The navel centre - or Manipura chakra - is the centre that helps us to digest not only our food, but our life. And when our inner fire is weakened we become sluggish, lack energy and willpower; we have trouble setting our goals, never mind achieving them. Our digestion can also become more difficult. In order to rekindle our inner fires, and strengthen this system we use the breath of fire in several yoga poses. It is an intense practice, but very effective.
Read more about the Manipura chakra in Marlene's article.