Physical and physiological profiles of taekwondo athletes

Profiling Combat Sports Athletes: Competitive History and Outcomes According to Sports Type and Current Level of Competition

BACKGROUND

This study aimed to investigate the competitive history (the age when training and competing started), training habits and patterns of winning and losing of competitive combat sports athletes across different combat sports as well as the level of competition (e.g. amateurs, state-level and elite).

METHODS

Competitors (N = 298) from mixed martial arts (MMA), Muay Thai/kickboxing, boxing, Brazilian jiu-jitsu (BJJ), wrestling, judo and traditional striking sports (TSS) completed an online questionnaire.

RESULTS

Most athletes began competing in their mid-teenage years and competing soon after except for wrestlers who began earlier. Elite athletes began training earlier than amateurs (13.75 ± 7.75 years and 16.2 ± 7.45 years, p<0.01, respectively). Training habits were similar across sports (~4 combat and ~3 non-combat training sessions per week), except for MMA and wrestling which did more combat sports-specific training than Judo and TSS. Wrestlers did more non-combat sports-specific training than all other sports. Elite athletes completed more combat sessions per week than their lower-level contemporaries (4.64 ± 2.49 and 3.9 ± 1.44, p=0.01, respectively). Patterns of winning or losing were consistent across sports, except for amateur athletes who were more likely to report all their victories by points and none of their victories by submission or pin. Additionally, elite athletes are less likely to report none of their victories coming by knockout.

CONCLUSIONS

Results may indicate that finishing ability is a key distinguisher of competitive level. The present study provides normative data for training and competing habits for athletes, support staff and regulators to use.

Effects of Four Weeks of Concurrent Taekwondo Plus Resistance Training on Post-exercise Blood Biomarkers of Physiological Stress in Previously-Trained Individuals

Background: Various training protocols have been used in combat sports, including Taekwondo (TKD), to rapidly improve performance and to avoid injury by balancing the exercise intensity and the athletes’ metabolic tolerance and hormonal response. However, little is known about such metabolic responses in previously-trained individuals. Objectives: To investigate the effects of a concurrent TKD plus resistance (RT) training program on post-exercise blood biomarkers of physiological stress in previously-trained individuals. Methods: Twenty-eight (16 males: 12 females) previously-trained individuals aged 20 - 26 years were matched by gender and randomly divided into either moderate- to vigorous-intensity exercising group (MODG) or a high-intensity exercising group (HIG). The MODG performed TKD training at a target training intensity of 55 - 70% (weeks 1 - 2) and 70 - 85% (weeks 3 - 4) maximum heart rate (HRmax) and RT training for four sets of 10 - 15 repetitions for each of the 13 whole-body RT exercises. The HIG performed TKD training at a target training intensity of 85 - 100% (weeks 1 - 2) and 95 - 100% (weeks 3 - 4) HRmax and RT training for five sets of 10 - 15 repetitions for each of the 13 whole-body RT exercises. A structured taekwondo tasks (sTT) test was conducted before and after the training period. Results: Significant post-exercise improvements were found for total testosterone (P = 0.02), free testosterone (P = 0.01), C/T ratio (P = 0.03) and lactate (P = 0.03) in the mixed gender HIG. With regards to the specific gender effects, post-exercise improvements were found in S-CPK in the male MODG and HIG, with improvements in uric acid only in the male HIG. In turn, post-exercise improvements were found for total testosterone, testosterone binding globulin, free testosterone in the female MODG and HIG, with post-exercise improvements in S-CPK and uric acid in the female HIG only. Conclusions: This study demonstrates that even a short period of concurrent taekwondo and resistance training improves adaptation and post-exercise responses to physiological stress, and such adaptation may even be more marked in previously-trained female athletes. Thus, this mode of training may provide a novel exercise training modality to rapidly improve an individuals’ capacity to exercise, especially in situations of plateau, while avoiding overtraining and an increased concomitant chance of illness and musculoskeletal injury.

Relationship between Indirect Measures of Aerobic and Muscle Power with Frequency Speed of Kick Test Multiple Performance in Taekwondo Athletes

This study aimed to determine the relationship between indirect measures of aerobic power and muscular power with Frequency Speed of Kick Test performance using multiple sets (FSKTmult) in high-level taekwondo athletes. We used a known-group method to test differences in FSKTmult performance between two groups designated as lower and higher performance in both aerobic power and muscular power. In total, 42 international or national taekwondo athletes of both sexes performed the FSKTmult, Progressive Specific Taekwondo Test (PSTT), and countermovement jump (CMJ). Our results showed that average of the three CMJ was moderately correlated with FSKTmult performance (r=0.44); whereas PSTT and FSKTmult were highly correlated (r=0.83). Moreover, the groups formed by lower and higher performance of time to exhaustion in PSTT, as well as the average of CMJ were able to discriminate performance in the FSKTmult (p ≤0.05). The present study thus suggests that aerobic and muscle power are important for FSKTmult performance.

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

ABSTRACT

Janowski, M, Zieliński, J, and Kusy, K. Exercise response to real combat in elite taekwondo athletes before and after competition rule changes. J Strength Cond Res 35(8): 2222-2229, 2021-We hypothesize that recent (2017) changes in competition rules significantly affected kinematic (mechanical activity) and physiological (cardiopulmonary indices and lactate concentration) profile of the taekwondo combat, which is currently becoming more demanding in terms of exercise intensity and fatigue. Twenty two male and female elite taekwondo athletes were followed up for over 2 years. In total, 258 real tournament combats were included in the analysis (133 in old rules and 125 in new rules). Kinematic and physiological characteristics were recorded using a biomonitor (BioHarness 3; Zephyr Technologies) worn by athletes during tournaments. Blood samples were drawn after each combat for lactate concentration. Our research showed that recent amendments of competition rules were linked to a noticeable shift toward higher kinematic output and, consequently, increased physiological response. Significant increments in kinematic variables (3-8%), heart rate (HR) (1.5-1.8%), energy expenditure (EE) (3-5%), overall physiological load (2-4%), and lactate concentration (∼15% immediately after exercise and ∼25% in recovery) suggest that new rules are more demanding, although the statistical effect size is only small or moderate. In conclusion, after competition rule changes, there has been a shift in taekwondo combat profile toward greater body movement dynamics, higher intensity, and greater postexercise fatigue. The values of key indices of exercise response (mechanical activity, HR, EE, and lactate concentration) during tournaments are near or exceeding the maximum attained during progressive exercise until exhaustion. Therefore, more focus is needed on taekwondo-specific high-intensity training and postcombat recovery to adapt athletes to increased competition requirements.

Effects of Functional Fitness Enhancement through Taekwondo Training on Physical Characteristics and Risk Factors of Dementia in Elderly Women with Depression

The purpose of this research is to identify the correlations between functional fitness enhancement through a long-term Taekwondo training program and the physical characteristics and risk factors of dementia among elderly women with depression. The study has found that conducting three 60-min Taekwondo training sessions a week for the duration of 12 weeks has enhanced a number of functional fitness indexes, including hand grip strength/weight (p < 0.01), 4-m gait speed (p < 0.001), 3-m timed up and go (p < 0.05), and figure-of-eight track (p < 0.05), and significantly improved general health condition indexes as well, including percent fat (p < 0.05), appendicular skeletal muscle mass index (p < 0.01), systolic blood pressure (p < 0.01), and diastolic blood pressure (p < 0.001). Furthermore, the arteriosclerosis index and cognitive function have been found to be improved with an increase of brain-derived neurotrophic factor (BDNF; which prevents dementia) and a significant decrease of β-amyloid—a risk factor of dementia—as a result of enhancements in serum lipids and adiponectin, confirming the positive effects of functional fitness enhancement on fighting depression, promoting physical characteristics, and reducing the risk factors of dementia.

