, (small)), non-dominant grip strength (F_(1,8) = 3.2; p = 0.01; η² = 0.24, (small)), CMJ (F_(1,8) = 8.8; p = 0.01; η² = 0.47, (small)), and LC (F_(1,8) = 124.2; p = 0.001; η² = 0.92, (moderate)).

CONCLUSIONS

The results of the present study show no significant difference between the NaHCO3 and placebo groups in RPE, handgrip strength, CMJ, and lactate concentration.

Behavioral and neurocognitive effects of judo training on working memory capacity in children with ADHD: A randomized controlled trial

BACKGROUND

Children with Attention Deficit Hyperactivity Disorder (ADHD) face deficits in working memory capacity that often persist into adulthood. In healthy peers, exercise targeting motor skill acquisition benefits visuospatial working memory, but its potential to reduce ADHD-related deficits remains unclear. We investigated the effect of a judo training program targeting motor skills on behavioral and neurocognitive indices of working memory capacity in children with ADHD.

METHODS

Children with ADHD aged 8 to 12 years (N = 57) were randomly allocated to a judo training group and a wait-list control group. The training program encompassed 120 min of judo per week over three months. Before and after the intervention period, participants completed a bilateral Change Detection task with low and high memory load conditions and the Movement Assessment Battery for Children-2 (MABC-2). The contralateral delay activity (CDA) elicited by the cognitive task was recorded using electroencephalography.

RESULTS

Compared to the control group, the judo training group showed a higher K-score on the Change Detection task and an increased negativity of the CDA on the high load condition following the intervention, when pretest scores (and confounders) were accounted for. In contrast, no group differences were found for MABC-2 score.

CONCLUSION

In children with ADHD, judo training may complement the pharmacological treatment by increasing the effectiveness of working memory maintenance processes. On a behavioral level, this improvement is accompanied with an increased capacity to store visuospatial information.

Analysis of Different Key Behavioral Patterns to Score in Elite Taekwondoists According to the Weight Category and Gender

Traditionally, research in taekwondo has focused on athletes' overall performance considering the entire sample of the tournament or analyzed selected bouts while ignoring behavioral differences of athletes according to their gender and weight category. Thus, the aim of this study was to analyze the behavioral patterns used to score points in the London Olympic Games according to gender and weight category [fin (FW), feather (FTW), light (LW), and heavy (HW)] of the athletes. A total of 24,940 actions were analyzed by using observational methodology, a mixed method methodology where lag sequential and polar coordinate analysis were applied. Different patterns could be seen in the actions performed prior to score between the weight categories for both genders. To score one point, females FW performed dodges, LW used indirect attacks and HW used direct attacks, posterior counterattacks, dodges and blocks. After scoring one-point, female athletes used a variety of actions, defensives like dodges (FW/LW) and blocks (LW), and offensives like simultaneous counterattacks (FW, FTW, LW) and posterior (FTW) as well as direct (FTW, HW) and indirect (FW) attacks. No patterns were found in males when scoring one-point, only LW competitors performed a sequence characterized by the performance of dodges followed by indirect attacks prior scoring while simultaneous counterattacks occurred after score one point. To score two points, similar patterns were found for all weight groups among female competitors. Females performed openings prior to scoring (LW/HW), while anticipatory (FW/FTW) and posterior counterattacks (LW) occurred after scoring, followed by cuts (FW), direct attacks (LW) and openings (HW). In males, FTW and HW used counterattacks prior to scoring (posterior and simultaneous), while FTW and LW also used counterattacks after scoring (anticipatory and simultaneous). Prior to scoring three points different patterns were found according to the weight category, while FW females used cuts and openings, LW used dodges and posterior counterattacks. After scoring three points, FW continued to use cuts, openings and posterior counterattacks while FTW used indirect attacks and HW used simultaneous counterattacks. On the contrary, similar behavior was found in males. FW and LWs used simultaneous counterattacks prior to scoring while they used defensive actions such as openings (FW) and dodges (LW) after scoring. Male FTW used also posterior counterattacks after scoring. Prior to scoring four points females reported different key behaviors. FW used anticipatory counterattacks and LW direct attacks whereas after scoring, FTW used dodges and openings. Similarities were found in males to score four points. LW and HW performed blocks prior scoring, FW and HW performed also direct attacks while FTW performed posterior counterattacks prior score. After scoring, defensives actions were performed such as dodges (LW) or cuts (FW, FTW, HW) and indirect attacks (LW, HW). This is one of the first studies analyzing behavioral patterns in taekwondo according to the weight category and gender of the athletes. The observed relationships identified different behavioral patterns according to the weight category for each gender and demonstrate the necessity to individualize trainings according to the athlete's characteristics (weight and gender). It is suggested that coaches and psychologists train athletes to improve their decision-making according to the successful patterns extracted in this study.

