I am starting with this because it is such a common and misunderstood subject. Recent research has focused on the effects of exercise on blood pressure. High blood pressure is not a disease but it is a powerful risk factor for some common diseases, mainly strokes and heart attacks.
Your blood pressure (BP) is expressed as a two figure quantity – say 120/80.
The higher figure is the systolic pressure which is the peak pressure reached when blood is pumped out from the heart to the main arteries.
The arterial pressure then falls to the lower figure which is the diastolic pressure, the lowest level reached before it is pushed up again by the next contraction of the heart.
A level of 140/90 or less is usually taken as normal. The picture is confused by the fact that blood pressure is not a steady figure; it is a fiction of the moment.
It varies with time of day, pressure of work, timing of meals and contact with other people – particularly doctors. We are all aware of “white coat” hypertension which is the condition in which blood pressure is markedly higher when measured by the doctor.
If you want to know what your blood pressure really is, take it yourself. There are plenty of reliable automatic home blood pressure machines which will give you a much more accurate picture of your BP, at whatever time of day you wish, than does the occasional snapshot BP taken in the surgery.
However it is measured, raised blood pressure is common in Western societies and it rises steadily with age. A recent American study found the prevalence of hypertension to be 9% for those aged 18-44, 40% for those aged 45-64 and 75% for 65 and over.
The definition of what constitutes a diagnosis of hypertension is problematic.
The level of 140/90 quoted above is a commonly used criterion and it has long been thought that lowering the BP below this figure is unlikely to result in clinical benefit. However a recent study from the US, the SPRINT Study, has indicated that getting the pressure down to 120 systolic may have substantial advantages over the higher target of 140.
The trouble with the drug treatment of any condition is the possibility (or probability) of side effects from the treatment. In the case of hypertension, the older the patient the worse the side effects, particularly “orthostatic hypotension” – a fall in blood pressure when standing with the danger of lightheadedness leading to falls.
As far as disease prevention is concerned, the lower your blood pressure is the better.
It is known that regular exercise and high levels of physical fitness both reduce the risk of developing high BP and are effective in lowering the BP of hypertensive people. Just how effective has been clarified by a recent study published in the British Journal of Sports Medicine1. There have been no head to head trials of drugs versus exercise for raised BP but this study looked at the data from 194 clinical trials of the impact of drugs on blood pressure and 194 trials looking at the effect of exercise programmes and involving a total of nearly 40,000 people.
The results showed that blood pressure was lower in people treated with drugs but for those with high blood pressure, exercise was just as effective as most drugs.
It is likely that reducing your BP with exercise and other lifestyle changes such as losing weight and cutting back on salt and alcohol intake are more risk-reducing than taking pills because each lifestyle change has many other benefits.
Often these can reduce BP sufficiently to allow the previously hypertensive patient to stop taking medication. This study suggests that exercise should be the first treatment offered to those diagnosed as having hypertension.