Oct. 8, 2004 -- People with high blood pressure may one day be able to take the problem into their own hands -- literally.
The studies were conducted at Canada's McMaster University in Hamilton, Ontario, using a specialized handgrip device.
In one test, participants performed 10 handgrip exercises three times a week for eight weeks, working at 30% of their maximal voluntary contraction.
The hand exercises helped significantly lower systolic blood pressure (the higher number in the reading, when the heart pumps blood to the rest of the body), say researcher Adrienne Visocchi and colleagues. Diastolic blood pressure (the lower number while the heart rests) did not change.
Ultrasound measurements of the vessels also showed that the carotid artery, one of the main arteries of the body became more flexible and less rigid after the hand exercises. More flexible vessels are a sign of healthy blood vessels.
"The results of this study indicate that isometric handgrip exercise improves resting systolic blood pressure and carotid artery distensibility [inflexibility]," say the researchers.
Handgrip exercises were also used in Cheri McGowan's experiment.
McGowan and colleagues studied eight people taking blood pressure medication who were 62 years old, on average. Participants had their blood pressure measured, then started training. They performed four sets of isometric handgrip exercises, holding each contraction for two minutes.
Subjects exercised alternate hands three times a week for eight weeks. After training, their systolic blood pressure dropped significantly.
They stopped blood flow to participants' forearms for five minutes and then used ultrasound to measure the artery's interior diameter when blood flow resumed. After training, the artery was dilated wider than before.
"Isometric handgrip training improves systolic blood pressure and endothelial [blood vessel] function in persons medicated for hypertension," say McGowan and colleagues.
However, the researchers aren't recommending this method to blood pressure patients just yet. Their handgrip is more sophisticated than commercial models, according to a news release.
Visocchi and McGowan presented their findings at the 2004 American Physiological Society Intersociety Meeting in Austin, Texas.