Oxygen is crucial for normal health. Nearly all chronic diseases are either based on or always accompanied by tissue hypoxia (low levels of oxygen in body cells) and poor results for the body oxygen test. A person can eat tons of supplements, drink canisters of super juices, practice yoga for many hours every day and do many other useful or encouraged things, but, if his or her body O2 levels remain unchanged, the health of this person will likely remain unchanged too. Frolov device effects: For an average sick person, breathing exercises with the Frolov device or Breathslim (a similar device) are the fastest and easiest method to increase body oxygenation. These exercises do not require a breathing teacher or practitioner. These are the reasons why the Frolov device or Breathslim is so effective for various health problems and people who have low body O2 content (Butyeko CP test). During the first decade of this century, over 2,000,000 Frolov devices were sold in Russia. This is the statistic of Russian company Dinamika, the main producer of Frolov devices. Since the Frolov device is a medical device (approved by FDA as well), Russians can buy Frolov devices in pharmacies. Over 500 Russian doctors endorse and encourage the use of the Frolov breathing device to their patients in order to normalize body oxygenation and other vital body characteristics. Clinical studies proved that breathing exercises with the Frolov device lead to improvements in key health parameters for people with numerous health problems ranging from heart disease and diabetes to asthma and COPD. While Dinamika provides instructions in English and other foreign languages (together with a DVD) for people who buy the foreign version of the Frolov device, these traditional instructions do not include lifestyle changes and the DIY body oxygen test that is exceptionally useful to monitor progress in one's health. In addition, there are people who want to defeat chronic diseases, not only obesity, using the Breathslim, a breathing device that is very similar to Frolov device. With these ideas in mind and after teaching the Buteyko breathing method and combined Buteyko-Frolov therapy to thousands of people, I decided to write this manual. While this book includes instructions developed by Dr. Sergey Zinatulin (the chief medical professional at Dinamika), there are many additions. First of all, it includes dozens of Western studies related to the body oxygen test and its description. Second, the book offers a complete program for breathing retraining: how to get more than 20 seconds for the body oxygen test 24/7 in order to stop progression of nearly all chronic diseases and eliminate medication and major symptoms of heart disease, asthma, bronchitis, sinusitis, chronic fatigue and many other conditions. This health program is based on elements of the Buteyko method and includes lifestyle modules related to sleep, physical exercise, nutritional deficiencies, and focal infections since each of these factors is crucial for health and higher body oxygenation. The book also includes a complete description of breathing exercises for development of diaphragmatic breathing (for beginners) and how to make the modified Frolov device and Breathslim (for advanced students with more than 25 seconds for the body oxygen test).