Physical Capacities and Combat Performance Characteristics of Male and Female Olympic Boxers.

Purpose: The study characterized the anthropometrical and cardiorespiratory profile, and the cardiorespiratory, bio-chemical and immunological responses to 3 × 3 min round (R) free-contact/combat boxing simulation, in elite Olympic Boxers (4 female and 10 male). Methods: The evaluation consisted of resting metabolic rate, anthropometric measurement, maximal graded test exercise (visit 1), free combat simulation (3 × 3 min R, 1 minute rest), and blood samples collected before, during and after the combat (visit 2). Results: Respectively, females and males had (mean±SD; or median: for non-parametric data) body fat percentage (17.2[3.5] and 4.6[0.8]%), predominantly mesomorphic somatotyping, and V˙O2MAX (50.0 ± 2.5 and 56.2 ± 5.2 ml.kg-1.min-1). The free combat simulation resulted in high cardiovascular strain [mean heart rate corresponding to R1: 92 ± 3; R2: 94 ± 2; and R3: 95 ± 2% of maximal HR] and blood chemistry indicative of acidosis (following R3: 7.21 ± 0.08 pH, bicarbonate 13.1 ± 3.6 mmol.L-1, carbon dioxide 13.9 ± 3.8 mmol.L-1, lactate 15.1 ± 3.8 mmol.L-1, and glucose 8.4 ± 1.3 mmol.L-1). Further, notable general catabolism, hematological and immune responses were evident post combat simulation (1-hour post R3: creatinine 95.2 ± 14.5 µmol.L-1, urea 6.4 ± 1.3 mmol.L-1, white blood cell accumulation 7.8 ± 2.6 × 109.L-1, hemoglobin 14.9 ± 0.8 g.dL-1 and hematocrit 43.7 ± 1.9%). Conclusions: Notable cardiovascular strain and acidosis are seen from the 3 × 3 free combat simulation whilst pronounced catabolism and immune responses are evident 1-hour post R3. This characterization is the first in male and female (who recently adopted the 3 × 3 min R format, as used by males) elite Olympic boxers and provides a characterization framework to assist practitioners and athletes in their attempts to deliver evidence-informed practice for specific conditioning session design.

Impact of Equation Choice on Resting Metabolic Rate Ratio in High-Level Men and Women Athletes.

Objective: To examine the impact of the RMR ratio cutoff point selected on the categorization of prevalence/absence of low energy availability among predictive equations in high-level athletes (n = 241 [99 women]; 52% competed at the World Championship and Olympic Games), and whether this categorization is influenced by sex and the predictive equation used.Methods: We assessed RMR using indirect calorimetry, predicted the RMR using the equations proposed by Harris-Benedict, FAO/WHO/UNU, de Lorenzo, ten Haaf and Wejis, Wong, Jagim, Cunningham, and Freire, and computed the RMR ratio for each equation.Results: We observed that the cumulative percentage of RMR ratio values increased at a faster rate using Jagim, ten Haaf and Wejis, and Cunningham equations compared to the other equations. At the 0.90 value (the most used cutoff point in literature), the Jagim equation categorized ≥ 50% of the athletes into "low energy availability". No Sex × Equation × Sport interaction effect was observed (F = 0.10, p = 1.0). There was a significant main effect to Sex (F = 11.7, p < 0.001, ES = 0.05), Sport (F = 16.4, p < 0.001, ES = 0.01), and Equation (F = 64.1, p < 0.001, ES = 0.19). Wong and FAO/WHO/UNU equations yielded the largest errors (assessed vs. predicted RMR) in men and women, respectively.Conclusion: The selected RMR ratio cutoff point influences the prevalence/absence of low energy availability characterization in high-level athletes and suggests that certain equations could bias its assessment.

Creatine and creatinine quantification in olympic athletes: dried blood spot analysis pilot study.

