Jonatas Ferreira da Silva Santos

The aim of the present study was to investigate whether, after scoring a goal, the team becomes more vulnerable to conceding a goal soon after. A total of 518 results were collected and integrated the data of the present study. The independent Chi-square test was used to analyze the data. The values of adjusted residue were observed, and all values outside the range of -1.96 to 1.96 were considered. All analyzes were performed using α = 5%. The scoring goal equalizer moment happened in the first-quarter 109 matches (21.0%), second-quarter 156 matches (30.1%), third-quarter 127 matches (24.5%), and fourth-quarter 126 matches (24.3%), totalizing 518 (100%) matches, but no association between season and scoring goal equalizer moment (χ² (30) = 28.196, p>0.05; Cramer’s V test: 0.135). The data collected showed that the equalizing goal can occur at different moments of the game, not only right after the first goal is score.

In combat sports, the specificity of the training requires that the athlete improve all performance indicators associated with the match. For this reason, muscle power seems to be determinant during the application of the techniques that result in scores, specifically punches, kicks, elbows, knees, throwing techniques, transitions to the groundwork and some groundwork techniques and sometimes, the win match by knockout. Based in these information’s, the present chapter will approach items referring to the muscle power manifestation and monitoring, and to the training prescription of exercises for the grappling, striking and mixed combat sports.

Specific training methods is an important aspect in the preparation of taekwondo athletes. The purpose of this study was to investigate the effect of a short-duration high-intensity interval training (HIIT) program with specific taekwondo techniques on anaerobic performance. Twelve taekwondo athletes were randomized into a control (n=6) or experimental groups (n=6). The experimental protocol consisted of 3 blocks of 6 sets of 10s all-out effort, with 10s passive recovery between sets and 1-min rest interval between blocks, conducted 3 days per week during 4-weeks. A three-way analysis of variance (ANOVA) (group, set and moment) with repeated measurements in the two last factors was conducted to compare the performance during each set of the Frequency Speed Kick Test (FSKT), and an ANOVA two-way (group and moment) with repeated measurements was used to compare the total number of kicks and kick decrement index (KDI). Both groups maintained their regular taekwondo training, which was exactly the same. Before and after the training program the athletes performed the FSKT. The experimental group increased (p<0.01) performance in each of the five sets of the FSKT and in the total number of kicks (p<0.001). No statistical difference was observed in the control group after 4-weeks or between the control and experimental group in any moment. A short-duration HIIT program with specific taekwondo techniques improved anaerobic performance measured through the FSKT. However, the fatigue index did not change.

Recently, the Frequency Speed of Kick Test (FSKT10s) and its intermittent version (5 x 10s/10s intervals, FSKTmult) have been used to assess physical fitness of taekwondo athletes, but no classificatory normative table was found for these tests. Thus, the aim of the study was to present two normative classificatory tables for both the FSKT10s and FSKTmult for male and female taekwondo athletes. One hundred fifteen male taekwondo athletes (median [interquartile range] age: 20 [17;27] years; body height: 175 [170;182] cm; body mass: 67 [60;78] kg; experience time: 6 [3;10] years) and seventy female taekwondo athletes (median [interquartile range] age: 19 [(17;24] years; body height: 162 [157;169] cm; body mass: 57 [50;64] kg; experience time: 5 [3;9] years) volunteered to participate in the study. Their skills ranged between 4th gub and 2nd dan. All the participants were evaluated during their competitive period and were familiarized with this test. The classificatory tables are presented in five scales, as follows: excellent (≥95th percentile); good (>75th percentile up to 94th percentile); regular (>25th percentile up to 74th percentile); poor (>6th percentile up to 24th percentile); and very poor (≤5th percentile). The classificatory tables for FSKT10s and FSKTmult can help coaches and strength and conditioning professionals to classify performance and monitor the physical fitness of taekwondo athletes in different stages of training and during the competitive season.

