Effects of Progressive and Velocity-Based Autoregulatory Resistance Training on Lower-Limb Movement Ability in Taekwondo Athletes

BACKGROUND

Both autoregulatory progressive resistance exercise (APRE) and velocity-based resistance training (VBRT) utilize real-time monitoring of athlete physical performance to adjust training loads to provide appropriate training stimuli. However, the monitoring and adjustment approaches differ between both methods. This study aimed to compare the effects of APRE and VBRT on the muscle strength, power, and agility of college taekwondo athletes.

HYPOTHESIS

Eight weeks of APRE and VBRT will promote similar results to strength gains in regards maximal strength, but VBRT will be superior to APRE in explosive power and agility.

STUDY DESIGN

Clinical trial.

LEVEL OF EVIDENCE

Level 3.

METHODS

Thirty taekwondo athletes were divided randomly into 2 groups (VBRT/APRE), and all participants completed an 8-week APRE/VBRT intervention. Maximum strength, explosive power, and agility performance were assessed during the squat 1-repetition maximum (1RM), countermovement jump (CMJ), drop jump (DJ), kicking strength test (KST), taekwondo-specific agility test (TSAT), and hexagon test (HT).

RESULTS

Highly significant time effects (P < 0.01) were observed for squat 1RM, CMJ, and TSAT in both the APRE and VBRT groups. However, there were no significant group-by-time differences for any of the measured outcomes to intergroup (P > 0.05), but APRE had a small effect size (ES) over VBRT for CMJ (ES = 0.48, η 2 p = 0.06), TSAT (ES = 0.26, η 2 p = 0.02), and HT (ES = 0.42, η 2 p = 0.05).

CONCLUSION

An 8-week autoregulatory APRE and VBRT can both effectively improve both the maximal strength, explosive power, and agility performance of taekwondo athletes, with APRE exhibiting potential advantages in improving CMJ, TSAT, and HT.

CLINICAL RELEVANCE

These results provide important insights into the selection of suitable resistance training programs by professional coaches, taking into account athlete needs, training efficiency, and safety considerations.

The effects of different work: Rest durations on physiological, neuromuscular, and ratings of perceived exertion responses during taekwondo-specific high-intensity interval training

Purpose

To investigate the effect of different work: rest durations on physiological, neuromuscular, and perceived exertion responses during taekwondo-specific high-intensity interval training (HIIT).

Methods

Thirteen moderate-trained taekwondo athletes (age: 21.7 ± 2.4 years; body mass: 69.1 ± 7.6kg; height: 174 ± 6 cm) completed a familiarization session and three HIIT trials. The trial consisted of three rounds of 2 min roundhouse kicks with 1 min of rest in between. In each round, the work: rest ratio was constant at 1:2, and the work: rest duration varied to be: short (2s:4s), medium (10s:20s), and long (20s:40s). Heart rate (HR) and oxygen uptake (V ˙ O2) were continuously measured. Blood lactate concentration ([La-]), countermovement jump (CMJ), and rating of perceived exertion (RPE) were recorded before trials and after each round. Energy contribution was estimated.

Results

HR,V ˙ O2, and CMJ were similar across protocols (P > .05) but, [La-] was higher during long than short work: rest duration protocol (P < .05). Relative aerobic energy contribution and RPE in round 3 were higher during long than short work: rest duration protocol (P < .05). Absolute and relative glycolytic energy contribution in rounds 1 and 2 were higher during long than short work: rest duration protocol (P < .05). Relative phosphate energy contribution in rounds 1 and 3 was lower during long than short work: rest duration protocol (P < .05).

Conclusion

Different work: rest durations of taekwondo-specific HIIT influenced [La-], energy system contributions, and RPE. The longer work: rest duration protocol (20s:40s) stressed more the glycolytic, aerobic energy systems and perceived exertion, and less the phosphagen energy system.

Exploring Gender-Specific Correlations Between Nutritional Intake, Body Composition, Psychological Skills, and Performance Metrics in Young Taekwondo Athletes

