17 resultados para elite athletes

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Athletes from many sports that are categorized by body mass tend to reduce it to fit in lower categories. Such reduction can compromise the athlete's performance and health. In order to determine the most appropriate category, the body composition is highly relevant, especially to avoid excessive reduction. Thus, this study analyzed the morphological profile of Brazilian Jiu-Jitsu elite athletes. The sample was composed of 11 athletes, aged 25.8 +/- 3.3 years, medalists in national and/or international competitions. The analysis was performed to determine the anthropometric body composition and somatotype. Body fat percentage from this population was 10.3 +/- 2.6 % fat, a high percentage of muscle mass (61.3 +/- 1.5 %), and predominant mesomorphic component (5.5 +/- 1.0) was observed. The points of highest and lowest fat accumulation were respectively abdominal (15.7 +/- 6.3 mm) and chest (6.8 +/- 1.5 mm) regions. It can be concluded that athletes from this sport showed higher body mass during the preparatory period than in competitive conditions (4.4 +/- 2.4 %); however, they showed low body fat, high muscle mass percentage and predominant mesomorphic component.

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Atletas de diversas modalidades esportivas categorizadas pela massa corporal a reduzem para se enquadrarem em categorias inferiores. Essas reduções podem comprometer o desempenho e a saúde dos atletas. Para a determinação da categoria mais adequada é de suma importância o conhecimento da composição corporal, para que se evite a redução excessiva. Desta forma, o presente estudo buscou analisar o perfil morfológico de atletas de elite de Brazilian Jiu-Jitsu. A amostra constitui-se de 11 atletas com 25,8 ± 3,3 anos, medalhistas em competições de nível nacional e/ou internacional. Realizou-se análise antropométrica para determinação de composição corporal e somatotipo. Observou-se percentual de gordura (10,3 ± 2,6%) dentro das indicações para esta população, alto percentual de massa muscular (61,3 ± 1,5%), assim como componente mesomórfico predominante (5,5 ± 1,0). Os pontos de maior e menor acúmulo de gordura foram as regiões abdominal (15,7 ± 6,3mm) e peitoral (6,8 ± 1,5mm), respectivamente. Conclui-se que atletas desta modalidade em período preparatório apresentam peso superior ao peso competitivo (4,4 ± 2,4%), embora apresentem níveis de massa gorda dentro das recomendações, alto percentual de massa muscular e componente mesomórfico predominante.

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The objective was to determine the effects of carbohydrate (CHO) supplementation on exercise-induced hormone responses and post-training intramyocellular lipid stores (IMCL). Twenty-four elite male athletes (28.0 +/- 1.2 years) were randomized to receive CHO (maltodextrin solution) or zero energy placebo solution (control group). The high-intensity running protocol consisted of 10 x 800 m at 100% of the best 3000-m speed (Vm3 km) and 2 x 1000 m maximal bouts in the morning and a submaximal 10-km continuous easy running in the afternoon of day 9. IMCL concentrations were assessed by H-1-MRS before (-day 9) and after training (day 9) in soleus (SO) and tibialis anterior (TA) muscles. Blood hormones were also measured before, during, and post-exercise. The percent change (Delta%) in TA-IMCL was higher in the CHO group (47.9 +/- 24.5 IMCL/Cr) than in the control group (-1.7 +/- 13.1, respectively) (P=.04). Insulin concentrations were higher in the CHO group post-intermittent running compared to control (P=.02). Circulating levels of free fatty acids and GH were lower in the CHO group (P>.01). The decline in performance in the 2nd 1000-m bout was also attenuated in this group compared to control (P<.001 and P=.0035, respectively). The hormonal milieu (higher insulin and lower GH levels) in the CHO group, together with unchanged free fatty acid levels, probably contributed to the increased IMCL stores. This greater energy storage capacity may have improved post-exercise recovery and thus prevented performance deterioration. (C) 2012 Elsevier Inc. All rights reserved.

