Post-aerobic-exercise autonomic responses in hypertensives — a randomized controlled trial

Background. Heart rate variability (HRV) response to an exercise bout may provide useful insight into autonomic stress reactivity. Considering that cardiovascular responses to a stressor may be predictive of certain diseases, it becomes critical to understand if high blood pressure can influence the autonomic nervous system response to acute exercise. We, therefore, undertook a study to investigate the effect of a single bout of aerobic exercise on autonomic responses in hypertensives. Material and methods. Twenty hypertensives were randomly assigned to one of the two experimental groups [control (CG) or exercise (EG)]. The exercise session was conducted on a treadmill and consisted of 40 min of running/walking at 60–70% HRreserve. In the control session, the participants remained seated in a quiet room for 40 min. After the exercise/control sessions, the HRV was recorded continuously for 60 min. Results. The EG presented an increase with a large effect size for LF [1.0 (post-30) and 1.0 (post-60)] and LF/HF [0.8 (post-30) and 1.1 (post-60)]. Additionally, a reduction with a large effect was observed for HF [–1.0 (post-30) and –1.0 (post-60)]. Conclusion. There is a considerable reduction in post-aerobic-exercise parasympathetic activity and an increase in sympathetic activity. Therefore, a single bout of aerobic exercise is not able to quickly improve the cardiac autonomic regulation

Cardiovascular and autonomic responses after exercise sessions with different intensities and durations

BACKGROUND: Several studies have reported the phenomenon of post-exercise hypotension. However, the factors that cause this drop in blood pressure after a single exercise session are still unknown. OBJECTIVE: To investigate the effects of aerobic exercise on the acute blood pressure response and to investigate the indicators of autonomic activity after exercise. METHODS: Ten male subjects (aged 25 ± 1 years) underwent four experimental exercise sessions and a control session on a cycle ergometer. The blood pressure and heart rate variability of each subject were measured at rest and at 60 min after the end of the sessions. RESULTS: Post-exercise hypotension was not observed in any experimental sessions (P > 0.05). The index of parasympathetic neural activity, the RMSSD, only remained lower than that during the pre-exercise session after the high-intensity session (&#916; = -19 ± 3.7 for 15-20 min post-exercise). In addition, this value varied significantly (P < 0.05) between the high- and low-intensity sessions (&#916; = -30.7 ± 4.0 for the high intensity session, and &#916; = -9.9 ± 2.5 for the low intensity session). CONCLUSION: The present study did not find a reduction in blood pressure after exercise in normotensive, physically active young adults. However, the measurements of the indicators of autonomic neural activity revealed that in exercise of greater intensity the parasympathetic recovery tends to be slower and that sympathetic withdrawal can apparently compensate for this delay in recovery

Relationship between Resting Heart Rate, Blood Pressure and Pulse Pressure in Adolescents

Background: High resting heart rate is considered an important factor for increasing mortality chance in adults. However, it remains unclear whether the observed associations would remain after adjustment for confounders in adolescents. Objectives: To analyze the relationship between resting heart rate, blood pressure and pulse pressure in adolescents of both sexes. Methods: A cross-sectional study with 1231 adolescents (716 girls and 515 boys) aged 14-17 years. Heart rate, blood pressure and pulse pressure were evaluated using an oscillometric blood pressure device, validated for this population. Weight and height were measured with an electronic scale and a stadiometer, respectively, and waist circumference with a non-elastic tape. Multivariate analysis using linear regression investigated the relationship between resting heart rate and blood pressure and pulse pressure in boys and girls, controlling for general and abdominal obesity. Results: Higher resting heart rate values were observed in girls (80.1 ± 11.0 beats/min) compared to boys (75.9 ± 12.7 beats/min) (p ≤ 0.001). Resting heart rate was associated with systolic blood pressure in boys (Beta = 0.15 [0.04; 0.26]) and girls (Beta = 0.24 [0.16; 0.33]), with diastolic blood pressure in boys (Beta = 0.50 [0.37; 0.64]) and girls (Beta = 0.41 [0.30; 0.53]), and with pulse pressure in boys (Beta = -0.16 [-0.27; -0.04]). Conclusions: This study demonstrated a relationship between elevated resting heart rate and increased systolic and diastolic blood pressure in both sexes and pulse pressure in boys even after controlling for potential confounders, such as general and abdominal obesity

Influência da prática regular de exercício aeróbio e resistido na hipotensão pós-exercício : revisão sistemática com metanálises

