Tapas
Tapas in Sanskrit means "heat". In Vedic religion and Hinduism, it is used figuratively, denoting spiritual suffering, mortification or austerity, and also the spiritual ecstasy of a yogin or tapasa (a derivative meaning "a practitioner of austerities, an ascetic"). The adjective tapasvin means "wretched, poor, miserable", but also "an ascetic, someone practicing austerities".
In the yogic tradition, tapasya may be translated as "essential energy", referring to a focused effort leading towards bodily purification and spiritual enlightenment. It is one of the Niyamas (observances of self-control) described in the Yoga Sutras of Patanjali. Tapasya implies a self-discipline or austerity willingly expended both in restraining physical urges and in actively pursuing a higher purpose in life. Through tapas, a yogi or spiritual seeker can "burn off" or prevent accumulation of negative energies, clearing a path toward spiritual evolution.
Asceticsism
Ascetics, also called yogis, saints, bawas, and similar thing across India are known for observing severe tapas such as refraining from food in an attempt to "yoke" their senses as well as many other forms of penance such as walking to pilgrimage sites and of course, yoga. Here we have some Hindu ascetics in various yoga poses:
Hindu ascetics are a part and parcel of Hindu society since becoming an ascetic is often considered the final stage of life- the Fourth Ashrama - "Sannyasa" or the Wandering Ascetic Stage- upon reaching seniority. Also known as a sadhu or swami in India, a religious ascetic or holy person. The class of sadhus includes renunciants of many types and faiths. They are sometimes designated by the term swami (Sanskrit svami, “master”), which refers especially to an ascetic who has been initiated into a specific religious order, such as the Ramakrishna Mission. In Shaivism the preferred term is sannyasi, and in Vaishnavism it is vairagi.
Sadhus may live together in monasteries (mathas) that usually belong to a particular order. They may also wander throughout the country alone or in small groups or isolate themselves in small huts or caves. They generally take vows of poverty and celibacy and depend on the charity of householders for their food. Their dress and ornaments differ according to sectarian allegiances and personal tastes; they usually wear ochre-coloured (more rarely, white) robes, and some are naked. They shave their heads, or they allow their hair to lie matted on their shoulders or twist it into a knot on top of their heads. They usually retain only the few possessions they carry with them: a staff (danda), a water pot (kamandalu), an alms bowl, prayer beads, and perhaps an extra cloth or a fire tong.
Click here for a quick summary of how to become a Hindu sadhu.
