The better you understand blood pressure readings, the more sense the changes make. The systolic pressure, the higher number, is the pressure in your arteries when your heart beats. The diastolic pressure, the lower number, is the pressure in your arteries between heartbeats. You can think of it as your minimum pressure when there is the least amount of pressure against your arterial walls.
Systolic Pressure
Every cell in your body requires oxygen and nutrients to function. The blood carries these substances to the cells. When you exercise, you increase the need for oxygen. The signal is sent out to increase your heart rate to speed the delivery of oxygenated blood to the cells. The heart beats faster and with more force to temporarily increase the volume of blood in the arteries. This increases the pressure on the walls of the arteries when the heart beats and causes the increase in your systolic blood pressure.
Variation
Both the systolic and diastolic pressures change and are usually lowest when you're asleep or resting. Systolic pressure rises more quickly and more frequently, not only with exercise, but with emotion and stress. Your true resting blood pressure is an important number and, due to daily fluctuations, it may be hard to pinpoint. For those with high blood pressure, 24-hour monitoring can help determine this number and improve the treatment of high blood pressure. As you age, your arteries tend to become less elastic and, for this reason, it is likely that your blood pressure will increase. Exercise, a healthy diet and weight management may minimize this.
Considerations
Fluctuations in blood pressure are normal. This is your body's response to the requirements of the cells. The fluctuations are greater in the systolic pressure. The diastolic tends to remain in the normal range in a healthy person. Just having someone take your blood pressure reading can increase the numbers in some people. Doctors call this white coat hypertension, and it isn't uncommon.
Expert Insight
If your arteries are narrowed, the blood pressure remains too high even at rest. The additional constant pressure against the small arteries in the brain greatly increases the risk of stroke. Damage to the coronary arteries contributes to heart disease. MayoClinic.com recommends that even healthy young people have their blood pressure measured at least every two years.
Benefits
An increase in heart rate and blood pressure are normal responses to a cardio workout. The heart is a muscle and exercise strengthens it. A sign that your workouts are working is the fairly rapid return to a normal heart rate and blood pressure when you're finished and have rested for a few minutes. Of course, if you have any medical conditions, check with your doctor about the maximum heart rate and blood pressure increase that is safe for you. A resting blood pressure of below 120/80 is now considered a healthy reading, according to the National Heart and Blood Institute.
References
- MayoClinic.com: High blood pressure (hypertension)
- National Heart and Blood Institute: What Is High Blood Pressure?
- "The Language of Medicine" 6th Edition; Davi-Ellen Chabner, BA, MAT; 2001
