Starting from the 1960's, yoga books and nearly all yoga teachers started to promote the deep-breathing myth: one should breathe more air (even at rest) and expel "toxic" CO2. However, hundreds of clinical studies showed and proved that hyperventilation reduces oxygen levels in cells, while CO2 is crucial for health. Deep breathing, as during pranayama, only looks deep. In reality, as ancient yoga texts teach, pranayama should be done with maximum breath holds and accumulation of CO2 in order to have slower breathing after the practice and 24/7. Only with progress in pranayama (extension of all stages), one can get main yoga benefits, weight loss and other effects. Millions of people believe in a myth that gaining health improvements from practicing yoga is about performing progressively more difficult poses. However, you can practice poses for months or years, but this does not provide any guarantee that your health is going to improve. Yoga benefits and true yoga spirit, as ancient yoga Sanskrit books teach, are in breathing less air 24/7, even less than the tiny medical respiratory norm. Then one can expect more oxygen in the brain and other organs, normal body weight, short natural sleep, and experience real measurable yoga benefits. Here are general ideas that are confirmed by hundreds of clinical studies quoted in this book: Severely sick and hospitalized people * Respiratory frequency at rest and during sleep: >25 breaths/min * Body oxygenation (result for the CP test): <10 s * Common effects: Sleep is often more than 10 hours (very poor quality), very low energy levels (chronic desire to lie down), numerous symptoms, and a need for medication. Majority of modern people * Respiratory frequency at rest and during sleep: 15-25 breaths/min * Body oxygen levels (result for the CP test): 10-25 s * Common effects: Sleep is often more than 7 hours (poor quality), low energy levels (chronic desire to sit), and some symptoms. Healthy people (medical norms for breathing) * Respiratory frequency at rest and during sleep: 10-12 breaths/min * Body O2 levels (result for the CP test): 40 s * Common effects: Sleep is about 6 hours naturally (good quality), normal energy levels, absence of chronic diseases and their symptoms, natural desire to have correct posture and stay throughout the day. Real yoga masters * Respiratory frequency at rest and during sleep: 3-5 breaths/min * Body oxygenation (result for the CP test): 2-3 minutes; maximum breath holding: 7-9 minutes * Common effects: Sleep is 2-3 hours naturally and without trying (excellent quality), very high energy levels (natural joy and craving for physical exercise), and natural desire to eat raw foods. You can eat tons of supplements and superfoods, drink canisters of herbal drinks, have hundreds of colonic irrigations, and practice yoga for many hours every day, but if your breathing (and body oxygen level) remains the same, you will suffer from the same symptoms and require the same dosage of medication.