Validity of an Interval Taekwondo-Specific Cardiopulmonary Exercise Test

ABSTRACT

Araujo, MP, Soares, PP, Hausen, MR, Julio, HS, Porto, F, and Gurgel, JL. Validity of an interval taekwondo-specific cardiopulmonary exercise test. J Strength Cond Res 35(7): 1956-1963, 2021-The objective of this study is to propose and validate an interval taekwondo-specific cardiopulmonary exercise test (ITKDtest) and compare it with running cardiopulmonary exercise test (CPET) and a continuous taekwondo-specific cardiopulmonary exercise test (CTKDtest). Fifteen athletes (age 22 ± 4 years; body mass 71.1 ± 10.2 kg; height 178.14 ± 8.3 cm; and body mass index 22.4 ± 2.4 kg·m-2) performed CPET, CTKDtest, and ITKDtest on a counterbalanced order. Oxygen uptake (V̇o2), heart rate (HR), and ventilatory thresholds (VTs 1 and 2) were measured during the 3 tests. ITKDtest started at 30 kicks per minute and increased 10 kicks each 2 minutes, with a period of passive recovery, lasting 1 minute. Interval protocol design simulated the temporal structure of an official taekwondo fight. Significant difference between specific tests was found for V̇o2 VT1 (p = 0.03), V̇o2 VT1 (%V̇o2peak) (p = 0.009), V̇o2 VT2 (p = 0.005), and V̇o2 VT2 (%V̇o2peak) (p = 0.013). Reliability was considered "excellent" for V̇o2peak (α = 0.902; SEM = 0.179), "good" for V̇o2 VT1 (α = 0.708; SEM = 3.823) and HRpeak (α = 0.803; SEM = 2.987), and "fair" for V̇o2 VT2 (α = 0.659; SEM = 4.498) and HR VT2 (α = 0.580; SEM = 8.868). Bland-Altman analyses reported a mean difference of 2.9 ± 6.6 ml·kg-1·min-1 (CPET-ITKDtest) and 1.4 ± 6.1 ml·kg-1·min-1 (CTKDtest-ITKDtest). ITKDtest may be used for measurement of cardiorespiratory variables commonly used in exercise prescription, whereas CTKDtest seems to be a more appropriate method to assess V̇o2 and HR at VTs.

The Impact of Age, Gender and Technical Experience on Three Motor Coordination Skills in Children Practicing Taekwondo

The study aim was to investigate the age, gender and technical level on motor coordination abilities of Taekwondo children. One hundred and fifteen children (83 male, 32 female), aged 7.76 ± 1.71 years, divided in three different groups, under 8 (5–7 years), under 10 (8–9 years) and under 12 (10–11 years), underwent three coordination skills tests: the ruler drop test (RDT), assessing visual reaction time, the hexagonal test (HT), assessing agility, and the target kick test (TKT), assessing kicking ability. MANOVA showed significant gender differences for TKT, in which females showed higher scores than males (p = 0.033). Significant differences were found in HT and TKT, where the under 12 group showed higher scores than younger athletes (p < 0.001). No differences amongst different age groups were found in RDT, showing that this could be a good predictor of Taekwondo performance, assessed at an early stage. High-level athletes showed better scores in all the tests than the low levels, as it was expected. Coordinative performance improves with age and is positively influenced by practicing a sports activity. The predisposition to a particular sport with a well-planned training may lead to a motor proficiency comparable to that reached by older athletes and better than same-age athletes.

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.

Effects of Regular Taekwondo Intervention on Health-Related Physical Fitness, Cardiovascular Disease Risk Factors and Epicardial Adipose Tissue in Elderly Women with Hypertension

Regular exercise has been proven to prevent hypertension and to help in the management of hypertension. There is a lack of studies examining changes in these issues as a result of Taekwondo training intervention. The aim of the current trial is to identify the effects of a regular Taekwondo (TKD) training program on health-related physical fitness (HRPF), cardiovascular disease (CVD) risk factors, inflammatory factors, and epicardial adipose tissue (EAT) in elderly women with hypertension. To accomplish this, 20 participants, who were older women with hypertension, were divided into a TKD group (n = 10) and a control group (n = 10). The TKD program was conducted in program for 90 min, three times a week, for 12 weeks. Outcomes, including body composition, blood pressure (BP), HRPF, cardiovascular risk factor and EAT, were measured before and after the Taekwondo program. The 12-week TKD program improved body composition, BP, HRPF, CVD risk factor, and EAT in elderly women with hypertension relative to controls. Meanwhile, EAT and interukin-1β (r = 0.530, p < 0.05), monocyte chemotactic protein-1 (r = 0.524, p < 0.05), triglyceride (r = 0.493, p < 0.05) and sedentary behavior (r = 0.459, p < 0.05) presented a positive correlation, while EAT and lean body mass (r = -0.453, p < 0.05) showed a negative correlation. The 12-week regular TKD training intervention was found to be effective in reducing the thickness of EAT measured by multi-detector computed tomography and can also enhance health-related physical fitness and risk factors of CVD in older individuals with hypertension.

[Analysis of muscle injuries and return-to-training in elite Taekwondo athletes: results of a prospective cohort study over a period of five years]

BACKGROUND

 Muscle injuries frequently occur in sports involving explosive movement patterns, and they can cause considerable downtime. There is a lack of detailed data on muscle injuries in Olympic elite Taekwondo.

METHODS

 All injuries sustained by 76 elite Taekwondo athletes from a national Olympic training centre during training and competition were prospectively recorded over a period of five years. Data on muscle injuries, including location and time elapsed until return-to-training, were extracted from medical records. Injuries were diagnosed by means of MRI and were classified according to the British Athletes Muscle Injury System. The relationship between MRI classification subgroups and time elapsed until return-to-training was assessed.

RESULTS

 Mean age of athletes was 22.5 ± 3.2 (16-27) years with an average Taekwondo experience of 12.1 ± 4.0 (7-20) years. Hamstring muscles were most commonly injured (48.4 %), followed by quadriceps muscles (32.3 %) and calf muscles (9.6 %). The analysis of MRI injury subgroups showed grade 1 (32.2 %) and grade 2 (41.9 %) injuries in most cases. A positive correlation was found between injury groups and return-to-training (r = 0.56). The comparison between different injury groups and time elapsed until return-to-training also revealed significant differences (p < 0.0001).

CONCLUSION

 Hamstring muscles are the most injured muscles in Taekwondo besides the quadriceps femoris muscle. Most injuries were mild to moderate (grade 1-2). The time needed for return-to-training increased significantly with the severity of injuries diagnosed by MRI.