Capillary dried blood spot (DBS) samples facilitate field-based collection without venipuncture. This pilot study aims to evaluate the viability of creatine (Cr) and creatinine (Crt) quantification using fresh capillary serum (CrS/CrtS) and DBS samples (CrDBS/CrtDBS), using Flow Injection Analysis Mass Spectrometry (FIA - MS). Nine Olympic Athletes provided a capillary blood sample to assess CrS/CrtS and CrDBS/CrtDBS quantified by FIA - MS. No difference between CrtS (mean ± SD: 813.6 ± 102.4 µmol/L) and CrtDBS (812.4 ± 108.1 µmol/L) was observed with acceptable variance [SEM 88.7; CV 10.7%; ICC 0.57 (CI 95% 0.06 - 0.84)] and agreement [very strong (Spearman: r = 0.77; p < 0.01) or strong (Pearson: r = 0.56; p = 0.04); Bland Altman: lower (-193) and upper (+196) limits of agreement]. CrS (mean ± SD: 691.8 ± 165.2 µmol/L) was significantly different to CrDBS (2911 ± 571.4 µmol/L) with unacceptable variance [SEM 171.6; CV 27%; ICC 0.002 (CI 95% -0.02 - 0.07)] and 'weak' agreement [Spearman: r = 0.21, p = 0.47 and Pearson: r = 0.06, p = 0.84; Bland Altman lower (-3367) and upper (-1072) limits of agreement]. Crt quantification is viable using both CrtS and CrtDBS (but not for Cr and CrS/CrDBS), with the DBS tissue handling technique offering several methodological and practice facing advantages. Future work should expand upon the sample size, explore sport/discipline relevant analytes across a full competitive season, including key training, recovery and performance blocks of their periodized performance plan.

New Predictive Resting Metabolic Rate Equations for High-Level Athletes: A Cross-Validation Study.

PURPOSE: The present study aims a) to assess the agreement between the measured resting metabolic rate (RMR) using indirect calorimetry and different predictive equations (predicted RMR), and b) to propose and cross-validate two new predictive equations for estimating the RMR in high-level athletes. METHODS: The RMR of 102 athletes (44 women) was assessed using indirect calorimetry, whereas the body composition was assessed using skinfolds. Comparisons between measured and predicted RMR values were performed using one-way ANOVA. Mean difference, root mean square error (RMSE), simple linear regression, and Bland-Altman plots were used to evaluate the agreement between measured and predicted RMR. The accuracy of predictive equations was analyzed using narrower and wider accuracy limits (±5% and ±10%, respectively) of measured RMR. Multiple linear regression models were employed to develop the new predictive equations based on traditional predictors (equation 1) and the stepwise method (equation 2). RESULTS: The new equations 1 and 2 presented good agreement based on the mean difference (3 and -15 kcal·d -1 ), RMSE (200 and 192 kcal·d -1 ), and R2 (0.71 and 0.74), respectively, and accuracy (61% of subjects between the limit of ±10% of measured RMR). Cunningham's equation provided the best performance for males and females among the existing equations, whereas Jagim's equation showed the worst performance for males (mean difference = -335 kcal·d -1 ; RMSE = 386 kcal·d -1 ). Compared with measured RMR, most predictive equations showed heteroscedastic distribution (linear regression's intercept and slope significantly different from zero; P ≤ 0.05), mainly in males. CONCLUSIONS: The new proposed equations can estimate the RMR in high-level athletes accurately. Cunningham's equation is a good option from existing equations, and Jagim's equation should not be used in high-level male athletes.

Heat Adaptation and Nutrition Practices: Athlete and Practitioner Knowledge and Use.

PURPOSE: To survey elite athletes and practitioners to identify (1) knowledge and application of heat acclimation/acclimatization (HA) interventions, (2) barriers to HA application, and (3) nutritional practices supporting HA. METHODS: Elite athletes (n = 55) and practitioners (n = 99) completed an online survey. Mann-Whitney U tests (effect size [ES; r]) assessed differences between ROLE (athletes vs practitioners) and CLIMATE (hot vs temperate). Logistic regression and Pearson chi-square (ES Phi [ϕ]) assessed relationships. RESULTS: Practitioners were more likely to report measuring athletes' core temperature (training: practitioners 40% [athletes 15%]; P = .001, odds ratio = 4.0, 95% CI, 2%-9%; competition: practitioners 25% [athletes 9%]; P = .020, odds ratio = 3.4, 95% CI, 1%-10%). Practitioners (55% [15% athletes]) were more likely to perceive rectal as the gold standard core temperature measurement site (P = .013, ϕ = .49, medium ES). Temperate (57% [22% hot]) CLIMATE dwellers ranked active HA effectiveness higher (P < .001, r = .30, medium ES). Practitioners commonly identified athletes' preference (48%), accessibility, and cost (both 47%) as barriers to HA. Increasing carbohydrate intake when training in the heat was more likely recommended by practitioners (49%) than adopted by athletes (26%; P = .006, 95% CI, 0.1%-1%). Practitioners (56% [28% athletes]) were more likely to plan athletes' daily fluid strategies, adopting a preplanned approach (P = .001; 95% CI, 0.1%-1%). CONCLUSIONS: Practitioners, and to a greater extent athletes, lacked self-reported key HA knowledge (eg, core temperature assessment/monitoring methods) yet demonstrated comparatively more appropriate nutritional practices (eg, hydration).

