According to Pāṇini, the term yoga can be derived from either of two roots, yujir yoga (to yoke) or yuj samādhau ("to concentrate"). In the context of the Yoga Sutras of Patanjali, the root yuj samādhau (to concentrate) is considered by traditional commentators as the correct etymology. In accordance with Pāṇini, Vyasa who wrote the first commentary on the Yoga Sutras, states that yoga means samādhi (concentration).
The early Buddhist texts describe yogic and meditative practices, some of which the Buddha borrowed from the śramaṇa tradition. The Pali canon contains three passages in which the Buddha describes pressing the tongue against the palate for the purposes of controlling hunger or the mind, depending on the passage. However, there is no mention of the tongue being inserted into the nasopharynx as in true khecarī mudrā. The Buddha used a posture where pressure is put on the perineum with the heel, similar to even modern postures used to stimulate Kundalini. Some of the major suttas that discuss yogic practice include the Satipatthana sutta (Four foundations of mindfulness sutta) and the Anapanasati sutta (Mindfulness of breathing sutta).
Another text which teaches yoga with an Advaita point of view is the Yoga-Yājñavalkya. This work contains extensive teachings on ten Yamas (ethical rules) and ten Niyamas (duties), and eight asanas. It also discusses a theory of nadis and prana (vital breath), and follows this with instructions on pranayama (breath control), pratyahara (sense withdrawal), meditation on mantras, meditative visualizations and Kundalini.
Tantra is a range of esoteric traditions that began to arise in India no later than the 5th century CE.[note 17] George Samuel states, "Tantra" is a contested term, but may be considered as a school whose practices appeared in mostly complete form in Buddhist and Hindu texts by about 10th century CE. Tantric yoga developed complex visualizations which included meditation on the body as a microcosm of the cosmos. They included also the use of mantras, pranayama, and the manipulation of the subtle body, including its nadis and cakras. These teachings on cakras and Kundalini would become central to later forms of Indian Yoga.
Some Christians integrate yoga and other aspects of Eastern spirituality with prayer and meditation. This has been attributed to a desire to experience God in a more complete way. In 2013, Monsignor Raffaello Martinelli, servicing Congregation for the Doctrine of the Faith, having worked for over 23 years with Cardinal Joseph Ratzinger (Pope Benedict XVI), said that for his Meditation, a Christian can learn from other religious traditions (zen, yoga, controlled respiration, Mantra), quoting Aspects of Christian meditation: "Just as "the Catholic Church rejects nothing of what is true and holy in these religions," neither should these ways be rejected out of hand simply because they are not Christian. On the contrary, one can take from them what is useful so long as the Christian conception of prayer, its logic and requirements are never obscured. It is within the context of all of this that these bits and pieces should be taken up and expressed anew." Previously, the Roman Catholic Church, and some other Christian organizations have expressed concerns and disapproval with respect to some eastern and New Age practices that include yoga and meditation.
Many trainees like to cycle between the two methods in order to prevent the body from adapting (maintaining a progressive overload), possibly emphasizing whichever method more suits their goals; typically, a bodybuilder will aim at sarcoplasmic hypertrophy most of the time but may change to a myofibrillar hypertrophy kind of training temporarily in order to move past a plateau. However, no real evidence has been provided to show that trainees ever reach this plateau, and rather was more of a hype created from "muscular confusion".[clarification needed]
If the meaning of yoga is understood as the practice of nirodha (mental control), then its goal is "the unqualified state of niruddha (the perfection of that process)", according to Baba Hari Dass. In that context, "yoga (union) implies duality (as in joining of two things or principles); the result of yoga is the nondual state", and "as the union of the lower self and higher Self. The nondual state is characterized by the absence of individuality; it can be described as eternal peace, pure love, Self-realization, or liberation."
^ "application or concentration of the thoughts, abstract contemplation, meditation , (esp.) self-concentration, abstract meditation and mental abstraction practised as a system (as taught by Patañjali and called the yoga philosophy; it is the second of the two sāṃkhya systems, its chief aim being to teach the means by which the human spirit may attain complete union with īśvara or the Supreme Spirit; in the practice of self-concentration it is closely connected with Buddhism". Monier-Williams, A Sanskrit Dictionary (1899)