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1.
Scand J Med Sci Sports ; 31(11): 2115-2122, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34343371

RESUMO

Brazilian Jiu-Jitsu (BJJ) is a popular martial art that exposes participants to recurrent intermittent asphyxiation due to controlled application of neck chokes. To what extent the sport impacts the regulation of cerebral blood flow (CBF) and cognition has not been examined. This study compared eleven elite Brazilian Jiu-Jitsu athletes (aged 30 ± 8 y) who trained 12 ± 6 hours/week for 8 ± 4 years against eleven cardiorespiratory fitness (CRF)- and age-matched controls. Internal carotid (ICA) and vertebral artery (VA) blood flow were measured via duplex ultrasound to determine global cerebral blood flow (gCBF). Mild cognitive impairment and sub-domains of memory, attention/concentration/visual motor coordination, and executive function were determined by psychometric testing. There was no evidence of mild cognitive impairment in the athletes, and cognitive function was comparable between groups (all p > 0.05). In contrast, resting gCBF was selectively elevated in the athletes (741 ± 186 mL∙min-1 vs. 573 ± 166 mL∙min-1 , p = 0.037) due to combined differences in ICA (+65 mL∙min-1 , p = 0.079) and VA (+19 mL∙min-1 , p = 0.277) flow. In conclusion, the sustained elevation in resting cerebral perfusion provides preliminary evidence for adaptive neuroprotection that is independent of CRF and likely mediated by choke-induced cerebral preconditioning and/or lifelong exposure to BJJ-specific high-intensity interval training.


Assuntos
Circulação Cerebrovascular/fisiologia , Cognição/fisiologia , Artes Marciais/fisiologia , Neuroproteção/fisiologia , Adulto , Atletas , Humanos , Masculino
2.
Med Sci Sports Exerc ; 53(8): 1648-1655, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34261995

RESUMO

INTRODUCTION: Although exercise is suggested to benefit inhibitory control in children and adolescents, the current evidence is limited to exercise-induced improvements for its interference control subtype. In contrast, the potential of exercise to facilitate response inhibition still remains unclear. However, the neurocognitive profile of martial arts athletes suggests that this sports category promises benefits for cognitive control processes related to response inhibition. The present randomized controlled trial therefore examined the effects of judo on behavioral and neurocognitive indices of response inhibition (N2, P3a, P3b) in preadolescent children. METHODS: Participants (N = 44) were randomly allocated to a martial arts group, who completed 120-min judo per week over 3 months, and a wait-list control group. At baseline and follow-up, participants completed the Movement Assessment Battery for Children-2 and a physical work capacity test on a bicycle ergometer at 170 bpm (PWC170). In addition, a computerized Go/NoGo task with simultaneous electroencephalographic recordings was administered. RESULTS: In the martial arts group, a greater decrease in NoGo error rate and a higher increase in NoGo N2 amplitude were found in comparison to the control group. These behavioral and neurocognitive changes were correlated. In contrast to N2, the P3a/b amplitude, Movement Assessment Battery for Children-2, and physical work capacity test at 170 bpm did not change differently between groups over the intervention period. CONCLUSIONS: The present findings indicate that judo promises benefits for response inhibition that are independent of alterations in motor skills and cardiorespiratory fitness. A change toward more effective conflict monitoring seems to underlie this improvement in cognitive performance.


Assuntos
Cognição , Inibição Psicológica , Artes Marciais/fisiologia , Aptidão Cardiorrespiratória , Criança , Eletroencefalografia , Teste de Esforço , Humanos , Destreza Motora , Testes Neuropsicológicos , Suíça
3.
J Sports Sci Med ; 20(3): 457-465, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34267585

RESUMO

The round house kick (RHK) is a common technique in taekwondo (TKD). The kicking action originates from the dynamic stability of the pivot leg. However, some knee injuries are caused by more difficult kicking strategies, such as kicks to the opponent's head. This study analyses the effects on TKD players in the lower extremity kinematic and neuromuscular reactions from different kicking heights. This study recruited 12 TKD players (age=20.3 ± 1.3 years, height = 1.72 ± 0.09 m, mass = 62.17 ± 9.45 kg) with no previous lower extremity ligament injuries. All athletes randomly performed 3 RHK at different heights (head, chest, and abdomen), repeating each kick 5 times. During the RHK action, the kinematics and muscle activations of the pivot leg were collected using six high-speed cameras and electromyography devices. The results found that during the RHK return period a high kicking position demonstrated larger knee valgus with the straight knee, and more hamstring activation on the pivot leg. The RHK pivot foot for TKD players encountered more risk of injury from high target kicking. The hamstring muscle played an important stabilizing role. It is recommended that sports medicine clinicians or sports coaches use this information to provide further protective injury prevention strategies.


