The dramatic increase in skin blood flow and sweating observed during heat stress is mediated by poorly understood sympathetic cholinergic mechanisms. One theory suggests that a single sympathetic cholinergic nerve mediates cutaneous active vasodilation (AVD) and sweating via cotransmission of separate neurotransmitters, because AVD and sweating track temporally and directionally when activated...

The incidence of arrhythmias during isometric sustained handgrip exercise and during dynamic graded bicycle exercise was compared in a group of 45 patients with various forms of heart disease on no antiarrhythmic therapy. Atrial arrhythmias were equally common during handgrip and bicycle exercise but ventricular arrhythmias were more frequent during handgrip exercise. Of the 45 patients, 38 per...

A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response of the muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle ...

We sought to determine whether oral contraception alters the gender-related differences observed in the exercise pressor reflex during isometric handgrip exercise. Fifteen men, fifteen normally menstruating women (WomenNM), and fifteen women taking monophasic oral contraceptives (WomenOC) completed two trials of a 3-min isometric handgrip exercise protocol performed at 30% of their maximal volu...

The objective of this study was to evaluate cardiac autonomic control and muscle vasodilation response during isometric exercise in sedentary and physically active older adults. Twenty healthy participants, 10 sedentary and 10 physically active older adults, were evaluated and paired by gender, age, and body mass index. Sympathetic and parasympathetic cardiac activity (spectral and symbolic hea...

Cardiac and peripheral vasomotor factors contribute to the rapid pressor response at the onset of isometric handgrip exercise. We tested the hypothesis that age enhances the sympathetic and vasoconstrictor response at the onset of isometric handgrip exercise so that the pressor response is maintained, despite a diminished cardiac function. Twelve young and twelve older (24 ± 3 and 63 ± 8 yr) in...

BACKGROUND Arterial stiffness of patients with coronary artery disease (CAD), which is expected to be increased due to a generalized atherosclerotic process of human body, may be more evident after the acute increase of blood pressure (BP) or peripheral vascular resistance. Isometric handgrip exercise is a simple and easily applicable method to achieve this goal. We investigated the changes of ...

To investigate the effects of muscle metaboreceptor activation during hypoxic static exercise, we recorded muscle sympathetic nerve activity (MSNA), heart rate, blood pressure, ventilation, and blood lactate in 13 healthy subjects (22 +/- 2 yr) during 3 min of three randomized interventions: isocapnic hypoxia (10% O(2)) (chemoreflex activation), isometric handgrip exercise in normoxia (metabore...

Aerobic and isometric training have been shown to reduce resting blood pressure, but simultaneous aerobic and isometric training have not been studied. The purpose of this study was to compare the changes in resting systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP) after 6 weeks of either (i) simultaneous walking and isometric handgrip exercise (WHG), (ii) walking (WLK), (...

Twenty-one patients with various heart diseases undergoing the coronary sinus catheterization had myocardial blood flow studies before and during isometric handgrip exercise. At 30% of the maximal voluntary contraction (MVC), handgrip increased both coronary sinus blood flow by 19.8% and myocardial O2 consumption by 21.0% on the average as compared to those at rest. At 20% of MVC, the increase ...