High Incidence of Hand Injuries From Blocking in Elite Taekwondo Despite the Use of Protective Gear: A 5-Year Descriptive Epidemiology Study

Background

Hand and wrist injuries are a common but underestimated issue in taekwondo. Detailed data on injury risk, patterns, and mechanism are missing.

Purpose

To evaluate (1) the fight time exposure-adjusted injury incidence rate (IIR) and clinical incidence and (2) injury site, type, sport-specific mechanism, and time loss in taekwondo.

Study Design

Descriptive epidemiology study.

Methods

Athletes from a single national Olympic taekwondo training center were investigated prospectively for hand and wrist injuries during training and competition over 5 years. The Orchard Sports Injury Classification System Version 10 was used to classify injury type, and analysis of the anatomic injury site was performed. The mechanism of injury was classified as due to either striking or blocking techniques.

Results

From a total of 107 athletes, 79 athletes (73.8%) with a total exposure time of 8495 hours were included in the final data set. During the study period, 75 injuries of the hand and wrist region were recorded despite the athletes using protective hand gear. The IIR was 13.9 (95% CI, 10.5-17.5) and was significantly higher during competition. The clinical incidence as an indicator for risk of injury was 60.7% (95% CI, 50.9-70.5). Finger rays were the most affected location (68%), and fractures (43%) and joint ligament injuries (35%) were the most common type of injury. Significantly more injuries were found on the dominant hand side (P < .001). Comparison of injury mechanisms demonstrated significantly more injuries at the finger rays deriving from blocking techniques (P = .0104). The mean time loss for all hand and wrist injuries was 15.7 ± 13.5 days (range, 3-45 days) and was highest for distal radial fractures, with a mean of 39.7 ± 4.8 days (range, 32-45 days).

Conclusion

There was a significantly higher IIR for acute hand and wrist injuries in elite taekwondo athletes during competition, which resulted in considerable time loss, especially when fractures or dislocations occurred. Significantly more injuries to the finger rays were found during blocking despite the use of protective hand gear. Improvement of tactical skills and blocking techniques during training and improved protective gear appear to be essential for injury prevention.

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.

The effects of instrument-assisted soft tissue mobilization rehabilitation exercise on range of motion, isokinetic strength, and balance in chronic ankle instability taekwondo players

We aimed to investigate change the instrument-assisted soft tissue mobilization (IASTM) rehabilitation exercise on range of motion (ROM), isokinetic ankle strength, and balance. We included 20 elite taekwondo players (chronic ankle instability) in Korea. They were divided into the IASTM group (n=10), control group (n=10). IASTM group were exercised with IASTM rehabilitation exercise four times per week for 8 weeks. The remaining control group did not receive exercise intervention between tests and served as the control. A goniometer was used to measure dorsi-flexion (D/F), plantar-flexion (P/F), a dynamometer was used to measure ankle isokinetic strength, and plantar foot pressure was used to measure static balance. The data were analyzed using repeated-measures analysis of variance. Significant differences were observed between the two groups in IASTM group and control group: ROM (right P/F, P<0.001; right D/F, P<0.01; left P/F, P<0.000; left D/F, P<0.000), isokinetic strength (right P/F 60°, P<0.000; right D/F 60°, P<0.000; left P/F 60°, P<0.000; left D/F 60°, P<0.000; right P/F 180°, P<0.000; right D/F 180°, P<0.000; left: P/F 180°, P<0.000, left D/F 180°, P<0.000), and balance test (static eye open, P<0.000; static eye close, P<0.000; postural stability, P<0.041). These results suggest that IASTM rehabilitation exercise improves ankle stability, muscle power, and body balance in chronic ankle instability taekwondo players.

Changes in the Hormonal Profile of Athletes following a Combat Sports Performance

Results

Following fighting, the adrenaline concentration was significantly higher in all athletes, most markedly in K (p < 0.001). Baseline cortisol and BDNF levels did not differ among the groups and rose significantly in all the groups after the performance. Baseline testosterone concentration was slightly higher in K than in JSW and rose in all the groups to reach similar levels; the increase in T was significantly higher than in K.

Conclusions

Despite substantial differences in the characteristics of the combat sports investigated, including the type of physical effort and the required balance between restraint and aggression, the performance in each of them gives rise to similar hormonal changes with a possible exception of karate showing higher stress hormone levels.

Differences in Fat Mass Estimation Formulas in Physically Active Adult Population and Relationship with Sums of Skinfolds

Changes in body composition and specifically fat mass, has traditionally been used as a way to monitor the changes produced by nutrition and training. The objective of the present study was to analyse the differences between the formulas used to estimate fat mass and to establish the existing relationship with the body mass index and sums of skinfolds measurement in kinanthropometry. A total of 2458 active adults participated in the study. Body mass index (BMI) and skinfolds were measured, and the Kerr, Durnin-Womersley, Faulkner and Carter equations were used to assess fat mass. Significant differences were found between all the formulas for the percentage of fat mass, ranging from 10.70 ± 2.48 to 28.43 ± 5.99% (p < 0.001) and fat mass from 7.56 ± 2.13 to 19.89 ± 4.24 kg (p < 0.001). The correlations among sums of skinfolds and the different equations were positive, high and significant in all the cases (r from 0.705 to 0.926 p < 0.001), unlike in the case of BMI, were the correlation was lower and both positive or negative (r from -0.271 to 0.719; p < 0.001). In conclusion, there were differences between all the formulas used to estimate fat mass; thus, for the evaluation of fat mass with kinanthropometry of an active adult, the use of the same formula is recommended on all occasions when the results are going to be compared or when an athlete is compared with a reference.

Allometric Modeling of Wingate Test among Adult Male Athletes from Combat Sports

Background and objectives: Athletes from combat sports are grouped into a series of weight categories that are intended to promote fair competition. Differences in performance are partly attributable to differences in body size. Consequently, ratio standards in which a performance variable is simply divided by an anthropometric characteristic such as body mass are often used, although this application is not recommended. This study aimed to obtain allometric models to interpret Wingate Anaerobic Test (WAnT) outputs among male adult athletes from combat sports. Materials and Methods: The sample was composed of 64 participants aged 18–39 years (24.2 ± 4.6 years). Stature and body mass (BM) were measured and air displacement plethysmography used to estimate fat mass and fat-free mass (FFM). Lower-limb lean soft tissue (LL-LST) was derived from dual energy X-ray absorptiometry. WAnT outputs were peak power (WAnT-PP) and mean power (WAnT-MP). Allometric models were obtained from simple and multiple linear regressions using log-transformed variables. Results: Models derived from a single three-dimension descriptor explained a large portion of variance: WAnT-PP (BM: 31.1%; FFM: 54%; LL-LST: 47.2%) and WAnT-MP (BM: 50.1%; FFM: 57.4%; LL-LST: 62.7%). Finally, the best proportional allometric models emerged from the combination of LL-LST and FFM (WAnT-PP: 55%; WAnT-MP: 65%). Conclusions: The relationship between weight categories and performance did not seem to be explained by the basic principles of geometric similarity.

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.