Introdução: Diversos estudos têm identificado a ocorrência do fenômeno hipotensão pós-exercício, no entanto, os moduladores dessa queda da pressão arterial após a realização de uma única sessão de exercício ainda permanecem obscuros. Objetivos: Reunir de forma sistemática os resultados de estudos e aplicar o modelo meta-analítico para identificar a influência da prática regular de exercícios físicos de característica aeróbia e resistida sobre a hipotensão pós-exercício em normotensos e hipertensos, além de verificar o impacto de outros possíveis influenciadores do efeito hipotensor, como o estado clínico, duração/volume e intensidade. Métodos: Para contemplar os objetivos propostos, a presente tese foi composta por dois estudos de revisão sistemática com metanálises. O primeiro trata-se de uma revisão sistemática com metanálises para verificar a influência da prática regular de exercícios aeróbios sobre a hipotensão pós-exercício. O segundo realizou uma revisão sistemática com metanálises para verificar a influência da prática regular de exercícios resistidos sobre a hipotensão pós-exercício. As buscas foram realizadas nas bases de dados Medline, Scientific Electronic Library Online (SciELO), Lilacs, EMBASE, SPORTDiscus e EBSCO sem limites de data até setembro de 2013. Os desfechos comparados foram: Pressão arterial sistólica e pressão arterial diastólica, considerando as diferenças entre prática regular de exercício aeróbio, estado clínico, duração/volume e intensidade. Foram avaliadas as diferenças das médias padronizadas e atribuído o tamanho do efeito hipotensivo seguido dos seus respectivos intervalos de confiança. Resultados: O presente estudo foi constituído por 121 estudos (88 com exercício aeróbio e 33 com exercício resistido). Especificamente para as metanálises constitui-se uma sub-amostra de nove estudos envolvendo exercício aeróbio e 19 envolvendo exercício resistido. O efeito hipotensor pós-exercício foi identificado nos dois modelos de exercício, independentemente da prática regular de exercício físico. Os sujeitos classificados como hipertensos apresentaram maior efeito hipotensivo em relação aos normotensos (-1,24; IC95%= -1,61 a -0,87 vs -0,33; IC95%= -0,52 a -0,15 - para pressão arterial diastólica, respectivamente) após a realização de exercício aeróbio. Conclusão: A magnitude da hipotensão pós-exercício não é influenciada pela prática regular de exercícios aeróbios e resistidos. Indivíduos hipertensos apresentam maior efeito hipotensor pós-exercício aeróbio quando comparados a seus pares normotensos. A duração/volume e intensidade aparentemente não exercem influência sobre a hipotensão pós-exercício.Introduction: Many studies have identified the occurrence of post-exercise hypotension, however the determinants of blood pressure reduction after a single exercise session remains unclear. Objectives: Combine the studies results and apply the metanalytic model to identify the influences of regular aerobic exercise on the post-exercise hypotension in normotensive and hypertensive subjects and verify the effect of other possible influencers as the clinical condition, duration/volume and intensity.Methods: This thesis consisted of two studies. The first conducted a systematic review and metanalysis to assess the influence of regular aerobic exercise on post-exercise hypotension. The second assess the influence of regular resistance exercise on post-exercise hypotension. Searches were conducted in Medline, Scientific Electronic Library Online (SciELO), Lilacs, EMBASE, SPORTDiscus and EBSCO until September 2013. The outcomes compared were: Systolic and diastolic blood pressure, considering the differences between regular practice of aerobic exercise, clinical status, duration/total work and intensity. We evaluated the standardized mean differences with confidence intervals. Results: This study consisted of 121 trials (88 with aerobic exercise and 33 with resistance exercise). For the meta-analysis, constitutes a sub-sample of nine and 19 studies for aerobic and resistance exercise, repectively. Post-exercise hypotensive effect was identified the two models of exercise, independently of regular exercise. Hypertensive subjects had greater hypotensive effect compared to normotensive (-1.24, 95%CI -1.61 to -0.87 vs -0.33, 95%CI -0.52 to -0.15 - to diastolic blood pressure, respectively) after aerobic exercise. Conclusion: The magnitude of post-exercise hypotension is not modulated by the regular practice of aerobic and resistance exercises. Hypertensive individuals have greater hypotensive effect after aerobic exercise when compared with normotensive. Duration/volume and intensity apparently no cause influences