Assuntos
Perna (Membro)/fisiologia , Artes Marciais/fisiologia , Músculo Esquelético/fisiologia , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Fenômenos Biomecânicos , Eletromiografia , Feminino , Músculos Isquiossurais/fisiologia , Quadril/fisiologia , Humanos , Traumatismos do Joelho/fisiopatologia , Articulação do Joelho/fisiologia , Masculino , Amplitude de Movimento Articular , Fatores de Risco , Análise e Desempenho de Tarefas , Adulto Jovem
4.
J Sports Sci Med ; 20(2): 310-316, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34211324

RESUMO

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.


Assuntos
Aptidão Cardiorrespiratória/fisiologia , Teste de Esforço/métodos , Artes Marciais/fisiologia , Adulto , Limiar Anaeróbio , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia
5.
Nutrients ; 13(5)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069892

RESUMO

Caffeine increases vertical jump, although its effects on kinetics and kinematics during different phases of bilateral and unilateral jumps remain unclear. The aim of this study was to identify the effects of 3 mg/kg on kinetic, kinematic and temporal variables in the concentric and eccentric phases of bilateral and unilateral countermovement jumps. A total of 16 Spanish national team traditional Jiu-Jitsu athletes took part in two experimental trials (3 mg/kg caffeine or placebo) in a randomized, double-blind crossover study. Sixty minutes after ingestion, bilateral and unilateral jumps were performed on a force platform. Compared to the placebo, caffeine increased bilateral jump height (p = 0.008; Δ% = 4.40), flight time (p = 0.008; Δ% = 2.20), flight time:contraction time (p = 0.029; Δ% = 8.90), concentric impulse (p = 0.018; Δ% = 1.80), peak power (p = 0.049; Δ% = 2.50), RSI-modified (p = 0.011; Δ% = 11.50) and eccentric mean braking force (p = 0.045; Δ% = 4.00). Additionally, caffeine increased unilateral RSI-mod in both legs (Left: p = 0.034; Δ% = 7.65; Right: p = 0.004; Δ% = 11.83), left leg flight time (p = 0.044; Δ% = 1.91), left leg jump height (p = 0.039; Δ% = 3.75) and right leg FT:CT (p = 0.040; Δ% = 9.72). Caffeine in a dose of 3 mg/kg BM in elite Jiu-Jitsu athletes is a recommended ergogenic aid as it increased performance of bilateral and unilateral vertical jumps. These increases were also accompanied by modified jump execution during the different phases of the countermovement prior to take-off.


Assuntos
Desempenho Atlético/fisiologia , Cafeína/administração & dosagem , Artes Marciais/fisiologia , Substâncias para Melhoria do Desempenho/administração & dosagem , Atletas , Fenômenos Biomecânicos , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Perna (Membro)/fisiologia , Masculino , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Adulto Jovem
6.
J Sports Sci ; 39(sup1): 125-131, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34180373

RESUMO

In Paralympic judo for athletes with vision impairment (VI judo) all eligible athletes (i.e. B1, B2 and B3 classes) compete against each other in the same competition. Evidence suggests that athletes with more impairment may be disadvantaged, but that more sensitive measures of performance are necessary to understand the impact of impairment on performance. The aim of this study was to investigate the relationship between Para sport class and technical variation, time-motion variables, and performance in Paralympic judo. All 175 judo matches from the Rio 2016 Paralympic Games were analysed across 129 competitors (82 male and 47 female). The main results indicated that athletes who demonstrated less technical variation also experienced less competitive success, with the functionally blind athletes (class B1) demonstrating less technical variation than partially sighted (class B2 and B3) athletes (p < 0.05). There was no difference in the time-motion variables between sport classes (p > 0.05). We conclude that measures of technical variation are sensitive to differences in impairment and are suitable for studies that investigate the impairment-performance relationship in VI judo. Results further confirm that some athletes with impairment are disadvantaged under the current rules of VI judo.


Assuntos
Desempenho Atlético/fisiologia , Artes Marciais/fisiologia , Paratletas , Esportes para Pessoas com Deficiência/psicologia , Transtornos da Visão/fisiopatologia , Análise de Variância , Desempenho Atlético/estatística & dados numéricos , Cegueira/fisiopatologia , Brasil , Feminino , Humanos , Internacionalidade , Masculino , Artes Marciais/classificação , Artes Marciais/estatística & dados numéricos , Paratletas/classificação , Fatores Sexuais , Esportes para Pessoas com Deficiência/classificação , Esportes para Pessoas com Deficiência/estatística & dados numéricos , Estatísticas não Paramétricas , Estudos de Tempo e Movimento , Acuidade Visual , Pessoas com Deficiência Visual/classificação
7.
J Int Soc Sports Nutr ; 18(1): 49, 2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34147116

