Effects of Beta-Alanine Supplementation on Physical Performance in Aerobic-Anaerobic Transition Zones: A Systematic Review and Meta-Analysis.

Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition zones is scarce and the results controversial. The aim of this systematic review and meta-analysis is to analyze the effects of BA supplementation on physical performance in aerobic-anaerobic transition zones. At the same time, the effect of different dosages and durations of BA supplementation were identified. The search was designed in accordance with the PRISMA® guidelines for systematic reviews and meta-analyses and performed in Web of Science (WOS), Scopus, SPORTDiscus, PubMed, and MEDLINE between 2010 and 2020. The methodological quality and risk of bias were evaluated with the Cochrane Collaboration tool. The main variables were the Time Trial Test (TTT) and Time to Exhaustion (TTE) tests, the latter separated into the Limited Time Test (LTT) and Limited Distance Test (LDT). The analysis was carried out with a pooled standardized mean difference (SMD) through Hedges' g test (95% CI). Nineteen studies were included in the systematic review and meta-analysis, revealing a small effect for time in the TTT (SMD, -0.36; 95% CI, -0.87-0.16; I2 = 59%; p = 0.010), a small effect for LTT (SMD, 0.25; 95% CI, -0.01-0.51; I2 = 0%; p = 0.53), and a large effect for LDT (SMD, 4.27; 95% CI, -0.25-8.79; I2 = 94%; p = 0.00001). BA supplementation showed small effects on physical performance in aerobic-anaerobic transition zones. Evidence on acute supplementation is scarce (one study); therefore, exploration of acute supplementation with different dosages and formats on physical performance in aerobic-anaerobic transition zones is needed.

Can Creatine Supplementation Interfere with Muscle Strength and Fatigue in Brazilian National Level Paralympic Powerlifting?

The aim of the present study was to analyze the effect of creatine (Cr) supplementation on peak torque (PT) and fatigue rate in Paralympic weightlifting athletes. Eight Paralympic powerlifting athletes participated in the study, with 25.40 ± 3.30 years and 70.30 ± 12.15 kg. The measurements of muscle strength, fatigue index (FI), peak torque (PT), force (kgf), force (N), rate of force development (RFD), and time to maximum isometric force (time) were determined by a Musclelab load cell. The study was performed in a single-blind manner, with subjects conducting the experiments first with placebo supplementation and then, following a 7-day washout period, beginning the same protocol with creatine supplementation for 7 days. This sequence was chosen because of the lengthy washout of creatine. Regarding the comparison between conditions, Cr supplementation did not show effects on the variables of muscle force, peak torque, RFD, and time to maximum isometric force (p > 0.05). However, when comparing the results of the moments with the use of Cr and placebo, a difference was observed for the FI after seven days (U3: 1.12; 95% CI: (0.03, 2.27); p = 0.02); therefore, the FI was higher for placebo. Creatine supplementation has a positive effect on the performance of Paralympic powerlifting athletes, reducing fatigue index, and keeping the force levels as well as PT.

Caffeine Supplementation for 4 Days Does Not Induce Tolerance to the Ergogenic Effects Promoted by Acute Intake on Physiological, Metabolic, and Performance Parameters of Cyclists: A Randomized, Double-Blind, Crossover, Placebo-Controlled Study.

The present study investigated whether the caffeine supplementation for four days would induce tolerance to the ergogenic effects promoted by acute intake on physiological, metabolic, and performance parameters of cyclists. A double-blind placebo-controlled cross-over design was employed, involving four experimental trials; placebo (4-day)-placebo (acute)/PP, placebo (4-day)-caffeine (acute)/PC, caffeine (4-day)-caffeine (acute)/CC and caffeine (4-day)-placebo (acute)/CP. Fourteen male recreationally-trained cyclists ingested capsules containing either placebo or caffeine (6 mg∙kg-1) for 4 days. On day 5 (acute), capsules containing placebo or caffeine (6 mg∙kg-1) were ingested 60 min before completing a 16 km time-trial (TT). CC and PC showed improvements in time (3.54%, ES = 0.72; 2.53%, ES = 0.51) and in output power (2.85%, ES = 0.25; 2.53%, ES = 0.20) (p < 0.05) compared to CP and PP conditions, respectively. These effects were accompanied by increased heart rate (2.63%, ES = 0.47; 1.99%, ES = 0.34), minute volume (13.11%, ES = 0.61; 16.32%, ES = 0.75), expired O2 fraction (3.29%, ES = 0.96; 2.87, ES = 0.72), lactate blood concentration (immediately after, 29.51% ES = 0.78; 28.21% ES = 0.73 recovery (10 min), 36.01% ES = 0.84; 31.22% ES = 0.81), and reduction in expired CO2 fraction (7.64%, ES = 0.64; 7.75%, ES = 0.56). In conclusion, these results indicate that caffeine, when ingested by cyclists in a dose of 6 mg∙kg-1 for 4 days, does not induce tolerance to the ergogenic effects promoted by acute intake on physiological, metabolic, and performance parameters.

