Exercise Response to Real Combat in Elite Taekwondo Athletes Before and After Competition Rule Changes

Short intermittent taekwondo test to assess athlete's physiological and metabolic profile

BACKGROUND

The aim of this study was to assess the effectiveness of a new Short Intermittent Taekwondo Test (SITT) in 17 black belt athletes.

METHODS

Maximal oxygen uptake (V̇O2max), carbon dioxide production (V̇CO2), respiratory exchange ratio (RER), heart rate (HR), and blood lactate concentration [La]+ during treadmill cardiopulmonary exercise test (CPET) and SITT were compared. SITT started with 10 sec of all-out kicks, alternating legs, and progressively increasing 5 s on each stage until the 4th stage. After the 4th stage the participants performed 25 s of turning kicks (Dolleo chagi), on each stage until the last (10th stage). The passive recovery phase after the 4th and the 7th stage lasted 30 s.

RESULTS

V̇O2max and maximal HRmax were not significantly different (P=0.85 vs. P=0.76) between tests, while RER and [La]+ were significantly higher in SITT than in CPET (P=0.002 vs. P=0.001). No difference in RPE (P=0.84) was found. A significant positive correlation between two tests for V̇O2max and HRmax was found.

CONCLUSIONS

Our findings showed that SITT induces physiological responses like CPET suggesting that it can be used to assess aerobic power in national taekwondo athletes, thus helping coaches to select correctly training intensities and monitor athletes' aerobic performance along the training phases.

Correlation analysis between biomechanical characteristics of taekwondo double roundhouse kick and effective scoring of electronic body protector

Objective: To explore the inherent relationship between lower limb biomechanical indicators and effective scoring values of double roundhouse kick (DRK) by taekwondo athletes, and to find key biomechanical factors that trigger effective scoring. Methods: Using the DAEDO Protector and Scoring System (PSS) in conjunction with the Vicon optical motion capture system and Kistler 3D force plate, kinematic and dynamic indicators of the front kicking motion were obtained from 12 professional taekwondo athletes (18.00 ± 2.20 years, 182.15 ± 8.62 cm and 70.00 ± 14.82 kg). The correlation between kinematics, dynamics, and scoring values was initially analyzed using bivariate linear correlation. Subsequently, based on the results of the linear correlation analysis, a stepwise regression analysis was performed to establish a stepwise regression equation. Results: The results reveal that during the First Hit, there is a significant positive correlation (r > 0, p < 0.05) between peak hip flexion angular velocity of the dominant leg, knee abduction angle, and peak foot horizontal plane linear velocity of the non-dominant leg with effective score. On the other hand, peak ankle flexion angular velocity of the non-dominant leg, peak foot sagittal plane linear velocity, peak hip abduction angle, and peak hip flexion angle of the dominant leg exhibit a significant negative correlation (r < 0, p < 0.05) with effective score. These correlations hold statistical significance (DW> 1.023). During the Second Hit, there is a significant positive correlation (r > 0, p < 0.05) between peak ankle internal rotation angular velocity of the dominant leg, foot coronal plane linear velocity, hip adduction angular velocity, and peak ankle internal rotation moment of the non-dominant leg with effective score. Conversely, peak hip flexion angle of the dominant leg shows a significant negative correlation (r < 0, p < 0.05) with effective score. All these variables have a statistically significant impact on effective score (DW > 1.023). Conclusion: Explosive power, body posture, adequate terminal velocity, and body rotation have an association with effective scoring of the electronic protector. The peak angular velocity of the ankle joint of the dominant leg and the peak linear velocity of the foot horizontal plane of the non-dominant leg significantly contribute to the effectiveness score of the electronic protector.

Time-motion analysis of taekwondo matches in the Tokyo 2020 Olympic Games

BACKGROUND

The aim of the present study was to determine the time-motion structure of high-level taekwondo matches during the Tokyo 2020 Olympic Games in relation to sex, match outcome, weight category and match round.

METHODS

Overall, 7007 actions were recorded during the analysis of 134 performances (67 rounds of 24 matches: four rounds of 16, eight quarterfinals, eight semifinals and four finals) in male and female flyweight (≤58 kg and ≤49 kg, respectively), and heavyweight categories (≥80 kg and ≥67 kg, respectively). The attack time (AT), number of AT (AN), skipping time (ST) and pause time (PT) were registered.

RESULTS

The AT/ST ratio was ~1:1.5. Male athletes performed significantly longer (P<0.001) sum PT than female athletes. Flyweight athletes differed significantly from their heavyweight counterparts by having longer (P<0.001) average and sum AT, greater (P<0.001) AN, higher (P<0.001) AT/ST ratio, shorter (P<0.001) average and sum ST, and lower (P<0.01) (AT+ST)/PT ratio. Rounds 2 and 3 had average PT significantly longer (P<0.01) than round 1. Round 3 had sum PT longer (P<0.001) and (AT+ST)/PT ratio lower than in round 1.

