Introduction

High blood pressure, also known as hypertension, develops when blood flows through your arteries at higher-than-normal pressures.

Systolic and Diastolic Pressure

Blood pressures (BP) are written as two numbers separated by a slash like this: 120/80 mm Hg, usually expressed as ‘120 over 80’.

• The first number is your systolic pressure: That is the force of the blood flow when blood is pumped out of the heart.
• The second number is your diastolic pressure: This is measured between heartbeats when the heart is filling with blood.

Your BP changes throughout the day based on your activities.

• A healthy systolic blood pressure is less than 120 mm Hg.
• A healthy diastolic pressure is less than 80 mm Hg.

Your BP is high when you have consistent systolic readings of 130 mm Hg or higher, or diastolic readings of 80 mm Hg or higher.

Category	Systolic and Diastolic Pressure (mm Hg)
Normal	Less than 120 systolic pressure AND Less than 80 diastolic pressure
Elevated	120 to 129 systolic pressure AND Less than 80 diastolic pressure
High Blood Pressure Stage 1	130 to 139 systolic pressure OR 80 to 89 diastolic pressure
High Blood Pressure Stage 2	140 or higher systolic pressure OR 90 or higher diastolic pressure
Hypertensive Crisis	Higher than 180 systolic pressure OR Higher than 120 diastolic pressure Contact your healthcare professional immediately.

What is Exercise Hypertension?

Exercise hypertension, or exercise-induced hypertension (EIH) is an excessive rise in BP during exercise. Many of those with EIH can have spikes in systolic pressure to 250 mmHg or greater.

EIH is defined differently for men and women:

• > 190 mm Hg for women; and
• > 210 mm Hg for men.

A rise in systolic BP to over 200 mm Hg when exercising at 100 W is pathological and a rise in pressure over 220 mm Hg needs to be controlled by the appropriate drugs.

Similarly, in healthy individuals the response of the diastolic pressure to ‘dynamic’ exercise (e.g. walking, running or jogging) of moderate intensity is to remain constant or to fall slightly (due to the improved blood flow), but in some individuals a rise of 10 mmHg or greater is found.

Recent work at Johns Hopkins Medicine involving a group of athletes aged 55 to 75 with mild hypertension has found a correlation of those with exercise hypertension to a reduced ability of the major blood vessels to change in size in response to increased blood flow (probably due to impaired function of the endothelial cells in the vessel walls). This is to be differentiated from stiffness of the blood-vessel walls, which was not found to be correlated with the effect.

If you wish to read in depth outline of EIH detailing the pathophysiological mechanisms, the prognostic value, clinical implications, possible treatment, and future direction in managing EIH then read this article by Mohammed and colleagues from 2020.

References

Mohammed, L.M., Dhavale, M., Abdelaal, M.K., Nasibul Alam, A.B.M., Blazin, T., Prajapati, D. & Mostafa, J.A. (2020) Exercise-Induced Hypertension in Healthy Individuals and Athletes: Is it an Alarming Sign? Cureus. 12(12), e11988.

National Heart, Lung, and Blood Institute. (2024) What is High Blood Pressure? Available from World Wide Web: https://www.nhlbi.nih.gov/health/high-blood-pressure. [Accessed: 12 September, 2024].