Isotonic sports drink promotes rehydration and decreases proteinuria following karate training / Suplemento hidroeletrolítico favorece reidratação e diminui proteinúria pós-treino em atletas karate

Abstract Introduction: Adequate hydration status in the sport is essential for good health, yet the relationship between hydration, proteinuria and sports is little studied. Objective: To analyze the influence of an isotonic sports drink as rehydration strategy on the hydration status and proteinuria after karate training. Methods: Ten athletes participated in this study. In the first session of standard training, called observation training session (STO), the athletes hydrated themselves according to their habits, and in the second session of standard training, called nutritional intervention training session (STIN), an ideal practice of hydration protocol was followed, using an isotonic sports drink as a rehydration liquid during the training. The hydration status was verified by monitoring the body weight before and after training, the urine specific gravity pre-and post-training and the urine volume post-training. To observe the influence of practice of hydration on the renal function post exercise proteinuria was measured. Results: We observed a statistically significant difference in urine density between the samples pre- and post-exercise only on STIN (p = 0.047). When we compare the sessions, there was a lower variation in body weight (p = 0.011) and higher urinary volume (p < 0.001), on nutritional intervention training. In STO, there was a higher percentage of athletes who showed proteinuria (70%) compared to the STIN (50%) in the urine sample after training. Conclusion: The use of isotonic sports drink as practice of hydration by karate athletes promoted rehydration during one session of training and reduce post-training proteinuria.

Resumo Introdução: Um adequado estado de hidratação durante a atividade esportiva é essencial para a manutenção da boa saúde, porém a relação entre hidratação, proteinúria e esportes é pouco estudada. Objetivo: analisar a influência de suplemento hidroeletrolítico (bebida esportiva isotônica) como estratégia de reidratação sobre o estado de hidratação e proteinúria após treino de Karate. Métodos: Dez atletas participaram deste estudo. Na primeira sessão de treino padronizado, denominada sessão de treino de observação (STO), os atletas se reidrataram segundo seus hábitos; na segunda sessão de treino padronizado, denominada sessão de treino de intervenção nutricional (STIN), foi seguido um protocolo ideal de prática de hidratação, utilizando-se de suplemento hidroeletrolítico como líquido reidratante durante o treino. O estado de hidratação foi verificado pelo monitoramento do peso corporal antes e após o treino, pela gravidade específica da urina pré e pós-treino e pelo volume urinário pós-treino. De forma a observar a influência da prática de hidratação sobre a função renal, a proteinúria pós-exercício foi medida. Resultados: Observou-se uma diferença estatisticamente significativa na densidade urinária entre as amostras coletadas pré e pós-exercício apenas na STIN (p = 0,047). Quando comparados entre sessões, houve menor variação ponderal (p = 0,011) e maior volume urinário (p < 0,001) no treino com intervenção nutricional. Na STO, houve um percentual mais elevado de atletas que apresentaram proteinúria (70%) em comparação a STIN (50%) na amostra de urina coletada após o treino. Conclusão: O uso de suplemento hidroeletrolitico como prática de hidratação por atletas de karate favoreceu a reidratação durante uma sessão de treino e reduziu a proteinúria pós-treino.

Isotonic sports drink promotes rehydration and decreases proteinuria following karate training.

