This book has been the most comprehensive book on the Buteyko method since 2006. The first edition was available only as a PDF file which had slightly more than 100 pages. Later, it has several major and many minor updates with added sections, results of new clinical trials, and new chapters. The current edition is about 3 times larger than the initial version. The book was written for Buteyko breathing practitioners and advanced students. It provides practical education in physiology of respiration, as well as some unique details related to the application of the Buteyko method. For example, the book provides a list of factors that is required to break through 40 s morning CP (control pause) threshold: the hardest challenge in breathing retraining and the Buteyko breathing technique. For more details, see the content of the book that includes Chapters and sub-Chapters.