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.

BackgroundStudies 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.ObjectiveTo analyze the inter-individual post-exercise hypotension responsiveness following acute citrulline supplementation in hypertensives.MethodsForty 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.ResultsUnlike 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.ConclusionCM 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.

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Background: L-citrulline malate supplementation promotes an increase in oxide nitric metabolites, which are considered important mediators of peripheral vasodilation. Thus, the supplementation with this substance might maximize the duration and magnitude of post-exercise hypotension. Objectives: To investigate the hypotensive effect of L-citrulline malate supplementation following a single session of aerobic exercise in normotensives. Methods: Forty adults, normotensives, sedentary, were randomly assigned to one of the four experimental groups (control-placebo, control-Lcitrulline, exercise-placebo and exercise-Lcitrulline). All participants ingested a sachet with placebo or L-citrulline with malate (6 grams), both dissolved in water and the ingestion was made 120 minutes before starting the experimental session. The subjects performed 40 minutes of walk/run at 60-70% of reserve heart rate. For the control session, they remained seated in rest during 40 minutes. The blood pressure was taken in rest and every 10 minutes until complete 60 minutes after the experimental session. The ambulatory blood pressure device take the readings every 20 minutes (awake time) and each 30 minutes (sleep time) over the course of 24 hours. Results: L-citrulline malate supplementation associated to aerobic exercise promoted significantly reductions on systolic blood pressure when compared with control-placebo at 20 min (net change[NC]: 9.7 mmHg [P=0.010]), 40 min (NC: 12.7 mmHg [P=0.010]), 50 min (NC: 12.1 mmHg [P=0.012]), 60 min (NC: 9.0 mmHg [P=0.050]) and overall mean (NC: 7.8 mmHg [P=0.018]) post exercise. Conclusion: Acute L-citrulline malate supplementation might potentiate the post-exercise hypotension effects in normotensive subjects.

A atuação do sistema nervoso autonômico está diretamente associada à condição fisiológica geral, sendo utilizada inclusive como demarcador de condição clínica, bem como indicador de risco para doenças cardiovasculares. No entanto, os estudos dessas relações têm sido conduzidos prioritariamente em população adulta. Nesse sentido, o objetivo do estudo foi analisar a associação entre prática habitual de atividade física, pressão arterial (PA) e variabilidade da frequência cardíaca (VFC) em crianças e adolescentes em Londrina, Paraná, Brasil. Estudo apresenta delineamento transversal, de modo que a amostra foi composta por 42 alunos da rede estadual de ensino, de ambos os sexos com idade entre 10 e 17 anos. Avaliou-se a massa corporal e estatura. Foram coletados ainda valores de PA sistólica e diastólica, VFC e a prática habitual de atividades físicas (PHAF) em diferentes domínios (geral, tempo livre, lazer e escola). O teste qui-quadrado foi empregado para avaliar as associações. Não foram identificadas associações estatisticamente significativas entre as variáveis cardiovasculares e a PHAF. A prática geral de atividades físicas habituais, bem como seus diferentes domínios, sejam eles no lazer, escola e tempo livre, não se associaram à valores aumentados de pressão arterial, bem como com os indicadores do comportamento autonômico de crianças e adolescentes.   Palavras-chave: Atividade Física. Pressão Arterial. Sistema Neural. Criança e Adolescente.   Abstract The role of the autonomic nervous system is directly related to the general physiological condition, including being used as a clinical condition path as well as a risk indicator for cardiovascular diseases. However, studies of these relationships have been conducted primarily in the adult population. Thus, the study aimed to analyze the association among habitual practice of physical activity, blood pressure (BP) and heart rate variability (HRV) in children and adolescents from Londrina, Paraná, Brazil. The study presents a cross-sectional design so that the sample consisted of 42 students from the state school system, of both sexes, aged between 10 and 17 years. Body mass and height were evaluated. Systolic and diastolic BP values, HRV, and habitual physical activity (HPA) were also collected in different domains (general, free time, leisure, and school). The chi-square test was used to assess associations. No statistically significant associations were identified between cardiovascular variables and HPA. The general practice of habitual physical activities, as well as their different domains, either leisure, school, or free time, were not associated with increased blood pressure values, as well as with the indicators of the autonomic nervous system in children and adolescents.   Keywords: Physical Activity. Blood Pressure. Neural System.  Children and  Adolescents.