INTRODUCTION: Adequate hydration status in the sport is essential for good health, yet the relationship between hydration, proteinuria and sports is little studied. OBJECTIVE: To analyze the influence of an isotonic sports drink as rehydration strategy on the hydration status and proteinuria after karate training. METHODS: Ten athletes participated in this study. In the first session of standard training, called observation training session (STO), the athletes hydrated themselves according to their habits, and in the second session of standard training, called nutritional intervention training session (STIN), an ideal practice of hydration protocol was followed, using an isotonic sports drink as a rehydration liquid during the training. The hydration status was verified by monitoring the body weight before and after training, the urine specific gravity pre-and post-training and the urine volume post-training. To observe the influence of practice of hydration on the renal function post exercise proteinuria was measured. RESULTS: We observed a statistically significant difference in urine density between the samples pre- and post-exercise only on STIN (p = 0.047). When we compare the sessions, there was a lower variation in body weight (p = 0.011) and higher urinary volume (p < 0.001), on nutritional intervention training. In STO, there was a higher percentage of athletes who showed proteinuria (70%) compared to the STIN (50%) in the urine sample after training. CONCLUSION: The use of isotonic sports drink as practice of hydration by karate athletes promoted rehydration during one session of training and reduce post-training proteinuria.

Rapid Weight Loss Elicits Harmful Biochemical and Hormonal Responses in Mixed Martial Arts Athletes.

The purpose of this study was to compare biochemical and hormonal responses between mixed martial arts (MMA) competitors with minimal prefight weight loss and those undergoing rapid weight loss (RWL). Blood samples were taken from 17 MMA athletes (Mean± SD; age: 27.4 ±5.3yr; body mass: 76.2 ± 12.4kg; height: 1.71 ± 0.05m and training experience: 39.4 ± 25 months) before and after each match, according to the official events rules. The no rapid weight loss (NWL, n = 12) group weighed in on the day of the event (~30 min prior fight) and athletes declared not having used RWL strategies, while the RWL group (n = 5) weighed in 24 hr before the event and the athletes claimed to have lost 7.4 ± 1.1kg, approximately 10% of their body mass in the week preceding the event. Results showed significant (p < .05) increases following fights, regardless of group, in lactate, glucose, lactate dehydrogenase (LDH), creatinine, and cortisol for all athletes. With regard to group differences, NWL had significantly (p < .05) greater creatinine levels (Mean± SD; pre to post) (NWL= 101.6 ± 15-142.3 ± 22.9µmol/L and RWL= 68.9 ± 10.6-79.5 ± 15.9µmol/L), while RWL had higher LDH (median [interquartile range]; pre to post) (NWL= 211.5[183-236] to 231[203-258]U/L and RWL= 390[370.5-443.5] to 488[463.5-540.5]U/L) and AST (NWL= 30[22-37] to 32[22-41]U/L and 39[32.5-76.5] to 72[38.5-112.5] U/L) values (NWL versus RWL, p < .05). Post hoc analysis showed that AST significantly increased in only the RWL group, while creatinine increased in only the NWL group. The practice of rapid weight loss showed a negative impact on energy availability and increased both muscle damage markers and catabolic expression in MMA fighters.

Carbohydrate-dependent, exercise-induced gastrointestinal distress.

Gastrointestinal (GI) problems are a common concern of athletes during intense exercise. Ultimately, these symptoms can impair performance and possibly prevent athletes from winning or even finishing a race. The main causes of GI problems during exercise are mechanical, ischemic and nutritional factors. Among the nutritional factors, a high intake of carbohydrate and hyperosmolar solutions increases GI problems. A number of nutritional manipulations have been proposed to minimize gastrointestinal symptoms, including the use of multiple transportable carbohydrates. This type of CHO intake increases the oxidation rates and can prevent the accumulation of carbohydrate in the intestine. Glucose (6%) or glucose plus fructose (8%-10%) beverages are recommended in order to increase CHO intake while avoiding the gastric emptying delay. Training the gut with high intake of CHO may increase absorption capacity and probably prevent GI distress. CHO mouth rinse may be a good strategy to enhance performance without using GI tract in exercises lasting less than an hour. Future strategies should be investigated comparing different CHO types, doses, and concentration in exercises with the same characteristics.

