In Germany, around one in three adults is affected by high blood pressure, also known as hypertension. If left untreated, high blood pressure can damage blood vessels and significantly increase the risk of a stroke.
Researchers at Canterbury Christ Church University have now found that isometric wall sitting can lower blood pressure. In order to maintain the lower value, even one training session per week was enough for a short period of time. The study was published in the specialist magazine “BMJ Open Sport & Exercise Medicine”.
Researchers examined the effects of isometric exercises. This is a form of strength training that tenses the muscles without moving the joints or changing the length of the muscles. These include wall sitting or planks. However, the study only tested wall sitting.
100 adults took part in the study, with an average age of 37. Their blood pressure was in the normal to high normal range and none of them were taking blood pressure medication. 80 participants trained, 20 formed the control group without training. A training session consisted of four sessions, each with two minutes of wall sitting and a two-minute sitting break in between.
Wall sitting was performed with an individually adjusted knee joint angle and a target heart rate of 95% of the maximum heart rate.
In the first four weeks, all 80 participants trained three times a week. Over the next four weeks, the groups continued in different ways: three times, twice, or once a week. One group stopped altogether. The researchers measured blood pressure and other values of the cardiovascular system.
After four weeks, the upper (systolic) blood pressure of the exercisers was about 9.5 mmHg lower than in the control group. For comparison: a blood pressure below 120/80 mmHg is considered optimal; high blood pressure is considered to be from 140/90 mmHg.
“Our results show that training three times a week was associated with better reduction of blood pressure and the maintenance of a broader range of physiological benefits,” Jim Wiles is quoted as saying in a statement. He is a co-author of the study.
“But even if you exercise just once a week, you can maintain some health benefits over a short period of four weeks, making it a practical option for people,” says Wiles.
"Exercise does not have to be all or nothing. Our results show that during times of stress, such as those that often occur, reducing to just one isometric exercise session per week can help maintain the positive effects on blood pressure already achieved until a more regular exercise schedule can be resumed," said Harry Swift from King's College London, who led the study, in the statement.
The researchers suspect that the vessels dilate more easily as a result of isometric training. This would allow the blood to flow with less resistance and the pressure on the vessel walls would be relieved. In the three sessions per week group, vascular resistance and heart rate variability, a measure of how the heart is controlled by the nervous system, remained favorable.
However, it is not possible without training: the group that stopped after four weeks no longer differed from the control group in the end.
"This flexibility could make isometric training a more sustainable way for people to regulate their blood pressure and support their long-term cardiovascular health," Swift said.