Effect of vision impairment on match-related performance and technical variation in attacking moves in Paralympic judo

In Paralympic judo for athletes with vision impairment (VI judo) all eligible athletes (i.e. B1, B2 and B3 classes) compete against each other in the same competition. Evidence suggests that athletes with more impairment may be disadvantaged, but that more sensitive measures of performance are necessary to understand the impact of impairment on performance. The aim of this study was to investigate the relationship between Para sport class and technical variation, time-motion variables, and performance in Paralympic judo. All 175 judo matches from the Rio 2016 Paralympic Games were analysed across 129 competitors (82 male and 47 female). The main results indicated that athletes who demonstrated less technical variation also experienced less competitive success, with the functionally blind athletes (class B1) demonstrating less technical variation than partially sighted (class B2 and B3) athletes (p < 0.05). There was no difference in the time-motion variables between sport classes (p > 0.05). We conclude that measures of technical variation are sensitive to differences in impairment and are suitable for studies that investigate the impairment-performance relationship in VI judo. Results further confirm that some athletes with impairment are disadvantaged under the current rules of VI judo.

Characteristics of Technical and Tactical Preparation of Elite Judokas during the World Championships and Olympic Games

The basis for achieving success in sport is technical preparation supported by adequate level of physical fitness. During judo competitions, athletes use technique to meet tactical objectives aimed to achieve victory. The modification of the rules of combat in judo that has been carried out in recent years has changed the course of competition. It seems to be interesting if there are relations between technical and tactical preparation expressed by means of indices and modification of the course of the fight caused by changes in the rules. The purpose of the paper was to determine the values of technical and tactical preparation of judokas during competition at the elite level. A hundred and twenty bouts during the Olympic Games in London in 2012 as well as 136 bouts fought during the World Championships in Rio de Janeiro in 2013 were analyzed. Verification was performed by calculating indicators of technical and tactical preparation. The results show a significant correlation between the indicators of technical and tactical preparation and the ranking in the general classification of the analyzed competitions. There were no statistically significant correlations between the change of fighting rules and the level of the examined indices of technical and tactical preparation. The results of the study verified the appropriate method of preparation for the competitions analyzed.

The Specific Judo Training Program Combined With the Whole Body Cryostimulation Induced an Increase of Serum Concentrations of Growth Factors and Changes in Amino Acid Profile in Professional Judokas

This study aimed to evaluate the effect of a specific training program, supported by 10 sessions of whole body cryostimulation, on growth factors concentrations, amino acids profile and motor abilities in professional judokas. Ultimately, twelve athletes took part in the study. They were randomly assigned to the cryostimulation group (CRY, n = 6) or the control group (CON, n = 6). During 2 weeks of the judo training program, the CRY group performed 10 cryo-sessions (3-min, at a temperature of -110°C) and the CON group rested passively. Anthropometric measurements, a strength test, the Special Judo Efficiency Test (SJET) were assessed 2 days before and after the judo training program. Blood samples were collected at rest, 1 h after the first and the second SJET and 1 h after the first and the last cryo-session to establish growth factors and amino acid concentrations. Lactate level was measured before, immediately after and 1 h after the first and the second SJET. The applied intervention resulted in a significant increase of resting concentrations of brain-derived neurotrophic factor (from 10.23 ± 1.61 to 15.13 ± 2.93 ng⋅ml^-1; p = 0.01) and insulin-like growth factor 1 (IGF-1; from 174.29 ± 49.34 to 300.50 ± 43.80 pg⋅ml^-1; p = 0.00) in the CRY group. A different response was registered 1 h directly post SJET in the CRY group (a significant increase of IGF-1, interleukin 15 and irisin: p = 0.01; p = 0.00; p = 0.03). Additionally, the significant drop of proline and leucine concentrations in the CRY group was obtained. Athletes' performance remained unchanged in both groups. However, subjects perceived positive changes induced by the intervention - not directly after cryostimulation but in response to the specific training workload. The increase of growth factors concentrations and the improvement of amino acid profile (proline and leucine) contributed to maintaining a high level of muscle function.

Significant Predictors of Sports Performance in Elite Men Judo Athletes Based on Multidimensional Regression Models

BACKGROUND

This research aimed to identify the most significant predictors of sports level using regression modeling.

METHODS

This study examined 16 judokas (aged 23 (±2.5)) from four weight categories, with four athletes in each category (66 kg, 73 kg, 81 kg and 90 kg). Each athlete was a member of the Polish National Team, an international master class (IM) or national master class (M). The tests were carried out twice (every two weeks) during the pre-competitive season in the morning, after a 10-min warm-up. The tests were performed according to the following protocol: Explosive Strength Lower Limbs (ExSLL) [W], Strength Endurance Lower Limbs (SELL) [%], Explosive Strength Upper Limbs (ExSUL) [W], Strength Endurance Upper Limbs (SEUL) [%]. The relationships between the dependent variable (ranking score) and the other analyzed variables (predictors) were estimated using the one-factor ridge regression analysis.