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In this study, the physiological responses and rate of perceived exertion in Brazilian jiu-jitsu fighters submitted to a combat simulation were investigated. Venous blood samples and heart rate were taken from twelve male Brazilian jiu-jitsu athletes (27.1+/-2.7 yrs, 75.4+/-8.8 kg, 174.9+/-4.4 cm, 9.2+/-2.4% fat), at rest, after a warm-up (ten minutes), immediately after the fight simulation (seven minutes) and after recovery (fourteen minutes). After the combat the rate of perceived exertion was collected. The combat of the Brazilian jiu-jitsu fighters did not change blood concentrations of glucose, triglycerides, total cholesterol, low density lipoprotein and very low density lipoprotein, ureia and ammonia. However, blood levels of high density lipoprotein were significantly higher post-fight (before: 43.0+/-6.9 mg/dL, after: 45.1+/-8.0 mg/dL) and stayed at high levels during the recovery period (43.6+/-8.1 mg/dL) compared to the rest values (40.0+/-6.6 mg/dL). The fight did not cause changes in the concentrations of the cell damage markers of creatine kinase, aspartate aminotransferase and creatinine. However, blood concentrations of the alanine aminotransferase (before: 16.1+/-7.1 U/L, after: 18.6+/-7.1 U/L) and lactate dehydrogenase (before: 491.5+/-177.6 U/L, after: 542.6+/-141.4 U/L) enzymes were elevated after the fight. Heart rate (before: 122+/-25 bpm, after: 165+/-17 bpm) and lactate (before: 2.5+/-1.2 mmol/L, after: 11.9+/-5.8 mmol/L) increased significantly with the completion of combat. Despite this, the athletes rated the fight as being light or somewhat hard (12+/-2). These results showed that muscle glycogen is not the only substrate used in Brazilian jiu-jitsu fights, since there are indications of activation of the glycolytic, lipolytic and proteolytic pathways. Furthermore, the athletes rated the combats as being light or somewhat hard although muscle damage markers were generated.

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Mortatti, AL, Moreira, A, Aoki, MS, Crewther, BT, Castagna, C, de Arruda, AFS, and Filho, JM. Effect of competition on salivary cortisol, immunoglobulin A, and upper respiratory tract infections in elite young soccer players. J Strength Cond Res 26(5): 1396-1401, 2012-The present study examined the effect of a 20-day period of competition on salivary cortisol, mucosal immunity, and upper respiratory tract infections (URTI) in young male soccer players (n = 14). The players were monitored during the main under-19 Brazilian soccer championship, in which 7 matches were played in 20 days. Saliva samples were collected in the morning of each match and analyzed for cortisol and immunoglobulin A (IgA). Signs and symptoms of URTI were assessed across the study and a rating of perceived exertion (RPE) was obtained for each match. Compared with match 1, a significant increase in player RPE was observed in matches 4-7 (p < 0.05). Significant (p < 0.05) increases in the reporting of URTI occurred between matches 2 and 3, and 6 and 7, and this was accompanied by significant decreases in salivary IgA levels. Significant (p < 0.05) correlations were also seen between the individual reports of URTI and the decrease in IgA levels in match 2 (r = -0.60) and match 6 (r = -0.65). These results suggest that decrements in mucosal immunity, as measured by salivary IgA concentrations, may lead to a greater incidence of URTI in elite young soccer players. It may be speculated that the physiological and psychological stressors imposed by training and competition in a short timeframe are major contributing factors to these responses. Thus, the monitoring of salivary IgA could provide a useful and noninvasive approach for predicting URTI occurrences in young athletes during short-term competitions, especially if frequent sampling and rapid measurements are made.

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The aim of the present study was to compare performance and physiological responses during arm and leg aerobic power tests of combat duration in male child, cadet and senior judo athletes. Power output and physiological parameters, i.e., peak oxygen uptake ((V)over dotO(2)peak), peak ventilation, peak heart rate, lactate, and rate of perceived exertion, of 7 child (under 15 years: age class U15, 12.7 +/- 1.1 yrs), 10 cadet (U17, 14.9 +/- 0.7 yrs) and 8 senior (+20, 29.3 +/- 9.2 yrs) male judo athletes were assessed during incremental tests of combat duration on an arm crank and a cycle ergometer. Children as well as cadets demonstrated higher upper body relative VO(2)peak than seniors (37.3 +/- 4.9, 39.2 +/- 5.0 and 31.0 +/- 2.1 ml.kg(-1).min(-1), respectively); moreover, upper and lower body relative VO(2)peak decreased with increasing age (r = -0.575, p < 0.003 and r = -0.580, p < 0.002, respectively). Children showed lower blood lactate concentrations after cranking as well as after cycling when compared to seniors (7.8 +/- 2.4 vs. 11.4 +/- 2.1 mmol.l(-1) and 7.9 +/- 3.0 vs. 12.0 +/- 1.9 mmol.l(-1), respectively); furthermore, blood lactate values after cranking increased with age (r = 0.473, p < 0.017). These differences should be considered in planning the training for judo athletes of different age classes.

