"Ordinarily, during an asthma attack, people panic and breathe quickly and as deeply as they can, blowing off more and more carbon dioxide. Breathing rate is controlled not by the amount of oxygen in the blood but by the amount of carbon dioxide, the gas that regulates the acid-base level of the blood.
Dr. Buteyko concluded that hyperventilation — breathing too fast and too deeply — could be the underlying cause of asthma, making it worse by lowering the level of carbon dioxide in the blood so much that the airways constrict to conserve it.
This technique may seem counterintuitive: when short of breath or overly stressed, instead of taking a deep breath, the Buteyko method instructs people to breathe shallowly and slowly through the nose, breaking the vicious cycle of rapid, gasping breaths, airway constriction and increased wheezing.
The shallow breathing aspect intrigued me because I had discovered its benefits during my daily lap swims. I noticed that swimmers who had to stop to catch their breath after a few lengths of the pool were taking deep breaths every other stroke, whereas I take in small puffs of air after several strokes and can go indefinitely without becoming winded. .....
In an interview, Mrs. Yakovlev-Fredricksen said: "People don't realize that too much air can be harmful to health. Almost every asthmatic breathes through his mouth and takes deep, forceful inhalations that trigger a bronchospasm," the hallmark of asthma.
"We teach them to inhale through the nose, even when they speak and when they sleep, so they don't lose too much carbon dioxide," she added. "