Maximal and Submaximal Cardiorespiratory Responses to a Novel Graded Karate Test.

The present study aimed to propose and assess the physiological responses of a novel graded karate test. Ten male national-level karate athletes (age 26 ± 5 yrs; body mass 69.5 ± 11.6 kg; height 1.70 ± 0.09 m) performed two exercise tests (separated by 2-7 days): 1) a running-based cardiopulmonary exercise test; 2) a graded karate test. The cardiopulmonary exercise test was comprised of an individualized ramp protocol for treadmill running, and the graded karate test was comprised of a sequence of 'kisami-gyaku-zuki" punching at a fixed frequency of a stationary target that becomes progressively distant. Cardiorespiratory responses, blood lactate concentration, and perceived exertion were measured. A verification phase was also performed in both tests to confirm the maximal physiological outcomes. The graded karate test evoked similar maximal responses to the running protocol: V̇O2 (57.4 ± 5.1 vs 58.3 ± 3.5 mL·kg-1·min-1; p = 0.53), heart rate (192 ± 6 vs 193 ± 10]beats.min-1; p = 0.62) and blood lactate (14.6 ± 3.4 vs 13.1 ± 3.0 mmol·L-1; p = 0.14) with a shorter duration (351 ± 71 vs 640 ± 9 s; p < 0.001). Additionally, the graded karate test evoked higher V̇O2 (72.6 ± 6.5 vs 64.4 ± 4.3 %V̇O2MAX; p = 0.005) and heart rate (89.4 ± 4.6 vs 77.3 ± 7.2 %HRMAX p < 0.001) at the ventilatory threshold and a higher heart rate (97.0 ± 2.4 vs 92.9 ± 2.2 %HRMAX; p = 0.02) at the respiratory compensation point. Incremental and verification phases evoked similar responses in V̇O2 and minute-ventilation during both tests. This novel displacement-based sport-specific test evoked similar maximal and higher submaximal responses, indicating a superior pathway to assess karate athletes.

The estimation of the resting metabolic rate is affected by the method of gas exchange data selection in high-level athletes.

BACKGROUND & AIMS: there is no consensus in the literature about the best method to estimate the RMR in a high-level athlete's cohort. Additionally, a shortening protocol may allow researchers, nutritionists, and clinicians to follow the RMR across the season and to propose better nutritional interventions, but this kind of protocol was not proposed in this cohort yet. Thus, this study aims to analyze the effect of the method of gas exchange data selection upon the RMR estimate and, possibly propose a shortening protocol with a valid and accurate RMR value. METHODS: Eighty-three healthy high-level athletes underwent a 30-minute RMR measurement with no rest period before the test. Different methods of gas exchange data selection were used: short and long time intervals (TI) [6-10, 11-15, 16-20, 21-25, 26-30, 6-25, or 6-30], Steady State (SS) with 3, 4, 5, or 10 min period length, and Filtering (low, medium, and high). Single and multiple linear regressions were used to examine the variance in the RMR provided by each method of gas exchange data selection. RESULTS: The High Filter method provided the lowest RMR estimate (1854 kcal.day-1), and most methods presented a mean absolute difference of ~43 kcal.day-1 from the High Filter method. There were no differences in RER among methods (F = 2.01, p = 0.10). Besides, twenty minutes of gas exchange measurement was necessary to obtain a valid and accurate RMR with no rest period before the test. The linear regression model that included sex, lean body mass, and fat mass better explained the variance in the RMR using the high filter method (~88%). CONCLUSIONS: The High Filter provided the lowest RMR value. Furthermore, a 20-minute protocol estimated a valid and accurate RMR value with no acclimation period before the measurement in high-level athletes.

