For Sally Magnusson it was incredible, "almost a miracle" to watch her eight-year-old, Siggy, begin to recover in a matter of days from a disease which had made his life a misery.
Sally, the daughter of Mastermind presenter Magnus Magnusson, had been pumping Siggy full of medication for the past five years in a desperate attempt to ease the asthma which left him wheezing and struggling for breath. Then she enrolled him on a course of five one-hour lessons in a new breathing method.
Muriel Rogers, a patient on another course, tells of the remarkable change she saw in an elderly man crippled with emphysema. From being hardly able to walk without painfully gasping for breath, she watched as, within a couple of days, he was able to move more easily and breathe more freely.
These are just an example of the hundreds of testimonials to the Buteyko method. Developed by a Russian professor who turned medical opinion on its head, it is based on the theory that asthmatics breathe in too much oxygen and not enough carbon dioxide, which the lungs need to pass the oxygen efficiently into the blood.
Yet, amazingly the Buteyko method is being ignored by British scientific establishment, despite statistics that show that 1,500 people die of asthma each year and a child is admitted to hospital with an attack every 10 minutes.
Although asthma sufferers - including MP Jonathon Aitken - say that the shallow breathing technique helped them conquer the illness, no hospital, university or Government-funded project is examining the Buteyko claims.
Even the National Asthma Campaign says:"There is no published research that proves the Buteyko technique is effective in the treatement of all cases of asthma. We believe it would be irresponsible to guarantee any treatment that has not undergone rigorous scientific trials."
Patients on Buteyko courses start with a few shallow breaths then try to hold their breath. When they release the air, they are told not to open their mouths or gasp for breath. Mrs Rogers says: "We were told to try to stifle coughs and eventually the desire to cough went. It was marked how the noise level changed in the room."
Professor Buteyko's method began to be widely used in Australia five years ago. Now nearly 10,000 people practise the technique. Studies suggest that 73% of asthmatics can reduce their medication after just 4 days of relearning how to breathe. Buteyko's exercises were bought to Britain by Australian Chris Drake, who runs courses at the hale clinic in London, an alternative therapy centre frequented by Princess Diana. He claims many of Britains three million sufferers could use the technique and save much of the country's 490 million pound asthma drug bill.
He says: "There was a double-blind clinical trial in Australia at Queenland university, which showed that the Buteyko group reduced the use of bronchodilators by 90% and reported an improvement in their symptoms.
"Why doesn't the National Asthma Campaign follow the progress of patients using the Buteyko method? In Australia there's hardly a journalist with asthma that doesn't use it because they've all tried to prove the method didn't work and ended up convinced it does."
A week-long course at the Hale CLinic costs 290 pounds, with a money-back promise if it fails. Patients are told to avoid heavy meals, protein and milk, to tape their mouths shut while sleeping and to sleep less. It can be unpleasant, but after a few days most people look and feel better.
Diana Clavert, 24, another Buteyko convert says: "I did the course in Septemeber last year and didn't feel much better until after Christmas. Now I am feeling much fitter, looking healthier and am far less slugish.
"My consultant and GP are very interested in my improvement. I thought they would be sceptical, but they weren't."
Clearly Buteyko isn't going to work for everyone and the success of the conventional medecine for what is a potentially life-threatening illness cannot be ignored.
As Greta Barnes, director of the National Asthma Training Centre, says: "Inhaled steroids have revolutionised asthma management and completely changed people's lives. We are now looking at preventing the problem rather than treating the attacks.
"As long as people don't stop taking their conventional medicine, I don't think there is any harm in looking at alternative treatments, but I feel there isn't enough research on the Buteyko method yet to show if it is valuable."
However, for Diane Calvert and many like her, the 290 pounds spent on a Buteyko course has not only cut back the amount she has to spend on drugs but helped her breathe more easily and live an active life.