RESULTS

There were significant intergroup and intragroup differences in the results of explosive strength and strength endurance of the lower and upper limbs. The best predictors were identified using regression modeling: ExSLL, SELL, and SEUL.

CONCLUSIONS

Increasing the value of these predictors by a unit should significantly affect the scores in the ranking table. Correlation analysis showed that all variables that are strongly correlated with the Polish Judo Association (PJA) ranking table scores may have an effect on the sports performance.

Risk assessment in different Judo techniques for children and adolescent athletes

Judo is a combat sport that involves throwing the opponent onto the back. When being thrown, head biomechanics may be related to head injury risk. This study aimed to assess head injury risks associated with four Judo techniques in children and adolescents with different experience levels. Twenty children (<12 years) and 20 adolescents (≥ 12 years) judoka were recruited. Each group was divided into non-expert and expert. Two inertial sensors were fixed on fallers' head and torso. Two backward (o-soto-gari and o-uchi-gari) and two forward (ippon-seoi-nage and tai-otoshi) techniques were performed. Peak of linear and angular head acceleration magnitude, impact time duration, neck angle, and the Gadd Severity Index were assessed. Children did not show differences between techniques or experience levels. In contrast, adolescents showed greater linear acceleration peak in o-soto-gari than tai-otoshi (p = 0.03), greater angular acceleration peak in o-soto-gari and o-uchi-gari than ippon-seoi-nage (p < 0.05), and greater neck flexion in o-uchi-gari than ippon-seoi-nage (p = 0.004). Compared to expert adolescents, non-expert adolescents showed greater angular acceleration peak, impact duration, and the Gadd Severity Index in o-soto-gari (p < 0.05) and greater neck extension in o-uchi-gari (p = 0.02). Current results pointed out higher risks for adolescents judoka while being thrown with backward techniques, especially for non-expert participants. This study highlights the need of training athletes in controlling head and neck during back falls from a young age to become expert judoka in adulthood.

Tracking 25 years of judo results from the World Championships and Olympic Games: Age and competitive achievement

We quantified the peak age of judokas during the World Championships (WC) and Olympic Games (OG) according to sex, weight category and competitive achievement and determined the relationship between competition year and athlete age. A retrospective study including 12,005 athletes who took part in the last 16 WC and 6 OG. Athletes were divided by sex, weight category and competitive achievement. Overall, females were younger than males, and older athletes competed at the OG compared to the WC. A weight category effect was also observed, with lighter athletes being younger than heavier athletes (p < 0.05). A competitive achievement effect was found for females, with athletes being defeated in the eliminatory phases being younger than those advancing further in the competitions (p < 0.05). Significant associations (p < 0.05) were shown between competition year and age category for males at the WC and for females at both the WC and OG. In general, lighter athletes are younger than heavier ones (p < 0.05). No difference in age was found  between males concerning their competitive achievement in WC and OG, whereas younger females are defeated in the eliminatory phases (p < 0.05).

Development of a Taekwondo Combat Model Based on Markov Analysis

The purpose of the present study was to examine male and female Olympic taekwondo competitors' movement patterns according to their tactical actions by applying a Markov processes analysis. To perform this study, 11,474 actions by male competitors and 12,980 actions by female competitors were compiled and analyzed. The results yielded 32 significant sequences among male competitors and 30 among female competitors. Male competitors demonstrated 11 sequences initiated by an attack, 11 initiated by a counterattack, and 10 initiated by a defensive action. Female competitors demonstrated nine sequences initiated by an attack, 11 initiated by a counterattack, and 10 initiated by a defensive move. The five most popular sequences were the opening and dodge, the direct attack and simultaneous counterattack, the dodge with a direct attack, the indirect attack and simultaneous counterattack, and the simultaneous counterattack with a direct attack. Markov chains help provide coaches and researchers with relevant information about the frequency of actions, both in terms of their frequency of occurrence and the order of their occurrence, during a real competition. It is suggested that coaches and athletes focus on these patterns when training for a real competition.