Objectives: Taekwondo performance is influenced by a complex and dynamic interplay of physical, nutritional, and psychological factors, all of which contribute to competitive success. However, the gender-specific relationships among these factors in young high-performance athletes remain understudied. This study aimed to fill in this knowledge gap. Methods: A cross-sectional study was conducted with 35 elite taekwondo athletes (male: n = 20, female: n = 15, age: 13 ± 1 years). Participants underwent anthropometric assessments, dietary evaluations, and psychological skill assessments during an 8-week training camp before the World Taekwondo Championships. Physical performance was assessed using the Frequency Speed of Kick Test (FSKTmult) and the Taekwondo-Specific Agility Test (TSAT). Statistical analyses included independent t-tests, correlation analyses, and regression models. Results: Males exhibited significantly higher fat-free mass (FFM: 42.8 ± 2.9 kg vs. 36.3 ± 1.6 kg, p < 0.001), skeletal muscle mass (SMM: 31.1 ± 2.2 kg vs. 28.2 ± 1.6 kg, p < 0.001), and energy intake (32.4 ± 4.6 kcal/kg vs. 29.3 ± 3.1 kcal/kg, p = 0.032) than females. Males also had greater dietary intakes of vitamin A, vitamin C, magnesium, and iron (all p < 0.05). There were no gender differences in any psychological attributes associated with emotional intelligence, sport success perception, and mental toughness. Although the total kick count in the FSKTmult was similar for male and female taekwondo athletes (100.2 ± 4.6 vs. 97.5 ± 5.9 kicks, p = 0.139), males outperformed females in round 4 (19.4 ± 1.1 vs. 18.6 ± 1.4 kicks, p = 0.048) and round 5 (18.2 ± 1.0 vs. 17.2 ± 1.0 kicks, p = 0.007) of this test, suggesting higher physical performance maintenance during the test. Regression models indicated that body mass (β = 0.901, p < 0.001) and calcium intake (β = 0.284, p = 0.011) predicted performance in males, while body mass (β = 1.372, p < 0.001), protein intake (β = 0.171, p = 0.012), and emotional regulation (β = 0.174, p = 0.012) were key predictors in females. Conclusions: These findings highlight the importance of an integrated approach to training, nutrition, and psychological preparation in optimizing taekwondo performance. While males and females demonstrated similar psychological resilience and total kick output in a taekwondo-specific test, males exhibited superior endurance in later test rounds of this test. Performance optimization in young elite taekwondo athletes may require the implementation of gender-specific training and nutrition strategies, emphasizing body weight control and calcium intake for males and protein intake for females.

Influence of Body Composition and Muscle Power Performance on Multiple Frequency Speed of Kick Test in Taekwondo Athletes

The Multiple Frequency Speed of Kick Test (FSKTmult) is used to investigate which characteristics are necessary for, contribute to, or limit the ability to repeat high-intensity intermittent efforts in taekwondo. This cross-sectional study investigated the relationship between anthropometric and body composition characteristics, muscle power performance, and sport-specific anaerobic performance. Nineteen black belt taekwondo athletes (mean ± SD age: 17.2 ± 2.4 years) volunteered to participate. Anthropometric and body composition characteristics (i.e., body height (BH), body mass (BM), fat mass (FM), body fat (BF%), and muscle mass (MM)) and physical performance (squat jump (SJ), countermovement jump (CMJ) tests, and FSKTmult) were assessed. Data were analyzed with correlation coefficients and simple linear regression. The statistical significance was set at p < 0.05. The total number of kicks in FSKTmult (FSKTtotal) was significantly and positively correlated with MM (r = 0.521, R2 = 0.27, p < 0.05) and negatively with BF% (r = -0.499, R2 = 0.25, p < 0.05). The FSKTtotal was significantly and positively correlated with SJ (r = 0.520, R2 = 0.27, p < 0.05) and CMJ (r = 0.508, R2 = 0.26, p < 0.05) performance. Body composition optimization, with appropriate physical training and dietary planning, is relevant in taekwondo as the improvement in the ability to repeat high-intensity intermittent efforts depends on MM, and its worsening on BF%. Lower limb muscle power positively influences the ability to repeat high-intensity intermittent efforts. Therefore, training programs should emphasize ballistic and plyometric exercises.

Anaerobic Sport-Specific Tests for Taekwondo: A Narrative Review with Guidelines for the Assessment

The ATP-PCr system represents the main source of energy during high-intensity attack actions in taekwondo matches. In contrast, the glycolytic system supports the maintenance of these actions when repeated techniques are performed. Given the close relationship between anaerobic energy systems and attack activity in combat, the literature relating to the use of sport-specific test protocols for anaerobic assessment has experienced a remarkable increase. This narrative review aims to illustrate the sport-specific anaerobic tests available in taekwondo by retracing and examining development and validation process for each test. Forty-one articles published between 2014 and 2023 were selected via the MEDLINE and Google Scholar bibliographic databases. These tests are the Taekwondo Anaerobic Test and Adapted Anaerobic Kick Test (i.e., continuous mode testing); the 10 s and multiple Frequency Speed of Kick Tests; the chest and head Taekwondo Anaerobic Intermittent Kick Tests; and the Taekwondo-Specific Aerobic-Anaerobic-Agility test (i.e., intermittent mode testing). Coaches and strength and conditioning professionals can use all the tests described in taekwondo gyms as they feature short and easy-to-implement protocols for monitoring and prescribing specific anaerobic training. The guidelines in this review evaluate each test from several perspectives: basic (e.g., validity, reliability, and sensitivity), methodological (e.g., continuous or intermittent mode testing) and application (e.g., time-motion structure and performance parameters). This comprehensive approach aims to assist stakeholders in selecting the most appropriate test.

