I found Buteyko Breathing much more useful than expected. This is one of the health tools I plan to use all my life.
I can feel the extra energy Buteyko creates, I don't need coffee any more to stay awake. I am able to easily eat less, I lost 6 kg weight in 5 weeks (specially the belly fat) and lowered my cholesterol from 195 to incredible 97 in 30 days. I does require dedication and some discipline - but the benefits far out-weight the investment.
My wife now follows my example. After only two easy Buteyko sessions she experienced an unpleasant skin reaction which was a detox crisis - - after this, she felt almost miraculously energised. Her goal is: losing weight :-)
I must add that Eduard's app is a real help and motivator doing the exercises, and I experienced Eduard's coaching as a great help, specially when experiencing a detox crisis, or when motivation is low.
Disclaimer: there is no guarantee of specific results and results will vary.