Psycho-physiological aspects of small combats in taekwondo: impact of area size and within-round sparring partners

The study investigated physiological and psychological responses to taekwondo combat sessions as a function of different area sizes and within-round sparring partners. Twenty-four adolescent (age: 17 ± 1years) male (n = 12) and female (n = 12) taekwondo athletes participated in the study. Each athlete confronted 1 (1vs.1; no sparring partner change) or 2 (1vs.2; within-round sparring partner change every minute) opponents in different area sizes (i.e., 4 × 4 m, 6 × 6 m, and 8 × 8 m) for 2 min. Blood lactate concentration ([La]) was measured before and after bouts. Heart rate (HR) was measured throughout the contests and rating of perceived exertion was assessed after bouts. Mean HR (HRmean) and percentage of maximum HR (%HRmax) determined during a 20-m multistage shuttle run test were used for analysis. Mood states were assessed before and after bouts and physical enjoyment was analyzed after bouts. The results showed higher HRmean and %HRmax values for the 1vs.1 compared to the 1vs.2 condition (p < 0.001) and [La] values were higher at post-combat measurements (p < 0.001). Moreover, tension and fatigue were higher in 6 × 6 m compared with 8 × 8 m (p = 0.022 and p = 0.023, respectively) and anger was higher in 6 × 6 m and 8 × 8 m in comparison with 4 × 4 m (p = 0.012 and p = 0.043, respectively). Confusion increased from before to after bouts (p < 0.001), from 4 × 4 m and 6 × 6 m area sizes to 8 × 8 m (p = 0.001 and p = 0.018, respectively), and from 1vs.1 to 1vs.2 (p < 0.001). Furthermore, vigour decreased from before to after bouts (p < 0.01). Taekwondo combat sessions are a specific conditioning exercise for athletes. Thus, coaches can use the 1vs.1 condition to elicit higher HR responses and 6 × 6 m area size to induce higher psychological stress, mimicking what occurs during a competition.

Effects of High-Intensity Interval Training in Hypoxia on Taekwondo Performance

PURPOSE

To evaluate the effects of a 6-week taekwondo-specific high-intensity interval training (HIIT) in simulated normobaric hypoxia on physical fitness and performance in taekwondoists.

METHODS

Eighteen male and female black-belt taekwondoists trained twice a week for 6 weeks in normoxia or in hypoxia (FiO2 = 0.143 O2). The HIIT was composed of specific taekwondo movements and simulated fights. Body composition analyses and a frequency speed of kick test during 10 seconds (FSKT10s) and 5 × 10 seconds (FSKTmult), countermovement jump (CMJ) test, Wingate test, and an incremental treadmill test were performed before and after training. Blood lactate concentrations were measured after the FSKTmult and Wingate tests, and a fatigue index during the tests was calculated.

RESULTS

A training effect was found for FSKT10s (+35%, P < .001), FSKTmult (+32%, P < .001), and fatigue index (-48%, P = .002). A training effect was found for CMJ height (+5%, P = .003) during the CMJ test. After training, CMJ height increased in hypoxia only (+7%, P = .005). No effect was found for the parameters measured during Wingate test. For the incremental treadmill test, a training effect was found for peak oxygen consumption (P = .002), the latter being 10% lower after than before training in normoxia only (P = .002).

CONCLUSIONS

In black-belt taekwondoists, hypoxic HIIT twice a week for 6 weeks provides tiny additional gains on key performance parameters compared with normoxic HIIT. Whether the trivial effects reported here might be of physiological relevance to improve performance remains debatable and should be tested individually.

Physical, physiological and psychological profiles of elite Turkish taekwondo athletes

Study aim: To identify the physical, physiological and psychological profiles of elite Turkish taekwondo athletes.

Material and methods: Twelve players of the Turkish national taekwondo team (age = 22.7 ± 2.8 years, BMI = 22.2 ± 1.4 kg/m2, body fat = 12.8 ± 3.4%) participated in the study. Anthropometric measurements including leg length and foot size were assessed. Maximal oxygen uptake, explosive power of leg extensors, isokinetic peak torque, muscular endurance, anaerobic power, agility, flexibility, maximal speed, reaction time, and postural balance were examined by incremental treadmill running, vertical jump, isokinetic strength, sit-ups and push-ups, Wingate, shuttle run, sit-and-reach, 30-meter sprint, multiple-choice reaction time, and General Postural Stability and Athlete Single Leg stability tests, respectively. Psychological characteristics including mental skills and mood states were evaluated using OMSAT-3 and POMS tests.

Results: VO2max, isokinetic peak torque and Wingate test mean power values were 54.1 ± 4.4 mL ∙ kg−1 ∙ min−1, 191.7 ± 19.2 N ∙ m, and 9 ± 0.7 W/kg, respectively. Postural stability index 0.18 ± 0.06, single leg stability index 0.82 ± 0.11, reaction time 0.344 ± 0.032 s, 10 × 5-m shuttle run 17.09 ± 0.68 s, 30-meter sprint 4.60 ± 0.23 s, and vertical jump 43.5 ± 6.1 cm were the other values reported. The highest scores for the 12 mental skills in OMSAT-3 were for goal setting (6.25 ± 0.45) and self-confidence (6.16 ± 0.45). The lowest score was for Imagery (5.64 ± 0.36). The results of six mood states of POMS showed higher scores on the Vigor-activity, Anger-Hostility and Tension-Anxiety scales and lower scores on Depression-Dejection, Fatigue-Inertia and Confusion-Bewilderment than norms.

Conclusions: The findings of this study revealed the physical, physiological, and psychological characteristics in taekwondo. The results of the tests could be useful for performance assessment of taekwondo players.

Transcranial Direct Current Stimulation: No Effect on Aerobic Performance, Heart Rate, or Rating of Perceived Exertion in a Progressive Taekwondo-Specific Test

PURPOSE

To investigate the effects of anodal transcranial direct current stimulation (a-tDCS) on the aerobic performance, heart rate (HR), and rating of perceived exertion (RPE) of highly trained taekwondo athletes.

METHODS

Twelve (8 men and 4 women) international/national-level athletes received a-tDCS or sham treatment over the M1 location in a randomized, single-blind crossover design. The stimulation was delivered at 1.5 mA for 15 min using an extracephalic bihemispheric montage. Athletes performed the progressive-specific taekwondo test 10 min after stimulation. HR was monitored continuously during the test, and RPE was registered at the end of each stage and at test cessation.

RESULTS

There were no significant differences between sham and a-tDCS in time to exhaustion (14.6 and 14.9, respectively, P = .53, effect size = 0.15) and peak kicking frequency (52 and 53.6, respectively, P = .53, effect size = 0.15) or in HR (P > .05) and RPE responses (P > .05).

CONCLUSIONS

Extracephalic bihemispheric a-tDCS over M1 did not influence the aerobic performance of taekwondo athletes or their psychophysiological responses, so athletes and staff should be cautious when using it in a direct-to-consumer manner.