A Comparative Analysis of High-Intensity Technique-Specific Intervals and Short Sprint Interval Training in Taekwondo Athletes: Effects on Cardiorespiratory Fitness and Anaerobic Power

Technique-specific high-intensity interval training (HIITTS) has been proven to be an effective method to enhance the sport-specific bio-motor abilities of taekwondo athletes. However, studies regarding its effects on comprehensive measures of cardiorespiratory fitness are limited. Furthermore, there is a lack of clarity regarding the extent of individual adaptations to this method compared to HIIT in the form of repeated sprints (HIITRS). This study compared the individual adaptations to HIITRS and HIITTS on cardiorespiratory fitness and anaerobic power in trained taekwondo athletes (age = 19.8 ± 1.3 years; body mass = 75.4 ± 9.1 kg; height = 1.73 ± 0.0 .m). All participants completed three sessions per week of a 60-minute regular taekwondo training. Following the 60-minute training, participants completed 3 sets of 10 × 4 s all-out HIITRS or same sets of repeated kicks with both legs (HIITTS) over a 6-week training period. In both groups, rest intervals were set at 15 seconds between efforts and one minute between sets. Before and after the training period, participants underwent a series of lab- and field-based tests to evaluate cardiorespiratory fitness and bio-motor abilities. Both interventions resulted in significant improvements in maximum oxygen uptake (V̇O2max), O2 pulse (V̇O2/HR), first ventilatory threshold (VT1), second ventilatory threshold (VT2), cardiac output (Q̇max), stroke volume (SV), peak power output (PPO), average power output (APO), squat jump (SJ), and countermovement jump (CMJ). However, linear speed (20-m speed time) and taekwondo-specific agility test (TSAT) only responded to HIITRS. HIITRS resulted in greater changes in V̇O2max, V̇O2/HR, VT2, and Q̇max, and higher percentage of responders in measured parameters than HIITTS. In addition, HIITRS elicited lower inter-individual variability (CV) in percent changes from pre- to post-training in all measured variables. These results suggest that incorporating 3 sessions per week of HIITRS into regular taekwondo training results in significantly greater and more homogenized adaptations in cardiorespiratory fitness and bio-motor abilities than HIITTS among trained taekwondo athletes.

Effects of Ischemic Preconditioning on Sport-Specific Performance in Highly Trained Taekwondo Athletes

Ischemic preconditioning (IPC), which involves episodes of blood flow restriction followed by reperfusion, has uncertain effects on athletes. Additionally, employing sports-specific tests that are highly familiar to athletes can enhance methodological rigor in determining IPC's effects on taekwondo performance. This study aimed to investigate IPC's influence on taekwondo athletes' performance through two studies. To induce occlusion in both studies, the cuff was inflated to an individualized occlusion pressure established for each athlete's lower limb, with four cycles of occlusion lasting five minutes each, alternated with five-minute reperfusion intervals. Both traditional frequentist statistics and Bayesian analysis were employed. In the first study, eleven high-level athletes were subjected to either IPC or a placebo (SHAM) procedure on both legs, followed by performing countermovement jumps (CMJs) and a specific taekwondo endurance test. However, no significant differences were observed in taekwondo endurance performance or CMJ between the IPC and SHAM conditions. The second study involved fourteen elite athletes who underwent the same IPC or SHAM conditions, performing CMJ and three bouts of the Multiple Frequency Speed of Kick test (FSKTmult) in three blocks, each separated by approximately thirty minutes. Again, the results indicated no significant differences in FSKTmult measures or CMJ performance between the two conditions. In conclusion, IPC did not significantly affect neuromuscular (in both studies), endurance (in the first study), or anaerobic (in the second study) performance in these taekwondo athletes.

Taekwondo win-loss determining factors using data mining-based decision tree analysis: focusing on game analysis for evidence-based coaching

BACKGROUND

Purpose In this study, the purpose of this study is to identify the determinants of winning and losing in taekwondo by applying decision tree analysis, one of the data mining techniques, based on the 2022 World taekwondo championships women's competition.

METHODS

272 women's games in the taekwondo championships in Guadalajara held by the WT in 2022 were used. For data processing, an independent sample t-test was performed for differences in game content variables according to the win/lose group, and a decision tree analysis was performed to confirm game content variables affecting the win/lose group. To check the predictive power of the model, classification accuracy, standard error, and misclassification estimates were calculated. All statistical significance levels were set at 0.05.

RESULTS

First, it was found that there was no statistically significant difference only in body attack (attempt) and number of kicking variables according to the winning and losing groups(p > .05), and there were differences in all other game content variables(p < .05). Second, as a result of conducting a decision tree analysis to confirm the determinants of winning and losing in taekwondo sparring, winning situation, tie situation, and number of kicks were identified as important variables.

CONCLUSION

The World taekwondo championships are analyzed in the currently changed taekwondo competition rules to identify important factors, and at the same time, based on this, data-based coaching is expected to improve performance.

The effects of pre-task music on choice visual reaction time in elite taekwondo athletes

OBJECTIVES

The effects of music on sport performance mainly involved endurance or resistance exercises overlooking possible effects on reaction time, which is deemed essential in martial arts for a proficient performance. Therefore, the aim of this study was to investigate the effects of the exposure to pre-task music on choice visual reaction time in elite taekwondo athletes.

DESIGN

Repeated measure study design.

