The blend of oxygen in the air we breathe remains at 21%, but the decrease in barometric pressure (or an increase in altitude) causes oxygen molecules to move further apart. As a result, the room air becomes “thinner.” This allows the lungs to  expand more easily into a deep breath since the body is very briefly exerting more pressure out than the air pressure is exerting in on the body. This deep-breath-lung-expansion increases the lymphatic drainage into the circulatory system by pressing against the thoracic duct, the largest lymph vessel that lies vertically along the front of the spine. This encourages lymph drainage into the left brachiocephalic vein, taking stress off all lymph valves throughout the body to promote lymph flow. Additionally, the lymph system of the brain, the glymphatic system, is also stimulated to reduce edema, inflammation and flush out toxins.

Your body notices that it’s environment is changing. The body adapts and adjusts to this change, in anticipation of any future environmental changes. This self-protection consists of the production of more red blood cells to carry oxygen to the tissues in deconditioned individuals, storage of extra cell energy in the brain and heart, growth of new blood vessels, release of antioxidants, and strengthening of neural pathways in the brain and spinal cord (aka plasticity). The body does all of this to prepare for and recover from any tissue damage resulting from changes in its environment. This bodily response is called pre-conditioning, or allostasis, where the body adapts to its environment or anticipates that future adaptations will have to be made.

Some examples: In cases of small or large muscle fiber tears, rapidly pulsing air pressure changes can increase the growth of new blood vessels to the damaged area, bringing blood and oxygen for promotion of healing. These air pressure changes can also benefit diabetes by assisting with blood sugar stabilization; and, with gradual exposure to brief periods of hypoxic stress, people with bronchial asthma may also notice that breathing and fighting off infections becomes easier.