RESUMO

PURPOSE: Previous investigations have found positive effects of acute ingestion of capsules containing 4-to-9 mg of caffeine per kg of body mass on several aspects of judo performance. However, no previous investigation has tested the effectiveness of caffeinated chewing gum as the form of caffeine administration for judoists. The main goal of this study was to assess the effect of acute ingestion of a caffeinated chewing gum on the results of the special judo fitness test (SJFT). METHODS: Nine male elite judo athletes of the Polish national team (23.7 ± 4.4 years, body mass: 73.5 ± 7.4 kg) participated in a randomized, crossover, placebo-controlled and double-blind experiment. Participants were moderate caffeine consumers (3.1 mg/kg/day). Each athlete performed three identical experimental sessions after: (a) ingestion of two non-caffeinated chewing gums (P + P); (b) a caffeinated chewing gum and a placebo chewing gum (C + P; ~2.7 mg/kg); (c) two caffeinated chewing gums (C + C; ~5.4 mg/kg). Each gum was ingested 15 min before performing two Special Judo Fitness Test (SJFT) which were separated by 4 min of combat activity. RESULTS: The total number of throws was not different between P + P, C + P, and C + C (59.66 ± 4.15, 62.22 ± 4.32, 60.22 ± 4.08 throws, respectively; p = 0.41). A two-way repeated measures ANOVA indicated no significant substance × time interaction effect as well as no main effect of caffeine for SJFT performance, SJFT index, blood lactate concentration, heart rate or rating of perceived exertion. CONCLUSIONS: The results of the current study indicate that the use of caffeinated chewing gum in a dose up to 5.4 mg/kg of caffeine did not increase performance during repeated SJFTs.


Assuntos
Atletas , Desempenho Atlético , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Goma de Mascar , Artes Marciais/fisiologia , Desempenho Atlético/fisiologia , Desempenho Atlético/estatística & dados numéricos , Cafeína/administração & dosagem , Estimulantes do Sistema Nervoso Central/administração & dosagem , Estudos Cross-Over , Método Duplo-Cego , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Masculino , Artes Marciais/estatística & dados numéricos , Aptidão Física , Placebos/administração & dosagem , Adulto Jovem
8.
J Int Soc Sports Nutr ; 18(1): 48, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34127014

RESUMO

BACKGROUND: This study aimed to investigate the effect of multi-ingredient intra- (BA) versus extra- (ALK) cellular buffering factor supplementation, combined with the customary intake of branched-chain amino acids (BCAA) and creatine malate (TCM), on body composition, exercise variables, and biochemical and hematological parameters in 9 elite taekwondo athletes. METHODS: Eight-week randomized double-blind crossover BA (5.0 g·day-1 of ß-alanine) versus ALK (0.07 g·kgFFM-1·day-1 of sodium bicarbonate) supplementation combined with BCAA (0.2 g·kgFFM-1·day-1) and TCM (0.05 g·kgFFM-1·day-1) during a standard 8-week taekwondo training period was implemented. In the course of the experiment, body composition (dual X-ray absorptiometry), aerobic capacity (ergospirometric measurements during an incremental treadmill test until exhaustion), and exercise blood biomarkers concentrations were measured. Data were analyzed using repeated measures within-between interaction analysis of variance with the inclusion of experimental supplementation order. RESULTS: The maximum post-exercise blood ammonia concentration decreased in both groups after supplementation (from 80.3 ± 10.6 to 72.4 ± 10.2 µmol∙L-1, p = 0.013 in BA; from 81.4 ± 8.7 to 74.2 ± 8.9 µmol∙L-1, p = 0.027 in ALK), indicating reduced exercise-related adenosine triphosphate degradation. However, no differences were found in body composition, aerobic capacity, blood lactate concentration, and hematological parameters after neither BA (combined with BCAA and TCM) nor ALK (combined with BCAA and TCM) supplementation. CONCLUSIONS: In highly trained taekwondo athletes, neither extra- nor intracellular buffering enhancement resulting from BA and ALK supplementation, combined with BCAA and TCM treatment, affects body mass and composition, maximum oxygen uptake, and hematological indices, even though certain advantageous metabolic adaptations can be observed.


Assuntos
Aminoácidos de Cadeia Ramificada/administração & dosagem , Amônia/sangue , Desempenho Atlético/fisiologia , Creatina/administração & dosagem , Suplementos Nutricionais , Artes Marciais/fisiologia , Bicarbonato de Sódio/administração & dosagem , beta-Alanina/administração & dosagem , Adaptação Fisiológica , Biomarcadores/sangue , Composição Corporal , Estudos Cross-Over , Método Duplo-Cego , Humanos
9.
PLoS One ; 16(6): e0235582, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34106936