High-Intensity Interval Training Prescription for Combat-Sport Athletes

CONTEXT

Combat sports are composed of high-intensity actions (eg, attacks, defensive actions, and counterattacks in both grappling and striking situations depending on the specific sport) interspersed with low-intensity actions (eg, displacement without contact, stepping) or pauses (eg, referee stoppages), characterizing an intermittent activity. Therefore, high-intensity interval training (HIIT) is at the essence of combat-sport-specific training and is used as complementary training, as well. HIIT prescription can be improved by using intensity parameters derived from combat-sport-specific tests. Specifically, the assessment of physiological indexes (intensity associated with the maximal blood lactate steady state, maximal oxygen consumption, and maximal sprint) or of time-motion variables (high-intensity actions, low-intensity actions, and effort:pause ratio) is a key element for a better HIIT prescription because these parameters provide an individualization of the training loads imposed on these athletes.

PURPOSE

To present a proposal for HIIT prescription for combat-sport athletes, exemplifying with different HIIT protocols (HIIT short intervals, HIIT long intervals, repeated-sprint training, and sprint interval training) using combat-sport-specific actions and the parameters for the individualization of these protocols.

CONCLUSIONS

The use of combat-sport-specific tests is likely to improve HIIT prescription, allowing coaches and strength and conditioning professionals to elaborate HIIT short intervals, HIIT long intervals, repeated-sprint training, and sprint interval training protocols using combat-sport actions, providing more specificity and individualization for the training sessions.

Repeated Sprint Training vs. Repeated High-Intensity Technique Training in Adolescent Taekwondo Athletes-A Randomized Controlled Trial

This study investigated the effects of 4-weeks repeated sprint (RST) vs. repeated high-intensity-technique training (RTT) on physical performance. Thirty-six adolescent taekwondo athletes (age: 16 ± 1 yrs) were randomly assigned to RST (10 × 35 m sprint, 10 s rest), RTT (10 × 6 s Bandal-tchagui, 10 s rest) and control (control group (CG): no additional training) groups. Additionally, to their regular training, RST and RTT trained 2×/week for 4 weeks. Training load (TL), monotony, and strain were calculated using the rating of perceived exertion scale. The progressive specific taekwondo (PSTT), 20 m multistage shuttle run (SRT_20m), 5 m shuttle run, agility T-test, taekwondo-specific agility (TSAT) and countermovement jump (CMJ) tests were performed before and after 4 weeks of training. Additionally, taekwondo athletes performed specific taekwondo exercises (i.e., repeated techniques for 10 s and 1 min). From week 1, mean TL increased continuously to week 4 and monotony and strain were higher at weeks 3 and 4 (p < 0.001). VO_2max calculated from SRT_20m and PSTT increased for RST and RTT in comparison to CG (p < 0.001). Agility performance during T-test and TSAT (p < 0.01) improved in RTT. The number of performed techniques during the 10 s specific exercise increased in RTT and RST (p < 0.01) for the dominant leg and in RTT for the non-dominant leg (p < 0.01). The number of techniques during the 1 min specific exercise was higher in RST and RTT compared to CG for the dominant leg (p < 0.001). Delta lactate at post-training was lower for RTT for both legs compared to RST and CG (p < 0.01). It is important to include a low-volume high-intensity training based on repeated sprint running or repeated technique in the training programs of adolescent taekwondo athletes.

Hamstring extensibility differences among elite adolescent and young dancers of different dance styles and non-dancers

Background

Hamstrings have been analyzed extensively due to their tendency to shorten and their effect in the lumbo-pelvic dynamics and the sagittal position of the spine in trunk flexion with extended knees positions. It has been demonstrated that practicing a certain sport results in long-term changes in hamstring extensibility. Despite this, adequate extensibility of the hamstring musculature is essential for the dancer’s performance. Several studies have found differences in the extensibility of the hamstrings depending on the dance style, but none have compared ballet, Spanish dance and modern dance. The purpose of the present research was to analyze the differences in hamstring extensibility among professional dance students based on dance style practiced and non-dancers.

Methods

The sample was comprised of 210 students from the Professional Dance Conservatory (70 for ballet, 70 for Spanish dance and 70 for modern dance) and 70 non-dancers. For the assessment of hamstring extensibility, the angle in the passive and active straight leg raise (PSLR and ASLR, respectively) test, and the scores of the pelvic tilt in sit-and-reach (SR) test and the toe-touch (TT) test were randomly conducted.

Results

The results showed significant differences for all the tests according to group (p < 0.001). In the PSLR and ASLR test, for both legs, and in the pelvic tilt in the SR test, the ballet dancers showed greater ranges of hamstring extensibility than the modern dancers and Spanish dancers (p ≤ 0.001). In the distance in the SR test and in the pelvic tilt in the TT test, the ballet dancers obtained higher values than the Spanish dancers (p = 0.004 and p = 0.003, respectively). The modern dancers showed higher ranges of hip flexion than the Spanish dancers in the ASLR test for both legs and in the pelvic tilt in the SR test (p from 0.007 to <0.001). Dancers showed significantly higher hamstring extensibility than non-dancers in all the tests (p < 0.001).

Conclusions

The systematic practice of dance, regardless of the style, seems to lead to high ranges of hamstring extensibility. Ballet dancers have the greatest hamstring extensibility.

Sport Medicine in the Prevention and Management of Cancer

Physical inactivity is a major concern in cancer patients despite the established preventative and therapeutic effects of regular physical exercise for this patient group. Sport not only plays an important role in supporting the development and maintenance of a physically active lifestyle but also is increasingly used as a health promotion activity in various populations. Nevertheless, the potential of sport as an effective strategy in the prevention and management of cancer has gained little attention. Based on the scant evidence to date, participation of cancer patients in supervised, well-tailored sport programs appears to be safe and feasible and is associated with an array of physical and psychological benefits. We propose that sport participation may serve as an alternative strategy in the prevention of cancer and sport medicine in the management of cancer. As with the traditional exercise modes, benefits derived from sport participation will be dependent on the sport undertaken and the physical/physiological, motor, and cognitive demands required. To this end, further work is required to develop a solid evidence base in this field so that targeted sport participation can be recommended for cancer patients.

Taekwondo Anaerobic Intermittent Kick Test: Discriminant Validity and an Update with the Gold-Standard Wingate Test

The aim of this study was to update the validity of the Taekwondo Anaerobic Intermittent Kick Test compared with the 30-s Wingate anaerobic test as the "Gold-Standard", squat jump and countermovement jump tests. The second objective was to examine whether this new specific test would be able to effectively discriminate between elite taekwondo athletes of different competitive levels. Twenty taekwondo athletes (15 males and 5 females) participated in the validation component, whereas 18 (14 males and 4 females) and 16 (13 males and 3 females) athletes participated in the reliability analysis of the Wingate anaerobic test and jumping tests, respectively. They performed these tests on two separate occasions (i.e., test-retest), in addition to the Taekwondo Anaerobic Intermittent Kick Test. To establish test’s discriminatory capability (i.e., construct validity), two subgroups were identified based on their international and national taekwondo performance: 10 elite (8 males and 2 females) and 9 sub-elite (7 males and 2 females) athletes. Wingate anaerobic test and jumping tests performances showed excellent reliability (ICC > 0.90, SEM < 5% for most variables). Significant correlations between Taekwondo Anaerobic Intermittent Kick Test, Wingate anaerobic test, and jumping tests’ variables were mostly "large". Elite taekwondo athletes showed greater taekwondo test performances compared with their sub-elite counterparts (p < 0.001). Receiving operating characteristic analysis indicated that the taekwondo specific test was able to effectively discriminate between elite and sub-elite taekwondo athletes. Overall, the findings of the current study support the concurrent validity of the Taekwondo Anaerobic Intermittent Kick Test. In particular, the Taekwondo Anaerobic Intermittent Kick Test showed good ability to effectively discriminate between taekwondo athletes of different competitive levels.