METHODS

Reaction time and mean Heart Rate (HRmean) were recorded in twenty young taekwondo athletes (17.5 ± 2.5 years old) while performing a roundhouse kick in response to different visual stimuli after three warmup conditions: listening to self-selected music (SM), research-selected music (RM) or no music (CC). Moreover, Feeling Scale (FS), Felt Arousal Scale (FAS) were recorded before (T0) and after warmup (T1) in each testing session.

RESULTS

SM and RM elicited significantly faster reaction times compared to CC (-3.3 % and -5.2 %, respectively). No significant difference in reaction time was observed between SM and RM. The FS and FAS scores were significantly higher at T1 compared to T0 in the SM and RM conditions, whereas no difference between T0 and T1 was observed in the CC condition. No difference was observed for HRmean between SM, RM and CC conditions.

CONCLUSIONS

Listening to SM and RM during the warmup improved choice visual reaction times in elite taekwondo athletes. These results suggest the use of music as a performance-enhancing strategy prior to combat competition or training in martial arts.

The enhancement of explosive power contributes to the development of anaerobic capacity: A comparison of autoregulatory progressive resistance exercise and velocity-based resistance training

Objectives

Due to the character of the taekwondo, the adenosine triphosphate-phosphocreatine system provides the energy for each kick, the glycolytic system supports the repeated execution of kicks, and the aerobic system promotes recovery between these movements and the bout. Therefore, taekwondo athletes require high explosive power and anaerobic capacity in order to carry out sustained and powerful attacks. So, the purpose of this study is to compare the effects of APRE and VBRT on lower-limb explosive power and anaerobic capacity in college taekwondo players.

Methods

A total of 30 taekwondo players completed an 8-week training intervention with autoregulatory progressive resistance exercise (APRE; n = 15) and velocity-based resistance training (VBRT; n = 15). Testing included the one-repetition maximum squat, countermovement jump (CMJ), taekwondo anaerobic intermittent kick test (TAIKT), and 30-s Wingate anaerobic test (WAnT).

Results

(1) Intragroup comparisons revealed significant effects for one-repetition maximum squat, peak power of CMJ (CMJPP), relative peak power of CMJ (CMJRPP), and total number of TAIKT (TAIKTTN) in both the APRE and VBRT groups. The VBRT group exhibited small effect sizes for time at peak power of WAnT (WAnTPPT) and moderate effect sizes for peak power of WAnT (WAnTPP), relative peak power of WAnT (WAnTRPP), and fatigue index of TAIKT (TAIKTFI), whereas the APRE group exhibited small effect sizes for TAIKTFI. (2) Intergroup comparisons revealed no significant effects in any of the results. However, VBRT demonstrated a moderate advantage in WAnTPP and WAnTRPP, whereas APRE had a small advantage in CMJPP and CMJRPP.

Conclusions

These findings suggest that APRE improved explosive power (CMJPP and CMJRPP) more, whereas VBRT improved anaerobic power output (WAnTPP and WAnTRPP) more. Both methods were found to have similar effects in improving the anaerobic endurance (WAnTPPT and TAIKTTN) and fatigue index (power drop of WAnT and TAIKTFI).

Examination of the effect of fascial therapy on some physical fitness parameters in taekwondo athletes

One of the objectives of this study is to determine the effect of the eight-week fascial therapy program on flexibility, vertical jump, standing long jump, speed and anaerobic strength parameters in taekwondo athletes. Another aim of the research is to create a therapy protocol that can be used in athletes related to performance development through the relaxation of the fascial system, which is considered an indicator of physical fitness and has numerous functions in the body. This study included 32 taekwondo players who were licensed, actively attending taekwondo training. In the study, two groups were formed as fascial therapy group (FTG) (n ​= ​16) and control group (CG) (n ​= ​16). After the groups were randomized, fascial relaxation techniques were applied to the fascial therapy group for eight weeks, up to twice a week, and for 30 ​min. According to the findings obtained as a result of the research, FTG ([-0.36 ​± ​0.17] seconds [s]) for the 20 ​m (m) Sprint (T2-T1) had a lower mean time than CG (0.00 ​± ​0.07) s, FTG (0.06 ​± ​1.95) for the Flamingo Balance Test (T2-T1) had a lower mean fall than CG (1.25 ​± ​1.13), FTG ([3.56 ​± ​2.37] centimeters [cm]) for the Sit & Reach Test (T2-T1) had a lower mean fall than CG ([-0.19 ​± ​1.28] cm), FTG ([5.75 ​± ​2.54] cm) had a higher jump distance than CG ([1.88 ​± ​8.11] cm) according to the results of Vertical Jump Test (T2-T1) and finally FTG ([9.13 ​± ​5.56] cm) had a longer distance than CG ([-0.31 ​± ​1.85] cm) according to the results of Standing Long Jump Test (T2-T1). The result of our study has shown that fascial techniques can be used safely by experienced physiotherapists and can be included in the training program. It is recommended that coaches of sports disciplines work with experienced physiotherapists on this subject and include fascial methods in their training programs.

