Quadriceps short-term resistance exercise in subjects with resistant hypertension

Arthur De Sá Ferreira,Ivan Cordovil,José Barbosa Filho,Juliana Flávia De Oliveira

doi:10.1590/s0103-51502011000400006

Abstract

INTRODUCTION: Resistant arterial hypertension may lead to muscle disuse and reduced functional capacity due to arterial and target-organs lesions. The main objective of this work is to evaluate the quadriceps strength and fatigue tolerance after a program of resistance exercise in subjects with resistant primary hypertension. METHODS: Six patients under pharmacological treatment were submitted to a four-week resistance exercise training program for the quadriceps (8-14 repetitions, 3 sets, 3 days per week). Strength was evaluated by isometric dynamometry, as the percentage change in maximum voluntary contraction over the four week program. Fatigue was analyzed by surface electromyography, as the change in both root mean square value and intercept of median frequency slope of vastus medialis and vastus lateralis. RESULTS: Significant increase in the maximum voluntary contraction was observed (p = 0.04). Fatigue tolerance was not improved as seen by root mean square as well as in the intercept of median frequency (p > 0.05). Additionally, no significant changes were observed in resting arterial blood pressure and heart rate throughout the training period. CONCLUSION: The prescribed protocol seemed to successfully increase localized muscle strength without negatively affecting the monitored cardiovascular variables in patients with resistant hypertension under pharmacological treatment.

Highlights

Resistant arterial hypertension may lead to muscle disuse and reduced functional capacity due to arterial and target-organs lesions
The aim of this study is to evaluate the acute effects of a four-week localized resistance exercise program in muscle strength and fatigue tolerance in patients with resistant hypertension under pharmacological treatment
A significant improvement (p = 0.04) on maximal voluntary contraction (MVC)% was observed over the training program, especially at the third and fourth weeks (108.7%, ranging from 80.4 to 122.9% at the third, and 107.0%, ranging from 90.0 to 114.6% at the fourth)

Summary

Introduction

Resistant arterial hypertension may lead to muscle disuse and reduced functional capacity due to arterial and target-organs lesions. Arterial adaptations include stiffening of large arteries, hypertrophied or remodeled medium-sized arteries [6, 7], and small vessels [8, 9], capillary rarefaction [9, 10], skeletal muscle insulin resistance [9], and impaired flow-mediated dilation mainly related to endothelial dysfunction. These pathological changes increases wave reflections and raises pulse pressure, while reducing the blood flow to cardiac and skeletal muscles. With the progression of hypertension, patients become severely limited in their daily activities, leading to reduced functional capacity, muscle disuse and serious secondary conditions

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