Systolic blood pressure, the upper half of your blood pressure, indicates how much force your heart and blood exert against arteries when the heart contracts. Diastolic pressure is the lower half of blood pressure and is a measure of how easy your blood flows from arterioles, the smallest branches of your arteries, into capillaries. Blood pressure increases or decreases in response to acute and long-term exercise training.
Types
Systolic and diastolic pressure is used to determine mean arterial pressure, or MAP, the physiologic average of systolic and diastolic pressure. MAP, total peripheral resistance pressure--resistance in the arteries and arterioles in your limb--and cardiac output change with exercise and are all relative to each other.
Steady State Aerobic Exercise
When you begin a moderate intensity three-mile run, your systolic blood pressure increases, then levels off. As you continue to exercise at a steady state, your arteries continue to dilate, decreasing your total peripheral resistance pressure and creating a decrease in your systolic blood pressure. Your diastolic blood pressure barely changes during steady-state exercise.
Graded Aerobic Exercise
When you start a hard run, your systolic blood pressure also increases. However, as your running intensity increases, your systolic blood pressure increases in direct proportion to your exercise intensity. Your diastolic blood pressure remains stable or may even slightly decrease with high levels of exercise intensity.
Resistance Training
Resistance training creates a short-term high blood pressure response. Systolic and diastolic pressures increase as your resistance increases. Additionally, the larger the muscle mass you work, the greater the increase in your blood pressure. Though you may experience a short term rise in blood pressure with each resistance-training workout, over time, your blood pressure response to resistance training will actually decrease.
Significance
During aerobic exercise, your blood vessels dilate, making it easier for blood to flow from your arterioles into your capillaries. Your muscles rhythmically contract and relax, further decreasing resistance to blood flow and increasing the rate at which blood is returned to the heart. During exercise, your cardiac output increases, which helps decrease your blood pressure. Exercise immediately increases your heart rate and also increases your stroke volume over time. Both variables lead to an increase in cardiac output, thereby contributing to a decrease in your blood pressure.
Acute resistance training on the other hand, due to intense non-rhythmic muscular contractions, increases compression on your blood vessels. Such contractions increase the resistance to blood flow, increasing your blood pressure during a bout of resistance training. As you get stronger and improve your muscular fitness, your blood pressure response to the same workout will decrease because you will be working at a lower percentage of your muscular strength.
Warnings
If you have heart or vascular disease, it is important to first check with your physician before exercise. Perform more rhythmic aerobic exercise to decrease your risk of a high blood pressure response to exercise. When you perform resistance training, keep your weights light to decrease the high blood pressure response typical of resistance training. Do not hold your breath while lifting weights, which further increases your blood pressure.
References
- "Exercise Physiology, Energy, Nutrition & Human Performance"; William D. McArdle, Frank I. Katch and Victor L. Katch; 2007
- "Personal Trainer Manual"; American Council on Exercise; 1997
