Resistance Training and the Effect of Load Blinding in Multiple Repetition Maximum Tests.

PURPOSE: To compare performance in successive 1-repetition maximum (1RM) tests with the load known or unknown. METHODS: Thirty-two resistance-trained men were randomly divided into 2 groups: load blinding (BLI; n = 16; age 28.1 [6.9] y, body mass 83.1 [11.5] kg, height 175.3 [5.8] cm) and load nonblinding (nBLI; n = 16; age 27.7 [4.1] y, body mass 83.2 [12.8] kg, height 178.7 [7.3] cm). The groups performed a 1RM test during 4 days (with an interval of 24-48 h) in the horizontal bench press with free weight. RESULTS: In the BLI, there were no significant changes throughout the tests, with a difference of 1.6% between the first and fourth 1RM tests. In the nBLI, there was a significant interaction with time, and the values of the second (P = .03), third (P = .02), and fourth (P = .01) tests were higher than the first test; in addition, the fourth test was significantly higher than the second test (P = .02). The percentage difference between the last and first 1RM tests was 7.1%. The comparison between the groups demonstrated differences in the third (P = .04) and fourth (P = .02) tests with higher values in the nBLI. The intraclass correlation coefficient between the first and fourth 1RM tests was .93 for the BLI and .91 for the nBLI. CONCLUSION: BLI does not influence 1RM testing in the bench press exercise.

L-arginine supplementation improves post-exercise hypotension in elderly women / Suplementação de l-arginina potencializa a hipotensão pós-exercício em mulheres idosas / La suplementación de l-arginina potencializa la hipotensión post ejercicio en mujeres de la tercera edad

ABSTRACT Introduction: L-Arginine supplementation increases plasma levels of nitric oxide (NO) metabolites, an important mediator of peripheral dilatation. Therefore, L-Arginine supplementation can improve the duration and magnitude of post-exercise hypotension. Objectives: This study investigated the effects of L-Arginine supplementation on post-exercise hypotension, femoral artery area and heart rate variability in elderly women. Methods: Twenty prehypertensive and hypertensive adult female participants were divided (in a random and balanced manner) into two groups (placebo and L-arginine). The participants ingested eight grams of inert substance (placebo group) or eight grams of L-Arginine (L-arginine group), dissolved in water, 90 min prior to the experimental session. The experimental session consisted of an isokinetic maximal strength test. Blood pressure was measured using an oscillometric device (Omron MX3 Plus, Bannockburn, US) every 10 minutes for 60 minutes after the experimental session. Femoral artery area (ultrasound) and heart rate variability were also analyzed. Data underwent repeated measures (ANOVA) analysis and respective assumptions. Results: L-Arginine supplementation associated with exercise produced a significant decrease in systolic blood pressure [placebo vs L-Arginine] (p <0.05) at the "half-life" time point (90 minutes after supplementation) (141±12 vs 130±11 mmHg) and 40 min. (146±13 vs 127±13 mmHg), 50 min. (145±20 vs 127±15 mmHg) and 60 min. (147±19 vs 129±14mmHg) post-exercise. No significant differences were identified in femoral artery area and heart rate variability. Conclusion: Acute L-Arginine supplementation can increase post-exercise hypotension effects in elderly women. Additionally, acute L-Arginine supplementation is not related to either femoral artery area or heart rate variability responses. Level of evidence I; Randomized clinical trial.

RESUMO Introdução: A suplementação de L-arginina aumenta os níveis plasmáticos dos metabólitos de óxido nítrico, um importante mediador da dilatação periférica. Dessa forma, é possível que a suplementação de L-arginina maximize a duração e a magnitude dos efeitos hipotensores pós-exercício. Objetivos: O presente estudo investigou os efeitos da suplementação de L-arginina na hipotensão pós-exercício, área da artéria femoral e variabilidade da frequência cardíaca em mulheres idosas. Métodos: Vinte participantes, adultas, pré-hipertensas e hipertensas foram divididas (de modo aleatório e equilibrado)em dois grupos (placebo e L-arginina). As participantes ingeriram oito gramas de substância inerte (grupo placebo) ou oito gramas de L-arginina (grupo L-arginina), dissolvido em água, 90 min antes da realização da sessão experimental. A sessão experimental consistia em um teste de força isocinética máxima. A pressão arterial foi aferida utilizando um dispositivo oscilométrico (Omron MX3 Plus, Bannockburn, EUA) a cada 10 minutos, durante 60 minutos, após o término da sessão experimental. Foram analisadas ainda a variabilidade da frequência cardíaca e a área da artéria femoral (ultrassom). Os dados foram submetidos à análise de variância para medidas repetidas (ANOVA) e seus respectivos pressupostos. Resultados: A suplementação de L-arginina associada ao exercício promoveu redução significativa da pressão arterial sistólica [placebo vs. L-arginina] (p<0,05) no intervalo de "meia-vida" (90 minutos após a suplementação) (141±12 vs. 130±11 mmHg) e aos 40 min. (146±13 vs. 127±13 mmHg), 50 min. (145±20 vs. 127±15 mmHg) e 60 min. (147±19 vs. 129±14 mmHg) pós-exercício. Não foram identificadas diferenças significativas na área da artéria femoral e na variabilidade da frequência cardíaca. Conclusão: A suplementação aguda de L-arginina pode potencializar os efeitos hipotensores pós-exercício em mulheres idosas. Além disso, a suplementação de L-arginina aguda não está associada às respostas de variabilidade da frequência cardíaca ou da área da artéria femoral. Nível de evidência I; Ensaio clínico randomizado.

