More than a quarter of adults in the UK are believed to have high blood pressure. When we are younger our bodies can more easily accommodate sudden fluctuations in blood pressure, but as we get older our blood vessels become stiffer and less flexible, setting the stage for serious health complications including heart attack and stroke. Some types of exercise, including isometric resistance training, can safely lower your blood reading, according to new research.
In basic terms, isometric resistance training (IRT) is a form of physical exercises that recruit muscles and exert tension without lengthening or shortening the tissue.
Although the muscle is flexed, it will not be compressed or expanded.
Examples of IRT include pushing against a wall or holding a plank.
This type of exercise is different from traditional strength training, where the muscles lengthen and shorten during movement.
Currently, IRT is not recommended by several international guidelines for the management of blood pressure, due to concerns over its safety.
However, exercise physiologists Harrison Hanford and Doctor Matthew Jones, said their research suggested otherwise.
Doctor Jones, the lead author of the study, said: “We were interested in how IRT reduced blood pressure in people with high blood pressure.
“We also wanted to know whether IRT was safe. We found that IRT was very safe and caused meaningful changes in blood pressure, almost as much as what you’d expect to see with blood pressure-lowering medication.”
Doctor Jones explained IRT is a time-efficient means of reducing blood pressure, needing only 12 minutes a day, two to three days per week to produce strong effects.
The vessels in the body carry over 7,500 litres of blood, which deliver oxygen and nutrients like glucose and amino acids to the body’s tissues.
When blood flows through the body, it exerts a force on the walls of the blood vessels, which is what causes blood pressure.
This pressure will rise and fall with the phases of the heartbeat. It is at its highest during systole.
Systolic pressure is when the heart contracts, forcing blood through the arteries. When the heart is at rest between beats, blood pressure falls to its lowest values, which is referred to as diastolic pressure.
A typical healthy individual produces a systolic pressure between 90 and 120 mm Hg (mercury), and diastolic pressure between 60 and 80 mm Hg. Taken together, a normal blood reading is a bit less than 120/90 mm Hg.
Doctor Jones said: “We also found IRT caused improvements in other measures of blood pressure including central blood pressure (the pressure in the heart’s largest artery – the aorta, and an important predictor of cardiovascular disease) and to a lesser extent ambulatory blood pressure (average blood pressure across a 24-hour period), neither of which had previously been reviewed.”
“While the studies included in our review normally used a specialised handgrip device, it’s possible we would see the same effects simply by asking participants to make a fist and squeeze it at a certain intensity for the prescribed amount of time.
“This means IRT could easily be performed while participants are sitting down watching TV.”
According to the British Heart Foundation, symptoms of high blood pressure include:
- Blurred vision
- Shortness of bread
- Chest pain
Certain lifestyle choices can raise the risk of high blood pressure, such as eating a diet high in sodium.
The NHS notes: “Salt raises your blood pressure. The more salt you eat, the higher your blood pressure. Aim to eat less than 6g of salt a day, which is about a teaspoonful.”
Furthermore, studies have identified excess body fat as one of the dominant predisposing factors to blood pressure elevation, therefore eating a diet rich in whole grains, fruits, vegetables and low-fat dairy can also lower blood pressure.