CONCLUSIONS

The rule changes and the implementation of the electronic score recording system had a major impact on the time-motion structure of combat by generating a considerably higher AT/ST ratio than in the past. The comparisons indicated that the structure of the combat is modulated by weight category and phase of the combat. In practice, coaches could develop sport-specific high-intensity interval training using the time-motion indexes of the present study as guidelines.

The relationship between physical fitness and competitive performance of Taekwondo athletes

The competition and physical fitness test results of the 2020 National Taekwondo Championship Series were analyzed using curve fitting, linear regression, and other statistical methods. As far as we know, it is the first Taekwondo competition that uses physical fitness test (PFT) scores as the 8-in-4 selection criteria. The results show that the probability of the final total score of the series of championships entering the top 8 or top 3 is exponentially related to PFT results. It finds that athletes with better PFT scores are more likely to enter the quarterfinals. Among athletes entering the semifinals, the athlete with the best physical fitness has the greatest probability of winning the championship. The difference in physical fitness between athletes is mainly reflected in the 30-meter sprint. Overall, the competitive performance of professional Taekwondo athletes is significantly positively correlated with their physical fitness, especially for female Taekwondo athletes. Through the results obtained, it is concluded that Taekwondo athletes need to strengthen physical training, specifically enhancing the explosive power.

Does sport type matter? The effect of sport discipline on cognitive control strategies in preadolescents

This study aimed to test the effects of specific sport practices on cognitive sensory-motor performance and underlying brain functions in children. Behavioral performance and event-related potentials (ERP) were investigated during a cognitive visuomotor task in 64 preadolescent children practicing racket (Rack) sports, martial arts (Mart), indoor climbing (Clim), or not practicing any sport (controls, Cont). At the behavioral level, response speed and accuracy were studied. At the electrophysiological level, motor, cognitive and sensory-attentional readiness, and post-perceptual attentional functions were investigated. Behavioral results showed that Mart players had the fastest response time (RT). Rack players had the most consistent RT and committed the lowest omission errors. Clim athletes were the most accurate in terms of false alarms. ERP results showed that motor readiness was largest in Mart players. The Rack group had the largest cognitive preparation and the Clim one had the largest sensory-attentional readiness activity. Rack and Mart players had the largest activity associated with post-perceptual attentional processing. This result shows that practicing specific sports may allow differential benefits on cognitive processing. Racket sports seem to stimulate action speed consistency and improve accuracy for omissions, increasing cognitive preparation, and post-perceptual attentional processing. Mart practice may allow a more speed-oriented response behavior, probably due to large motor preparation and allocation of post-perceptual attentional resources, but only when response execution is required. Indoor climbing may favor response accuracy reducing unwanted responses as indexed by an increased sensory-attentional readiness. Overall, all the considered sports disciplines may improve cognitive processing, but each one is associated with different benefits on cognitive performance by possibly stimulating separate brain processing. This kind of information could be crucial to select the more appropriate sport depending on individual demands.

Relative and Chronological Age in Successful Athletes at the World Taekwondo Championships (1997-2019): A Focus on the Behaviour of Multiple Medallists

The aims of this study were to investigate the relative and chronological age among taekwondo world medal winners (by gender, Olympic 4-year period, Olympic weight category; N = 740), and to study the behaviour of multiple medallists (N = 156) to monitor changes in weight categories and wins over time. The observed birth quartile distribution for the heavyweight category was significantly skewed (p = 0.01). Female athletes (22.2 ± 3.5 years) achieve success at a significantly younger age (p = 0.01) than their male counterparts (23.6 ± 3.3 years). In the weight categories, female flyweights were significantly younger than those welterweights (p = 0.03) and heavyweight (p = 0.01); female featherweights were significantly younger than those heavyweights (p = 0.03). Male flyweights and featherweights were significantly younger than those welterweights and heavyweights (p = 0.01). When a taekwondo athlete won a medal several times, he/she did so within the same Olympic weight category group and won two medals in his/her career (p = 0.01). Multiple medallists of the lighter and heavier groups did not differ in the number of medals won but in the time span in which they won medals (p = 0.02). The resources deployed by stakeholders to achieve success in these competitions highlight an extremely competitive environment. In this sense, the information provided by this study can be relevant and translated into key elements.

Exploring the age of taekwondo athletes in the Olympic Games: an analysis from Sydney 2000 to Rio 2016

BACKGROUND

The aim of this study was to quantify the age at which taekwondo athletes competed in the Olympic Games and to provide initial insights into weight category changes over time.

