Inner Fire Yoga, or Tum-mo, is the basic method used in the advanced stage of most tantra systems.  When doing this practice, we will need to visualize our body in a certain way.  This is called the "Vajra Body" and incorporating it into our self-image  provides  a useful way to work with our bodily energies.  The structures visualized are not actually there when the body is autopsied. There are correlates with our physical bodies, yet that is only part of the picture.  When we close our eyes and feel our bodies, it is hard to deny that different parts of the body have different energies and feelings.  In any case, to do the practices, one needs to suspend disbelief and visualize the postulated structures and energies.  After extended practice, the visualizations become internalized and become  powerful tools for calming ourselves, connecting with the body and channeling energy.

Rationale:      As babies, we are born with blissful energy freely flowing throughout our entire body.  As we develop, this energy is inhibited by the traumas of life and  stored in our neuromuscular systems.  We no longer breathe freely and our muscles become distorted with tension and stored psychic and physical pain. Inner Fire Yoga teaches us a method to free up this trapped energy and use it to our advantage.

Inner Fire Yoga as a Way to Redirect the Energy of Anger, Sexual Desire and Other Emotions:  If we look carefully at emotion, we find that an emotion is actually a energized physical sensation in one part of the body or another.  Thoughts are superimposed on these energies. The energy of emotion can scatter us, or we can learn to use it to center ourselves.  In Inner Fire Yoga,  energy is generated and collected in the navel chakra and spread upward through the center of our body, centering and energizing us in a positive way.

Sexual desire and anger can be very useful.   Sexual energy in most adults is usually limited to the area of the sexual chakra.  When this energy is spread throughout the body,  it really isn't just sexual anymore.  It is a total body energized or "blissful" feeling. This is not the ordinary limited bliss of orgasm.  Sexual energy can be freed up and distributed throughout the body by moving it into the navel chakra and then doing the Inner Fire Yoga.  Anger is energy also, but the energy can be harmful.  In the inner fire yoga we can learn to take the energy of anger (usually felt in the solar plexus) and throw it also into the navel chakra as fuel.

The "blissful" body is only half of the equation in Tantra. The other half is the indispensable understanding of  non-dual awareness, or "emptiness" (the mind free or empty of conceptual divisions).