Effects of Different Fatigue Levels on Physiological Responses and Pacing in Judo Matches

Franchini, E, Takito, MY, Alves, ED, Shiroma, SA, Julio, UF, and Humberstone, C. Effects of different fatigue levels on physiological responses and pacing in judo matches. J Strength Cond Res 33(3): 783-792, 2019-The objective of this study was to compare athletes' pacing during judo match simulation between different fatigue states. Twelve judo athletes (30.2 ± 3.2 years old, 85.6 ± 10.8 kg, 181.0 ± 5.7 cm, 19 ± 7 years of judo experience) completed three 4-minute matches against the same opponents, at 15-minute intervals in 3 different conditions: after warm-up (Control; C); after a regular training session (totaling 90 minutes); after a high-intensity interval exercise (2 blocks of 10 sets of 20-second all-out uchi-komi, with 10-second interval between sets and 5-minute interval between blocks). All matches were mediated according to the official rules, filmed, and analyzed concerning: rating of perceived recovery (RPR), rating of perceived exertion (RPE), heart rate (before and after match), blood lactate concentrations [La] before, peak after match and delta (peak minus the prematch values), and time-motion measures (frequencies and durations of actions). Time-motion measures included athlete displacement without contact, gripping, attack, feint, groundwork combat, pauses, and high- to low-intensity effort ratio. The experimental conditions resulted in different physiological and perceived responses prematch (HR, [La], RPR) and postmatch simulations (HR and [La]peak), with no change in RPE and few changes in technical variables. There was a decrease in grip dispute time, and increase in time of displacement without contact. These technical changes were enough to preserve the pace during the matches, which seemed to be controlled by the athletes to maintain their number of attacks, feints, and RPE.

Upper-body Wingate test classificatory table for adult judo athletes

The aims of this study were to compare the upper-body Wingate test performance of judo athletes from different weight categories and to create a classificatory table for this test. A total of 179 judo athletes performed an upper-body Wingate test, following standardized recommendations (30-sec duration, and a load equivalent to 0.06 kg/kg of body mass). Absolute and relative peak power (PP) and mean power (MP) were determined. Weight categories were compared through a one-way analysis of variance, followed by Tukey test. The effect size was determined by partial eta squared. There was a large effect of weight category in absolute PP and MP, with lower values for the lighter categories (P<0.05), but it is important to note that absolute PP and MP did not differ (P>0.05) between subsequent weight categories. Moreover, when the relative PP and MP were considered, no significant differences were found (P>0.05). The higher values of PP and MP achieved by heavier judo athletes compared to lighter ones during the upper-body Wingate test is likely related to the higher total muscle mass presented by the first group compared to the later. Indeed, judo athletes from different weight category presented similar relative PP and MP, likely due to the judo training demands as well as consequence of a selection of athletes with the higher potential to develop upper-body anaerobic fitness. Finally, the normative classificatory table created may be useful as a reference in judo athletes’ anaerobic evaluation.

An Analysis Model for Studying the Determinants of Throwing Scoring Actions During Standing Judo

In judo, the attacking system is grounded on several determinants of the chances to throw. In our study, data regarding four determinants of the attacking system were collected in order to classify the standing scoring actions: the attacking type (direct/counter-attack), the throwing area (forward/backward), the technique’s category (based on motor criteria), and the lateral structure of fighting (contenders with a symmetrical/asymmetrical position). To study the usefulness of such an analysis, the standing scoring actions of the 2013 Judo World Championship were analyzed as an example of elite judo’s attacking system (n = 775). The Pearson’s chi-squared test and Cramér’s V were used to analyze the hypothesis of a uniform distribution or the association between variables and the strength of such an association, respectively. The scoring actions (p < 0.001) were mostly direct attacks (82.6%), in the forward throw area (57.5%), and in an asymmetrical position (67.2%). All of the variables were associated (p < 0.05; V = 0.11–0.54), with higher proportions of counter-attacks and attacks occurring on the backward thrown area during asymmetrical structures than the expected. Some categories of techniques were observed more than expected, depending on the symmetrical or asymmetrical structure. Our data augment the knowledge of standing judo by showing features of the attacking system, suggesting strategies for optimizing performance.

Physiological and performance changes in national and international judo athletes during block periodization training

Block periodization (BP) has been proposed as an alternative approach for application in the context of high-level sports. Despite its growing acceptance, there is no empirical evidence of BP adoption in high-level judo athletes. Therefore, this study aimed to compare the maximal strength, muscle power, judo-specific performances, and hormonal concentration changes of state/national level (NG) and international level (IG) judo athletes subjected to BP. Twenty-one elite judo athletes (international level = 10; 21.7±1.9 years, 167.2±7.6 cm, 67.6±9.4 kg, 15.7±1.9 years of practice; national level = 11; 21.9±3.0 years, 167.5±9.1 cm, 71.8±16.5, 15.9±3.0 years of practice) were subjected to 13-week BP training (5-week accumulation phase [ACP], 5-week transmutation phase [TP], and 3-week realization phase [RP]). The judo-specific performance (SJFT) increased as there was observed a decrease in the SJFT index (final heart rate [HR] (bpm) + HR1 min after the test divided by the number of throws) for both NG (effect size [ES] = 0.83) and IG (ES = 0.53) from ACP to TP (p < 0.05). The row exercise maximal strength decreased (p < 0.05; ES = 1.35) after the ACP but returned to the baseline level after the TP, for the whole group (ES = 1.39). The athletes did seem to cope appropriately with the demands of BP, as besides increases in SJFT performance no significant changes were observed for cortisol and testosterone concentrations. This is the first study to demonstrate that judo athletes from different competitive levels subjected to BP improved SJFT, likely due to an appropriate balance between training loads and recovery. Thus, the BP approach may be a useful alternative periodization strategy for high-level judo athletes.