RESUMEN Introducción: La suplementación de L-arginina aumenta los niveles plasmáticos de los metabolitos de óxido nítrico, un importante mediador de la dilatación periférica. De esa forma, es posible que la suplementación de L-arginina maximice la duración y la magnitud de los efectos hipotensores post ejercicio. Objetivos: El presente estudio investigó los efectos de la suplementación de L-arginina en la hipotensión post ejercicio, área de la arteria femoral y variabilidad de la frecuencia cardíaca en mujeres de la tercera edad. Métodos: Veinte participantes, adultas, pre hipertensas e hipertensas fueron divididas (de modo aleatorio y equilibrado) en dos grupos (placebo y L-arginina). Las participantes ingirieron ocho gramos de sustancia inerte (grupo placebo) u ocho gramos de L-arginina (grupo L-arginina), disuelta en agua, 90 minutos antes de la realización de la sesión experimental. La sesión experimental consistía en un test de fuerza isocinética máxima. La presión arterial fue medida utilizando un dispositivo oscilométrico (Omron MX3 Plus, Bannockburn, EE.UU.) a cada 10 minutos, durante 60 minutos, después del término de la sesión experimental. Fueron analizadas además la variabilidad de la frecuencia cardíaca y el área de la arteria femoral (ultrasonido). Los datos fueron sometidos a análisis de variancia para medidas repetidas (ANOVA) y sus respectivas premisas. Resultados: La suplementación de L-arginina asociada al ejercicio promovió reducción significativa de la presión arterial sistólica [placebo vs. L-arginina] (p<0,05) en el intervalo de "media vida" (90 minutos después de la suplementación) (141±12 vs. 130±11 mmHg) y a los 40 min. (146±13 vs. 127±13 mmHg), 50 min. (145±20 vs. 127±15 mmHg) y 60 min. (147±19 vs. 129±14 mmHg) post ejercicio. No fueron identificadas diferencias significativas en el área de la arteria femoral ni en la variabilidad de la frecuencia cardíaca. Conclusión: La suplementación aguda de L-arginina puede potencializar los efectos hipotensores post ejercicio en mujeres de la tercera edad. Además, la suplementación de L-arginina aguda no está asociada a las respuestas de variabilidad de la frecuencia cardíaca o del área de la arteria femoral. Nivel de evidencia I; Ensayo clínico aleatorizado.

Inter-Individual Responses to Citrulline Malate Oral Supplementation on Post-Exercise Hypotension in Hypertensives: A 24-Hour Analysis / Respostas Interindividuais à Suplementação Oral de Citrulina Malato na Hipotensão Pós-Exercício em Hipertensos: Uma Análise de 24 Horas

Abstract Background: Studies have persuasively demonstrated that citrulline has a key role in the arginine-nitric oxide system, increasing nitric oxide bioavailability, an important mediator of peripheral vasodilation. Objective: To analyze the inter-individual post-exercise hypotension responsiveness following acute citrulline supplementation in hypertensives. Methods: Forty hypertensives were randomly assigned to one of the four experimental groups (control-placebo, control-citrulline, exercise-placebo, and exercise-citrulline). They ingested placebo or citrulline malate [CM] (6 grams). During the exercise session, individuals performed 40 minutes of walking/running on a treadmill at 60-70% of HR reserve. For the control session, the individuals remained seated at rest for 40 minutes. Office blood pressure (BP) was taken every 10 minutes until completing 60 minutes after the experimental session. The ambulatory BP device was programmed to take the readings every 20 minutes (awake time) and every 30 minutes (sleep time) over the course of 24 hours of monitoring. Statistical significance was defined as p < 0.05. Results: Unlike the other experimental groups, there were no "non-responders" in the exercise/citrulline (EC) for "awake" (systolic and diastolic BP) and "24 hours" (diastolic BP). The effect sizes were more consistent in the EC for systolic and diastolic ambulatorial BP response. The effects were "large" (> 0.8) for "awake", "asleep", and "24 hours" only in the EC for diastolic BP. Conclusion: CM supplementation can increase the post-exercise hypotensive effects in hypertensives. In addition, the prevalence of non-responders is lower when associated with aerobic exercise and CM supplementation.