Time-motion analysis in men's breaking: A longitudinal study

Quantifying the effort of a sport confrontation by determining its temporal structure is of concern to the scientific community. In breaking this has not yet been sufficiently studied. The objectives of the study were to longitudinally analyze the temporal and sequential parameters of male breaking battles to determine the evolution of these parameters and to establish a model of temporal structure. All Red Bull BC One dancers from 2011 to 2021 (n = 152 dancers) participated. By using observational methodology, all battles were analyzed (n = 142). To obtain the results, we employed different analysis techniques: descriptive, normality tests, Student's t-test or Mann-Whitney, one factor ANOVA or Kruskall-Wallis and effect size (Cohen's d or Hedges' g). The significance level established for the study was ρ ≤ 0.05. The results define the temporal and sequential structure of the battles. With these, breaking professionals will be able to develop precise and adequate training for these athletes. We conclude that approaches to dancing and battling have evolved. The effort that the athlete must exert is increasing and will therefore require better preparation to cope with the physical demands required for a sport that will be incorporated into the Olympics program in 2024.

Low- or moderate-carbohydrate calorie-restricted diets have similar effects on body composition and taekwondo performance after high-carbohydrate recovery meals

Low-carbohydrate (LC) diets are popular among general and athletic populations attempting to lose body mass. This study investigated the effect of a 7-day LC or moderate-carbohydrate (MC) calorie-restricted diet followed by 18-h recovery on body composition and taekwondo-specific performance. In this randomised cross-over study, 12 male taekwondo athletes consumed an LC (10% of carbohydrate, 41% of protein, 49% of fat, and 15.8 ± 0.4 kcal/kg/day) or an isocaloric MC diet (60% of carbohydrate, 30% of protein, and 10% of fat) for 7 days. The participants then consumed a carbohydrate-rich recovery dinner (39.2 ± 3.1 kcal/kg) followed by breakfast (6.2 ± 0.4 kcal/kg) in both the trials. Three repeated sprint ability (RSA) tests were conducted after breakfast. The taekwondo-specific reaction battery was administered before the first RSA test and after each RSA test. The participants experienced similar magnitudes of significant loss of body mass in the LC (-2.4 ± 1.7%) and MC (-2.3 ± 1.7%) trials. Fat mass and fat percentage significantly decreased in the MC trial but remained unchanged in the LC trial after body mass loss. Fat free mass was maintained in both the trials. The average and peak power in the RSA tests and the premotor reaction time were similar between the trials. The participants experienced significantly higher fatigue in the LC trial. In conclusion, both the diets can help athletes rapidly lose body mass while maintaining performance as long as an adequate amount of carbohydrate is consumed during the recovery period.

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.

Intermittent Fasting Promotes Weight Loss without Decreasing Performance in Taekwondo

Intermittent fasting (IF) is commonly used by combat sports athletes for weight loss. However, IF can decrease performance. This study aimed to investigate the effect of IF on total body mass (TBM) and Taekwondo performance. Nine athletes (seven male, two female; 18.4 ± 3.3 years) underwent 4 weeks of 12 h IF. TBM, countermovement jump (CMJ), mean kicks (MK), and total number of kicks (TNK) were compared weekly. Performance was measured in the fed state (FED) and fast state (FAST). Results showed decreased TBM in week 1 (62.20 ± 6.56 kg; p = 0.001) and week 2 (62.38 ± 6.83 kg; p = 0.022) compared to pre-intervention (63.58 ± 6.57 kg), stabilizing in week 3 (62.42 ± 6.12 kg), and no significant change in week 4 (63.36 ± 6.20 kg). CMJ performance in week 1 was lower in FED (35.26 ± 7.15 cm) than FAST (37.36 ± 6.77 cm; p = 0.003), but in week 3, FED (38.24 ± 6.45 cm) was higher than FAST (35.96 ± 5.05 cm; p = 0.047). No significant differences were found in MK and TNK in FSKTmult. RPE, KDI, and HR were similar between FED and FAST (p < 0.05). [LAC] was higher post-test compared to pre-test (p = 0.001), with higher concentrations in FED than FAST (p = 0.020). BG was higher in FED than FAST (p < 0.05) before physical tests. Therefore, IF promotes decreased TBM without decreasing performance.

Repeated High-Intensity Technique Training and Repeated Sprint Training Elicit Similar Adjustment in Physiological Responses But Divergent Perceptual Responses and Combat-Related Performances in Adolescent Taekwondo Matches

PURPOSE

This study investigated the effects of 4 weeks of repeated sprint training (RST) versus repeated high-intensity technique training (RTT) on the physiological responses (ie, blood lactate), mean and peak heart rate, rating of perceived exertion, technical-tactical performance, and time-motion variables during simulated taekwondo combats.

METHODS

Twenty-four taekwondo athletes (18 male and 6 female; age: 16 [1] y) were randomly and equally assigned to RST (10 × 35-m running sprints interspersed by 10-s rest) or RTT (10 × 6-s bandal-tchagui kicking executions interspersed by 10-s rest) groups in addition to their regular training. Both groups performed simulated combats before and after training.

