SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Judo

27

Understanding the physiological response to the most common judo training modalities may help to improve the prescription and monitoring of training programs. This review is based on search results using the following terms: “judo”, “judo and training”, “judo and physiology”, “judo and specific exercises”, and “judo and combat practice”. Uchi-komi (repetitive technical training) is a specific judo exercise that can be used to improve aerobic and anaerobic fitness. Effort:pause ratio, total session duration, number and duration of individual sets as well as the type of technique can be manipulated in order to emphasize specific components of metabolism. Nage-komi (repetitive throwing training) can also be used to improve aerobic and anaerobic fitness, depending of the format of the training session. Randori (combat or fight practice; sparring) is the training modality most closely related to actual judo matches. Despite the similarities, the physiological demands of randori practice is not as high as observed during real competitive matches. Heart rate has not shown to be an accurate measure of training intensity during any of the previously mentioned judo training modalities. High-volume, high-intensity training programs often lead judo athletes to experience overtraining-related symptoms, with immunesupression being one of the most common. In conclusion, judo training and judo-specific exercise should be manipulated in order to maximize training response and competitive performance.

Concepts: Biology, Physiology, Cellular respiration, Exercise, Pulse, Exercise physiology, Anaerobic exercise, Judo

25

The aim of the study was to determine the anthropometric and fitness profiles of European half-heavyweight judokas by success in competition. For this purpose, we compared 5 international medallists (elite) with 5 national medallists (sub-elite). All male judokas won at least one medal in the half-heavyweight category during the previous two years. The testing in this cross-sectional study was performed during 4 days. All subjects underwent anthropometric assessment with body mass, height, skinfold, and limb circumference measures, the body fat percentage was estimated by manual bioimpedance. The physical fitness evaluation consisted in peak torques for thigh and shoulder muscles, handgrip strength, high and long jumps, medicine-ball throw, pull-ups, dead lift, bench press, deep squat, VO2max, Max Power and Tokui Waza tests. The statistical analysis by a T-Student test showed significant differences for forearm and upper-arm circumferences, peak torques, pull ups, bench press, dead lift, deep squat, VO2max, Max Power and Tokui Waza tests. Our results showed that elite judokas have a superior fitness profile than sub-elite athletes from the half-heavyweight category. Moreover, elite judokas seem to have a higher arm muscle mass than sub-elite athletes, but a similar body fat percentage. This study could be of interest for judo coaches with athletes competing in the half-heavyweight category, since some tests that discriminate by judo success for this specific weight category are described. Few studies analyse anthropometric and fitness profiles in half-heavyweight male judokas, so additionally our results can be used as a reference for coaches, athletes and scientists.

Concepts: Muscle, Adipose tissue, Body mass index, Body fat percentage, Bodybuilding, Powerlifting, Weight training exercises, Judo

25

Abstract In this study, eight judo athletes who are major candidates for the Japan national team were recruited as participants. Kinematic analysis of exemplary ukemi techniques was carried out using two throws, o-soto-gari, a throw linked to frequent injury, and o-uchi-gari. The aim of this study was to kinematically quantify the timing patterns of exemplary ukemi techniques and to obtain kinematic information of the head, in a sequence of ukemi from the onset of the throw to the completion of ukemi. The results indicated that the vertical velocity with which the uke’s head decelerated was reduced by increasing the body surface exposed to the collision with the tatami and by increasing the elapsed time. In particular, overall upper limb contact with the tatami is greatly associated with deceleration. In o-soto-gari, the impulsive force on the faller’s head as the head reached the lowest point was 204.82 ± 19.95 kg m · s(-)(2) while in o-uchi-gari it was 118.46 ± 63.62 kg m · s(-2), z = -1.75, P = 0.08, and it did present a large-sized effect with r = 0.78. These findings indicate that the exemplary o-soto-gari as compared to o-uchi-gari is the technique that causes more significant damage to the uke’s head.

Concepts: Classical mechanics, Velocity, Kinematics, Judo

24

Although caffeine is one of the most commonly used substances in combat sports, information about its ergogenic effects on these disciplines is very limited. The aim of this investigation was to determine the effectiveness of ingesting a moderate dose of caffeine to enhance overall performance during a simulated Brazilian Jiu-jitsu (BJJ) competition.

Concepts: Effect, Caffeine, Brazil, Mixed martial arts, Judo, Combat sports, Jujutsu, Brazilian Jiu-Jitsu

22

In the International Blind Sports Federation (IBSA) judo Sports Classes B1, B2, and B3 compete against each other within weight- and gender-specific categories. B1 athletes are totally blind, whereas B2 and B3 are partially sighted.

