In order to have good blood, you must breathe well. Full, deep inspirations of pure air, which fill the lungs with oxygen, purify the blood. Proper breathing promotes a bright color in the blood and imparts a life-giving current to every part of the body. Good respiration soothes the nerves, stimulates the appetite, renders digestion more perfect, and induces sound, refreshing sleep.
The lungs should be allowed the greatest freedom possible. Their capacity is developed by free action, if the lungs are cramped and compressed their capacity diminishes. A sedentary lifestyle, or stooping at your work, is a common practice that leads to many ill effects. In such a position it is impossible to breathe deeply. Superficial breathing then becomes a habit, and the lungs lose their power to expand. A similar effect is produced by overly tight clothing. If sufficient room is not given to the lower part of the chest, then the abdominal muscles, which were designed to aid in breathing, are unable to be fully utilized and the lungs thus become restricted in their action.
Thus an insufficient supply of oxygen is received. The blood moves sluggishly and the poisonous waste matter which should be thrown off in the exhalations from the lungs is retained, and the blood becomes impure. Not only the lungs, but the stomach, liver, and brain are affected. The skin becomes sallow, digestion is retarded, the heart is depressed, the brain is clouded, thoughts are confused, gloom sets in, the whole system becomes depressed and inactive, and peculiarly susceptible to disease.
The human body expels 70 percent of its toxins from breathing. So the lungs are constantly throwing off impurities and they need to be constantly supplied with fresh air. Impure air does not afford the necessary supply of oxygen, and the blood passes to the brain and other organs without being vitalized. Hence the necessity of thorough ventilation. To live in close, ill-ventilated rooms, where the air is dead and vitiated, can weaken your entire system. Your body can become peculiarly sensitive to the influence of cold and even slight exposures may induce disease. It is close confinement indoors that makes many people pale and feeble. Breathing the same air over and over until it becomes laden with poisonous matter thrown off through the lungs and pores, brings all the impurities right back into the blood.