According to hatha yoga there are six major factors which prevent yoga, or union, from occurring. In hatha yoga, union means uniting the two energy forces in the body – that is, the pranic and mental energy flowing in pingala and ida nadis. Hatha yoga is the process of balancing the flow of these two alternating forces to bring perfect physical and mental equilibrium and awakening of sushumna and kundalini. When a sadhaka is in the process of uniting the two opposite forces of ida and pingala, he must avoid all activities which waste energy and distract the mind. Therefore, in Hatha Yoga Pradipika (1:15) it is written:
Atyaahaarah prayaasshva prajalpo niyamagrahah;
Janasangashcha laulyam cha shadbhiryogo vinashyati.
Overeating, exertion, talkativeness, adhering to rules, being in the company of common people and unsteadiness (wavering mind) are the six (causes) which destroy yoga.
One major obstacle to yoga, or union, is overeating. When the body is overloaded with food, it becomes sluggish and the mind becomes dull. Over a period of time toxins build up in the body, constipation sets in and the whole physical and mental system becomes blocked. If the body is toxic and lethargic, how can one expect to make progress in sadhana? Whatever sadhana is done will act as a purification, so the sadhana time will just be spent removing toxins and disease. If overeating and its consequences are avoided, however, the sadhana will help one to progress more quickly. Swami Sivananda of Rishikesh and many other yogis have said that the stomach should be half filled with food, one quarter with water and one quarter with air.
The next advice is that the hatha yogi should avoid overexerting or overstraining the body and mind. Hard physical labour or intense mental work taxes the energy system concerned and can create further imbalance between the two energies. The hatha yogi has to conserve and build up his store of energy for spiritual purposes and should not waste it in performing any unnecessary physical or mental feats.
Too much talking dissipates vital energy and wastes time which could be better spent in awakening the inner awareness. Gossiping with people who have low morals, base consciousness and sensuous desires cannot enlighten one's soul, rather, their negative vibrations may have an influence. Social situations and irrelevant discussions definitely distract the mind from sadhana.
Although Yogi Swatmarama advises that a sadhaka should not adhere to strict rules and regulations, the guru's instructions must be followed. As far as social rituals and religious doctrines are concerned, it is unnecessary that they be maintained for spiritual progress. Sadhana is not dependent on social morals nor are its effects promoted by religious practices. Adhering to rules makes one narrow minded. Yoga is meant to expand the consciousness, not to limit it. A yogi should have a free and open mind. If one is accustomed to taking a cold bath every morning before practice, and one day there is no water, the practitioner should not be disturbed. Take a bath when water is available. The mind should be flexible and able to adjust to circumstances.
Unsteadiness means an imbalanced body metabolism, inability to hold one posture for a period of time and a wavering mind. Obviously yoga cannot be achieved under these conditions. When there is physical, mental, emotional and psychic imbalance, the energy is dispersed, but if the energy is properly channeled all the bodily systems become stable, and physical and mental steadiness develop automatically. Unsteadiness also means wavering willpower, such as rising at three am one day, and sleeping in until seven the next morning due to feeling lazy. When there is inconsistency and irregularity in lifestyle, further imbalance in the body will ensue. An unswerving mind and a steady body cultivate yoga.
If one can live in a hermitage all these obstacles will be avoided naturally. If it is not possible to live in such a place, however, one must try to develop the habit of avoiding all activities which are useless, time consuming and energy depleting, and channel all the desires and actions into spiritual ventures. Apart from these obstacles, the Tantraraja Tantra mentions that the six obstacles to yoga are kama, lust, krodha, anger, lobha, greed, moha, infatuation, abhimana, pride, and mada, arrogance. The six obstacles described in hatha yoga and in tantra are interwoven and interlinked.