METHODS

For the first analysis, the study included all 611 taekwondo athletes who competed in the Olympics between 2000 and 2016; for each sex, a three-way ANOVA (edition of Olympic Games, competitive achievement, weight category) was performed to detect differences in the age of athletes. For the second analysis, we considered all 109 taekwondo athletes who took part in more than one edition of the Olympics between 2000 and 2016; chi-squared goodness of fit tests were performed to study the number of participations and changes in weight category of these athletes.

RESULTS

Female athletes, with a mean age of 23.8 ± 4.1 years, are significantly younger (p=0.001) than their male counterparts, with a mean age of 25.1 ± 3.9 years. In weight category, lighter athletes being younger than heavier ones in both females (22.7 ± 3.7 vs 24.5 ± 4.2 yrs., p=0.04) and males (23.6 ± 3.8 vs 26.7 ± 3.8 yrs., p=0.001; 24.2 ± 3.5 vs 26.7 ± 3.8 yrs., p=0.001). When an athlete reaches Olympic competition several times, he/she generally competes in the same weight category (p=0.001) and takes part in two consecutive editions (p=0.001). Heavier athletes have greater longevity at Olympic level than lighter athletes (p=0.002).

CONCLUSIONS

The current data provides important information for national federations engaged in the selection of athletes for Olympic competitions.

The effect of multi-ingredient intra- versus extra-cellular buffering supplementation combined with branched-chain amino acids and creatine on exercise-induced ammonia blood concentration and aerobic capacity in taekwondo athletes

Background

This study aimed to investigate the effect of multi-ingredient intra- (BA) versus extra- (ALK) cellular buffering factor supplementation, combined with the customary intake of branched-chain amino acids (BCAA) and creatine malate (TCM), on body composition, exercise variables, and biochemical and hematological parameters in 9 elite taekwondo athletes.

Methods

Eight-week randomized double-blind crossover BA (5.0 g·day⁻¹ of β-alanine) versus ALK (0.07 g·kg_FFM⁻¹·day⁻¹ of sodium bicarbonate) supplementation combined with BCAA (0.2 g·kg_FFM⁻¹·day⁻¹) and TCM (0.05 g·kg_FFM⁻¹·day⁻¹) during a standard 8-week taekwondo training period was implemented. In the course of the experiment, body composition (dual X-ray absorptiometry), aerobic capacity (ergospirometric measurements during an incremental treadmill test until exhaustion), and exercise blood biomarkers concentrations were measured. Data were analyzed using repeated measures within-between interaction analysis of variance with the inclusion of experimental supplementation order.

Results

The maximum post-exercise blood ammonia concentration decreased in both groups after supplementation (from 80.3 ± 10.6 to 72.4 ± 10.2 µmol∙L⁻¹, p = 0.013 in BA; from 81.4 ± 8.7 to 74.2 ± 8.9 µmol∙L⁻¹, p = 0.027 in ALK), indicating reduced exercise-related adenosine triphosphate degradation. However, no differences were found in body composition, aerobic capacity, blood lactate concentration, and hematological parameters after neither BA (combined with BCAA and TCM) nor ALK (combined with BCAA and TCM) supplementation.

Conclusions

In highly trained taekwondo athletes, neither extra- nor intracellular buffering enhancement resulting from BA and ALK supplementation, combined with BCAA and TCM treatment, affects body mass and composition, maximum oxygen uptake, and hematological indices, even though certain advantageous metabolic adaptations can be observed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12970-021-00451-3.

The Effect of Sports Rules Amendments on Exercise Intensity during Taekwondo-Specific Workouts

We aimed to compare the change in exercise response to taekwondo-specific circuit workouts before and after competition rule amendments. A total of 240 workouts in 15 elite athletes were analyzed over two years. Physiological and kinematic data were gathered with the wireless Bioharness system along with capillary blood samples for lactate concentration. Progressive exercise tests until exhaustion were periodically performed to obtain reference data. The rule changes resulted in significant increases (mainly medium or large effects) in the physiological (2.9-14.4%) and kinematic (4.8-10.1%) response to taekwondo-specific workouts. The largest increases were for peak breathing rate (12.0%), energy expenditure (6.6%), blood lactate immediately after exercise (10.2%) and at the 30th min of recovery (14.4%), and peak kinematic activity (10.1%). Significant differences between taekwondo-specific workouts and tournament combats persisted after the shift from old to new rules, ranging from 2.4 to 38.5% for physiological and from 2.9 to 15.5% for kinematic variables. The largest workout-combat differences were revealed for post-exercise (15.9%) and recovery (38.5%) blood lactate, peak (-15.8%) and relative (-15.0%) breathing rate, and mechanical (13.5%) and physiological (14.2%) intensity. Our study suggests that the rule amendments significantly modify the exercise response to discipline-specific workouts and that taekwondo-specific training sessions do not fully recreate the tournament demands in terms of physiological and kinematic load.