RESUMO

The aim of this study is to analyze how isokinetic knee and hip peak torques and roundhouse kick velocities are related to expertise level (elite vs. sub-elite) in taekwondo athletes. Seven elite and seven sub-elite athletes were tested for kick-specific variables (KSV, composed of kinematic variables and power of impact) and for concentric isokinetic peak torque (PT) at 60°/s and 240°/s. First, KSVs and PTs were compared between groups, then PTs were correlated with KSVs. Parametric variables with larger effect sizes (Cohen's d) were entered in a stepwise linear discriminant analysis (LDA), generating an equation to estimate competitive level. Between-group differences were found in hip flexors (p = 0.04, d = 0.92) and extensors (p = 0.04, d = 0.96) with PT at 240°/s. Hip flexion PT at 60°/s and 240°/s correlated negatively with kick time (R = -0.46, p = 0.0499 and R = -0.62, p = 0.01 respectively). Hip flexion torque at 60°/s correlated positively (R = 0.52, p = 0.03) with peak linear velocity of the foot (LVF) and power of impact (R = 0.51, p = 0.03). Peak torque of hip extension at 60°/s and hip abduction at 240°/s also correlated with LVF (R = 0.56, p = 0.02 and R = 0.46, p = 0.0499). Hip extension at 60°/s correlated positively with peak linear velocity of the knee (R = 0.48, p = 0.04). The LDA showed an accuracy of 85.7% (p = 0.003) in predicting expertise level based on hip flexion and extension torques at 240°/s and on knee extension velocity during the kick. The study demonstrates that hip muscle strength is probably the dominant muscular factor for determining kick performance. Knee angular velocity combined with hip torques is the best discriminator for competitive level in taekwondo athletes.


Assuntos
Desempenho Atlético/fisiologia , Exercício Físico , Perna (Membro)/fisiologia , Artes Marciais/fisiologia , Fenômenos Biomecânicos , Exercício Físico/fisiologia , Feminino , Humanos , Masculino , Torque , Adulto Jovem
10.
J Int Soc Sports Nutr ; 18(1): 40, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34044858

RESUMO

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.


Assuntos
Desempenho Atlético/fisiologia , Sacarose na Dieta/administração & dosagem , Frutose/administração & dosagem , Artes Marciais/fisiologia , Adolescente , Bebidas , Glicemia/metabolismo , Índice de Massa Corporal , Comportamento Competitivo/fisiologia , Estudos Cross-Over , Sacarose na Dieta/efeitos adversos , Método Duplo-Cego , Frutose/efeitos adversos , Azia/etiologia , Humanos , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia
11.
PLoS One ; 16(5): e0251266, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33970947

RESUMO

The aim of this study was to quantify typical training load and periodisation practices of MMA athletes. MMA competitors (n = 14; age = 22.4 ± 4.4 years; body mass = 71.3 ± 7.7 kg; stature = 171 ±9.9 cm) were observed during training for 8 consecutive weeks without intervention. Seven athletes were training for competitive bouts whilst the remaining 7 were not. Daily training duration, intensity (RPE), load (sRPE and segRPE), fatigue (short questionnaire of fatigue) and body region soreness (CR10 scale) were recorded. Using Bayesian analyses (BF10≥3), data demonstrate that training duration (weekly mean range = 3.9-5.3 hours), sRPE (weekly mean range = 1,287-1,791 AU), strain (weekly mean range = 1,143-1,819 AU), monotony (weekly mean range = 0.63-0.83 AU), fatigue (weekly mean range = 16-20 AU) and soreness did not change within or between weeks. Between weeks monotony (2.3 ± 0.7 AU) supported little variance in weekly training load. There were no differences in any variable between participants who competed and those who did not with the except of the final week before the bout, where an abrupt step taper occurred leading to no between group differences in fatigue. Training intensity distribution corresponding to high, moderate and low was 20, 33 and 47%, respectively. Striking drills accounted for the largest portion of weekly training time (20-32%), with MMA sparring the least (2-7%). Only striking sparring and wrestling sparring displayed statistical weekly differences in duration or load. Athletes reported MMA sparring and wrestling sparring as high intensity (RPE≥7), BJJ sparring, striking sparring and wrestling drills as moderate intensity (RPE 5-6), and striking drills and BJJ drills as low intensity (RPE≤4). We conclude that periodisation of training load was largely absent in this cohort of MMA athletes, as is the case within and between weekly microcycles.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Exercício Físico/fisiologia , Artes Marciais/fisiologia , Esforço Físico/fisiologia , Estresse Fisiológico/fisiologia , Adolescente , Adulto , Teorema de Bayes , Feminino , Humanos , Masculino , Adulto Jovem
12.
Int J Sport Nutr Exerc Metab ; 31(3): 259-267, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33626503

RESUMO

Rapid weight loss or "weight cutting" is a common but potentially harmful practice used in mixed martial arts competition. Following the official weigh-in, competitors refeed and rehydrate themselves in a process known as rapid weight gain (RWG) to realize a potential competitive advantage. While data from surveys and small series have indicated the majority of mixed martial arts athletes engage in rapid weight loss, there is a lack of officially collected data from sanctioning organizations describing its prevalence. The present investigation represents a summary of the data collected between December 2015 and January 2018 by the California State Athletic Commission. In total, 512 professional mixed martial artists (455 males and 57 females) were included. Of these, 503 (98%) athletes gained body mass between weigh-in and their bouts. Total RWG between weigh-in and competition was 5.5 ± 2.5 kg, corresponding to an 8.1% ± 3.6% body mass increase. Total RWG was 5.6 ± 2.5 kg (8.1% ± 3.6%) for males and 4.5 ± 2.3 kg (8.0% ± 3.8%) for females. More than one quarter of men and one third of women gained >10% body mass between weigh-in and competition. Athletes from leading international promotions gained more absolute, but not relative, body mass than those from regional promotions. Our findings indicate RWG is nearly ubiquitous in professional , with a similar prevalence in male and female athletes. Trends based on promotion suggest a larger magnitude of RWG in presumably more experienced and/or successful mixed martial artists from leading international promotions.


