To practice yoga, as suggested here, one first has to close the door of all sense enjoyment. This practice is called pratyahara, or withdrawing the senses from the sense objects. Sense organs for acquiring knowledge, such as the eyes, ears, nose, tongue and touch, should be fully controlled and should not be allowed to engage in self-gratification. In this way the mind focuses on the Supersoul in the heart and the life force is raised to the top of the head. In the Sixth Chapter this process is described in detail. But as mentioned before, this practice is not practical in this age. The best process is Krsna consciousness. If one is always able to fix his mind on Krsna in devotional service, it is very easy for him to remain in an undisturbed transcendental trance, or in samadhi.