Absolute and Relative Strength, Power and Physiological Characteristics of Indian Junior National-Level Judokas

The physical qualities that underpin successful junior judokas requires continuing investigation. We investigated the physical and physiological characteristics of junior national level judokas. We tested 25 (15 male, 10 female) Indian judokas for absolute and relative strength (back-squat and bench-press one-repetition maximum (1RM) as well as isometric handgrip), aerobic (RAMP test) and lower-body anaerobic power (Wingate 6-s sprint and countermovement jump), change-of-direction (5-0-5 test) and speed (30 m sprint). Athletes were grouped according to national-level competition placing (gold-medal winners (GM; n = 8), all medal winners (MW; n = 13), non-medallists (NM; n = 12), and NM plus silver and bronze; all others (AO; n = 17)). Stepwise discriminant function analysis determined characteristics likely to predict successful performance. Independent t-tests and effect size (Hedge’s g) analyses were performed between groups. GM demonstrated greater lower-body absolute (20.0%; g = 0.87, p = 0.046) and relative 1RM strength (21.0%; g = 0.87, p = 0.047), and greater lower-body absolute (25.4%; g=1.32, p=0.004) and relative (27.3%; g = 1.27, p = 0.005) anaerobic power compared to AO. Furthermore, anaerobic power can correctly predict 76.5% and 62.5% of AO and GM athletes, respectively. No differences were observed between MW and NM groups. The results suggest the importance of lower-body strength and power for junior national-level judokas and provides information for professionals working with these athletes.

Differences between anthropometric indicators and the impact force of taekwondo kicks performed with the dominant and non-dominant limb

Study aim: Taekwondo is known for its very dynamic sports fighting, in which the athletes perform strikes mainly with their lower limbs. The aim of the study was to compare the differences between the impact force of strikes performed with the dominant and non-dominant limbs and its correlation with anthropometric indicators.

Material and methods: Six elite Olympic taekwondo players took part in the research (20.0 ± 3.2 years, 185.0 ± 8.5 cm, 75.3 ± 10.9 kg). Body composition including body mass, percent of body fat (FATP), fat mass (FATM), fat-free mass (FFM) and muscle mass (MM) was determined by bioelectric impedance analysis. Maximal strike impact force (Fmax) and Fmax relative to FFM (Fmax · FFM−1) of roundhouse kick (dollyo chagi) and side kick (yop chagi) were measured using a dynamometric punching bag with an embedded accelerometer.

Results: We found significant differences between the dominant limb (DL) and non-dominant limb (NL) in anthropometric analysis: FATP was 10.52 ± 5.38 % and 11.32 ± 4.83 %, FFM was 11.87 ± 0.97 kg and 11.43 ± 1.09 kg, MM was 11.25 ± 0.92 kg and 10.82 ± 1.02 kg for DL and NL respectively. In dollyo chagi Fmax and Fmax · FFM−1 were higher for DL than NL and were 2733 ± 748 N and 2206 ± 778 N, 41.34 ± 8.16 N · kg−1 and 33.29 ± 9.02 N · kg–1 respectively. Yop chagi has a lower impact force compared to dollyo chagi. Fmax and Fmax · FFM−1 for DL and NL were 1763 ± 303 N and 1779 ± 372 N, 26.76 ± 3.07 N · kg−1 and 26.9 ± 3.57 N · kg–1 respectively. We found a significant correlation between Fmax in yop chagi and FFM (R = 0.83, p < 0.05).

Conclusions: Athletes should fight using a stance where the dominant limb is moved further away from the target in order to strike with maximum force.

Caffeine Supplementation Improves Anaerobic Performance and Neuromuscular Efficiency and Fatigue in Olympic-Level Boxers

BACKGROUND

this study examined the effects of caffeine supplementation on anaerobic performance, neuromuscular efficiency and upper and lower extremities fatigue in Olympic-level boxers.

METHODS

Eight male athletes, members of the Spanish National Olympic Team, were enrolled in the study. In a randomized double-blind, placebo-controlled, counterbalanced, crossover design, the athletes completed 2 test sessions after the intake of caffeine (6 mg·kg^-1) or placebo. Sessions involved initial measures of lactate, handgrip and countermovement jump (CMJ) performance, followed by a 30-seconds Wingate test, and then final measures of the previous variables. During the sessions, electromiography (EMG) data were recorded on the gluteus maximus, biceps femoris, vastus lateralis, gastrocnemius lateral head and tibialis anterior.

RESULTS

caffeine enhanced peak power (6.27%, p < 0.01; Effect Size (ES) = 1.26), mean power (5.21%; p < 0.01; ES = 1.29) and reduced the time needed to reach peak power (-9.91%, p < 0.01; ES = 0.58) in the Wingate test, improved jump height in the CMJ (+2.4 cm, p < 0.01), and improved neuromuscular efficiency at peak power in the vastus lateralis (ES = 1.01) and gluteus maximus (ES = 0.89), and mean power in the vastus lateralis (ES = 0.95) and tibialis anterior (ES = 0.83).

CONCLUSIONS

in these Olympic-level boxers, caffeine supplementation improved anaerobic performance without affecting EMG activity and fatigue levels in the lower limbs. Further benefits observed were enhanced neuromuscular efficiency in some muscles and improved reaction speed.

The A-allele of the FTO Gene rs9939609 Polymorphism Is Associated With Decreased Proportion of Slow Oxidative Muscle Fibers and Over-represented in Heavier Athletes

Guilherme, JPLF, Egorova, ES, Semenova, EA, Kostryukova, ES, Kulemin, NA, Borisov, OV, Khabibova, SA, Larin, AK, Ospanova, EA, Pavlenko, AV, Lyubaeva, EV, Popov, DV, Lysenko, EA, Vepkhvadze, TF, Lednev, EM, Govorun, VM, Generozov, EV, Ahmetov, II, and Lancha Junior, AH. The A-allele of the FTO gene rs9939609 polymorphism is associated with decreased proportion of slow oxidative muscle fibers and over-represented in heavier athletes. J Strength Cond Res 33(3): 691-700, 2019-The purpose of this study was to explore the frequency of the FTO T > A (rs9939609) polymorphism in elite athletes from 2 cohorts (Brazil and Russia), as well as to find a relationship between FTO genotypes and muscle fiber composition. A total of 677 athletes and 652 nonathletes were evaluated in the Brazilian cohort, whereas a total of 920 athletes and 754 nonathletes were evaluated in the Russian cohort. It was found a trend for a lower frequency of A/A genotype in long-distance athletes compared with nonathletes (odds ratio [OR]: 0.65; p = 0.054). By contrast, it was found an increased frequency of the A-allele in Russian power athletes. The presence of the T/A + A/A genotypes rather than T/T increased the OR of being a Russian power athlete compared with matched nonathletes (OR: 1.45; p = 0.002). Different from that observed in combat sports athletes of lighter weight categories, the A-allele was also over-represented in combat sports athletes of heavier weight categories. The presence of the T/A + A/A genotypes rather than T/T increased the OR of being a combat sports athlete of heavier weight categories compared with nonathletes (OR: 1.79; p = 0.018). Regarding the muscle fibers, we found that carriers of the A/A genotype had less slow-twitch muscle fibers than T-allele carriers (p = 0.029). In conclusion, the A/A genotype of the FTO T > A polymorphism is under-represented in athletes more reliant on a lean phenotype and associated with decreased proportion of slow-twitch muscle fibers, while is over-represented in strength and heavier athletes.

