“The eight divisions of yoga performance are described as (1) control of the senses, (2) strict following of the rules and regulations, (3) practice of the different sitting postures, (4) control of the breath, (5) withdrawing the senses from sense objects, (6) concentration of the mind, (7) meditation and (8) self-realization. After self-realization, there are eight further perfectional stages, which are called yoga-siddhis. The system of yoga entails controlling the mind, and the Lord of the mind is Aniruddha. It is stated that Aniruddha is four-handed, with Sudarsana cakra, conchshell, club and lotus flower. There are twenty-four forms of Vishnu, each differently named. Among these twenty-four forms, Sankarsana, Aniruddha, Pradyumna and Vasudeva are depicted very nicely in the Caitanya-caritamrta, where it is stated that Aniruddha is worshiped by the yogis. Meditation upon voidness is a modern invention of the fertile brain of some speculator. Actually, the process of yoga meditation, as prescribed in this verse, should be fixed upon the form of Aniruddha. By meditating on Aniruddha one can become free from the agitation of acceptance and rejection. When one’s mind is fixed upon Aniruddha, one gradually becomes God-realized; he approaches the pure status of Krishna consciousness, which is the ultimate goal of yoga.
It is understood herein that Kardama Muni meditated in yoga for ten thousand years before attaining perfection. Similarly, we have information that Valmiki Muni also practiced yoga meditation for sixty thousand years before attaining perfection. Therefore, yoga practice can be successfully performed by persons who have a very long duration of life, such as one hundred thousand years; in that way, it is possible to have perfection in yoga. Otherwise, there is no possibility of attaining real perfection. Following the regulations, controlling the senses and practicing the different sitting postures are merely the preliminary practices. We do not know how people can be captivated by the bogus yoga system in which it is stated that simply by meditating fifteen minutes daily one can attain the perfection of becoming one with God. This age (Kali-yuga) is the age of bluffing and quarrel. Actually, there is no possibility of attaining yoga perfection by such paltry proposals. The Vedic literature, for emphasis, clearly states three times that in this age of Kali–kalau nasty Eva nasty Eva nasty Eva–there is no other alternative, no other alternative, no other alternative than harer nama, chanting the holy name of the Lord.”
Source: “A.C. Bhaktivedanta Swami Prabhupada (2014 edition), ” Srimad Bhagavatam”, Third Canto, Chapter 21 – Text 04 & 06
A.C. Bhaktivedanta Swami Prabhupada (2014 edition), ” Srimad Bhagavatam”, Third Canto, Chapter 26 – Text 28