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It is well known that weightlifting can strengthen our biceps and quadriceps. Now, there is growing evidence that strengthening the muscles we use to breathe is also beneficial. New research shows that a daily dose of strength training for the diaphragm and other respiratory muscles helps promote heart health and lower high blood pressure.
“The muscles we use to breathe atrophy, just like the rest of our muscles tend to do as we age,” says researcher Daniel Craighead, an integrative physiologist at the University of Colorado at Boulder. To test what happens when these muscles are properly trained, he and his colleagues recruited healthy volunteers between the ages of 18 and 82. to try a daily five-minute technique using a resistance breathing trainer called PowerBreathe. The hand-held machine – one of many on the market – resembles an inhaler. When people breathe into it, the device offers resistance, which makes it harder to inhale.
How it works
“We found that taking 30 breaths a day for six weeks lowers systolic blood pressure by about 9 millimeters of mercury,” says Craighead. And these reductions are in line with what one would expect with conventional aerobic exercise, he says, such as walking, running or cycling.
A normal blood pressure reading is below about 120/80 mmHg, according to the Centers for Disease Control and Prevention. These days, some medical professionals diagnose patients with high blood pressure if their average reading is consistently 130/80 mmHg or higher, the CDC notes.
The impact of a sustained 9 mmHg reduction in systolic blood pressure (the first number in the report) is significant, says Michael Joyner, a physician at the Mayo Clinic who studies how the nervous system regulates blood pressure. “It’s the kind of reduction you see with blood pressure medication,” says Joyner. Research has shown that many common blood pressure medications cause a reduction of about 9 mmHg. Reductions are greater when people combine multiple drugs, but a reduction of 10 mmHg is correlated with a 35% lower risk of stroke and a 25% lower risk of heart disease.
Training also helps prevent high blood pressure
“I think it’s promising,” Joyner says of the prospects for integrating respiratory muscle training into preventive care. It could be beneficial for people who can’t do traditional aerobic exercise, he says, and the simplicity is also appealing, given that people can easily use the device at home.
“Taking a deep, resistant breath offers a new and unconventional way to generate the benefits of exercise and physical activity,” Joyner concluded in an editorial published alongside an earlier study in the Journal of the American Heart Association.
Then how exactly does breathing training lower blood pressure? Craighead highlights the role of endothelial cells, which line our blood vessels and promote the production of nitric oxide – a key compound that protects the heart. Nitric oxide helps widen our blood vessels, promoting good blood circulation, which prevents plaque buildup in the arteries. “What we found was that six weeks of IMST [inspiratory-muscle strength training] will increase endothelial function by about 45%,” says Craighead.
Good for all ages, and may help athletes’ endurance
It’s long been known that deep diaphragmatic breathing — often used during meditation or mindfulness practices — can also help lower blood pressure. Strength training with the PowerBreathe device works in a similar way, engaging respiratory muscles and promoting nitric oxide production. The particular benefit of the IMST machine, says Craighead, is that it takes less time to get the benefit of it because the little machine adds the resistance that gives the muscles a good workout. His research is funded by the National Institutes of Health.
The new study builds on the previous study and adds to the evidence that IMST – which is essentially strength training for the respiratory muscles – is beneficial for adults of all ages. “We were surprised at how effective IMST is in lowering blood pressure,” Craighead said. Before the results came in, he suspected healthy young adults might not benefit as much. “But we found robust effects,” he says, pointing to a significant drop in blood pressure in participants of all ages. He says the finding suggests that IMST could help healthy young people prevent heart disease and the rise in blood pressure that tends to occur with aging.
There may also be benefits for elite cyclists, runners and other endurance athletes, he says, citing data that six weeks of IMST increased aerobic exercise tolerance by 12% in middle-aged and older adults.
“So we think the IMST consisting of just 30 breaths a day would be very useful in endurance exercise events,” says Craighead. It is a technique that athletes could add to their training programs. Craighead, whose marathon personal best is 2 hours and 21 minutes, says he took the IMST on as part of his own training.
The technique is not intended to replace exercise, he warns, or replace medication for people whose blood pressure is so high they are at high risk of having a heart attack or stroke. . Instead, says Craighead, “it would be a good complementary intervention for people who are already taking other healthy lifestyle approaches.”
This is how Theresa D. Hernandez, 61, views breathing exercises. She lives in Boulder, has a family history of high blood pressure, and was involved in Colorado research. When the study began, she had blood pressure readings close to the threshold at which doctors recommend medication.
“It was a surprise that something so simple could be so profound in terms of impact,” Hernandez says of the six weeks of breathing exercises. “My blood pressure had to be below the threshold so that I didn’t need to take medication,” she says.
Her blood pressure has dropped significantly and she says she plans to stick with it – five minutes a day.