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Rev. bras. med. esporte ; 25(4): 333-337, July-Aug. 2019. tab, graf
Artigo em Inglês | LILACS-Express | ID: biblio-1013661

RESUMO

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.

2.
Arq Bras Cardiol ; 113(2): 218-228, 2019 Jul 10.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31291417

RESUMO

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.

3.
Eur J Sport Sci ; : 1-7, 2019 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-30955455

RESUMO

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.

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