Resumo Fundamento: Estudos demonstraram de maneira persuasiva que a citrulina tem um papel fundamental no sistema arginina-óxido nítrico, aumentando a biodisponibilidade do óxido nítrico, um importante mediador da vasodilatação periférica. Objetivo: Analisar a responsividade interindividual da hipotensão pós-exercício após suplementação aguda com citrulina em hipertensos. Métodos: Quarenta hipertensos foram aleatoriamente designados para um dos quatro grupos experimentais (controle-placebo, controle-citrulina, exercício-placebo e exercício-citrulina). Eles ingeriram placebo ou citrulina malato [CM] (6 gramas). Durante a sessão de exercício, os indivíduos realizaram 40 minutos de caminhada/corrida em esteira a 60-70% da FC de reserva. Para a sessão de controle, os indivíduos permaneceram sentados em repouso por 40 minutos. A medida da pressão arterial (PA) no consultório foi realizada a cada 10 minutos até completar 60 minutos após a sessão experimental. O dispositivo ambulatorial de PA foi programado para fazer as leituras a cada 20 minutos (tempo de vigília) e a cada 30 minutos (tempo de sono) ao longo de 24 horas de monitoramento. A significância estatística foi definida como p < 0,05. Resultados: Diferentemente de outros grupos experimentais, não houve "não respondedores" no exercício/citrulina (EC) para "acordado" (PA sistólica e diastólica) e "24 horas" (PA diastólica). Os tamanhos de efeito foram mais consistentes no EC para a resposta sistólica e diastólica da PA ambulatorial. Os efeitos foram "grandes" (> 0,8) para "acordado", "dormindo", e para "24 horas" apenas no EC para a PA diastólica. Conclusão: A suplementação com CM pode aumentar os efeitos hipotensivos pós-exercício em hipertensos. Além disso, a prevalência de "não respondedores" é menor quando associada ao exercício aeróbico e à suplementação com CM.

Inter-Individual Responses to Citrulline Malate Oral Supplementation on Post-Exercise Hypotension in Hypertensives: A 24-Hour Analysis.

BACKGROUND: Studies have persuasively demonstrated that citrulline has a key role in the arginine-nitric oxide system, increasing nitric oxide bioavailability, an important mediator of peripheral vasodilation. OBJECTIVE: To analyze the inter-individual post-exercise hypotension responsiveness following acute citrulline supplementation in hypertensives. METHODS: Forty hypertensives were randomly assigned to one of the four experimental groups (control-placebo, control-citrulline, exercise-placebo, and exercise-citrulline). They ingested placebo or citrulline malate [CM] (6 grams). During the exercise session, individuals performed 40 minutes of walking/running on a treadmill at 60-70% of HR reserve. For the control session, the individuals remained seated at rest for 40 minutes. Office blood pressure (BP) was taken every 10 minutes until completing 60 minutes after the experimental session. The ambulatory BP device was programmed to take the readings every 20 minutes (awake time) and every 30 minutes (sleep time) over the course of 24 hours of monitoring. Statistical significance was defined as p < 0.05. RESULTS: Unlike the other experimental groups, there were no "non-responders" in the exercise/citrulline (EC) for "awake" (systolic and diastolic BP) and "24 hours" (diastolic BP). The effect sizes were more consistent in the EC for systolic and diastolic ambulatorial BP response. The effects were "large" (> 0.8) for "awake", "asleep", and "24 hours" only in the EC for diastolic BP. CONCLUSION: CM supplementation can increase the post-exercise hypotensive effects in hypertensives. In addition, the prevalence of non-responders is lower when associated with aerobic exercise and CM supplementation.

Caffeine and resistance exercise: the effects of two caffeine doses and the influence of individual perception of caffeine.

