Inverted poses are an extremely important group of asanas. Inverted asanas reverse the action of gravity on the body; instead of everything being pulled towards the feet, the orientation shifts towards the head. Similarly, on the emotional and psychic levels, inverted asanas turn everything upside down, throwing a new light on old patterns of behavior and being. Generally, these practices improve health, reduce anxiety and stress and increase self-confidence. They also increase mental power, concentration and stimulate the chakras.
Even if you can’t do a full yoga practice, just try to get upside down every single day for at least a few minutes. An inversion practice can be as simple as a standing forward bend or legs up the wall or as complex as a scorpion handstand. Whatever your strength, energy level, and balance allow, put your heart above your head and reap the many benefits of inverting.
There are four major systems in the body that the practice of inversions positively influences: cardiovascular, lymphatic, nervous, and endocrine.
The circulatory system is comprised of the heart, lungs and the entire system of vessels that feed oxygen and collect carbon dioxide and other waste products from the cells. Arteries fan out in an intricate tributary system from the heart, which pumps freshly oxygenated blood from the lungs outward. Veins return blood to the heart and, unlike arteries, make up a low-pressure system that depends on muscular movement or gravity to move blood along. One-way valves at regular intervals prevent backwash and keep fluids moving towards the heart in a system know as venous return. Turning yourself upside down encourages venous return.
Inversions also ensure healthier and more effective lung tissue. When standing or sitting upright, gravity pulls our fluids earthward, and blood "perfuses" or saturates the lower lungs more thoroughly. The lower lung tissue is thus more compressed than the upper lungs. As a result, the air we inhale moves naturally into the open alveoli of the upper lungs. Unless we take a good, deep breath, we do not raise the ration of air to blood in the lower lungs. When we invert, blood perfuses the well-ventilated upper lobes of the lungs, thus ensuring more efficient oxygen-to-blood exchange and healthier lung tissue.
Inverting also gives the heart a break. The heart works persistently to ensure that freshly oxygenated blood makes its way up to the brain and its sensory organs. When inverting, the pressure differential across the body is reversed, and blood floods to the brain with little work from the heart.
The lymphatic system is responsible for waste removal, fluid balance, and immune system response. Lymph vessels arise among the capillary beds of the circulatory system, but comprise a separate system that transports stray proteins, waste materials, and extra fluids, filtering the fluid back through the lymph nodes and dumping what remains into the circulatory system at the subclavian veins, under the collarbones. The lymphatic system is analogous to a sewage system, an intricate, underground network tied to every house in town which keeps the citizens healthy.
Lymph, like the blood returning to your heart via the veins, is dependent upon muscular movement and gravity to facilitate its return. Because the lymphatic system is a closed pressure system and has one-way valves that keep lymph moving towards the heart, when one turns upside down, the entire lymphatic system is stimulated, thus strengthening your immune system. Viparita karani is a good example of this, as it is a mild inversion that one can enjoy with no stress on the body.
There is a theory in yoga that organs become displaced over time due to gravity. Inversions help return organs to their original places where they function most effectively.
During menstruation women are advised to avoid inversions. When the body is inverted, gravity causes the vessels supplying blood to the uterus to be partially blocked, and this can temporarily stop the flow. The energy of the body at this time in a woman’s cycle is moving down into the earth. Going upside down during the menses disturbs this natural rhythm and can result in a feeling of shakiness, disorientation, or nausea. During your moon cycle, it is important to honor your body by going with, rather than against, this natural flow.
The fountain of youth - the esoteric side of inversions
"In Yoga philosophy we have a “nectar of life” called Amritabindu that we store in our crown chakra. It is written that after taking food, the blood absorbs the nutrients and after 32 days 1 drop of new blood is made. It takes 32 drops of this new blood to make one single drop of Amritabindu (vital life nectar). This amritabindhu is stored in the Sahasrara (crown) chakra. Our amritabindhu can be depleted by living badly, eating badly, and thinking negative thoughts—it begins to travel downwards and is consumed by the upward flow of agni (our digestive fire) at the third chakra. When amritabindhu is lost, life itself is lost.
The practice of inverted asana particularly sarvangasana (shoulder stand) and sirsasana (headstand) are the method for storing our amritabindhu. When we are inverted our amritabindhu remains safely in Sahasrara chakra, its downward flow is prevented—leading to an extension of our life span. The agni always travels in an upward direction, in the inverted asana it travels towards the anus cleansing and purifying the organs of digestion and the rectum/anus. If mula bandha is strong and the digestive fire can travel all the way to the anus and the Muladhara chakra (root chakra) it will stimulate the release of Traya Granthis (knots that block our energy flow) and begin the gradual process of awakening our Kundalini energy." - Excerpts from Astanga Yoga by Lino Miele