Analysis of Dehydration and Strength in Elite Badminton Players

Background: The negative effects of dehydration on aerobic activities are well established. However, it is unknown how dehydration affects intermittent sports performance. The purpose of this study was to identify the level of dehydration in elite badminton players and its relation to muscle strength and power production. Methodology: Seventy matches from the National Spanish badminton championship were analyzed (46 men?s singles and 24 women?s singles). Before and after each match, jump height and power production were determined during a countermovement jump on a force platform. Participants? body weight and a urine sample were also obtained before and after each match. The amount of liquid that the players drank during the match was also calculated by weighing their individual drinking bottles. Results and Discussion: Sweat rate during the game was 1.1460.46 l/h in men and 1.0260.64 l/h in women. The players rehydrated at a rate of 1.1060.55 l/h and 1.0160.44 l/h in the male and female groups respectively. Thus, the dehydration attained during the game was only 0.3760.50% in men and 0.3260.83% in women. No differences were found in any of the parameters analyzed during the vertical jump (men: from 31.8265.29 to 32.9064.49 W/kg; p.0.05, women: from 26.3664.73 to 27.2564.44 W/kg; p.0.05). Post-exercise urine samples revealed proteinuria (60.9% of cases in men and 66.7% in women), leukocyturia (men = 43.5% and women = 50.0%) and erythrocyturia (men = 50.0% and women = 21.7%). Conclusions: Despite a moderate sweat rate, badminton players adequately hydrated during a game and thus the dehydration attained was low. The badminton match did not cause muscle fatigue but it significantly increased the prevalence of proteinuria, leukocyturia and erythrocyturia

ANKLE TAPING DOES NOT IMPAIR PERFORMANCE IN JUMP OR BALANCE TESTS

This study aimed to investigate the influence of prophylactic ankle taping on two balance tests (static and dynamic balance) and one jump test, in the push off and the landing phase. Fifteen active young subjects (age: 21.0 ± 4.4 years) without previous ankle injuries volunteered for the study. Each participant performed three tests in two different situations: with taping and without taping. The tests were a counter movement jump, static balance, and a dynamic posturography test. The tests and conditions were randomly performed. The path of the center of pressures was measured in the balance tests, and the vertical ground reaction forces were recorded during the push-off and landing phases of the counter movement jump. Ankle taping had no influence on balance performance or in the push off phase of the jump. However, the second peak vertical force value during the landing phase of the jump was 12% greater with ankle taping (0.66 BW, 95% CI -0.64 to 1.96). The use of prophylactic ankle taping had no influence on the balance or jump performance of healthy young subjects. In contrast, the taped ankle increased the second peak vertical force value, which could be related to a greater risk of injury produced by the accumulation of repeated impacts in sports where jumps are frequently performe

Análise da influência da bandagem funcional de tornozelo no tempo de reação do fibular longo em sujeitos saudáveis Analysis of ankle taping influence in the peroneal reaction time in healthy subjects

OBJETIVOS: O objetivo deste estudo foi analisar a influência da bandagem funcional de tornozelo no tempo de reação do fibular longo de indivíduos sadios. MÉTODOS: A amostra foi composta por oito indivíduos do gênero masculino, fisicamente ativos, sem histórias prévias de lesões de tornozelo e, com os resultados negativos aos testes de instabilidade articular de tornozelo. Foram usados como instrumentos da pesquisa, a bandagem funcional de tornozelo tipo bota fechada, para realizar o teste uma plataforma capaz de inclinar 30o no plano frontal simulando a entorse lateral do tornozelo e um eletromiógrafo de oito canais (Bortec Electronics Incorporation, Canadá) para aquisições dos sinais eletromiográficos. Os sinais EMG foram coletados juntamente com o sinal da plataforma (sincronismo). A coleta dos dados foi realizada em dois momentos, primeiramente sem a bandagem e logo após com a bandagem. RESULTADOS: Os indivíduos tinham idade média de 23,3 anos (± 2,8), massa corpórea de 74,4kg (± 9,4), estatura de 1,7m (± 0,4) e IMC de 23,7kg/m2 (± 2,4). O estudo encontrou diferença estatisticamente significativa p = 0,018 na situação da bandagem funcional de tornozelo com diminuição do tempo de reação do fibular longo. CONCLUSÃO: Acreditamos que esta melhora se deva ao íntimo contato da bandagem com os receptores cutâneos do tornozelo, aumentando a ativação do reflexo fibular, com consequente ganho proprioceptivo e, assim, aumentando a habilidade dos sujeitos em responder a situações súbitas de entorses. O estudo demonstrou diminuição no tempo de reação do fibular longo de indivíduos sadios com o uso da bandagem funcional de tornozelo quando submetidos à inclinação lateral súbita do tornozelo.<br>OBJECTIVE: The aim of this study was to analyze the influence of the ankle functional tape on long fibular reaction time in health subjects. METHODS: The sample was composed of eight physically active male subjects, without ankle injury history and with negative results on ankle joint instabilities tests. The instruments used in this research were an ankle functional tape(closed boot type), a platform capable to 30° frontal inclination and an eight-channel electromyograph (Bortec Electronics Incorporation, Canada) for the electrical signals acquisition. The EMG signals were collected concomitantly to the platform (synchronism). Data were collected in two moments: firstly without tape and immediately after, with the tape. RESULTS: The subject average age was 23.3 years (± 2.8), body mass of 74.4 kg (± 9.4), height of 1.7 m (± 0.4) and BMI of 23.7 kg/m2. The research found statistically significant difference of p = 0.018 when the subjects were using the functional ankle tape, with a decreasing of reaction time in long fibular. CONCLUSION: We believe that this increase is related to the close contact of the functional tape with the ankle cutaneous receptors, increasing the fibular reflex activation, with a consequent proprioceptive gain and hence increasing the subjects' ability to respond to sudden ankle sprains. The study showed decrease in long fibular reaction time of health subjects while using this kind of ankle tape when submitted to a sudden lateral ankle inclination

Effects of Exercise on the Urinary Proteome

Exercise-induced proteinuria has been observed and studied for more than a century. It was found that different sport disciplines alter the urinary proteome in different ways. Moderate-intensity exercise results in increased glomerular filtration, meaning that medium-sized proteins are excreted in higher amounts, while high-intensity exercise of short duration also increases the excretion of low molecular weight proteins as a result of tubular dysfunction. Exhaustive exercise may lead to the excretion of hemoglobin or myoglobin, which changes the urinary proteome considerably. Studies comparing protein maps of different sport types compared to a control group showed that quality and quantity of urinary proteins are interindividually different. In addition, urine samples collected before and after exercise exhibit substantially different protein patterns even from the same person. Therefore, further studies investigating the urinary proteome are desirable. As the variation of protein content and composition in urine are generally much higher than in other matrices, respective studies need to be well controlled and homogenous groups of volunteers should be chosen. In addition to the sport-related physiological and biochemical interest, exercise-induced protein changes also need to be considered for biomarker measurements from urine samples for kidney or other diseases