Assuntos
Índice de Massa Corporal , Artes Marciais/fisiologia , Ganho de Peso , Perda de Peso , Desempenho Atlético , California , Anonimização de Dados , Ingestão de Alimentos , Feminino , Hidratação/métodos , Humanos , Internacionalidade , Masculino , Artes Marciais/classificação , Artes Marciais/estatística & dados numéricos , Estudos Retrospectivos , Fatores Sexuais , Fenômenos Fisiológicos da Nutrição Esportiva
13.
Sci Rep ; 11(1): 905, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441596

RESUMO

Human voice pitch is highly sexually dimorphic and eminently quantifiable, making it an ideal phenotype for studying the influence of sexual selection. In both traditional and industrial populations, lower pitch in men predicts mating success, reproductive success, and social status and shapes social perceptions, especially those related to physical formidability. Due to practical and ethical constraints however, scant evidence tests the central question of whether male voice pitch and other acoustic measures indicate actual fighting ability in humans. To address this, we examined pitch, pitch variability, and formant position of 475 mixed martial arts (MMA) fighters from an elite fighting league, with each fighter's acoustic measures assessed from multiple voice recordings extracted from audio or video interviews available online (YouTube, Google Video, podcasts), totaling 1312 voice recording samples. In four regression models each predicting a separate measure of fighting ability (win percentages, number of fights, Elo ratings, and retirement status), no acoustic measure significantly predicted fighting ability above and beyond covariates. However, after fight statistics, fight history, height, weight, and age were used to extract underlying dimensions of fighting ability via factor analysis, pitch and formant position negatively predicted "Fighting Experience" and "Size" factor scores in a multivariate regression model, explaining 3-8% of the variance. Our findings suggest that lower male pitch and formants may be valid cues of some components of fighting ability in men.


Assuntos
Agressão/fisiologia , Voz/fisiologia , Acústica , Adulto , Agressão/psicologia , Antropometria , Atletas/psicologia , Biomarcadores , Sinais (Psicologia) , Humanos , Masculino , Artes Marciais/fisiologia , Fenótipo , Discriminação da Altura Tonal/fisiologia , Comportamento Sexual/fisiologia , Comportamento Sexual/psicologia , Percepção Social/psicologia
14.
J Int Soc Sports Nutr ; 18(1): 10, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33478522

RESUMO

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.


Assuntos
Anaerobiose/efeitos dos fármacos , Creatina/farmacologia , Artes Marciais/fisiologia , Substâncias para Melhoria do Desempenho/farmacologia , Bicarbonato de Sódio/farmacologia , Anaerobiose/fisiologia , Análise de Variância , Desempenho Atlético , Creatina/administração & dosagem , Suplementos Nutricionais , Metabolismo Energético , Fadiga/diagnóstico , Humanos , Ácido Láctico/sangue , Masculino , Substâncias para Melhoria do Desempenho/administração & dosagem , Esforço Físico/fisiologia , Polissacarídeos/administração & dosagem , Polissacarídeos/farmacologia , Bicarbonato de Sódio/administração & dosagem , Adulto Jovem
15.
BMJ Case Rep ; 14(1)2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431453

RESUMO

Mitochondrial diseases are rare, often go undiagnosed and can lead to devastating cascades of multisystem organ dysfunction. This report of a young woman with hearing loss and gestational diabetes illustrates a novel presentation of a cardiomyopathy caused by a previously described mutation in a mitochondrial gene, MT-TL1. She initially had biventricular heart dysfunction and ventricular arrhythmia that ultimately recovered with beta blockade and time. She continues to participate in sport without decline. It is important to keep mitochondrial diseases in the differential diagnosis and understand the testing and management strategies in order to provide the best patient care.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Cardiomiopatias/diagnóstico , Miopatias Mitocondriais/diagnóstico , RNA de Transferência de Leucina/genética , Taquicardia Ventricular/genética , Adulto , Cardiomiopatias/complicações , Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/genética , Angiografia Coronária , Análise Mutacional de DNA , Diagnóstico Diferencial , Ecocardiografia , Feminino , Testes Genéticos , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Artes Marciais/fisiologia , Miopatias Mitocondriais/complicações , Miopatias Mitocondriais/tratamento farmacológico , Miopatias Mitocondriais/genética , Mutação , Taquicardia Ventricular/diagnóstico , Resultado do Tratamento , Troponina/sangue
16.
Rev. bras. med. esporte ; 27(1): 70-74, Jan.-Mar. 2021. tab
Artigo em Inglês | LILACS | ID: biblio-1156107