Home Advantage in Judo: Analysis by the Combat Phase, Penalties and the Type of Attack

Previous studies indicate positive home advantage in judo; however, the factors that influence home advantage have yet to be fully explored. This study investigated the potential differences in technical-tactical variables between home and visiting athletes. A total of 1411 video recorded matches were analyzed (123 home, 1288 away) from 36 international judo competitions contested in 2011-12. The matches were analyzed by the following criteria: combat phases (approach, gripping, attack, defense, groundwork and pause), penalties (by the athlete or the opponent) and the types of attacks (with or without a score). Elite judo athletes competing in their home country attacked more frequently using trunk/leg couple techniques (p < 0.011) and scored more frequently with arm/leg couple techniques (p < 0.001), while visiting judo athletes received fewer scores from penalties (p < 0.001) and engaged in more frequent pauses during competition (p < 0.01). The results of this study provide an outline of technical-tactical differences that may contribute to home advantage in judo.

Strength-Power Performance of Visually Impaired Paralympic and Olympic Judo Athletes From the Brazilian National Team: A Comparative Study

Loturco, I, Nakamura, FY, Winckler, C, Bragança, JR, da Fonseca, RA, Filho, JM, Zaccani, WA, Kobal, R, Cal Abad, CC, Kitamura, K, Pereira, LA, and Franchini, E. Strength-power performance of visually impaired paralympic and olympic judo athletes from the brazilian national team: a comparative study. J Strength Cond Res 31(3): 743-749, 2017-The aim of this study was to compare the muscle power and maximal isometric strength capacities of Olympic and visually impaired Paralympic judo athletes. Twenty-eight elite judo athletes (7 men and 7 women per group) from the permanent Brazilian National Paralympic and Olympic teams took part in this study. After a specific warm-up, the athletes performed loaded jump squat (JS), bench press (BP), and standing barbell row (SBR) exercises to determine their values of maximum mean propulsive power (MPP) in these respective exercises. The maximal isometric strength (MIS) was also determined for both upper and lower limbs, through the use of BP and half-squat (HS) exercises. Finally, the jumping ability was assessed using unloaded squat jump (SJ). The magnitude-based inference was used to compare the groups. The Olympic judo athletes presented a likely higher SJ height than the Paralympic athletes. The Olympic group presented almost certainly higher MPP in the loaded JS and in the SBR exercises and likely higher MPP in the BP exercise. Importantly, in the MIS assessments the differences between groups in the HS and BP exercises were rated as unclear. In conclusion, our results showed that both Olympic and Paralympic judo athletes present similar levels of maximal isometric strength, but muscle power performance is superior in Olympic athletes.

Effects of distinct practice conditions on the learning of the o soto gari throwing technique of judo

The aim of this study was to investigate the effects of different types of practice on learning the o soto gari, focusing on the kuzushi (unbalancing the opponent). A total of 64 children (mean age 9.19 ± 1.41 years) were assigned to one of four groups: (1) static traditional practice, i.e., uchikomi - repetition of the moving pattern that characterises the technique up to the point of throwing; (2) in motion traditional practice - uchikomi with the tori (player executing the technique) moving/walking; (3) whole practice with pre-kuzushi - full technique with a preparatory component for kuzushi; (4) progressive parts practice with pre-kuzushi - progressively introducing kuzushi, tsukuri (set-up to execute the technique) and kake (final part of the technique; projection) with pre-kuzushi. Pre-test, acquisition, post-test and retention test were carried out. Movements were video recorded and analysed regarding three aspects: global technique of the tori, occurrence of a movement pattern performed by the tori to unbalance the uke (player receiving the "attack"), and occurrence of actual unbalance (kuzushi). Results showed no significant differences between-groups. However, different within-groups improvements suggest that using a uchikomi with pre-kuzushi can help learners deal with the motor actions of pulling and pushing in order to unbalance the opponent.

Content Validation of a Catalog of Exercises for Judo

This study aimed to assess the content validity of a catalog of 76 judo exercises. Two groups of raters comprising 16 judo experts evaluated the following content validity indicators: Clarity of Language, Practical Pertinence, Theoretical Relevance, and the Dimension of each exercise. The results confirmed the content validity of the judo training catalog with indicators showing scores greater than 0.80. These findings suggest that all 76 judo exercises are pertinent, representative of judo training and understandable for judo coaches. Thus, this catalog of judo exercises may help judo coaches in the selection and recording of exercises.

