Wouldn’t breathing through a straw do the the same thing? I might need one of these pretty soon, I signed on to shoot behind the scenes video on an indy film in Colorado. The elevation is going to be about 10,000 feet. Far from the 1000 feet I’m used to.
Just as you might use weights to strengthen your arm muscles, breathing in through POWERbreathe for a few minutes twice daily, makes your inspiratory muscles work harder – thereby increasing their strength and endurance.
PowerBreathe, Dumbbells for Your Lungs