Ardha means half and Matsyendra is the name of a legendary Sidha or sage.  The words Ardha Matsyendrasana give no indication as to how the pose should be done, its literal translation is Half Lord of the Fish.  However, there must be an explanation for why certain asanas are named after wise people;  could it just be that some of their wisdom and insight are needed to do the postures properly?

In one of the many stories, Matsyendra has been swallowed by a giant fish after being thrown into the ocean as an infant.  He overhears Shiva teaching the mysteries of yoga to Parvati and becomes completely fascinated by it.  Matsyendra is given divine form by Shiva and begins to teach Hatha Yoga. 

Yogis believe that youthfulness is a question of suppleness of the spine or in other words that we are only as old as our spine.  By keeping our backbone flexible and long, our body will be healthy. 

Spinal movements include flexion (forward bending), extension (backward bending), lateral flexion (right and left side) and rotation.  The spinal muscles are concerned with extending the spine, the muscles at the front of the spine with flexing it.  Bending sideways and twisting involve a combination of muscles from the front and the back of the body.

Twists are some of the most beneficial postures, physically and mentally.  They can be done in any position, supine, prone, standing or inverted, and the pull of gravity will be felt differently, accordingly.  Twists can be done with many variations, but you don’t need to do an advanced twist to get most of the benefits, you just need to do it right!   All too often we are willing to sacrifice the quality of a posture for what we perceive to be a more advanced pose and we introduce elements of rigidity and aggressiveness that have no part in the practice and are potentially dangerous.  What happened to the principle of non-ahimsa (non violence)?

Our daily activities involve a lot of forward bending often associated with an element of twisting too.  However,  most of the twisting we do is very gentle and not held for very long.

Ardha Matsyendrasana is a twist we know well.  Like many other postures, this one is deceptively easy, there’s nothing spectacular about it, we don’t seem to be doing much from the outside because most of the movement is initiated from the inside.  It is, however, quite a complex posture that requires flexible hips, so for beginners it is best to approach it in stages.   Difficult though they may be for some of us, twists must not be omitted from any yoga practice for their benefits far outweigh the amount of discomfort we may experience whilst doing them.  Twists are introspective postures that enable us to go deep within and which help develop both our physical and our spiritual sides.  Twisting is one of the ways to purify the body to free the mind.

Benefits
Physical benefits:
Twists are wonderful poses done on their own and as a counterpose for forward bends and backward bends (as they relieve lower back compression).   They allow us to bring the front of the body (conscious) towards the back of the body (unconscious) and make us feel whole again.

When we move into a twist, the blood is forced away from a particular area (compression), and when we release from it, freshly oxygenated blood is allowed to flood the internal organs.  Twisting poses massage the abdominal area with a "squeeze and soak" effect (like a sponge), squeezing the internal organs and soaking them with fresh blood.
The benefits of the twists are more obvious as we release from it.  But first we need to go to the unmoving heart of the twist and hold it for some time to give the body enough time to make the necessary adjustments and integrate them.

Twists are particularly good for the lower back and the spine because of their upward and inward movement.  They strengthen the small muscles between the vertebrae, hydrate the spinal discs, maintain the alignment of the spine and lengthen it, keeping it mobile, elastic and well lubricated.   Twists tone the roots of the spinal nerves and relax the sympathetic nervous system.

• Twists tone and broaden the lower back muscles and slim the waist;
• The hip and stomach muscles used are also toned and stretched from repeated practices of the pose;
• Twists improve circulation and the flow of energy;
• Kidneys and abdominal organs are activated, massaged, nourished and cleansed to help them function at an optimal level;
• Twists are most beneficial postures for intestinal disorders - flatulence, chronic enlargement of the spleen and liver problems;