RESUMO

ABSTRACT Introduction Dehydration has been described as one of the main factors of reduced performance in combat sports activities, leading to death in extreme cases. Objective To investigate the pre-training hydration status and changes in fluid homeostasis during two taekwondo training sessions. Methods Eighteen male college athletes (age 22.6 ± 3.37 years) were assessed. The study design aimed to reproduce the conditions of a 90-minute taekwondo training session, divided into three stages: a) warm-up exercises (20 min); b) poomsae (30 min) and c) technical training (40 min). The athletes had ad libitum water intake during training. To assess the hydration status we considered body mass (BM), the amount of liquid consumed and urine output, which enabled us to establish absolute and relative fluid loss in kg and percentage as well as the sweating rate. We also considered urine specific gravity (USG), urine color (U-COL), and subjective sensation of thirst (Sthirst) before and after the training session. Pre- and post-training results were compared separately in each session and between sessions. Results There was a significant difference (P<0.05) in pre-training BM between the two days of training. There was a significant difference (P<0.05) in the final BM on both days of the experiment. Most subjects had relative dehydration below 2%. A significant difference (P<0.05) was recorded pre and post training for U-COL and Sthirst, with the highest rates obtained at the end of each session. Participants always started training at a low dehydration status (USG >1,020g.ml-1). Conclusions The athletes tended to start the training sessions in dehydration status, which increases over the course of the training. Ad libitum water intake was not sufficient to balance fluid loss. Changes in fluid levels between sessions were similar. Level of Evidence II; Therapeutic Studies Investigating the Results Level of Treatment.


RESUMO Introdução A desidratação tem sido descrita como um dos principais fatores de redução de desempenho em atividades de luta, levando, em casos extremos, à morte. Objetivos Investigar o estado da hidratação antes do treino e as alterações no balanço hídrico corporal durante dois treinamentos de taekwondo. Métodos Foram avaliados 18 atletas universitários do sexo masculino (22,6 ± 3,37 anos). O desenho do estudo procurou reproduzir uma condição de treinamento de taekwondo com duração de 90 minutos, dividido em três etapas: a) aquecimento (20 min.), b) poomsae (30 min.) e c) treino técnico (40 min.). Durante o treino, adotou-se o consumo de água ad libitum. Para avaliar o estado de hidratação, considerou-se a massa corporal (MC), a quantidade de líquido consumido e o volume de urina produzido, o que permitiu estabelecer a perda hídrica absoluta e relativa em kg e porcentagem, além da taxa de sudorese. Foi considerada ainda a gravidade específica da urina (GEU), bem como sua coloração (COL-U), além da sensação subjetiva de sede (SSede) antes e depois do treino. Os resultados antes e depois do treino foram comparados de forma isolada em cada sessão, assim como entre as sessões. Resultados Houve diferença significativa (P < 0,05) da MC pré-treinamento entre os dois dias de treino. Houve redução significativa (P < 0,05) da MC final em ambos os dias de experimento. A maior parte dos avaliados apresentou desidratação relativa inferior a 2%. Registrou-se diferença significativa (P < 0,05) antes e depois do treino para COL-U e para SSede, com os maiores índices obtidos ao final de cada sessão. Os participantes sempre iniciaram o comparados de forma isolada em cada sessão, assim como entre as sessões. Resultados Houve diferença significativa (P < 0,05) da MC pré-treinamento entre os dois dias de treino. Houve redução significativa (P < 0,05) da MC final em ambos os dias de experimento. A maior parte dos avaliados apresentou desidratação relativa inferior a 2%. Registrou-se diferença significativa (P < 0,05) antes e depois do treino para COL-U e para SSede, com os maiores índices obtidos ao final de cada sessão. Os participantes sempre iniciaram o treinamento em leve estado de desidratação (GEU > 1.020 g.ml-1). Conclusões Os atletas tendem a iniciar os treinamentos em estado de desidratação, que se amplia durante o treino. O consumo de líquidos ad libitum não foi suficiente para equilibrar a perda hídrica. As alterações hídricas entre as sessões foram semelhantes. Nível de Evidência II; Estudos terapêuticos- Investigação dos resultados do tratamento.