Functional Movement Screening Performance of Brazilian Jiu-Jitsu Athletes From Brazil: Differences Considering Practice Time and Combat Style

Boscolo Del Vecchio, F, Foster, D, and Arruda, A. Functional movement screening performance of Brazilian jiu-jitsu athletes from Brazil: differences considering practice time and combat style. J Strength Cond Res 30(8): 2341-2347, 2016-Brazilian jiu-jitsu (BJJ) is a grappling combat sport that athletes, lying (guard fighter) or kneeling (pass fighter) on the mat, attempt to force their opponents to submit. Brazilian jiu-jitsu practices may result in muscular imbalances, which increase the risk of injury. Instead, the Functional Movement Screen (FMS) is an evaluation routine that could be related to injury incidence and seeks to detect muscular imbalance and movement dysfunction. Thus, the aim of the study was to investigate the injury profile and the FMS score and their relationship, with consideration for the BJJ fight style. Sports injuries were recorded in the last 12 months of 33 BJJ athletes, and the statistical analyses were applied to a routine evaluation FMS and a score of 14 points or less was considered low performance in FMS. We used a logistic regression; the effect size (ES) was calculated, and 5% was assumed as the statistical significance level. Pass fighters showed a higher percentage of injuries on the thorax (24.24%) than did guard fighters (6.67%, p = 0.01). Upper limbs were the most injured part of the body (χ = 36.7; p < 0.001), and they were 79% of the injuries that occurred in training sessions (χ = 14.53; p < 0.001). Despite the lack of statistical differences in the FMS performance between guard and pass fighters (t = 1.97; p = 0.05), its magnitude was considered medium (ES = 0.77). There was an association between FMS and presence of injury (χ = 4.95; p = 0.03). Considering the FMS score as a predictor and the presence or absence of injury as the dependent variable, the data met a Wald coefficient of 4.55, p = 0.03 and Exp (B) = 5.71. The study found that almost half of the sample had injuries in the upper limbs and a quarter had injuries in the lower limbs in the last year. A poor FMS score was observed, and lower scores in the FMS were associated with a higher risk of injury in BJJ athletes.

Perceived training intensity and performance changes quantification in judo

The objective of this study was to determine the methods of quantification for training and performance, which would be the most appropriate for modeling the responses to long-term training in cadet and junior judo athletes. For this, 10 young male judo athletes (15.9 ± 1.3 years, 64.9 ± 10.3 kg, and 170.8 ± 5.4 cm) competing at a regional/state level volunteered to take part in this study. Data were collected during a 2-year training period (i.e., 702 days) from January 2011 to December 2012. Their mean training volume was 6.52 ± 0.43 hours per week during the preparatory periods and 4.75 ± 0.49 hours per week during the competitive periods. They followed a training program prescribed by the same coach. The training load (TL) was quantified through the session rating of perceived exertion (RPE) and expressed in arbitrary unit (a.u.). Performance was quantified from 5 parameters and divided into 2 categories: performance in competition and performance in training. The evaluation of performance in competition was based on the number of points per level. Performance in training was assessed through 4 different tests. A physical test battery consisting of a standing long jump, 2 judo-specific tests that were the maximal number of dynamic chin-up holding the judogi, and the Special Judo Fitness Test was used. System modeling for describing training adaptations consisted of mathematically relating the TL of the training sessions (system input) to the change in performance (system output). The quality of the fit between TL and performance was similar, whether the TL was computed directly from RPE (R = 0.55 ± 0.18) or from the session RPE (R = 0.56 ± 0.18) and was significant in 8 athletes over 10, excluding the standing jump from the computation of the TL, leading to a simplest method. Thus, this study represents a first attempt to model TL effects on judo-specific performance and has shown that the best relationships between amounts of training and changes in performance were obtained when training amounts were quantified simply from RPE.

