Blood pressure is the force per unit area pushed against the walls of our arteries during a cardiac cycle. The pressure experienced when the left ventricle of our heart contracts, when 70 to 100ml of blood is pumped into the aorta is felt throughout the arterial system. This pressure is called the systolic pressure. The pressure left in the arteries when the ventricle relaxes and arteries recoil, is called the diastolic pressure.
Traditionally, “normal” blood pressure is said to vary with age. For a middle age adult, the normal systolic pressure was 120-140 mmHg. The normal diastolic pressure was 80-90 mmHg. When a higher pressure is measured consistently in an individual, he is said to have high blood pressure (hypertension). However, according to new WHO guidelines, normal adult blood pressure is defined as a blood pressure of 120 mm Hg1 when the heart beats (systolic) and a blood pressure of 80 mm Hg when the heart relaxes (diastolic). When systolic blood pressure is equal to or above 140 mm Hg and/or a diastolic blood pressure equal to or above 90 mm Hg the blood pressure is considered to be raised or high.
Prescriptions for anti-hypertensive medications have soared in recent years. Almost all physicians now aim for the WHO target of 120/80.
Facts: Blood Pressure Changes During Exercise
1. Heavy resistance exercise dramatically increases blood pressure. Hypertensive individuals should avoid heavy resistance training. Light training is relatively safe.
During steady rate exercise like jogging and biking at constant speed, systolic pressure increases sharply for the first few minutes and levels off. Prolonged steady rate exercise will actually lower systolic pressure. Hence, steady rate exercises are safe and beneficial to hypertensive individuals.
Running on a treadmill, gradually increasing the speed and inclination puts tremendous stress on the heart and circulatory system. Healthy individuals may experience systolic pressures of 200 mmHg. Hypertensive individuals should never perform such exercises without medical supervision.
Upper body exercise increase systolic pressure more than lower body exercises. Exercises like chin ups, bench presses, push ups and dips involve smaller muscle groups in the arms. Exercises involving larger muscle groups like legs are recommended for hypertensive individuals. They should not be overzealous about training arm muscles.
5. It is important to note that regardless of the type of exercise, the individual’s systolic pressure drops slightly below pre-exercise level for almost 12 hours during the recovery phase. All types of exercises, when done safely and correctly, will benefit the hypertensive individual.
6. Body inversion – hanging upside down , has been practised by certain people who believe that that it offers health benefits. While evidence of benefits are lacking, hanging upside down certainly increases one’s systolic pressure. It is quite likely that head stands can have negative effects on hypertensive practitioners.
Heart Rate & Optimal Training Intensity
How fast? How long? How painful? Nobody wants to work harder than necessary. Unfortunately. there is no guaranteed method to determine what an optimal training intensity is for you. To get an approximate optimal training rate for yourself, go do a stress test on the treadmill. Regardless of medical condition, remember that this exericse must be done under medical supervision. Find out your maximum heart rate attained during exercise. Next, multiply that by 70%.
Not perfectly accurate, but your optimal exercise intensity should be roughly 70% of your maximum heart rate in a stress test. If your maximum heart rate in a stress test is 200 beats per minute, target an exercise intensity that brings your heart rate to 135 beats per minute.