Without lungs, a person could not live because our body cannot survive without oxygen for more than five to ten minutes. The lungs are an organ consisting of two lung wings. They are pale pink in color in a healthy adult. Anatomically, their shape resembles a tree that is full of fruits. These fruits are small bags that we call alveoli and they "bear" fruit, i.e. gas exchange takes place in them: oxygen enters our body and carbon dioxide is expelled from our body through a process called diffusion. The air passing through the respiratory tract gets rid of dust and harmful substances before it reaches the lungs. Many muscles are involved in the breathing process. The diaphragm is the largest respiratory muscle and plays an extremely important role in proper breathing. Diaphragmatic breathing is the most effective, the most economical and the healthiest. Breathing is controlled by the medulla oblongata and the pons. The nervous system keeps the metabolism in balance before and during muscle work and synchronizes the work of all systems in the body. Lung volumes and capacities are used to make diagnoses in pulmonology. One of the many diagnostic methods used in pulmonology is spirometry. Spirometry is simply the measurement of breath and lung function. In sports, it is very important that people who manage training processes are educated about the physiology of breathing in general, and what happens to our body, and especially to the respiratory system, during muscle work, that is, during the training process.