Frequência dos defeitos de aprumo em equinos da raça quarto de milha de modalidade esportiva / Comparison of postural defects in american quarter horses in sports modality

Posture defects are known to be predisposing factors in the development of musculo-skeleton lesions. The present study therefore aimed to investigate the frequency of postural defects, evaluating and comparing quarter horses in sports modalities of cutting and team penning. The posture of 30 quarter horses from the Sérgio Martins Stud in Uberlândia was evaluated, of which 20 practiced cutting and the remaining 10 did team penning. The animals posture was examined by visual evaluation, which involved three views, the cranial, lateral and caudal. The distribution of frequency and statistical analysis were carried out using Fisher"s Exact Test. In the cranial view, the defects found were open and closed posture at the front and knock-knees. The lateral view identified the following defects; leaning forward, buck-knees and camped back. From the caudal view, the defects found were open and closed hind posture and cow-hocks. On comparing, by means of statistical tests, the main postural defects that showed statistical significance, cowhock and closed hind posture were the most common for animals that did team penning. We can conclude that these animals had a higher frequency of cowhocks and closed hind posture than animals that practiced cutting.

Os defeitos de aprumo são conhecidos como fatores predisponentes no desenvolvimento de lesões no aparelho locomotor. Dessa forma, objetivou-se com este trabalho averiguar a frequência de defeitos de aprumo, avaliando e comparando equinos da raça quarto de milha de modalidades esportivas apartação e team penning. Foram avaliados os aprumos de 30 equinos da raça quarto de milha, sendo 20 da modalidade esportiva apartação e 10 de team penning. Os animais foram examinados por avaliação visual dos aprumos, onde foram observados pelas três vistas, cranial, lateral e caudal. Foi realizada a distribuição de frequência e a análise estatística por meio do Fishers Exact Test. Na vista cranial, foram encontrados os defeitos de aprumo aberto e fechado de frente e joelho cambaio. Na vista lateral, identificou os seguintes defeitos; debruçado de frente e transcurvo e avançado e plantado de trás. Na vista caudal, encontrou os defeitos de aprumo aberto e fechado de trás e jarrete fechado. Ao comparar, por meio do teste estatístico, os maiores defeitos de aprumos foram os animais com defeito de jarrete fechado e com o defeito fechado de trás, na modalidade team penning. Portanto, os animais da modalidade team penning tiveram uma frequência para jarrete fechado e fechado de trás maior do que os animais de apartação.

Frequência dos defeitos de aprumo em equinos da raça quarto de milha de modalidade esportiva / Comparison of postural defects in american quarter horses in sports modality

Posture defects are known to be predisposing factors in the development of musculo-skeleton lesions. The present study therefore aimed to investigate the frequency of postural defects, evaluating and comparing quarter horses in sports modalities of cutting and team penning. The posture of 30 quarter horses from the Sérgio Martins Stud in Uberlândia was evaluated, of which 20 practiced cutting and the remaining 10 did team penning. The animals posture was examined by visual evaluation, which involved three views, the cranial, lateral and caudal. The distribution of frequency and statistical analysis were carried out using Fisher"s Exact Test. In the cranial view, the defects found were open and closed posture at the front and knock-knees. The lateral view identified the following defects; leaning forward, buck-knees and camped back. From the caudal view, the defects found were open and closed hind posture and cow-hocks. On comparing, by means of statistical tests, the main postural defects that showed statistical significance, cowhock and closed hind posture were the most common for animals that did team penning. We can conclude that these animals had a higher frequency of cowhocks and closed hind posture than animals that practiced cutting.(AU)

Os defeitos de aprumo são conhecidos como fatores predisponentes no desenvolvimento de lesões no aparelho locomotor. Dessa forma, objetivou-se com este trabalho averiguar a frequência de defeitos de aprumo, avaliando e comparando equinos da raça quarto de milha de modalidades esportivas apartação e team penning. Foram avaliados os aprumos de 30 equinos da raça quarto de milha, sendo 20 da modalidade esportiva apartação e 10 de team penning. Os animais foram examinados por avaliação visual dos aprumos, onde foram observados pelas três vistas, cranial, lateral e caudal. Foi realizada a distribuição de frequência e a análise estatística por meio do Fishers Exact Test. Na vista cranial, foram encontrados os defeitos de aprumo aberto e fechado de frente e joelho cambaio. Na vista lateral, identificou os seguintes defeitos; debruçado de frente e transcurvo e avançado e plantado de trás. Na vista caudal, encontrou os defeitos de aprumo aberto e fechado de trás e jarrete fechado. Ao comparar, por meio do teste estatístico, os maiores defeitos de aprumos foram os animais com defeito de jarrete fechado e com o defeito fechado de trás, na modalidade team penning. Portanto, os animais da modalidade team penning tiveram uma frequência para jarrete fechado e fechado de trás maior do que os animais de apartação.(AU)