We can live without food for weeks, without water for a few days, and without air for only a couple of short minutes. We spend a lot of time eating and carefully watching what we eat and drink, but practically do not pay attention to the air we breathe. The amount of oxygen inhaled can change all your ideas about the body, health and performance, and regardless of your physical fitness. And whether you're an unsportsmanlike person just trying to get off the couch, a "weekend warrior" running 10km on occasion or a professional athlete who needs to have an edge over the competition - the amount of air inhaled is a big factor in many aspects of your life. In this book, you will discover the fundamental relationship between oxygen and the body. Improved fitness depends on increased oxygen supply to muscles, organs and tissues. Increased oxygenation not only improves health - it also allows you to increase the intensity of exercise with a decrease in shortness of breath. In short, you will be able to improve your health and fitness, as well as increase performance.