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.

New Predictive Resting Metabolic Rate Equations for High-Level Athletes: A Cross-validation Study.

PURPOSE: The present study aims a) to assess the agreement between the measured resting metabolic rate (RMR) using indirect calorimetry and different predictive equations (predicted RMR), and b) to propose and cross-validate two new predictive equations for estimating the RMR in high-level athletes. METHODS: The RMR of 102 athletes (44 women) was assessed using indirect calorimetry, while the body composition was assessed using skinfolds. Comparisons between measured and predicted RMR values were performed using one-way ANOVA. Mean difference, Root Mean Square Error, Simple Linear Regression, and Bland-Altman plots were used to evaluate the agreement between measured and predicted RMR. The accuracy of predictive equations was analyzed using narrower and wider accuracy limits (±5% and ± 10%, respectively) of measured RMR. Multiple linear regressions models were employed to develop the new predictive equations based on traditional predictors (Equation 1) and the stepwise method (Equation 2). RESULTS: The new Equations 1 and 2 presented good agreement based on the mean difference (3 and -15 kcal.d-1), RMSE (200 and 192 kcal.d-1), and R2 (0.71 and 0.74), respectively, and accuracy (61% of subjects between the limit of ±10% of measured RMR). Cunningham's equation provided the best performance for males and females among the existing equations, whereas Harris & Benedict's equation showed the worst performance for males (mean difference = 406 kcal.d-1; RMSE = 473 kcal.d-1). Compared to measured RMR, most predictive equations showed heteroscedastic distribution (linear regression's intercept and slope significantly different from zero; p ≤ 0.05), mainly in males. CONCLUSIONS: The new proposed equations can estimate the RMR in high-level athletes accurately. Cunningham's equation is a good option from existing equations, and Harris & Benedict's equation should not be used in high-level male athletes.

Covid-19 and its effect on olympic sport: the importance of studying social isolation and the harm it causes, in order to minimize it / Covid-19 e seu efeito no esporte olímpico: a importância de estudar o isolamento social e seus danos a fim de minimizá-los / Covid-19 y su efecto en el deporte olímpico: la importancia de estudiar el aislamiento social y sus daños a fin de minimizarlos

ABSTRACT In March 2020, the World Health Organization (WHO) declared the disease caused by the SARS-CoV2 virus, known as COVID-19, to be a pandemic. The sporting world, too, is suffering from the global effects of this disease, with the postponement or cancellation of competitions, including the 2020 Tokyo Olympic Games. As a proposal for containing the disease, social isolation was declared. Despite the importance of this measure, it was harmful for Olympic athletes, as they had to stay away from their training site and trainers, as well as their interdisciplinary teams. It is therefore important to study this harm caused, in order to minimize it. In general, it is believed that regular physical activity is associated with improved immune system functioning. The lack of training can therefore have significant consequences for the performance and health of the Olympic athlete. From the athlete's point of view, the impaired immune system, due to the reduced frequency of physical exercise, leaves them more vulnerable to contracting or developing infections or other diseases. The risk of harm due to the decreased performance of preventive works is also evident in this population. The reductions in training load and intensity can cause changes in the athlete's body composition and affect various aspects of cardiorespiratory fitness, as well as reducing strength levels and muscle potency. In relation to the athlete's mental health, two aspects are particularly challenging: isolation and uncertainty. Based on the possible harm caused by social isolation, the need is seen for a specific and joint work, in an attempt to minimize it. This work addresses the following topics: (I) context: transmission, symptoms, diagnosis, treatment, discharge criteria, isolation and post-pandemic consequences; (II) harm and proposals: nutritional, physiological, biomechanical and psychological. Level of evidence II; Review Article.

