Effects of Warm-Ups with Weighted Vests and Resistance Bands on Physical Fitness and Combat Ability of Kumite Karate Athletes.

The purpose of this study was to investigate whether a dynamic warm-up either with weighted vests (WVs) or with resistance bands (RBs) may enhance the physical fitness and combat ability of kumite karate athletes. Nine male athletes (age range from 16 to 30 years), participated in this study. Athletes followed three different warm-up programs in a randomized order: (a) with their body mass only (C), (b) with a WV of 10% load of their body mass and (c) with a wearable RB of 10% tension of their body mass. Following the warm-up, athletes performed the following tests: countermovement jump (CMJ), standing long jump (LJ), punch and kick reaction time, bench press throws, T-Half test and the kick frequency test. CMJ remained unaltered following the WV and RB warm-up compared to the C. Standing long jump increased significantly following the RB warm-up compared to the C (2.2 ± 1.7%, p = 0.011). Punch reaction time was significantly shortened following the RB warm-up compared to C (-7.3 ± 5.9%, p = 0.019). No changes were observed for kick reaction time, bench press throws or the T-Half test. The kick decrement index, measured from the kick frequency test, was significantly decreased following the RB warm-up compared to the C (33.1 ± 20.2%, p = 0.011). These results suggest that an RB warm-up may significantly enhance the physical fitness and combat ability in kumite karate athletes.

Plyometric Training's Effects on Young Male Karatekas' Jump, Change of Direction, and Inter-Limb Asymmetry.

This study analysed the effects of performing a plyometric training programme on different types of jumping and specific changes of direction, and their respective asymmetries in karatekas. Twenty male karatekas (age 19 ± 4 years) were distributed in two groups, the control group (CG) and the experimental group (EG). The EG group (n = 10) performed a 6-week intervention of unilateral plyometric training, performing countermovement jumps (CMJ), drop jumps (DJ), and long jumps (SH). The tests performed at the beginning and at the end of the intervention were a unilateral and bilateral countermovement jump test (CMJ), single-leg hop test (SH), single-leg side-hop test (SSH), triple hop test (TH), and change of direction in a karate position test (MKUKS). The EG group obtained improvements in the CMJ with the stronger (p = 0.01; ES = 0.39) and weaker leg (p = 0.01; ES = 0.59), in the SH with the weaker leg (p = 0.01; ES = 0.45), in the SSH with the weaker leg (p = 0.03; ES = 0.33), in the MKUKS (p = 0.00; ES = 0.98), and improved the asymmetries obtained in the TH (p = 0.02; ES = -0.85). The GC group obtained significant differences in the CMJ with the stronger (p = 0.03; ES = 0.46) and weaker leg (p = 0.00; ES = 0.69), in the bilateral CMJ (p = 0.02; ES = 0.24), in the SH with the weaker leg (p = 0.00; ES = 0.34), in the TH with the stronger (p = 0.00; ES = -0.15) and weaker leg (p = 0.01; ES = 0.09), and in the MKUKS test (p = 0.04; ES = -0.94). A between-group analysis showed improvements of the EG over the GC in the TH with the stronger leg (p = 0.02; ES = 1.05). Performing plyometric training provides improvements in jumping, mainly in horizontal jumps, reducing inter-limb asymmetries in repetitive jumps.

Differences in Force-Velocity Profiles During Countermovement Jump and Flywheel Squats and Associations With a Different Change of Direction Tests in Elite Karatekas.

The force-velocity (F-v) relationship has been proposed as a biomechanical characteristic to comprehensively evaluate neuromuscular capabilities within different tasks such as vertical jumping, sprinting and bench pressing. F-v relationship during flywheel (FW) squats was already validated, however, it was never compared to F-v profile of vertical jumps or associated with change of direction (CoD) performance. The aims of our study were (1) to compare F-v profiles measured during counter movement jumps (CMJs) and FW squats, (2) to determine correlations of F-v mechanical capacities with different CoD tests, (3) to investigate the portion of explained variance in CoD tests with the F-v outcome measures. A cross-sectional study was conducted on 39 elite karatekas. They performed CMJs and FW squats using progressive loads to calculate F-v profile outcome variables and different CoD tests (CoD at 90°, CoD at 180°, t-test, short karate specific test (KST) and long KST). Our results showed significantly higher values in all F-v outcome variables (F0-theoretical maximal force, V0-maximal unloaded velocity, Pmax-maximal power output, F-vslope-the slope of F-v relationship) calculated from CMJs compared to FW squats (all p < 0.01). Significant positive moderate correlations between the tasks were found for F0 and Pmax (r = 0.323-0.378, p = 0.018-0.045). In comparison to F-v outcome variables obtained in FW squats, higher correlations were found between F-v outcome variables calculated from CMJs and CoD tests. The only significant correlation in F-v outcome variables calculated from FW squats was found between Pmax and short KST time. For all CoD tests, only one F-v predictor was included; more specifically-CMJ-F0 for CoD 90°, CoD 180° and t-test, and FW-Pmax for short KST performance. To conclude, our results showed that F-v relationship between CMJs and FW squats differed significantly and cannot be used interchangeably for F-v profiling. Moreover, we confirmed that high force and power production is important for the successful performance of general and karate specific CoD tasks.

