Carbon dioxid dulls the nerves of sensation and the brain action and may produce more or less stupor. It may be because the circulation in some part of the body is sluggish (most often the portal circulation through the liver), so that sufficient oxygen is not carried to that part.
Relief from this “inertness” is experienced most quickly by exercise to quicken the circulation and supply the oxygen. Exercise in one’s room by the open window, or at least with the air in the room pure, is often preferable to outdoor exercise, because the body can be nude, or so loosely clothed that the oxygen may not only enter the lungs but also circulate about the skin.
Fifteen minutes of brisk exercise in one’s room is better than a five-mile walk, because if the exercises are intelligently selected, every organ and tissue is used, while walking exercises only about one-fourth of the muscles.
After sleeping in a room in which the air is impure, one arises fatigued, because the supply of oxygen is insufficient to liberate the energy required for circulation and catabolism.
Harmony, either mental or physical, is rest.
With a little more intelligence in keeping up the supply of oxygen, in establishing correct breathing habits, and in understanding the law of distribution of circulation, which means the harmony of forces, this tired world could not only draw a deep, restful breath, but would be invigorated to enjoy life to the full.
Sleep
During sleep all the processes of the body are retarded.
Blood flow and breathing become slower and the digestive processes slacken. For this reason, if one goes to bed immediately after eating a heavy meal, digestion is retarded. This may react on the nerves, producing fitful or unrestful sleep. Fever or nightmare may result. The annoying, sleepy feeling which often comes on after a meal indicates a lack of balance in the system—usually that more food has been eaten than the body requires. Lessening the amount of food and increasing the exercise and the oxygen, and cleansing the intestinal tract will prevent it.