RESUMO Em março de 2020, a Organização Mundial da Saúde (OMS) declarou como pandemia a doença causada pelo vírus SARS-CoV2, conhecida como COVID-19. O mundo do esporte acompanha e sofre os efeitos globais dessa enfermidade, com o adiamento ou cancelamento de competições, inclusive os Jogos Olímpicos de Tóquio 2020. Como proposta para contenção da doença, foi determinado o isolamento social. Apesar de importante, esta medida traz danos aos atletas olímpicos pelo afastamento do local de treinamento e de treinadores, assim como de sua equipe interdisciplinar. Portanto, entende-se a importância de estudar esses danos a fim de minimizá-los. De forma geral, acredita-se que a atividade física regular esteja associada à melhora do funcionamento do sistema imunológico. Assim, a falta de treinamento pode levar a consequências importantes para o desempenho e a saúde do atleta olímpico. Do ponto de vista da saúde do atleta, o comprometimento do sistema imunológico pela redução da regularidade do exercício físico deixa o atleta mais vulnerável a contrair e desenvolver infecções ou outras patologias. Além disso, o risco de lesões considerando a diminuição da realização dos trabalhos preventivos é evidente nessa população. As reduções da carga e da intensidade de treino podem provocar mudanças na composição corporal do atleta e afetar diversos componentes da aptidão cardiorrespiratória, assim como reduzir níveis de força e potência muscular. Com relação à saúde mental do atleta, dois aspectos são os mais desafiadores: o isolamento e a incerteza. A partir dos possíveis danos causados pelo isolamento social, entende-se a necessidade de um trabalho específico e em conjunto, na tentativa de minimizá-los. Neste trabalho serão abordados os seguintes tópicos: (I) contexto: transmissão, sintomas, diagnóstico, tratamento, critérios de alta, isolamento e consequências pós-pandemia; (II) danos e propostas: nutricionais, fisiológicas, biomecânicas, bioquímicas e psicológicas. Nível de evidência II; Artigo de Revisão.

RESUMEN En marzo de 2020, la Organización Mundial de la Salud (OMS) declaró como pandemia a la enfermedad causada por el virus SARS-CoV2, conocida como COVID-19. El mundo del deporte acompaña y sufre los efectos globales de esa enfermedad, con la postergación o cancelación de competiciones, inclusive los Juegos Olímpicos de Tokio 2020. Como propuesta para contención de la enfermedad, se determinó el aislamiento social. A pesar de importante, esta medida trae daños a los atletas olímpicos por el alejamiento del local de entrenamiento y de entrenadores, así como de su equipo interdisciplinario. Por lo tanto, se entiende la importancia de estudiar esos daños a fin de minimizarlos. De forma general, se cree que la actividad física regular esté asociada a la mejora del funcionamiento del sistema inmunológico. Así, la falta de entrenamiento puede llevar a consecuencias importantes para el desempeño y la salud del atleta olímpico. Desde el punto de vista de la salud del atleta, el compromiso del sistema inmunológico por la reducción de la regularidad del ejercicio físico deja al atleta más vulnerable a contraer y desarrollar infecciones u otras patologías. Además, el riesgo de lesiones considerando la disminución de la realización de los trabajos preventivos es evidente en esa población. Las reducciones de la carga y de la intensidad de entrenamiento pueden provocar cambios en la composición corporal del atleta y afectar diversos componentes de la aptitud cardiorrespiratoria, así como reducir niveles de fuerza y potencia muscular. Con relación a la salud mental del atleta, dos aspectos son los más desafiantes: el aislamiento y la incertidumbre. A partir de los posibles daños causados por el aislamiento social, se entiende la necesidad de un trabajo específico y en conjunto, en la tentativa de minimizarlos. En este trabajo serán abordados los siguientes tópicos: (I) contexto: transmisión, síntomas, diagnóstico, tratamiento, criterios de alta, aislamiento y consecuencias postpandemia; (II) daños y propuestas: nutricionales, fisiológicas, biomecánicas, bioquímicas y psicológicas. Nivel de evidencia II; Artículo de Revisión.

Repeated Exposure to Taekwondo Combat Modulates the Physiological and Hormonal Responses to Subsequent Bouts and Recovery Periods.

