Blood pressure is a measure of the pressure exerted by the circulating blood upon the walls of blood vessels. Blood has a normal, safe pressure during certain activities and positions, but your pressure can increase dramatically during exercises. However, a sustained high blood pressure, also known as hypertension, is a risk factor for a stroke, heart failure and myocardial infarction.
Types
There are two main measurements of blood pressure. Systolic pressure is defined as the pressure that occurs when the heart contracts. Diastolic pressure is defined as the pressure that occurs when the heart relaxes. Blood pressure is written as two numbers. The systolic pressure is on top, and the diastolic pressure is on bottom. It's measured by a unit known as mmHg, or millimeters of mercury.
Measurements
At rest, a blood pressure measurement of no more than 120/80 mmHg is considered optimal. True hypertension begins when you reach a systolic pressure of 140 or a diastolic pressure of 90. The positive confirmation of either measurement will qualify you for a hypertensive state. Hypertension is broken down into three stages. The highest stage of hypertension, stage 3, is measured by a systolic pressure of at least 180 or a diastolic pressure of at least 110.
Exercise
Normally in an upright position, exercise will cause the systolic pressure to increase and the diastolic pressure to stay the same or even decrease. This phenomenon is due to the fact that the artery size increases during the resting beat and will therefore lower diastolic blood pressure. An increase in diastolic pressure of more than 10 mmHg may be associated with coronary heart disease. Likewise, a failure of the systolic pressure to rise with an increase in intensity, known as exertional hypotension, is a potential indicator of cardiovascular problems. If you are running, then it is normal for your blood pressure to be 200/80 mmHg.
Position
A 2003 study in the "Journal of Human Hypertension" found that both systolic and diastolic pressure were significantly higher when patients were in a lying position than in an upright sitting position. Blood pressure readings were also higher when the arms were placed on the bed compared to when the arms were supported at a right atrium level.
Considerations
According to Dr. Gabe Mirkin, a former Associate Clinical Professor in Pediatrics at the Georgetown University School of Medicine and teaching fellow at Johns Hopkins Medical School, blood pressure can increase to 300/200 mmHG while performing a leg press on your back with very heavy weights (see reference 3). This is considered perfectly normal.
References
- University of New Mexico: Exercise and Resting BP
- National Heart, Lung and Blood Institute: What Is High Blood Pressure?
- Dr. Mirkin: High Blood Pressure During Exercise
- "Journal of Human Hypertension;" Both Body and Arm Position Significantly Influence Blood Pressure Measurement; RT Netea, JWM Lenders, P Smits and Th Thien; March, 2003