RESUMEN Introducción La deshidratación ha sido descrita como uno de los principales factores de reducción del desempeño en actividades de lucha, llevando, en casos extremos, a la muerte. Objetivos Investigar el estado de la hidratación antes del entrenamiento y las alteraciones en el balance hídrico corporal durante dos entrenamientos de taekwondo. Métodos Se evaluaron 18 atletas universitarios del sexo masculino (22,6 ± 3,37 años). El diseño del estudio intentó reproducir una condición de entrenamiento de taekwondo con duración de 90 minutos, dividido en tres etapas: a) calentamiento (20 min); b) poomsae (30 min); y c) entrenamiento técnico (40 min). Durante el entrenamiento, se adoptó el consumo de agua ad libitum. Para evaluar el estado de hidratación, se consideró la masa corporal (MC), la cantidad de líquido consumido y el volumen de orina producido, lo que permitió establecer la pérdida hídrica absoluta y relativa en kg y porcentaje, además de la tasa de sudoración. Fue considerada además la gravedad específica de la orina (GEO), así como su coloración (COL-O), además de la sensación subjetiva de sed (SSed), antes y después del entrenamiento. Los resultados antes y después del entrenamiento fueron comparados de forma aislada en cada sesión, así como entre las sesiones. Resultados Hubo diferencia significativa (P<0,05) de la MC preentrenamiento entre los dos días de entrenamiento. Hubo reducción significativa (P<0,05) de la MC final en ambos días de experimento. La mayor parte de los evaluados presentó deshidratación relativa inferior a 2%. Se registró diferencia significativa (P<0,05) antes y después del entrenamiento para COL-O y para SSed, con los mayores índices obtenidos al final de cada sesión. Los participantes siempre iniciaron el entrenamiento en leve estado de deshidratación (GEO > 1.020 g.ml-1). Conclusiones Los atletas tienden a iniciar los entrenamientos en estado de deshidratación, que se amplía durante el entrenamiento. El consumo de líquidos ad libitum no fue suficiente para equilibrar la pérdida hídrica. Las alteraciones hídricas entre las sesiones fueron semejantes. Nivel de Evidencia II; Estudios terapéuticos - Investigación de los resultados del tratamiento.


Assuntos
Humanos , Masculino , Adulto , Adulto Jovem , Equilíbrio Hidroeletrolítico/fisiologia , Artes Marciais/fisiologia , Ingestão de Líquidos , Urinálise , Atletas
17.
J Sports Med Phys Fitness ; 61(3): 386-400, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33092328

RESUMO

INTRODUCTION: Some methods such as ergo nutritional aids, cooling or massage among others could improve recovery in combat sports (CS). The effects, doses, duration, and timing of these methods remains unknown. Nowadays, there is no clear consensus regarding the recovery strategies and it is necessary to understand the type of fatigue induced in CS and its underlying mechanisms. The main aim of this article is to review the update literature related to recovery strategies in CS. EVIDENCE ACQUISITION: A literature search was conducted following preferred reporting items for review statement on the topic of: "combat sports," "recovery," "nutrition," "fatigue," "ergogenic aids," "weight cutting" and "hydration." EVIDENCE SYNTHESIS: The initial search of the literature detected 369 articles about CS. Later, 307 were excluded after being determined unrelated to recovery or after failure to fulfill the inclusion criteria. Of the 80 included articles, 19 satisfied the final inclusion criteria. CONCLUSIONS: To optimize CS performance, adequate recovery is required during training and competition processes. Traditional ergo nutritional supplementation of carbohydrates and proteins combined. Besides, the consumption of evidence supported supplementation (green tea, beetroot gels, creatine or alkaline water) improve recovery processes. Further methods of recovery including physical (cold water immersion, massage or photobiomodulation) and physiological (types of active recovery, sleep and rest) therapies have also been shown useful. This narrative review elucidates the important role of recovery techniques in CS.


Assuntos
Artes Marciais/fisiologia , Descanso/fisiologia , Desempenho Atlético/fisiologia , Suplementos Nutricionais , Humanos , Massagem , Sono
18.
Med Sci Sports Exerc ; 53(4): 673-683, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33105389

RESUMO

PURPOSE: This study aimed to evaluate the effects of low energy availability (EA) on health and performance indices associated with the Male Athlete Triad and Relative Energy Deficiency in Sport (RED-S) models. METHODS: Over an 8-wk period, a male combat sport athlete adhered to a phased body mass (BM) loss plan consisting of 7-wk energy intake (EI) equating to resting metabolic rate (RMR) (1700 kcal·d-1) (phase 1), 5 d of reduced EI (1200-300 kcal·d-1) before weigh-in (phase 2), and 1 wk of ad libitum EI postcompetition (phase 3). EA fluctuated day by day because of variations in exercise energy expenditure. Regular assessments of body composition, RMR, cardiac function, cardiorespiratory capacity, strength and power, psychological state and blood clinical chemistry for endocrine, bone turnover, hydration, electrolyte, renal, liver, and lipid profiles were performed. RESULTS: BM was reduced over the 8-wk period by 13.5% (72.5 to 62.7 kg). No consequences of Male Athlete Triad or RED-S were evident during phase 1, where mean daily EA equated to 20 kcal·kg·fat free mass (FFM)-1·d-1 (range, 7 to 31 kcal·kg FFM-1·d-1) and BM and fat mass (FM) losses were 6.5 and 4.4 kg, respectively. However, consequences did present in phase 2 when mean daily EA was consistently <10 kcal·kg FFM-1·d-1, as evidenced by alterations to endocrine hormones (e.g., testosterone <5 nmol.L-1) and reduced RMR (-257 kcal·d-1). CONCLUSION: Data demonstrate that 7 wk of daily fluctuations in EA equating to a mean value of 20 kcal·kg FFM-1·d-1 permits reductions of BM and FM without perturbations to physiological systems associated with the Male Athlete Triad and RED-S. By contrast, a subsequent period of five consecutive days of EA <10 kcal·kg FFM-1·d-1 induced consequences of Male Athlete Triad and RED-S.