Bridge, CA, Sparks, SA, McNaughton, LR, Close, GL, Hausen, M, Gurgel, J, and Drust, B. Repeated exposure to taekwondo combat modulates the physiological and hormonal responses to subsequent bouts and recovery periods. J Strength Cond Res 32(9): 2529-2541, 2018-This study examined the physiological and hormonal responses to successive taekwondo combats using an ecologically valid competition time structure. Ten elite male international taekwondo competitors (age 19 ± 3 years) took part in a simulated championship event. The competitors performed 4 combats that were interspersed with different recovery intervals (63 ± 4, 31 ± 3 and 156 ± 5 minutes, respectively). Heart rate (HR) was measured during the combats and venous blood samples were obtained both before and after each combat to determine the plasma metabolite and hormone concentrations. The plasma noradrenaline (21.8 ± 12.8 vs. 15.0 ± 7.0 nmol·l) and lactate (13.9 ± 4.2 vs. 10.5 ± 3.2 mmol·l) responses were attenuated (p < 0.05) between combat 1 and 4. Higher (p < 0.05) HR responses were evident in the final combat when compared with the earlier combats. Higher (p < 0.05) resting HR (139 ± 10 vs. 127 ± 12 b·min), plasma lactate (3.1 ± 1.2 vs. 2.0 ± 0.7 mmol·l), glycerol (131 ± 83 vs. 56 ± 38 µmol·l) and nonesterified free fatty acid (0.95 ± 0.29 vs. 0.71 ± 0.28 mmol·l) concentrations were measured before combat 3 compared with combat 1. Repeated exposure to taekwondo combat using an ecologically valid time structure modulates the physiological and hormonal responses to subsequent bouts and recovery periods. Strategies designed to assist competitors to effectively manage the metabolic changes associated with the fight schedule and promote recovery between the bouts may be important during championship events.

Eliciting Higher Maximal and Submaximal Cardiorespiratory Responses During a New Taekwondo-Specific Aerobic Test.

PURPOSE: To propose and validate new taekwondo-specific cardiopulmonary exercise tests. METHODS: Twelve male national-level taekwondo athletes (age 20 [2] y, body mass 67.5 [5.7] kg, height 175 [8] cm, and training experience 7 [3] y) performed 3 separate exercise tests in a randomized counterbalanced order: (1) a treadmill running cardiopulmonary exercise test (CPET) and (2) continuous and (3) interval taekwondo-specific cardiopulmonary exercise tests (cTKDet and iTKDet, respectively). The CPET was administered using an individualized ramp protocol. Taekwondo tests comprised sequences of turning kicks performed on a stationary target. The impacts were recorded via an electronic scoring sensor used in official competition. Stages on the cTKDet and iTKDet lasted 1 min and progressively reduced the kick interval duration. These were guided by a sound signal, starting with 4.6 s between kicks and reducing by 0.4 s every minute until the test ended. Oxygen uptake (V˙O2), heart rate (HR), capillary blood lactate, and ratings of perceived exertion were measured. RESULTS: Modest differences were identified in V˙O2max between the tests (F2,22 = 3.54; P = .046; effect size [ES] = 0.16). Maximal HR (HRmax) was higher during both taekwondo tests (F2,22 = 14.3; P = .001; ES = 1.14) compared with CPET. Specific tests also yielded higher responses in the first ventilatory threshold V˙O2 (F2,22 = 6.5; P = .04; ES = 0.27) and HR (F2,22 = 12.3; P < .001; ES = 1.06), and HR at the second ventilatory threshold (F2,22 = 5.7; P = .02; ES = 0.72). CONCLUSIONS: Taekwondo-specific cardiopulmonary tests enhance the validity of some cardiopulmonary responses and might therefore be considered to optimize routine diagnostic testing and training prescription for this athletic group.

Relação da atividade física e percentual de gordura de escolares / Relationship of the physical activity and percentage of fat of schoolars

Objetivo: identificar o Nível de Atividade Física e Percentual de Gordura Corporal de escolares. Método: estudo quantitativo, transversal, por amostragem composta de 640 escolares (Idade: 10±1 anos; Massa Corporal, 37,25±13,90kg; Estatura, 1,45±0,08m; IMC, 17,50±5,04kg/m²). O NAF por meio PAQ-C, %GC pelo método de dobras cutâneas e o IMC. Resultados: há diferenças significativas (p < 0,01, d = 0,37) no escore do PAQ-C entre os sexos, com superioridade nos valores masculinos; foram encontradas diferenças significativas na distribuição dos níveis de atividade física divididos pelo sexo (p < 0,0001, d = 6,7) e na distribuição do %CG pelo sexo (p < 0,0001, d=0,28). Conclusão: foram identificados índices de obesidade dentre os escolares (43% e 53,10%, populações feminina e masculina, respectivamente) ao mesmo tempo em que essa população apresenta que é ativa ou moderadamente ativa fisicamente (67,07% e 67,56%, masculino e feminino, respectivamente); contudo, não foi identificada associação entre Nível de Atividade Física e Percentual de Gordura Corporal. Estes resultados corroboram os achados gerais da literatura que demonstram que o NAF não é fator determinante para o valor Percentual de Gordura Corporal. (AU)