Influence of linear and undulating strength periodization on physical fitness, physiological, and performance responses to simulated judo matches

To determine the most effective strength periodization model is important to improve judo athletes' performance. Thus, the aim of this study was to compare the effects of linear and daily undulating periodized resistance training on anthropometrical, strength, and judo-specific performance. For this, 13 adult male judo athletes (LP = 6 and DUP = 7) completed a 8-week training program concomitantly to a typical judo training program. Athletes were submitted to a physical fitness test battery, before and after 8 weeks of training, consisting of: (a) maximal strength evaluation: bench press, squat, and row exercises 1 repetition maximum (1RM) tests, and handgrip maximal isometric strength; (b) power evaluation: standing long jump test; (c) strength endurance evaluation: dynamic and isometric chin-up tests gripping the judogi; (d) anthropometry measurements: body mass, height, skinfold thickness and circumferences; (e) judo-specific fitness: performance during the Special Judo Fitness Test (SJFT); (f) match simulation: three 5-minute judo match simulations separated by 15-minute passive recovery. Eight weeks of linear and undulating strength training protocols induced similar significant (P ≤ 0.05) decreases in skinfold thicknesses (-6.5%) and increases in flexed arm (2.0%) and forearm (1.8%) circumferences, maximal isometric handgrip strength (4.6% and 6.1% for right and left hands, respectively), isometric strength endurance chin-up performance gripping the judogi (18.9%), maximal dynamic strength for row (11.5%), bench press (11.6%) and squat exercises (7.1%), total weight lifted at 70% 1RM for bench press (15.1%) and squat (9.6%) exercises, number of throws during sets B (3.1%) and C (9.5%) of the SJFT (resulting in increased total number of throws, 5.5%), and decreased index in this test, -4.2%). However, no changes were observed in the physiological, rating of perceived exertion, or technical actions during 3 match simulations. Thus, it seems that the short-term adaptations were not transferable to the match condition.

Muscle torque and its relation to technique, tactics, sports level and age group in judo contestants

The aim of this study was to perform a comparative analysis of maximal muscle torques at individual stages of development of athletes and to determine the relationship between muscle torques, fighting methods and the level of sports performance.

The activity of 25 judo contestants during judo combats and the effectiveness of actions were evaluated. Maximum muscle torques in flexors/extensors of the body trunk, shoulder, elbow, hip and knee joints were measured. The level of significance was set at p≤0.05; for multiple comparisons the Mann-Whitney U test, p≤0.016, was used. Intergroup differences in relative torques in five muscle groups studied (elbow extensors, shoulder flexors, knee flexors, knee extensors, hip flexors) were not significant. In cadets, relative maximum muscle torques in hip extensors correlated with the activity index (Spearman’s r=0.756). In juniors, maximum relative torques in elbow flexors and knee flexors correlated with the activity index (r=0.73 and r=0.76, respectively). The effectiveness of actions correlated with relative maximum torque in elbow extensors (r=0.67). In seniors, the relative maximum muscle torque in shoulder flexors correlated with the activity index during the second part of the combat (r=0.821).

Olympic preparation in Brazilian judo athletes: description and perceived relevance of training practices

The aim of this study was to describe the training routines used by judo athletes and their perception concerning the relevance, effort made, concentration needed, and pleasure obtained during the training sessions conducted 6 months before their Olympic participation and to compare with medal winners and other competitors in these aspects. Sixty-one Olympic Brazilian judo athletes (men = 39; women = 22), representing 66.3% of all Brazilian participants in this Olympic sport (from 1964 to 2008), including 10 medal winners (9 men and 1 woman) answered a questionnaire concerning their training routines. Mann-Whitney and Student's t-test for independent samples were used. Judo medalists and nonmedalists in the Olympic Games did not differ in: (a) the age when they started to practice and to compete in judo, (b) the age when they competed in the Olympic Games, (c) hours of training per week and per training session and the number of training sessions per day in their preparation for this event, (d) frequency and time spent for performing judo-specific and general exercises and their perceived relevance, effort, pleasure, and concentration for these activities performed during the preparation for the Olympic Games. The only differences found were the groundwork (ne-waza) randori practice, which was less frequently performed by medal winners, and perceived relevance attributed to this activity, which was considered less relevant by the medal winners compared with nonmedal winners. Thus, judo Olympic medal winners and nonmedalists did not differ in many training aspects in the final phase of their preparation to the Olympic Games.

A comparison of time-motion and technical-tactical variables between age groups of female judo matches

The aim of the study was to verify differences between age groups of female judo matches in time-motion and technical-tactical analysis. The sample was composed of pre-cadet (13-14 years, n = 148), cadet (15-16 years, n = 228), junior (17-19 years, n = 104) and senior (>20 years, n = 237) groups. The time-motion indicators consisted of total combat time, standing combat time, displacement without contact, gripping time, total time of techniques, groundwork combat time and pause time, per match and by each combat/pause cycle. Technical and tactical variables were also collected. The one-way analysis of variance and a post hoc test were conducted, P ≤ 0.05. Cadets, with a median of 7 (2, 12), had a number of combat/pause cycles different from junior, with 3 (1, 8.5). Regarding time-motion per match and per cycle, senior had longer total combat time, standing combat time and gripping time than other groups. Senior presented lower frequency of leg techniques than pre-cadet, cadet and junior. Time-motion and technical-tactical variables effects in female judo athletes emphasise the difference between seniors and other groups.