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Background and Study Aim: The grip strength endurance is important for Brazilian Jiu-Jitsu (BJJ). Thus, the aims of this study were: a) to test the reliability of two kimono grip strength tests named maximum static lift (MSL) and maximum number of repetitions (MNR) and b) to examine differences between elite and non-elite BJJ players in these tests. Material/Methods: Thirty BJJ players participated into two phases: "A" to test reliability and "B" to compare elite and non-elite. In phase A, twenty participants performed the MSL and, 15 min later, the MNR in two occasions with 24-h interval. In phase B, ten other BJJ practitioners (non-elite) and ten athletes (elite) performed the same tests. The intraclass correlation coefficient (ICC) two way fixed model (3,1), Bland-Altman plot and the limits of agreement were used to test reliability, correlation between the tests were evaluated by Pearson correlations and independent T test (P<0.05) was utilized to compare elite vs. non-elite. Results: The ICC was high for repeated measurements on different days of phase A (MSL: r=0.99 and MNR: r=0.97). Limits of agreement for time of suspension were -6.9 to 2.4-s, with a mean difference of -2.3 s (CI: -3.3 to -1.2-s), while for number of repetitions the limits of agreement were -2.9 to 2.3-rep, with a mean difference of -0.3-rep (CI: -0.9 to 0.3-rep). In phase B, elite presented better performance for both tests (P<0.05) compared to non-elite (56 +/- 10-s vs. 37 +/- 11-s in MSL and 15 +/- 4-rep vs. 8 +/- 3-rep in MNR). Moderate correlation were found between MSL and MNR for absolute values during test (r=0.475; p=0.034), and retest phases (r=0.489; p=0.029), while moderate and high correlations in the test (r=0.615; p=0.004) and retest phases (r=0.716; p=0.001) were found for relative values, respectively. Conclusions: These proposed tests are reliable and both static and dynamic grip strength endurance tests seem to differentiate BJJ athletes from different levels.

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Objective: To determine the prevalence of exercise-induced bronchoconstriction among elite long-distance runners in Brazil and whether there is a difference in the training loads among athletes with and without exercise-induced bronchoconstriction. Methods: This was a cross-sectional study involving elite long-distance runners with neither current asthma symptoms nor a diagnosis of exercise-induced bronchoconstriction. All of the participants underwent eucapnic voluntary hyperpnea challenge and maximal cardiopulmonary exercise tests, as well as completing questionnaires regarding asthma symptoms and physical activity, in order to monitor their weekly training load. Results: Among the 86 male athletes recruited, participation in the study was agreed to by 20, of whom 5 (25%) were subsequently diagnosed with exercise-induced bronchoconstriction. There were no differences between the athletes with and without exercise-induced bronchoconstriction regarding anthropometric characteristics, peak oxygen consumption, baseline pulmonary function values, or reported asthma symptoms. The weekly training load was significantly lower among those with exercise-induced bronchoconstriction than among those without. Conclusions: In this sample of long-distance runners in Brazil, the prevalence of exercise-induced bronchoconstriction was high.

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OBJETIVO: Determinar a prevalência de broncoespasmo induzido por exercício em corredores brasileiros de longa distância de elite e se há uma diferença na carga de treinamento entre atletas com e sem broncoespasmo induzido por exercício. MÉTODOS: Estudo transversal com corredores de longa distância de elite sem sintomas atuais de asma e sem diagnóstico de broncoespasmo induzido por exercício. Todos os participantes foram submetidos ao teste de hiperventilação voluntária eucápnica e ao teste cardiopulmonar de esforço máximo e responderam a questionários sobre sintomas de asma e atividade física para monitorizar sua carga de treinamento semanal. RESULTADOS: Dos 86 atletas do sexo masculino recrutados, 20 concordaram em participar do estudo, dos quais 5 (25%) foram diagnosticados com broncoespasmo induzido por exercício. Não foram evidenciadas diferenças entre os atletas com e sem broncoespasmo induzido por exercício em relação a características antropométricas, consumo de oxigênio de pico, valores basais de função pulmonar ou sintomas de asma relatados. A carga de treinamento semanal foi significativamente menor nos atletas com broncoespasmo induzido por exercício do que naqueles sem esse diagnóstico. CONCLUSÕES: Nesta amostra de corredores de longa distância brasileiros, a prevalência de broncoespasmo induzido por exercício foi alta.