RESULTS

Delta lactate and peak heart rate were attenuated following training (P < .001 and P = .03, respectively), with no differences identified between RTT and RST conditions. Rating of perceived exertion decreased after training only in the RTT (P = .002). Time fighting and preparatory activities increased following training (P < .001), with higher values observed following RTT than RST (P < .001). Nonpreparatory time decreased after training (P < .001), with more pronounced reductions observed following RTT when compared to RST (P < .001). The number of single attacks decreased only following RST (P < .001), whereas combined attacks increased only after RTT training (P < .001).

CONCLUSIONS

Similar adjustments in the physiological responses to combat were observed following 4 weeks of either RST or RTT, but RTT elicited more favorable perceptual responses and combat-related performance. This highlights the importance of specificity of training and its effective transfer to combat.

Injury Incidence and Its Characteristics in Korean Youth and Collegiate Taekwondo Sparring Athletes: A Retrospective Study

This study aimed to identify the incidence of injury and its characteristics in Korean youth and collegiate Taekwondo athletes during 2021 and to provide a suggestion regarding injury incidence. A total of 183 athletes (95 youth and 88 collegiate athletes) who were registered with the Korea Taekwondo Association (KTA) participated. The research was based on the injury questionnaire developed by the International Olympic Committee (IOC). The questionnaire consists of a total of seven items, including four items related to demographic characteristics and three items related to injuries (locations of injury, types of injury, and causes of injury). A frequency analysis was performed to identify the injury characteristics. Additionally, the injury incidence rate (IIR) was calculated based on 1000 athletic exposures (AEs) during 2021. The IIRs for one recent year (2021) showed 4.43/1000 AEs and 3.13/1000 AEs in youth and collegiate Taekwondo athletes, respectively. The frequency analysis showed that finger (youth: 17.3%, collegiate: 14.6%), contusion (youth: 25.3%, collegiate: 23.8%), and contact with other athletes (youth: 57.6%, collegiate: 54.4%) ranked the highest in terms of the locations of injury, types of injury, and causes of injury, respectively. A continuing injury tracking system can play a key role in accumulating big data for identifying risk factors and developing interventions to reduce injury in Taekwondo sparring.

PHYSICAL TRAINING INTERVENTION ON THE FUNCTIONAL STATUS OF TAEKWONDO ATHLETES

ABSTRACT Introduction: Taekwondo is a fighting and confrontational game that requires exceptionally high physical and psychological qualities from athletes. It has higher requirements on the athlete’s explosive power, coordination ability, spatial perception, and psychosocial quality. Any slight body changes in an athlete can destabilize the nervous system and cause changes in the immune system. These changes can increase the risk factor during training and competition. Objective: Monitor the physical function of taekwondo athletes. Methods: This paper discusses the essential role of biochemical indicators in taekwondo training. At the same time, it explores the relationship between physical function and the training effect of taekwondo athletes. Taekwondo athletes underwent a one-year training program. The program monitored and recorded the athletes’ biochemical parameters during training. The relationship between the training program formulation and the biochemical indicators of taekwondo athletes was analyzed. Results: The overall average level of nitrogen and urea in the blood was significantly higher than that of the setting phase after a large amount of exercise (P<0.05). Changes in blood urea after the routine were relatively stable (P>0.05). Most participants demonstrated hemoglobin in the normal range and reached its upper limit after winter training. Conclusion: The quality of the biochemical indicators of the athlete directly affects his performance. Sanguine nitrogen and hemoglobin are the main biochemical indicators for monitoring Taekwondo athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Does the Type of Anaerobic Test Matter? A Comparison between the Anaerobic Intermittent Kick Test and Wingate Anaerobic Test in Taekwondo Athletes

The specificity of training as well as the specificity of monitoring the training process are believed to be fundamental principles to efficiently plan and carry out the preparation and performance development of athletes. The Anaerobic Intermittent Kick Test (TAIKT) is a sport-specific field test used to specifically evaluate the anaerobic profile of Taekwondo athletes. The aim of this study was to verify whether TAIKT and the 'gold standard' Wingate Anaerobic test (WAnT) were both efficient means to optimally determine the anaerobic power and anaerobic capacity of Greek Taekwondo athletes at a middle-high technical level. Fifteen athletes, 10 females and 5 males (mean age 23.4 ± 4.14 years), underwent the two anaerobic tests (TAIKT and WAnT). The peak of power, the anaerobic capacity, and the peak of blood lactate (BL) were recorded. The two tests showed a moderate correlation with the r value ranging between 0.353 and 0.428, if applied to a sample of middle-high technical level athletes. Regarding the peak of BL, data indicated 40% concordance between the two tests with a coefficient of variation of 12%. Consequently, the two tests were correlated even if not interchangeable due to the different type of exercise required in these assessments. In conclusion, to assess the anaerobic performances and physiological characteristics of Taekwondo athletes, independently of their technical level, the WAnT resulted suitable, while to better assess the functional performance and specific demands of Taekwondo, the TAIKT is more indicated.