Santos, JFS and Franchini, E. Frequency speed of kick test performance comparison between female taekwondo athletes of different competitive levels. J Strength Cond Res 32(10): 2934–2938, 2018—Construct validity is a desirable characteristic in any performance test to differentiate athletes. However, no taekwondo-specific test was investigated with this purpose. The purpose of this study was to compare female taekwondo athletes grouped in different competitive levels. Forty-two female taekwondo athletes divided into International/National (median [interquartile range]; n = 21, age: 20 [18–25] years; body mass: 60 [53–72] kg; height: 164 [161–170] cm; and practice time: 8 [5–13] years) and State/Regional group (median [interquartile range]; n = 21; age: 18 [17–25] years; body mass: 57 [52–63] kg; height: 165 [160–172] cm; and practice time: 5 [2–8] years) volunteered to participate in this study. The female taekwondo athletes performed frequency speed of kick test (FSKT) with 10 seconds (FSKT_10s) and intermittent 90 seconds (FSKT_mult) during the competitive period. Differences between international/national and state/regional group were observed, with superiority to international/national group, for FSKT_10s (U = 114.5, p = 0.007, ESr (effect size) = −0.42 [small]), FSKT₁ (U = 127.0, p = 0.016, ESr = −0.37 [small]), FSKT₂ (U = 108.5, p = 0.004, ESr = −0.45 [small]), FSKT₃ (U = 127.0, p = 0.015, ESr = −0.37 [small]), and FSKT_total (U = 124.0, p = 0.015, ESr = −0.38 [small]). Based on the results of this study, the FSKT seems to be a good tool to discriminate performance of female taekwondo athletes and could be used by coaches and athletes in their evaluation routines.

Purpose: To investigate the effect of sodium bicarbonate (NaHCO₃) on performance and estimated energy system contribution during simulated taekwondo combat. Methods: Nine taekwondo athletes completed two experimental sessions separated by at least 48 h. Athletes consumed 300 mg/kg body mass of NaHCO₃ or placebo (CaCO₃) 90 min before the combat simulation (three rounds of 2 min separated by 1 min passive recovery), in a double‐blind, randomized, repeated‐measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration [La⁻] and rating of perceived exertion (RPE) were measured before and after each round, whereas heart rate (HR) and the estimated contribution of the oxidative (W_OXI), ATP (adenosine triphosphate)‐phosphocreatine (PCr) (W_PCR), and glycolytic systems were calculated during the combat simulation. Results: [La⁻] increased significantly after NaHCO₃ ingestion, when compared with the placebo condition (+14%, P = 0.04, d = 3.70). NaHCO₃ ingestion resulted in greater estimated glycolytic energy contribution in the first round when compared with the placebo condition (+31%, P = 0.01, d = 3.48). Total attack time was significantly greater after NaHCO₃ when compared with placebo (+13%, P = 0.05, d = 1.15). W_OXI, W_PCR, VO₂, HR and RPE were not different between conditions (P > 0.05). Conclusion: NaHCO₃ ingestion was able to increase the contribution of glycolytic metabolism and, therefore, improve performance during simulated taekwondo combat.

[This corrects the article DOI: 10.1371/journal.pone.0142078.].

This study analysed the physiological, nutritional and performance profiles of athletes practicing Brazilian jiu-jitsu. To this end, 15 athletes that practiced Brazilian jiu-jitsu (aged: 28 ± 5 years; 8 brown belts and 7 black belts; training experience: 11 ± 4 years) underwent anthropometric measurements (body composition and somatotype), dietary evaluation (24 h recall) and physical fitness tests (movement time, dynamometer handgrip, kimono grip strength, vertical jump and sit-and-reach tests). The athletes had 12.7 ± 4.8% of body fat, 59.2 ± 5.0% of muscle mass and their somatotype was dominated by the mesomorphic component (5.3 ± 2.0), followed by endomorphic (3.7 ± 1.5) and ectomorphic (1.4 ± 0.9) components. Nutritional assessment suggested a diet consisting of 54 ± 7% of carbohydrates, 19 ± 4% of protein and 27 ± 6% of lipids. Movement time on the handgrip tests was 0.42 ± 0.05 s, for handgrip strength, 53 ± 7 kgf was found for the dominant hand and 50 ± 9 kgf for the non-dominant hand. For the countermovement jump, the jiu-jitsu athletes reached 41 ± 5 cm. Athletes remained 30 ± 14 s in the maximum static suspension test gripping a kimono, and reached 27 ± 8 cm in the sit-and-reach test. Overall the sample presented average levels of body fat, elevated muscle mass and a predominantly mesomorphic somatotype. Diet was generally poor, with low carbohydrate intake, high protein intake and adequate lipid intake. Maximum isometric handgrip strength was consistent with observations of other athletes in this sport discipline. However, the performance in the maximum static suspension test gripping a kimono was lower than in other Brazilian jiu-jitsu athletes. Movement time was comparable and lower body muscle power was worse compared to athletes in similar sports. Additionally, flexibility was rated as poor.