Use of the anaerobic speed reserve to normalize the prescription of high-intensity interval exercise intensity

The aim of this study was to compare the perceptual and physiological responses and time-to-exhaustion in high intensity interval exercise (HIIE) protocols that are prescribed based on the relative anaerobic speed reserve (ASR) or maximal aerobic speed (MAS) in athletes with different ASR values, as well as the coefficient of variation (CV) of the abovementioned variables. Eleven long-distance runners and ten rugby players were submitted to five experimental sessions on different days; the first and second session were intended for the determination of the anthropometry, MAS and maximal sprint (MSS). In the subsequent sessions, three HIIE_15:15s protocols were performed until exhaustion (110%MAS, Δ25%ASR, and Δ50%ASR) in random order. The anthropometric characteristics and variables obtained from the MAS and MSS tests in the different groups were compared by Student's unpaired t-test. The analysis of mixed models for repeated measures (groups and protocols) was used to compare the speed, delta blood lactate, rating of perceived exertion, and time-to-exhaustion. Rugby players presented higher ASR (13.6 ± 0.9 km h^-1) compared to long-distance runners (12.6 ± 0.9 km h^-1) (P = .049). For the HIIE_15:15s protocols, there were no protocol and group interaction effects. However, lower CV values were observed for time-to-exhaustion (a mean reduction of 52%) and delta blood lactate (a mean reduction of 48%) in Δ25%ASR and Δ50%ASR when compared to 110%MAS. Furthermore, the rating of perceived exertion CV was similar in all HIIE_15:15s protocols. The prescription of intensity of HIIE based on the ASR was able to reduce the inter-subject variability of lactate and time-to-exhaustion in rugby players and long-distance runners.

Identification of elite performance characteristics in a small sample of taekwondo athletes

Along with the increasing popularity of taekwondo, there is a need of evidence-based talent identification (TID) and development programs based upon profiles of future elite athletes. This study first aims to investigate the differences between elite and non-elite taekwondo athletes in anthropometry, physical performance and motor coordination. The second aim is to demonstrate the applicability of z-scores in TID research. A total of 98 Taekwondo athletes between 12 and 17 years old were tested using a generic test battery consisting of four anthropometrical (Height, Weight, Fat Percentage, BMI), six physical performance (Sit & Reach, Sprint 5m, Sprint 30m, Counter Movement Jump, Squat Jump, Endurance Shuttle Run) and three motor coordination tests (Moving Sideways, Jumping Sideways, Walking Backwards). Based on the individual success at international competition level, 18 were categorised as elite athletes and 80 were considered as non-elite. T-tests (step 1) on raw test scores and MANOVAs on z-scores (step 2) were conducted to examine differences between the elite and non-elite taekwondo athletes for anthropometry, physical performance and motor coordination tests. Finally, z-scores were reconverted to raw scores to demonstrate practical significance for coaches. Overall, elite taekwondo athletes score better compared to the non-elite group. The MANOVA analysis better scores for elites on fat percentage (-0.55 versus 0.12;p = 0.006), BMI (-0.37 versus 0,08;p = 0.067) sprint speed 30m (-0.48 versus 0.11;p = 0.029), counter movement jump (0.79 versus -0.18;p = 0.000), squat jump (0.42 versus -0.11;p = 0.041), moving sideways (0.79 versus -0.18;p = 0.000) and walking backwards (0.54 versus -0.12;p = 0.006). This study confirms our knowledge on physical profiles of elite taekwondo athletes and expands our knowledge to the domain of motor coordination. This study showed how the z-score method can be used to distinguish between elite and non-elite athletes, the former being low in number by definition.

Body composition of elite Olympic combat sport athletes

Physique traits of a range of elite athletes have been identified; however, few detailed investigations of Olympic combat sports (judo, wrestling, taekwondo and boxing) exist. This is surprising given the importance of body composition in weight category sports. We sought to develop a descriptive database of Olympic combat sport athletes, compare variables relative to weight division and examine differences within and between sports. Additionally, we investigated the appropriateness of athletes' self-selected weight classes compared to an internationally recognised classification system (the NCAA minimum wrestling weight scheme used to identify minimum 'safe' weight). Olympic combat sport athletes (56♂, 38♀) had body mass (BM), stretch stature and dual-energy X-ray absorptiometry derived body composition assessed within 7-21 days of competition. Most athletes were heavier than their weight division. Sport had an effect (p < .05) on several physique traits, including; lean mass, lean mass distribution, stretch stature and BMI. BM was strongly positively correlated (r > 0.6) with; fat free mass, fat mass and body fat percentage, however, was not predictive of total mass/weight division. The Olympic combat sports differ in competitive format and physiological requirements, which is partly reflected in athletes' physique traits. We provide reference ranges for lean and fat mass across a range of BM. Lighter athletes likely must utilise acute weight loss in order to make weight, whereas heavier athletes can potentially reduce fat mass.

Can Match-Mimicking Intermittent Practice Be Used as a Simulatory Training Mode of Competition Using Olympic Time Frame in Elite Taekwondo Athletes?

Aim: The physiological realities between Taekwondo (TKD) simulation kicking training and TKD competition according to the Olympic time frame remain unclear. The purpose of this study is to establish an Olympic match-simulated kicking model and compare its effects with real TKD competition on physiological challenges and hormonal responses during serial matches in elite athletes.

Method: Sixteen elite TKD athletes randomly were assigned into either a TKD match-simulated kicking group (TMSK; N = 8, age: 21.3 ± 0.2 years) or a simulated TKD competition group (STC; N = 8, age: 21.6 ± 0.5 years). Both groups performed either simulated kicking or TKD competitions in the same time-course order, and all physiological parameters and blood sampling time-points were identical between groups. The heart rate (HR) and rating of perceived exertion (RPE) were recorded during each match-simulated kicking and TKD competition session. Blood samples were obtained before competition (Pre-Comp.), after competition—in ths case meaning four consecutive matches (End-Comp.), and 24 h after the first match (Next day) for determination of biomarkers of muscle damage (myoglobin and CK), hematological profiles, and hormonal profiles (testosterone and cortisol).

Results: The responses of HR, RPE, and blood lactate levels during the consecutive testing sessions showed no differences between TMSK and STC. The changes in CK and myoglobin were greater in STC (p < 0.05), and a greater decrease in red blood cell (RBC) loss was observed in the STC group (p < 0.05). Compared with TMSK, the inflammatory state, reflected by the ratios of neutrophils-to-lymphocyte (NLR) and platelets-to-lymphocyte (PLR), was higher in STC (p < 0.05). Moreover, the catabolic state (cortisol/testosterone) was greater in STC than in TMSK (p < 0.05).