Reliability and Validity of a New Taekwondo-Specific Change-of-Direction Speed Test With Striking Techniques in Elite Taekwondo Athletes: A Pilot Study

The purpose of this study was to examine the test-retest reliability, and convergent and discriminative validity of a new taekwondo-specific change-of-direction (COD) speed test with striking techniques (TST) in elite taekwondo athletes. Twenty (10 males and 10 females) elite (athletes who compete at national level) and top-elite (athletes who compete at national and international level) taekwondo athletes with an average training background of 8.9 ± 1.3 years of systematic taekwondo training participated in this study. During the two-week test-retest period, various generic performance tests measuring COD speed, balance, speed, and jump performance were carried out during the first week and as a retest during the second week. Three TST trials were conducted with each athlete and the best trial was used for further analyses. The relevant performance measure derived from the TST was the time with striking penalty (TST-TSP). TST-TSP performances amounted to 10.57 ± 1.08 s for males and 11.74 ± 1.34 s for females. The reliability analysis of the TST performance was conducted after logarithmic transformation, in order to address the problem of heteroscedasticity. In both groups, the TST demonstrated a high relative test-retest reliability (intraclass correlation coefficients and 90% compatibility limits were 0.80 and 0.47 to 0.93, respectively). For absolute reliability, the TST's typical error of measurement (TEM), 90% compatibility limits, and magnitudes were 4.6%, 3.4 to 7.7, for males, and 5.4%, 3.9 to 9.0, for females. The homogeneous sample of taekwondo athletes meant that the TST's TEM exceeded the usual smallest important change (SIC) with 0.2 effect size in the two groups. The new test showed mostly very large correlations with linear sprint speed (r = 0.71 to 0.85) and dynamic balance (r = -0.71 and -0.74), large correlations with COD speed (r = 0.57 to 0.60) and vertical jump performance (r = -0.50 to -0.65), and moderate correlations with horizontal jump performance (r = -0.34 to -0.45) and static balance (r = -0.39 to -0.44). Top-elite athletes showed better TST performances than elite counterparts. Receiver operating characteristic analysis indicated that the TST effectively discriminated between top-elite and elite taekwondo athletes. In conclusion, the TST is a valid, and sensitive test to evaluate the COD speed with taekwondo specific skills, and reliable when considering ICC and TEM. Although the usefulness of the TST is questioned to detect small performance changes in the present population, the TST can detect moderate changes in taekwondo-specific COD speed.

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.

Interrelationship between specific high-intensity intermittent efforts ability with aerobic capacity and slow stretch-shortening cycle utilization in taekwondo athletes

BACKGROUND: Repeat high-intensity intermittent efforts is a taekwondo-specific ability but the influence of aerobic capacity and dynamic strength characteristics on this ability has received relatively little attention in the literature. OBJECTIVE: To examine the relationship between specific high-intensity intermittent efforts with aerobic capacity and slow stretch-shortening cycle utilization in taekwondo athletes. METHODS: Nineteen taekwondo male athletes were assessed by squat jump (SJ), countermovement jump (CMJ), 20-meter shuttle run (20MSR), and frequency speed of kick test multiple (FSKTMULT). From the FSKTMULT, total kicks and kick decrement index [KDI] were calculated. Additionally, from both jump tests, the slow stretch-shortening cycle utilization (Slow SSC Utilization) was determined from the eccentric utilization ratio [EUR], pre-stretch augmentation [PSA], and reactive strength index [RSI]. RESULTS: There were positive and significant correlations between total kicks with 20MSR (r= 0.85; p= 0.00) and SJ (r= 0.66; p< 0.05). The multiple regression model demonstrated that total kicks where significantly influenced by 20MSR (R2= 71%; p= 0.00). Additionally, only EUR and RSI explained total kicks performance to a greater proportion (R2= 76%). CONCLUSIONS: The FSKTMULT total kicks performance is positively correlated and influenced by aerobic capacity and slow SSC utilization.

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.

Physical Characteristics and Physical Fitness Profiles of Korean Taekwondo Athletes: A Systematic Review

This study aimed to present a standard and normal distribution of Taekwondo athletes’ physical characteristics and physical fitness profiles using a systematic review. A systematic search was conducted using four Korean databases (Research Information Sharing Service, National Digital Science Library, DBpia, and Korean Studies Information Service System). From 2010 to 2020, we reviewed 838 papers on Taekwondo athletes’ physical characteristics and physical fitness factors (e.g., body composition, muscle strength, muscular endurance, flexibility, cardiorespiratory fitness, power, agility, balance, speed, and reaction time). Of them, 24 papers were selected and analyzed. The criteria for selecting the physical characteristics and physical fitness factors for data extraction were set to have a total sample size of more than 30 individuals and included two or more studies. The sample size and average and standard deviation of physical characteristics and physical fitness factors were extracted from each selected study. In this study, the estimation error of all variables, except for the eyes-closed single-leg stance (15.71%), was less than 8%. Therefore, it was confirmed that there was no problem with the validity of the estimated values. These results could be used as an essential objective basis for evaluating the physical characteristics and physical fitness profiles of Taekwondo athletes in most countries worldwide and setting training goals.