Concepts: Myopia, Visual impairment, Blindness, Low vision, Vision loss, Paralympic Games, British B class submarine, Judo

22

Scientific information about the effects of caffeine intake on combat sport performance is scarce and controversial. The aim of this study was to investigate the effectiveness of caffeine to improve Brazilian Jiu-jitsu (BJJ)-specific muscular performance. Fourteen male and elite BJJ athletes (29.2 ± 3.3 years; 71.3 ± 9.1 kg) participated in a randomized double-blind, placebo-controlled and crossover experiment. In two different sessions, BJJ athletes ingested 3 mg kg(-1) of caffeine or a placebo. After 60 min, they performed a handgrip maximal force test, a countermovement jump, a maximal static lift test and bench-press tests consisting of one-repetition maximum, power-load, and repetitions to failure. In comparison to the placebo, the ingestion of the caffeine increased: hand grip force in both hands (50.9 ± 2.9 vs. 53.3 ± 3.1 kg; respectively p < .05), countermovement jump height (40.6 ± 2.6 vs. 41.7 ± 3.1 cm; p = .02), and time recorded in the maximal static lift test (54.4 ± 13.4 vs. 59.2 ± 11.9 s; p < .01).The caffeine also increased the one-repetition maximum (90.5 ± 7.7 vs. 93.3 ± 7.5 kg; p = .02), maximal power obtained during the power-load test (750.5 ± 154.7 vs. 826.9 ± 163.7 W; p < .01) and mean power during the bench-press exercise test to failure (280.2 ± 52.5 vs. 312.2 ± 78.3 W; p = .04). In conclusion, the pre-exercise ingestion of 3 mg kg(-1) of caffeine increased dynamic and isometric muscular force, power, and endurance strength in elite BJJ athletes. Thus, caffeine might be an effective ergogenic aid to improve physical performance in BJJ.

Concepts: Clinical trial, Caffeine, Brazil, Grip strength, Mixed martial arts, Nootropic, Judo, Jujutsu

1

Mixed martial arts (MMA) is a combat sport underpinned by techniques from other combat disciplines, in addition to strategies unique to the sport itself. These sports can be divided into two distinct categories (grappling or striking) based on differing technical demands. Uniquely, MMA combines both methods of combat and therefore appears to be physiologically complex requiring a spectrum of mechanical and metabolic qualities to drive performance. However, little is known about the physiological characteristics that distinguish higher- from lower-level MMA athletes. Such information provides guidance for training interventions, performance testing and talent identification. Furthermore, while MMA incorporates techniques from both grappling and striking sports, it is unknown precisely how these disciplines differ physiologically. Understanding the relationship between higher-level competitors in grappling and striking combat sports can provide further insight into the development of the optimal performance profile of a higher-level MMA athlete.

Concepts: Mixed martial arts, Wrestling, Judo, Grappling, Combat sport, Martial arts, Combat sports, Hand to hand combat

0

In 2020, Japan will host the Tokyo Olympic and Paralympic Games in 2020 (Tokyo 2020) which will involve a large population influx from various countries to Tokyo, the most populated city in Japan. We summarize the potential health risks for visitors to Tokyo 2020, related to communicable disease risks and other health threats, based on recent national and local surveillance reports.

Concepts: Epidemiology, Demography, United Kingdom, Olympic Games, Paralympic Games, World Wheelchair and Amputee Games, Special Olympics World Games, Judo

0

Combat sports involve body contact through striking, kicking and/or throwing. They are anecdotally referred to as ‘dangerous’, yet long-term investigation into specific injury rates is yet to be explored.

Concepts: Epidemiology, Illness, Kick, Mixed martial arts, Boxing, Judo, Combat sport, Contact sport

0

It is generally accepted that proper learning of the breakfall technique during early judo training is essential for attenuating the risk of judo-related head injury. Therefore, it is critical to understand the kinematics and head injury risks of breakfall motion to design a more safe and effective judo teaching paradigm that results in reduction of injury risk. We aimed to investigate the biomechanics of judo backward breakfalls by comparing osoto-gari and ouchi-gari in novice judokas. Twelve male novice judokas (age: 21.3 years, SD = 0.6 years; height: 1.74 m, SD = 0.04 m; body weight: 71.3, SD = 6.4 kg; body mass index: 23.5, SD = 2.3) volunteered to participate in this study. The kinematic data of the breakfall motion for both osoto-gari and ouchi-gari were collected using a three-dimensional motion analysis technique (200 Hz). We observed significant differences between the movement patterns for the two techniques, especially in the lower extremity movements. In addition, a significantly greater peak extension momentum (osoto-gari: 1.29, SD = 0.23 kg m(2 )s(-1); ouchi-gari: 0.84, SD = 0.29 kg m(2 )s(-1)) and lower head position along the vertical axis (osoto-gari: 0.18, SD = 0.05 m; ouchi-gari: 0.31, SD = 0.08 m) with a large effect size were found in the breakfall for osoto-gari. Our results suggest that a different paradigm is needed for effectively teaching each breakfall technique that will enable us to substantially lower the risk of judo-related head injuries in novice judokas.

Concepts: Mass, Body mass index, Injuries, Effect size, Classical mechanics, Kinematics, Body weight, Judo