A simple breathing exercise that takes only five minutes a day could help lower blood pressure and reduce stroke, according to a series of experimental studies led by US researchers.

Known as inspiratory-muscle strength training, the time-saving ‘workout’ can be done at home or in the office using a hand-held breathing device, without breaking a sweat.

“It’s basically strength-training for the muscles you breathe in with,” University of Colorado Boulder researcher Daniel Craighead said.

The technique was first developed in the 1980s as a way to wean people with respiratory problems off ventilators.

The patients would take deep breaths through the training device, which then ‘sucks back’ to provide resistance, thus building muscle strength.

But its potential for lowering blood pressure was only recently discovered by accident.

In 2016, University of Arizona researchers found people with sleep apnoea developed stronger diaphragm muscles thanks to the technique.

Just 30 inhalations a day with resistance was enough for a more restful slumber.

The same researchers also noticed an unexpected side effect: The study participants started experiencing a dramatic decline in systolic blood pressure – twice as much of a decrease as with aerobic exercise.

More than one third of adult Australians have high blood pressure, which is diagnosed as a reading above 140/90mmHg. That means anything higher than 140 (systolic) or 90 (diastolic), or both, is considered a health risk.

High blood pressure is a major risk factor for stroke, and regular aerobic workouts have been shown to help reduce a person’s risk.

However, many adults are not getting enough exercise, prompting the University of Colorado researchers to trial the novel idea in a small group of patients.

“Our goal is to develop time-efficient, evidence-based interventions that those busy mid-life adults will actually perform,” Professor Doug Seals, director of UC’s Integrative Physiology of Aging Laboratory, said.

Participants in the UC study experienced a 10mmHg drop in systolic blood pressure in six weeks, and performed better in exercise tests, compared to people using a ‘sham’ breathing device.

The study sample was small and involved a group of healthy, active individuals in middle age. Therefore, the researchers stressed their findings were preliminary, and curious individuals should see their doctor before considering inspiratory training.

Researchers claim the breathing device could lower blood pressure. Photo: University of Colorado

Professor Jacqueline Phillips of Macquarie University told The New Daily that, although it was still in its early stages, she was monitoring the space closely.

“Any fall in blood pressure is promising,” the heart-health researcher said.

However, she cautioned against reading too much into the study.

“It would be great if five minutes a day could solve people’s problems, but I don’t think it will,” Professor Phillips said.

“But if there’s an easier method that people can incorporate into their routine, and a way to help people get off their medication, that’s a good thing.”

Lifestyle changes, such as regular exercise and reducing salt intake, is the main treatment option for people with mild or high blood pressure. More severe cases are managed with medicines.

Stroke Foundation Clinical Council chair Professor Bruce Campbell said the research was interesting, but more work needed to be done.

He encouraged all adults to get their blood pressure checked regularly.

“Worryingly, many people don’t realise they have high blood pressure. It has no immediate symptoms, but over time, it puts extra stress on blood vessels, causing them to narrow or break down,” Professor Campbell said.

“Research has shown the number of strokes would be practically cut in half (48 per cent) if high blood pressure alone was eliminated.

“I encourage everyone to have their blood pressure checked regularly with a GP, pharmacist or via a digital health check machine.”

Preliminary results from the Inspiratory Muscle Strength Training clinical trial were presented at the Experimental Biology conference in Florida in early April.