A comparison of time-motion performance between age groups in judo matches

The aim of this study was to compare time-motion indicators during judo matches performed by athletes from different age groups. The following age groups were analysed: Pre-Juvenile (13-14 years, n = 522), Juvenile (15-16 years, n = 353); Junior (19 years, n = 349) and Senior (>20 years, n = 587). The time-motion indicators included: Total Combat Time, Standing Combat Time, Displacement Without Contact, Gripping Time, Groundwork Combat Time and Pause Time. Analysis of variance (ANOVA) one-way and the Tukey test, as well as the Kruskal-Wallis test and Mann-Whitney (for non-parametric data), were conducted, using P < 0.05 as significance level. The results showed that all analysed groups obtained a median of 7 (first quantile - 3, third quantile - 12) sequences of combat/pause cycles. In total time of combat, the result was: for Total Combat Time, Standing Combat Time and Gripping Time: Pre-Juvenile and Senior were significantly longer than Juvenile and Junior. Considering Displacement Without Contact, Junior was significantly longer than all other age groups. For Groundwork Combat Time, Senior was significantly longer than all other age groups and Pre-Juvenile was longer than Junior. These results can be used to improve the physiological performance in intermittent practices, as well as technical-tactical training during judo sessions.

Energy System Contributions to the Special Judo Fitness Test

Purpose:

This study investigated the energy system contributions of judo athletes to the Special Judo Fitness Test (SJFT).

Methods:

Fourteen male judo athletes performed the SJFT, which comprised three periods of judo activity (A = 15 s, B and C = 30 s) interspersed with 10 s rest intervals. During this test, one athlete threw two others positioned 6 m from each other using the ippon-seoi-nage technique. The fractions of the aerobic, anaerobic alactic and anaerobic lactic systems were calculated based on oxygen uptake, the fast component of excess postexercise oxygen uptake, and changes in net blood lactate, respectively. The contribution of the three energy systems was compared using a repeated measures analysis of variance and Bonferroni’s multiple comparisons test. Compound symmetry, or sphericity, was determined by Mauchly’s test. A level of significance of 5% (P < .05) was adopted in all analyses.

Results:

The alactic energy system presented a higher (F = 20.9; P < .001; power observed = 1.0) contribution (86.8 ± 23.6 kJ; 42.3 ± 5.9%) during the test when compared with both aerobic (57.1 ± 11.3 kJ; 28.2 ± 2.9%) and lactic (58.9 ± 12.1 kJ; 29.5 ± 6.2%) energy systems (P < .001 for both comparisons).

Conclusions:

The higher alactic contribution seems to be a consequence of the high-intensity efforts performed during the test, and its intermittent nature. Thus, when using the SJFT, coaches are evaluating mainly their athletes’ anaerobic alactic system, which can be considered to be the most predominant system contributing to the actions (techniques) performed in the match.

Tracking 10-Year Competitive Winning Performance of Judo Athletes across Age Groups

Little information is available concerning early specialization and competitive success in judo across the early training years. Thus, the present objective was to verify the stability of individual competitive performance of a state-level championship for judo athletes who had been previously successful. For this, 406 athletes from six age groups (9 to 20+ years old) of each sex were followed for 10 years. Using recorded data from the São Paulo State Judo Federation beginning in 1999, the scores and standings for these judo players were analyzed. The proportion of medal winners during this period was not constant, differing from the grand mean in all groups of both 204 males and 202 females. At the end of this period, only 7% of the male and 5% of the female athletes had maintained their competitive levels. Successful competitive performance in early judo competition was not associated with success later in adulthood.

A Review of Time-Motion Analysis and Combat Development in Mixed Martial Arts Matches at Regional Level Tournaments

Mixed martial arts (MMA) have become a fast-growing worldwide expansion of martial arts competition, requiring high level of skill, physical conditioning, and strategy, and involving a synthesis of combat while standing or on the ground. This study quantified the effort-pause ratio (EP), and classified effort segments of stand-up or groundwork development to identify the number of actions performed per round in MMA matches. 52 MMA athletes participated in the study ( M age = 24 yr., SD = 5; average experience in MMA = 5 yr., SD = 3). A one-way analysis of variance with repeated measurements was conducted to compare the type of action across the rounds. A chi-squared test was applied across the percentages to compare proportions of different events. Only one significant difference ( p<.05) was observed among rounds: time in groundwork of low intensity was longer in the second compared to the third round. When the interval between rounds was not considered, the EP ratio (between high-intensity effort to low-intensity effort plus pauses) was 1:2 to 1:4. This ratio is between ratios typical for judo, wrestling, karate, and taekwondo and reflects the combination of ground and standup techniques. Most of the matches ended in the third round, involving high-intensity actions, predominantly executed during groundwork combat.