According to a study, five minutes of exercises using the device daily for six weeks improved the subjects' efforts on a treadmill by 12 percent. The resistance muscle strength training involves inhaling through the device called a POWERBreathe Medic, which can be available on NHS prescription or costs £29.99 to buy.
It's a way of fighting breathlessness and helps older people especially.
Kaitlin Freeberg, of the University of Colorado said this is a "novel form of physical training" that "increases exercise tolerance" and helps break down fat.
Some people struggle with NHS weekly targets of 150 minutes of moderate exercise, or 75 of vigorous exertion.
The findings were presented at the American Physiological Society annual meeting.