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Regardless of what particular school or type of yoga we practice, it is unlikely that many of us are really practicing yoga. Rather we are more likely to focus on only 1 of the 8 limbs of yoga - yoga asana.

Yoga asana are the physical positions and postures of yoga that started were really only starting to develop in importance with the development of Hatha Yoga. While exact dates are not well established, yoga has existed for a lot longer than the practice of modern asana.

These asana have been developed over more than 1500 years to promote physical health as part of a greater Hatha yoga practice. Each asana is carefully designed to focus on particular areas of the body. The specific effects of an asana include:

• Building strength in specific muscle groups
• Stretching specific soft tissues including muscles, ligament and tendons
• Opening specific joints
• Developing balance and concentration
• Massaging and stimulating internal organs

Individually these effects can have significant benefits, but by combining individual asana into a carefully developed and balanced routine the Hatha yoga practitioner can develop their entire physical body, internal organ function and mental clarity.

How do yoga asana work

Although yoga and asana are not considered to be scientific by western definitions, the practice of asana is considered by yoga masters to be very carefully developed and refined based on several well-developed underlying principles and health objectives.

Gravity

One of the key principles of asana is that of gravity. Asana use gravity in a variety of ways, the most important being in developing strength. By resisting body weight on arms or legs the asana can develop upper body or leg strength and muscle tone in the same way a weightlifter would in a gym. With yoga asana the weight being resisted varies only with our own body weight, and each pose can only apply the same amount of body weight meaning that all muscles are developed proportionately so long as each pose is held for an equivalent amount of time. After we can easily hold our body weight in a particular pose, holding the pose for longer builds additional strength and stamina.

Blood flow and nutrients

Blood flow to specific areas of the body brings many health benefits. By working specific muscles, soft tissue and joints, the body brings additional blood flow providing the needed oxygen. This additional blood also brings needed nutrition to those areas, which is essential for general health as well as the speedy recovery from injury and damage. The key way to bring blood to these areas is through stretching. In addition to the increased blood flow, stretching loosens and relaxes soft tissue such as muscles, ligaments and tendons and opens joints, all of which helps to relieve tension and pressure on nerves in these areas.

Deep breathing

During the practice of asana, we are encouraged to control our breath with long deep inhalations and exhalations. In some poses it is even encouraged to still the breath with the lungs full or the lungs empty for periods of 20 seconds to 1 minute. The first benefit of this controlled breathing is to bring our focus and consciousness to the present, to our current actions. By being able to control this focus, we can improve our concentration. Secondly by breathing in this controlled way, we improve the efficiency of our respiratory system, bringing more oxygen to the body and to the organs, muscles and soft tissue being worked on.

Central nervous system and internal organs

Although yoga texts don't tend to describe yoga in the terms used by modern medicine, many of the concepts are analogous to medical structures. With nerves represented as Nadis or energy channels and the Chakras representing key glands. The purpose of asana is to rejuvenate the whole body by conditioning these individual systems to make sure they are working optimally.

One of the key focuses of asana is in on the central nervous system, which comprises the spine and brain. In yoga this could be referred to as the Nadis and crown Charkra. The Central Nervous System is one of the most critical structures in the human body, controlling all movement and thought and passing the control signals to all the nerves throughout the body. Clearly if the function of this core control channel is impeded, it can have an effect on the function of the whole body. One of the plainest examples of this is through back pain and sciatica. Through the misalignment of, or damage to, the spinal disks or vertebrae that protect the spinal cord and root nerves, those same nerves can be pinched or irritated which can lead to intense pain and numbness in the back, as well as referred pain and numbness in the legs or feet. While the causes of damage to the spine can be many and varied, poor posture is a key cause of back pain. Asana for the spine help to bring the fluids that contain the nutrient required to repair the damaged soft tissues and can b effective in healing back problems. However these asana are not always sufficient since poor posture and back pain can also be cause by other elements such as tight hamstring muscles in the back of the legs or gluteus and piriformis muscle groups in the buttocks. Therefore a holistic approach is required to correct the back injury.

Other key systems that asana are designed to address is the glandular and lymphatic systems, particularly the endocrine system. The endocrine glands, which include the thymus, thyroid, pituitary pineal, hypothalamus, adrenal and sex glands release their secretions directly into the blood stream. The secretions made by these glands have an enormously profound effect on the body's health function controlling everything from height and weight to metabolism and emotions. Asana are designed to stimulate these glands in a variety of ways from increasing blood flow to those in the brain (hypothalamus, pituitary and pineal) or thyroid in the neck to gently massage and stimulate through bends and twists of the abdomen.

The next key systems that asana stimulate are the internal organs and digestive systems. Both of these systems are critical to taking in nutrition and expelling waste and toxins from the body, and are particularly important for good health. Asana improve the functioning of these systems through stimulation and gentle massage provided by abdominal bends and twist as well as movement of the hips and legs.

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Featured Posture Naukasana (Boat pose)

Technique Lie face down on the floor legs straight together, arms in front. Exhale and lift the arms, head, shoulders and upper back as well as both legs off the floor as high as possible. If possible, only the abdominal muscles should be bearing the body weight. Breathe normally in the final position for as long as possible 10 to 20 seconds. Relax back to the ground. Repeat the pose. Counter pose Any foreward bending asana Benefits Anatomical - The pose is particularly effective in strengthening the back muscles to support the spine and improve posture.