The hatha-yoga system, or breathing system, is especially recommended for those who are very absorbed in the concept of bodily existence, but one who can perform the simple process of chanting Hare Krsna can fix the mind more easily
SB Canto 3
The yogi should clear the passage of vital air by breathing in the following manner: first he should inhale very deeply, then hold the breath in, and finally exhale. Or, reversing the process, the yogi can first exhale, then hold the breath outside, and finally inhale. This is done so that the mind may become steady and free from external disturbances.
These breathing exercises are performed to control the mind and fix it on the Supreme Personality of Godhead. Sa vai manah krsna-padaravindayoh: (SB 9.4.18) the devotee Ambarisa Maharaja fixed his mind on the lotus feet of Krsna twenty-four hours a day. The process of Krsna consciousness is to chant Hare Krsna and to hear the sound attentively so that the mind is fixed upon the transcendental vibration of Krsna's name, which is nondifferent from Krsna the personality. The real purpose of controlling the mind by the prescribed method of clearing the passage of the life air is achieved immediately if one fixes his mind directly on the lotus feet of Krsna. The hatha-yoga system, or breathing system, is especially recommended for those who are very absorbed in the concept of bodily existence, but one who can perform the simple process of chanting Hare Krsna can fix the mind more easily.
Three different activities are recommended for clearing the passage of breath: puraka, kumbhaka and recaka. Inhaling the breath is called puraka, sustaining it within is called kumbhaka, and finally exhaling it is called recaka. These recommended processes can also be performed in the reverse order. After exhaling, one can keep the air outside for some time and then inhale. The nerves through which inhalation and exhalation are conducted are technically called ida and pingala. The ultimate purpose of clearing the ida and pingala passages is to divert the mind from material enjoyment. As stated in Bhagavad-gita, one's mind is his enemy, and one's mind is also his friend; its position varies according to the different dealings of the living entity. If we divert our mind to thoughts of material enjoyment, then our mind becomes an enemy, and if we concentrate our mind on the lotus feet of Krsna, then our mind is a friend. By the yoga system of puraka, kumbhaka and recaka or by directly fixing the mind on the sound vibration of Krsna or on the form of Krsna, the same purpose is achieved. In Bhagavad-gita it is said that one must practice the breathing exercise (abhyasa-yoga-yuktena (BG 8.8)). by virtue of these processes of control, the mind cannot wander to external thoughts (cetasa nanya-gamina). Thus one can fix his mind constantly on the Supreme Personality of Godhead and can attain (yati) Him.
Practicing the yoga system of exercise and breath control is very difficult for a person in this age, and therefore Lord Caitanya recommended, kirtaniyah sada harih: (CC Adi 17.31) one should always chant the holy name of the Supreme Lord, Krsna, because Krsna is the most suitable name of the Supreme Personality of Godhead. The name Krsna and the Supreme Person Krsna are nondifferent. Therefore, if one concentrates his mind on hearing and chanting Hare Krsna, the same result is achieved.