Assuntos
Desempenho Atlético/fisiologia , Desempenho Atlético/psicologia , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Artes Marciais/fisiologia , Artes Marciais/psicologia , Atletas , Metabolismo Basal , Composição Corporal/fisiologia , Índice de Massa Corporal , Aptidão Cardiorrespiratória/fisiologia , Frequência Cardíaca , Humanos , Masculino , Força Muscular/fisiologia , Contração Miocárdica , Deficiência Energética Relativa no Esporte/sangue , Deficiência Energética Relativa no Esporte/fisiopatologia , Volume Sistólico , Testosterona/sangue , Fatores de Tempo , Perda de Peso/fisiologia , Adulto Jovem
19.
Phys Ther Sport ; 47: 15-22, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33125966

RESUMO

OBJECTIVE: To verify the effects of successive judo matches on interlimb asymmetry and bilateral deficit in judo athletes. DESIGN: Repeated measures; SETTING: University Judo center. PARTICIPANTS: Fourteen male judo athletes. OUTCOME MEASURES: Four simulated matches consisting of 4-min. Before the first match and after each match athletes were submitted to single leg tests - Countermovement Jump (SLCMJ) and Standing Long Jump (SLSLJ), and handgrip strength (HGS) in the dominant and non-dominant limbs. Interlimb asymmetry was calculated in both jumps and handgrip strength tests. RESULTS: Most jump-derived variables did not change the magnitude of asymmetry throughout the matches (p > 0.05), with the exception of jump height asymmetry in SLCMJ, that increased after the second match (p = 0.001). The HGS decreased in both hands from the first match (p < 0.001), without asymmetry. The highest bilateral strength deficit was observed in post-match 1 and post-match 2 (close to 10%). CONCLUSION: Four-successive judo matches did not change the magnitude of interlimb asymmetry, with exception of SLCMJ height, which increased after the second match. The handgrip strength decreased throughout the matches, but similarly in both hands. Finally, the direction of asymmetry showed consistency throughout the matches only for SLCMJ height.


Assuntos
Extremidades/fisiologia , Força da Mão , Artes Marciais/fisiologia , Adulto , Atletas , Teste de Esforço/métodos , Lateralidade Funcional , Humanos , Masculino , Movimento , Força Muscular , Adulto Jovem
20.
Res Q Exerc Sport ; 92(1): 1-10, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32023202

RESUMO

Purpose: The aim of this study was to compare strength-endurance handgrip performance and muscle coactivation between judo athletes and untrained young males. Method: The sample was 38 judo athletes and 38 untrained young males, between 12 and 15 years-old. Maturational status was evaluated by age at peak height velocity. A maximal isometric handgrip test (three 5-s repetitions, with 90-s intervals) and an isometric strength-endurance handgrip test (ten 10-s all-out isometric handgrip repetitions, 20-s intervals) was conducted in dominant (D) and nondominant (ND) hands, using a dynamometer with EMG monitor to detect muscle activation. Results: ANCOVA analysis, controlling for maturational status, showed that judo athletes had higher values of maximal absolute (D = 33.6 ± 8.9 kgf vs 29.1 ± 9.0 kgf; ND = 33.8 ± 9.9 kgf vs 28.1 ± 8.1 kgf) and relative strength to body mass (D = 0.64 ± 0.12 kg/kgf vs 0.57 ± 0.13 kg/kgf; ND = 0.64 ± 0.16 kg/kgf vs 0.56 ± 0.14 kg/kgf). Moreover, judo athletes presented lower strength mean fatigue index (33.2 ± 6.9 % vs 37.9 ± 8.7 %) and muscle coactivation (48 ± 19.8 % vs 57.5 ± 22 %), only in the dominant hand, during the isometric strength-endurance handgrip test. During all repetitions of isometric endurance test there were no group or interaction between factors effects for absolute strength, relative strength and muscle coactivation. Conclusion: In summary, judo athletes present higher maximal absolute and relative strength and strength-endurance performance, concomitantly with decreased muscles co-activation (primary in dominant hand) during handgrip tests.


Assuntos
Força da Mão/fisiologia , Artes Marciais/fisiologia , Músculo Esquelético/fisiologia , Resistência Física/fisiologia , Adolescente , Antropometria , Criança , Estudos Transversais , Eletromiografia , Lateralidade Funcional , Humanos , Contração Isométrica , Masculino , Fadiga Muscular , Dinamômetro de Força Muscular , Condicionamento Físico Humano/fisiologia , Maturidade Sexual
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