Postexercise decrease in arterial blood pressure, total peripheral resistance and in circulatory responses to brief...

Area of Science:

• Cardiovascular Physiology
• Exercise Science
• Hypertension Research

Background:

• Mild hypertension is characterized by elevated systolic blood pressure (SBP) and diastolic blood pressure (DBP).
• The circulatory after-response to exercise in hypertensive individuals requires further investigation.
• Arterial chemoreceptor function and its modulation by exercise in hypertension are not fully understood.

Purpose of the Study:

• To compare the circulatory after-response to moderate exercise in mildly hypertensive (HTS) and normotensive male subjects (NTS).
• To examine the circulatory and arterial chemoreceptor responses to hyperoxia at rest and post-exercise in both groups.

Main Methods:

• 20-minute moderate exercise on a cycloergometer (55% heart rate reserve).
• Continuous finger arterial blood pressure (BP) monitoring (Finapres).
• Impedance rheography for stroke volume, cardiac output, and arm blood flow.
• 3-minute hyperoxic inactivation of arterial chemoreceptors.

Main Results:

• Hypertensive subjects (HTS) showed significant reductions in SBP, DBP, total peripheral resistance (TPR), and arm vascular resistance (AVR) for 60 minutes post-exercise.
• Normotensive subjects (NTS) exhibited only a transient decrease in TPR.
• Hyperoxia reduced BP and TPR in HTS, an effect attenuated post-exercise.

Conclusions:

• A single session of moderate dynamic exercise has a prolonged antihypertensive effect in mildly hypertensive men.
• Moderate exercise can be considered an effective physiological intervention for reducing elevated blood pressure in mild hypertension.
• Attenuated sympatho-excitatory arterial chemoreceptor reflex activity may contribute to post-exercise hypotension in HTS.