Correction: Physiological responses and external validity of a new setting for taekwondo combat simulation.

[This corrects the article DOI: 10.1371/journal.pone.0171553.].

Proposal of a New Specific Cardiopulmonary Exercise Test for Taekwondo Athletes.

The objective of this study is to evaluate the cardiorespiratory variables of Taekwondo athletes while performing incremental exercise test on an ergometer using a ramp protocol and to propose a specific protocol for assessing these physiological variables during Taekwondo practice. Fourteen athletes participated in 2 incremental exercise tests: a treadmill exercise test (TREADtest) and a Taekwondo-specific exercise test (TKDtest). The TKDtest consists in 1-minute stages of kicks with an incremental load between then. The subjects perform kicks each time a sound signal was heard. Heart rate (HR), oxygen uptake (V[Combining Dot Above]O2), and their reserve correspondents (V[Combining Dot Above]O2R and reserve heart rate [HRR]) were divided into quartiles to verify their kinetics along the tests. Significant difference between 2 tests was found only for V[Combining Dot Above]O2R (p = 0.03). Regarding the quartiles, significant differences were found for HR in the first (p = 0.030) and second (p = 0.003). Analyzing the regression curves, significant differences were found for HR for intercept (p = 0.01) and slope (p = 0.05) and HRR for slope (p = 0.02). Analysis showed that significant reliability, with intraclass correlation coefficient (ICC), was found for the V[Combining Dot Above]O2peak (ICC = 0.855, p = 0.003), V[Combining Dot Above]O2 in ventilatory thresholds 1 (ICC = 0.709, p = 0.03) and 2 (ICC = 0.848, p = 0.003). Bland-Altman analyses reported a mean difference ± the 95% limits of agreement of 2.2 ± 8.4 ml·kg·min to V[Combining Dot Above]O2peak. The TKDtest is reliable for measurement of cardiorespiratory variables, and the behavior of these variables differs mainly from TREADtest, probably because of the motor task performed.

Physiological responses and external validity of a new setting for taekwondo combat simulation.

Combat simulations have served as an alternative framework to study the cardiorespiratory demands of the activity in combat sports, but this setting imposes rule-restrictions that may compromise the competitiveness of the bouts. The aim of this study was to assess the cardiorespiratory responses to a full-contact taekwondo combat simulation using a safe and externally valid competitive setting. Twelve male national level taekwondo athletes visited the laboratory on two separate occasions. On the first visit, anthropometric and running cardiopulmonary exercise assessments were performed. In the following two to seven days, participants performed a full-contact combat simulation, using a specifically designed gas analyser protector. Oxygen uptake ([Formula: see text]), heart rate (HR) and capillary blood lactate measurements ([La-]) were obtained. Time-motion analysis was performed to compare activity profile. The simulation yielded broadly comparable activity profiles to those performed in competition, a mean [Formula: see text] of 36.6 ± 3.9 ml.kg-1.min-1 (73 ± 6% [Formula: see text]) and mean HR of 177 ± 10 beats.min-1 (93 ± 5% HRPEAK). A peak [Formula: see text] of 44.8 ± 5.0 ml.kg-1.min-1 (89 ± 5% [Formula: see text]), a peak heart rate of 190 ± 13 beats.min-1 (98 ± 3% HRmax) and peak [La-] of 12.3 ± 2.9 mmol.L-1 was elicited by the bouts. Regarding time-motion analysis, combat simulation presented a similar exchange time, a shorter preparation time and a longer exchange-preparation ratio. Taekwondo combats capturing the full-contact competitive elements of a bout elicit moderate to high cardiorespiratory demands on the competitors. These data are valuable to assist preparatory strategies within the sport.