Conclusion: We demonstrated that, compared with TMSK, the STC produced greater muscle damage, inflammatory responses, and catabolic stress in the Olympic competition time frame in elite male TKD athletes. Although TMSK is capable of eliciting similar physiological challenges as TKD competition, the muscle damage and hormonal profiles provoked by TMSK were not comparable to TKD competition. Our findings provide science-based data and better understanding for coaches, athletes, and sports scientists to develop TKD-specific training programs for Olympic preparation.

Considerations When Assessing Endurance in Combat Sport Athletes

Combat sports encompass a range of sports, each involving physical combat between participants. Such sports are unique, with competitive success influenced by a diverse range of physical characteristics. Effectively identifying and evaluating each characteristic is essential for athletes and support staff alike. Previous research investigating the relationship between combat sports performance and measures of strength and power is robust. However, research investigating the relationship between combat sports performance and assessments of endurance is less conclusive. As a physical characteristic, endurance is complex and influenced by multiple factors including mechanical efficiency, maximal aerobic capacity, metabolic thresholds, and anaerobic capacities. To assess endurance of combat sports athletes, previous research has employed methods ranging from incremental exercise tests to circuits involving sports-specific techniques. These tests range in their ability to discern various physiological attributes or performance characteristics, with varying levels of accuracy and ecological validity. In fact, it is unclear how various physiological attributes influence combat sport endurance performance. Further, the sensitivity of sports specific skills in performance based tests is also unclear. When developing or utilizing tests to better understand an athletes' combat sports-specific endurance characteristic, it is important to consider what information the test will and will not provide. Additionally, it is important to determine which combination of performance and physiological assessments will provide the most comprehensive picture. Strengthening the understanding of assessing combat sport-specific endurance as a physiological process and as a performance metric will improve the quality of future research and help support staff effectively monitor their athlete's characteristics.

Acute caffeine supplementation in combat sports: a systematic review

Caffeine used as a supplement has been shown to improve physical and cognitive performance in several sport modalities due to its effects on the central nervous system. This review assesses the direct effects of caffeine supplementation on performance in combat sports. Using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines, relevant studies were identified through the Medline, Scopus and SPORTDiscus databases. Of 1053 search results, only 9 articles fulfilled the inclusion criteria. Of these, three studies detected no ergogenic effect of caffeine supplementation, while six studies did observe a significant positive effect. Supplementation with 3-6 mg/kg of caffeine was found to increase the glycolytic contribution to energy metabolism during the execution of real or simulated combats, as indicated by elevated blood lactate concentrations. Caffeine intake was also noted to improve levels of strength, power and upper arm muscular endurance. These effects were not paralleled by an increase in the exertion perceived by the athlete.

Anthropometric and Physical Qualities of Elite Male Youth Rugby League Players

Rugby league is a collision team sport played at junior and senior levels worldwide, whereby players require highly developed anthropometric and physical qualities (i.e. speed, change-of-direction speed, aerobic capacity, muscular strength and power). Within junior levels, professional clubs and national governing bodies implement talent identification and development programmes to support the development of youth (i.e. 13-20 years) rugby league players into professional athletes. This review presents and critically appraises the anthropometric and physical qualities of elite male youth rugby league players aged between 13 and 20 years, by age category, playing standard and playing position. Height, body mass, body composition, linear speed, change-of-direction speed, aerobic capacity, muscular strength and power characteristics are presented and demonstrate that qualities develop with age and differentiate between playing standard and playing position. This highlights the importance of anthropometric and physical qualities for the identification and development of youth rugby league players. However, factors such as maturity status, variability in development, longitudinal monitoring and career attainment should be considered to help understand, identify and develop the physical qualities of youth players. Further extensive research is required into the anthropometric and physical qualities of youth rugby league players, specifically considering national standardised testing batteries, links between physical qualities and match performance, together with intervention studies, to inform the physical development of youth rugby league players for talent identification and development purposes.

Validity and Reliability of a New Test of Planned Agility in Elite Taekwondo Athletes

Chaabene, H, Negra, Y, Capranica, L, Bouguezzi, R, Hachana, Y, Rouahi, MA, and Mkaouer, B. Validity and reliability of a new test of planned agility in elite taekwondo athletes. J Strength Cond Res 32(9): 2542-2547, 2018-This study aimed to examine the validity, reliability, and sensitivity of a new test of planned agility in elite taekwondo athletes and to establish its relationship with sprint-time, jumping ability, and dynamic balance. Twenty-seven (20 males and 7 females) taekwondo athletes participated in this study. They performed taekwondo-specific agility test (TSAT) in 2 occasions (i.e., test-retest). In addition, they performed jumping ability (i.e., squat jump, countermovement jump, standing long jump, and 3-hop jump), sprint-time (5- and 20-m dash), and dynamic balance (i.e., Y-test) tests along with a planned agility test (i.e., T-test). To establish TSAT's construct validity, 2 subgroups were identified based on their international and national taekwondo results: top elite (9 males and 2 females) and elite (11 males and 2 females). Taekwondo-specific agility test showed high relative and absolute reliability as well as a good ability to detect small and meaningful performance change. Top-elite athletes showed greater (p < 0.001) TSAT performances (4.5 ± 0.4 seconds) compared with their elite (5.3 ± 0.4 seconds) counterparts. Receiving operating characteristic (ROC) analysis showed that TSAT was able to discriminate athletes of different competitive level as revealed by an area under the ROC curve of 0.94 (95% confidence interval: 0.76-0.99). Taekwondo-specific agility test demonstrated significant association with the T-test (r = 0.71; shared variance = 50%), which is considered as a gold-standard planned agility test. In addition, results showed moderate-to-large associations between TSAT and jumping ability, sprint-time, and dynamic balance tests. The TSAT might be considered as a valid and reliable test to evaluate specific agility of taekwondo athletes.

Effects of 9 Months of Martial Arts Training on Cardiac Autonomic Modulation in Healthy Children and Adolescents

PURPOSE

The aim of the study was to evaluate the cardiac autonomic modulation after 9 months of martial arts practice in healthy children and adolescents.

METHOD

The study included 59 children and adolescents who were divided into 3 groups: judo, Muay Thai, and control. Heart rate variability was measured by a heart rate monitor, model Polar RS800CX. The intervention occurred twice a week on nonconsecutive days, lasting 60 minutes each session. A 1-way analysis of variance was used to compare participants at baseline. The comparisons between groups at baseline and after the intervention were carried out by a 2-way analysis of variance for repeated measures.

RESULTS

After 9 months of intervention, significant increases were observed for root mean square successive differences, with higher values post compared with baseline (19.5%; P = .04). For SD1, an interaction effect was observed, with increased posttraining values compared with baseline (24.1%; P = .04) for the judo group. Qualitative analysis of the Poincaré plot showed greater dispersion of RR intervals, mainly beat to beat, after the judo intervention compared with the baseline. The Muay Thai and control groups presented no improvement.

CONCLUSION

After 9 months of intervention, there were increases in cardiac autonomic modulation of children and adolescents participating in judo training. The practice of martial arts, such as judo, can be encouraged from an early age to improve cardiovascular system functioning, possibly providing protection against cardiovascular problems.