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The aim of this study was to compare time-motion indicators during judo matches performed by athletes from different age groups. The following age groups were analysed: Pre-Juvenile (13-14 years, n=522), Juvenile (15-16 years, n 353); Junior (19 years, n = 349) and Senior (>20 years, n = 587). The time-motion indicators included: Total Combat Time, Standing Combat Time, Displacement Without Contact, Gripping Time, Groundwork Combat Time and Pause Time. Analysis of variance (ANOVA) one-way and the Tukey test, as well as the Kruskal-Wallis test and Mann-Whitney (for non-parametric data), were conducted, using P < 0.05 as significance level. The results showed that all analysed groups obtained a median of 7 (first quantile - 3, third quantile - 12) sequences of combat/pause cycles. In total time of combat, the result was: for Total Combat Time, Standing Combat Time and Gripping Time: Pre-Juvenile and Senior were significantly longer than Juvenile and Junior. Considering Displacement Without Contact, Junior was significantly longer than all other age groups. For Groundwork Combat Time, Senior was significantly longer than all other age groups and Pre-Juvenile was longer than Junior. These results can be used to improve the physiological performance in intermittent practices, as well as technicaltactical training during judo sessions.

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The purpose of this study was to investigate energy system contributions and energy costs in combat situations. The sample consisted of 10 male taekwondo athletes (age: 21 +/- 6 years old; height: 176.2 +/- 5.3 cm; body mass: 67.2 +/- 8.9 kg) who compete at the national or international level. To estimate the energy contributions, and total energy cost of the fights, athletes performed a simulated competition consisting of three 2 min rounds with a 1 min recovery between each round. The combats were filmed to quantify the actual time spent fighting in each round. The contribution of the aerobic (WAER), anaerobic alactic (W-PCR), and anaerobic lactic (Wleft perpendicularLA-right perpendicular) energy systems was estimated through the measurement of oxygen consumption during the activity, the fast component of excess post-exercise oxygen consumption, and the change in blood lactate concentration in each round, respectively. The mean ratio of high intensity actions to moments of low intensity (steps and pauses) was similar to 1:7. The W-AER, W-PCR and (Wleft perpendicularLA-right perpendicular) system contributions were estimated as 120 +/- 22 kJ (66 +/- 6%), 54 +/- 21 kJ (30 +/- 6%), 8.5 kJ (4 +/- 2%), respectively. Thus, training sessions should be directed mainly to the improvement of the anaerobic alactic system (responsible by the highintensity actions), and of the aerobic system (responsible by the recovery process between high- intensity actions).

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The purpose of this study was to determine the physiological, anthropometric, performance, and nutritional characteristics of the Brazil Canoe Polo National Team. Ten male canoe polo athletes (age 26.7 +/- 4.1 years) performed a battery of tests including assessments of anthropometric parameters, upper-body anaerobic power (Wingate), muscular strength, aerobic power, and nutritional profile. In addition, we characterized heart rate and plasma lactate responses and the temporal pattern of the effort/recovery during a simulated canoe polo match. The main results are as follows: body fat, 12.3 +/- 4.0%; upper-body peak and mean power, 6.8 +/- 0.5 and 4.7 +/- 0.4 W . kg(-1), respectively; 1-RM bench press, 99.1 +/- 11.7 kg; peak oxygen uptake, 44.3 +/- 5.8 mL . kg(-1) . min(-1); total energy intake, 42.8 +/- 8.6 kcal . kg(-1); protein, carbohydrate, and fat intakes, 1.9 +/- 0.1, 5.0 +/- 1.5, and 1.7 +/- 0.4 g . kg(-1), respectively; mean heart rate, 146 +/- 11 beats . min(-1); plasma lactate, 5.7 +/- 3.8 mmol . L-1 at half-time and 4.6 +/- 2.2 mmol . L-1 at the end of the match; effort time (relative to total match time), 93.1 +/- 3.0%; number of sprints, 9.6 +/- 4.4. The results of this study will assist coaches, trainers, and nutritionists in developing more adequate training programmes and dietary interventions for canoe polo athletes.