Although caffeine is a widely used ergogenic resource, some information regarding its effects on resistance exercises is still lacking. The objective of the present study was to verify the acute effect of the ingestion of two different doses of caffeine on performance during a session of resistance exercises and to analyze the perception of the subjects in relation to the intake of caffeine. Following a double-blind, randomised, cross-over, controlled, and non-placebo design, 14 trained and healthy men (24.7 ± 6.8 years; 79.8 ± 9.8 kg; 177.3 ± 8.5 cm) performed a training session in chest-press, shoulder-press, and biceps curl exercises (3 sets until exhaustion; 70% 1RM; 3 min rest interval; 2 s for each concentric and eccentric phase) on three non-consecutive days after ingestion of 3 mg.kg-1 caffeine (CAF3), 6 mg.kg-1 caffeine (CAF6), or no substance (CON). Subjects were informed that one of the caffeine doses would be placebo. The total number of repetitions performed in CON (93.6 ± 22.4) was significantly lower than in CAF3 (108.0 ± 19.9, P = 0.02) and in CAF6 (109.3 ± 19.8, P = 0.03) and there were no differences between caffeine doses. Eight subjects noticed that caffeine was in CAF3 and six in CAF6 and there were no differences in the number of repetitions between sessions in which the subjects perceived and did not perceive caffeine. In conclusion, caffeine doses of 3 or 6 mg.kg-1 similarly increased performance in resistance upper limb exercises, independent of the subject's perception of substance ingestion.

Acute citrulline oral supplementation induces greater post-exercise hypotension response in hypertensive than normotensive individuals / Suplementação oral aguda de citrulina induz maior resposta hipotensiva pós-exercício em indivíduos hipertensos do que normotensos

ABSTRACT Objective To investigate whether acute citrulline supplementation might influence post-exercise hypotension in normotensive and hypertensive individuals. Methods Following a randomized double-blind design, twenty normotensive (28±7 years, 74±17kg, 1.7±0.09m) and 20 hypertensive individuals (55±12 years, 76±15kg, 1.59±0.09m) were randomly assigned to one of the four experimental groups (Normotensive-Placebo; Normotensive-Citrulline; Hypertensive-Placebo; Hypertensive-Citrulline). The placebo groups ingested 6g of corn starch and the citrulline groups ingested 6g of citrulline dissolved in water. The participants performed 40 minutes of walking/running on a treadmill at 60-70% heart rate reserve. Blood pressure was measured immediately after a 60-min exercise session using an oscillometric device and 24-h ambulatory monitoring. Results The post-exercise hypotension was more pronounced in hypertensives and the Hypertensive-Citrulline group showed a consistent systolic blood pressure reduction during the laboratorial phase, which can be seen by looking at the mean of 60 minutes (-15.01mmHg vs -3.14mmHg [P=0.005]; -4.16mmHg [P=0.009]; -6.30mmHg [P=0.033] in comparison with the Normotensive-Placebo, Normotensive-Citrulline, and Hypertensive-Placebo groups, respectively). During ambulatory blood pressure monitoring, the Hypertensive-Citrulline group showed a significant reduction in systolic blood pressure (-21.05mmHg) in the awake period compared with the Normotensive-Citrulline group (-3.17mmHg [P=0.010]). Conclusion Acute citrulline oral supplementation can induce greater post-exercise hypotension response in hypertensive than normotensive individuals.

RESUMO Objetivo Investigar se a suplementação aguda de citrulina pode influenciar a hipotensão pós-exercício em indivíduos normotensos e hipertensos. Métodos Seguindo delineamento duplo-cego randomizado, vinte indivíduos normotensos (28±7 anos, 74±17kg, 1,7±0,09m) e 20 hipertensos (55±12 anos, 76±15kg, 1,59±0,09m) foram randomizados e distribuídos em um dos quatro grupos experimentais (Normotenso-Placebo; Normotenso-Citrulina; Hipertenso-Placebo; Hipertenso--Citrulina). Os grupos placebo ingeriram 6g de amido de milho e os grupos citrulina 6g de citrulina, dissolvidos em água. Os participantes realizaram 40 minutos de caminhada/corrida em esteira a uma intensidade entre 60-70% da frequência cardíaca de reserva. A pressão arterial foi aferida imediatamente após a sessão de exercício por 60 minutos usando um equipamento oscilométrico, e durante 24 horas por monitorização ambulatorial. Resultados A hipotensão pós-exercício foi mais pronunciada nos hipertensos e o grupo Hipertenso-Citrulina mostrou uma redução consistente da pressão arterial sistólica durante a fase laboratorial, o que pode ser visto pela média de 60 minutos (-5,01mmHg vs -3,14mmHg [P=0,005]; -4,16mmHg [P=0,009]; -6,30mmHg [P=0,033] em comparação com o Normotenso-Placebo, Normotenso-Citrulina e Hipertenso-Placebo, respectivamente). Durante a monitorização ambulatorial da pressão arterial, o Hipertenso-Citrulina demonstrou uma redução significativa na pressão arterial sistólica (-21,05mmHg) durante a vigília em comparação com o Normotenso-Citrulina (-3,17mmHg [P=0,010]). Conclusão A suplementação oral aguda de citrulina induz maior resposta hipotensiva pós-exercício em indivíduos hipertensos do que normotensos.