Somatotype Profiles of Montenegrin Karatekas: An Observational Study.

Competitive karate activity involves numerous factors affecting performance in sport. Physical structure and somatotype is considered to be one of them. This study aimed to determine whether there are differences between karate athletes in five male and five female official weight categories in different anthropometric measurements and to determine the somatotype profiles of athletes divided by weight categories. This study consisted of a total of 27 male karate athletes (21.88 ± 4.66 years) and 24 female karate athletes (20.29 ± 3.14 years). Measurements were taken in April 2020. Athletes are classified into official weight categories according to World Karate Federation rules. Somatotypes were calculated using anthropometry. One-way analysis of variance and Tukey's post hoc tests were used for statistical analysis to compare group differences regarding weight categories. Anthropometric parameters were highest in the heaviest categories compared to lighter categories. All male subjects were endomorphic mesomorph, except for category <84 kg, which was endomorphic ectomorphs. Somatotype analysis of male categories found a difference between the <75 kg and <84 kg in endomorphy. In mesomorphy, there is no difference between categories. Perceiving ectomorphy, there is a significant difference between the first category and the >84 kg. Profiling female athletes, three different types of somatotypes were obtained concerning the weight category. The lightest weight category was predominantly endomorphic ectomorphs, and two weight categories were ectomorphic endomorphs (<61 kg and <68 kg), and the other two weight categories were endomorphic mesomorphs (<55 kg and >68 kg). Somatotype differences in the female karate athletes were observed only in the ectomorphy components, between <50 kg and <61 kg. The present study points to how the somatotypes profiles of karate athletes differ between weight categories.

Analysis of anticipation by 3D motion capturing - a new method presented in karate kumite.

Anticipation is an important performance factor in karate kumite. A new approach analysing anticipation in realistic combat situations by motion capturing with a high temporal resolution is presented. The advantage of this approach is that both karate athletes interacting sports specific can be recorded synchronously; thus, the presented method has the potential to analyse visual information pickup due to coordination pattern of interaction between real athletes. The aim is to demonstrate the usability of the current method for anticipation research and to investigate if the distance between two athletes and their attacking technique play a role in the reaction of the defending athlete. Furthermore, relevant cues lying within each attacking technique and little individual differences are shown. Four male karate athletes took part in this study. Logistic regression indicated that both factors (distance × attacking technique) play a significant role in reaction. However, a correlation between these factors shows that only the attacking technique is a good predictor for reaction. Results show that the attacking technique jabbing punch (jap. Kizami-Zuki) was easier to anticipate than the attacking techniques reverse punch (jap. Gyaku-Zuki) and the round kick (jap. Mawashi-Geri).

Association between neuromuscular tests and kumite performance on the brazilian karate national team.

The aim of this study was to verify the relationship of strength and power with performance on an international level karate team during official kumite simulations. Fourteen male black belt karate athletes were submitted to anthropometric data collection and then performed the following tests on two different days: vertical jump test, bench press and squat maximum dynamic strength (1RM) tests. We also tested power production for both exercises at 30 and 60%1RM and performed a kumite match simulation. Blood samples were obtained at rest and immediately after the kumite matches to measure blood lactate concentration. Karate players were separated by performance (winners vs. defeated) on the kumite matches. We found no significant differences between winners and defeated for strength, vertical jump height, anthropometric data and blood lactate concentration. Interestingly, winners were more powerful in the bench press and squat exercises at 30% 1RM. Maximum strength was correlated with absolute (30% 1RM r = 0.92; 60% 1RM r = 0.63) and relative power (30% 1RM r = 0.74; 60% 1RM r = 0.11, p > 0.05) for the bench press exercise. We concluded that international level karate players' kumite match performance are influenced by higher levels of upper and lower limbs power production. Key PointsMuscle power at low workloads seems to be a reasonable predictor of karate performance.There are differences in neuromuscular characteristics between winners and defeated karate players among an international level karate team.Karate players rely more on muscle power, rather than on muscle strength.