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.

Effects of two different doses of carbohydrate ingestion on taekwondo-related performance during a simulated tournament

Background

Carbohydrate (CHO) ingestion enhances exercise performance; however, the efficacy of CHO intake on repeated bouts of exercise simulating a taekwondo tournament is unknown. Therefore, the purpose was to compare the effects of two different doses of CHO on a sports-specific kicking test during a simulated taekwondo tournament compared to placebo (PLA).

Methods

In a double-blind, randomized-placebo controlled, cross-over trial, eleven junior male professional taekwondo athletes (age: 16 ± 0.8 years, body mass: 55.3 ± 7.3 kg) ingested one of three solutions: (i) high dose (C45): 45 g of CHO (60 g∙h^− 1), (ii) low dose (C22.5): 22.5 g of CHO (30 g∙h^− 1; both solutions containing 2:1 glucose:fructose), or a PLA immediately following each kicking test. The kicking test was repeated 5 times, separated by 45 mins of rest, simulating a typical taekwondo competition day. Ratings of perceived exertion (RPE) and gastrointestinal discomfort (GI) scores were collected immediately after, and blood glucose before each test.

Results

The results revealed that C45 and C22.5 did not improve total, successful, or percentage of successful kicks compared to PLA (p > 0.05). Blood glucose was significantly higher following both CHO conditions compared with PLA across all five tests (p < 0.05). There were no differences between treatments or across tests for RPE (p > 0.05).

Conclusion

CHO intake, independent of the dose, did not alter taekwondo kick performance during a simulated taekwondo tournament.

Effects of 4 Weeks of a Technique-Specific Protocol with High-Intensity Intervals on General and Specific Physical Fitness in Taekwondo Athletes: An Inter-Individual Analysis

The aim of this research was to compare the effects of a technique-specific high-intensity interval training (HIIT) protocol vs. traditional taekwondo training on physical fitness and body composition in taekwondo athletes, as well as to analyse the inter-individual response. Utilising a parallel controlled design, sixteen male and female athletes (five females and 11 males) were randomly divided into an experimental group (EG) that participated in the technique-specific HIIT and a control group (CG) that participated in traditional taekwondo training. Both groups trained three days/week for four weeks. Squat jump (SJ), countermovement jump (CMJ), 5-metre sprint (5M), 20-metre shuttle run (20MSR), taekwondo specific agility test (TSAT), multiple frequency speed of kick test (FSKT_MULT), total kicks, and kick decrement index (KDI), as well as body composition were evaluated. Results indicate that there are no significant differences (p > 0.05) in the factors group and time factor and group by time interaction (p > 0.05). Although percentage and effect size increases were documented for post-intervention fitness components in TSAT, total kicks, KDI, and 20MSR, responders and non-responders were also documented. In conclusion, a HIIT protocol based on taekwondo-specific technical movements does not report significant differences in fitness and body composition compared to traditional taekwondo training, nor inter-individual differences between athletes.

Short-term co-ingestion of creatine and sodium bicarbonate improves anaerobic performance in trained taekwondo athletes

BACKGROUND

Creatine (CR) and sodium bicarbonate (SB) alone improve anaerobic performance. However, the ergogenic effects of CR and SB co-ingestion on taekwondo anaerobic performance remains unknown.

METHODS

Forty trained taekwondo athletes (21 ± 1 y.; 180.5 ± 7.3 cm; 72.7 ± 8.6 kg) were randomized to: (i) CR and SB (CR + SB; 20 g of CR+ 0.5 g·kg^- 1·d^- 1 of SB), (ii) CR, (iii) SB, (iv) placebo (PLA), or (v) control (CON) for 5 days. Before and after supplementation, participants completed 3 bouts of a Taekwondo Anaerobic Intermittent Kick Test (TAIKT) to determine changes in peak power (PP), mean power (MP), and fatigue index (FI). Blood lactate (BL) was measured before, immediately following, and 3 min post-TAIKT.

RESULTS

PP and MP increased over time (P < 0.05) following CR + SB, CR, and SB ingestion, with no changes in the PLA or CON groups. There was a greater increase over time in MP following CR + SB (Absolute Δ: 1.15 ± 0.28 W∙kg⁶⁷) compared to CR (Absolute Δ: 0.43 ± 0.33 W∙kg⁶⁷; P < 0.001) and SB (Absolute Δ: 0.73 ± 0.24 W∙kg⁶⁷; P = 0.03). There were no significant time and condition effect for FI (P > 0.05). BL increased following exercise across all groups; however, CR + SB and SB post-exercise BL was lower compared to CR, PLA, and CON (P < 0.05).

CONCLUSION

Short-term CR and SB alone enhance TAIKT performance in trained taekwondo athletes. Co-ingestion of CR and SB augments MP compared to CR and SB alone, with similar PP improvements.