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The aim of this study was to evaluate the effect of carbohydrate supplementation on free plasma DNA and conventional markers of training and tissue damage in long-distance runners undergoing an overload training program. Twenty-four male runners were randomly assigned to two groups (CHO group and control group). The participants were submitted to an overload training program (days 1-8), followed by a high-intensity intermittent running protocol (10 x 800 m) on day 9. The runners received maltodextrin solution (CHO group) or zero energy placebo solution as the control equivalent before, during, and after this protocol. After 8 days of intensive training, baseline LDH levels remained constant in the CHO group (before: 449.1 +/- 18.2, after: 474.3 +/- 22.8 U/L) and increased in the control group (from 413.5 +/- 23.0 to 501.8 +/- 24.1 U/L, p < 0.05). On day 9, LDH concentrations were lower in the CHO group (509.2 +/- 23.1 U/L) than in the control group (643.3 +/- 32.9 U/L, p < 0.01) post-intermittent running. Carbohydrate ingestion attenuated the increase of free plasma DNA post-intermittent running (48,240.3 +/- 5,431.8 alleles/mL) when compared to the control group (73,751.8 +/- 11,546.6 alleles/mL, p < 0.01). Leukocyte counts were lower in the CHO group than in the control group post-intermittent running (9.1 +/- 0.1 vs. 12.2 +/- 0.7 cells/mu L; p < 0.01) and at 80 min of recovery (10.6 +/- 0.1 vs. 13.9 +/- 1.1 cells/mu L; p < 0.01). Cortisol levels were positively correlated with free plasma DNA, leukocytes, and LDH (all r > 0.4 and p < 0.001). The results showed that ingestion of a carbohydrate beverage resulted in less DNA damage and attenuated the acute post-exercise inflammation response, providing better recovery during intense training.

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The aim of this study was to investigate the methods adopted to reduce body mass (BM) in competitive athletes from the grappling (judo, jujitsu) and striking (karate and tae kwon do) combat sports in the state of Minas Gerais, Brazil. An exploratory methodology was employed through descriptive research, using a standardized questionnaire with objective questions self-administered to 580 athletes (25.0 +/- 3.7 yr, 74.5 +/- 9.7 kg, and 16.4% +/- 5.1% body fat). Regardless of the sport, 60% of the athletes reported using a method of rapid weight loss (RWL) through increased energy expenditure. Strikers tend to begin reducing BM during adolescence. Furthermore, 50% of the sample used saunas and plastic clothing, and only 26.1% received advice from a nutritionist. The authors conclude that a high percentage of athletes uses RWL methods. In addition, a high percentage of athletes uses unapproved or prohibited methods such as diuretics, saunas, and plastic clothing. The age at which combat sport athletes reduce BM for the first time is also worrying, especially among strikers.

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Introduction: The ankle sprain is one of the most common injuries in athletes. Direct evaluation of the ligament laxity can be obtained through the objective measurement of extreme passive inversion and eversion movements, but there are few studies on the use of the evaluation of the passive resistive torque of the ankle to assess the capsule and ligaments resistance. Objective: The aim of this study was to compare the inversion and eversion passive torque in athletes with and without ankle sprains history. Method: 32 female basketball and volleyball athletes (16.06 +/- 0.8 years old; 67.63 +/- 8.17 kg; 177.8 +/- 6.47 cm) participated in this study. Their ankles were divided into two groups: control group (29), composed of symptom-free ankles, and ankle sprain group, composed of ankles which have suffered injury (29). The resistive torque at maximum passive ankle movement was measured by the isokinetic dynamometer and the muscular activity by electromyography system. The athletes performed 2 repetitions of inversion and eversion movement at 5, 10 and 20 degrees/s and the same protocol only at maximum inversion movement. Results: The resistive passive torque during the inversion and eversion was lower in the ankle sprain group. This group also showed lower torques at the maximum inversion movement. No differences were observed between inversion and eversion movement. Conclusions: Ankle sprain leads to lower passive torque, indicating reduction of the resistance of the lateral ankle ligaments and mechanical laxity.